JP7252386B2 - Semiconductor device and method for manufacturing semiconductor device - Google Patents

Description

The present disclosure relates to a semiconductor device mounted with a semiconductor element and a manufacturing method thereof.

In recent years, by applying LSI manufacturing technology, so-called micromachines (MEMS: Micro Electro Mechanical Systems) in which various semiconductor elements are mounted on a microfabricated Si substrate (silicon wafer) are becoming widespread. In the manufacture of such micromachines, anisotropic etching using an alkaline solution is applied as a microfabrication technique for Si substrates. By anisotropic etching, fine recesses for mounting semiconductor elements can be formed in the Si substrate with high accuracy.

For example, Patent Literature 1 discloses a semiconductor device (LED package) based on micromachine manufacturing technology. The semiconductor device has a concave portion having a bottom surface and side surfaces formed in a Si substrate, and an LED chip is mounted on the bottom surface of the concave portion. The LED chip is housed in the recess. Further, electrodes electrically connected to the LED chip are formed on the bottom and side surfaces of the recess. The electrodes are patterned by photolithography and etching with respect to a Ti layer and a Cu layer formed by a sputtering method or the like on a Si substrate including recesses. After forming the electrodes, the LED chip is mounted on the bottom surface of the recess, and the recess is filled with a sealing resin, thereby manufacturing the semiconductor device.

For example, in the semiconductor device disclosed in Patent Document 1, even if a semiconductor element different from an LED chip is mounted, the semiconductor element is covered with a sealing resin. If the semiconductor element generates a relatively large amount of heat when energized, the thermal conductivity of the sealing resin is lower than that of the Si substrate. I have a problem.

JP 2005-277380 A

The present disclosure has been conceived in view of the above circumstances, and an object thereof is to provide a semiconductor device capable of efficiently releasing heat generated from a semiconductor element to the outside, and a method of manufacturing the semiconductor device. to do.

A semiconductor device provided by a first aspect of the present disclosure includes: a semiconductor element having an element main surface and an element back surface facing opposite sides in a thickness direction; a wiring section electrically connected to the semiconductor element; a conductive electrode pad; a sealing resin covering a part of the semiconductor element; It overlaps with the first heat dissipation layer when viewed from the side.

In a preferred embodiment of the semiconductor device, the first heat dissipation layer and the electrode pad are made of the same material.

In a preferred embodiment of the semiconductor device, the material is a Ni layer, a Pd layer and an Au layer laminated together.

In a preferred embodiment of the semiconductor device, the electrode pad and the first heat dissipation layer are insulated.

In a preferred embodiment of the semiconductor device, the semiconductor device further includes a second heat dissipation layer insulated from the wiring portion, and the second heat dissipation layer is wider than the semiconductor element in the thickness direction. It is arranged in the facing direction and at least partially overlaps with the semiconductor element when viewed from the thickness direction.

In a preferred embodiment of the semiconductor device, both the second heat dissipation layer and the wiring portion are composed of a base layer and a plating layer laminated on each other.

In a preferred embodiment of the semiconductor device, the underlying layer is composed of a Ti layer and a Cu layer laminated to each other, and the plated layer is composed of Cu.

In a preferred embodiment of the semiconductor device, the semiconductor device further includes a substrate made of a semiconductor material on which the wiring portion is arranged, and an insulating layer for insulating the substrate and the wiring portion.

In a preferred embodiment of the semiconductor device, the semiconductor device further comprises: a substrate made of a semiconductor material on which the wiring portion is arranged; and an insulating film for insulating the substrate and the wiring portion, The substrate has a mounting surface on which the semiconductor element is mounted, the mounting surface includes a covered region formed with the insulating film and an exposed region exposed from the insulating film, and the second heat dissipation layer comprises: , at least a part of the exposed region is in contact with the mounting surface.

In a preferred embodiment of the semiconductor device, the semiconductor material is Si.

In a preferred embodiment of the semiconductor device, the semiconductor device further includes a conductive columnar body protruding from the wiring portion in the thickness direction, and the electrode pad is in contact with the columnar body.

In a preferred embodiment of the semiconductor device, the columnar body faces in the same direction as the back surface of the element and has a top surface exposed from the sealing resin, and the sealing resin extends in the same direction as the back surface of the element. and the top surface and the resin main surface are both flush with the back surface of the device.

In a preferred embodiment of the semiconductor device, the top surface is covered with the electrode pad, and the electrode pad and the first heat dissipation layer are aligned in the thickness direction.

In a preferred embodiment of the semiconductor device, the semiconductor device further includes a bonding layer electrically connected to the wiring portion and bonding the semiconductor element.

A method for manufacturing a semiconductor device provided by the second aspect of the present disclosure includes a step of preparing a substrate made of a semiconductor material, a wiring portion forming step of forming a wiring portion arranged on the substrate, a thickness a semiconductor element mounting step of electrically connecting a semiconductor element having an element main surface and an element back surface facing in directions opposite to each other to the wiring part with the element main surface facing the substrate; a sealing resin forming step of forming a sealing resin; a semiconductor element exposing step of removing a part of the sealing resin to expose the back surface of the element; The method is characterized by comprising a first heat dissipation layer forming step of forming a layer and an electrode pad forming step of forming an electrode pad electrically connected to the wiring portion.

In a preferred embodiment of the method for manufacturing the semiconductor device, both the first heat dissipation layer and the electrode pads are formed by electroless plating.

In a preferred embodiment of the method for manufacturing the semiconductor device, the step of forming the first heat dissipation layer and the step of forming the electrode pad are collectively performed.

A preferred embodiment of the method for manufacturing a semiconductor device further includes a second heat dissipation layer forming step of forming a second heat dissipation layer disposed between the semiconductor element and the substrate in the thickness direction.

In a preferred embodiment of the method for manufacturing a semiconductor device, the step of forming the second heat dissipation layer and the step of forming the wiring portion include forming a base layer by sputtering and forming a plated layer by electroplating. and a step.

In a preferred embodiment of the method for manufacturing a semiconductor device, the step of forming the second heat dissipation layer and the step of forming the wiring portion are collectively performed.

A preferred embodiment of the method for manufacturing a semiconductor device further includes a columnar body forming step of forming a columnar body having conductivity and protruding from the wiring portion in the thickness direction. The columnar body faces the same direction as the back surface of the element and has a top surface exposed from the sealing resin. In the electrode pad forming step, the electrode pad is formed to cover the top surface.

According to the semiconductor device of the present disclosure, heat generated from the semiconductor element can be efficiently released to the outside.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

1 is a plan view of a semiconductor device according to a first embodiment; FIG. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1; FIG. 3 is an enlarged view (partially enlarged cross-sectional view) of a part of the cross-sectional view shown in FIG. 2 ; FIG. 3 is an enlarged view (partially enlarged cross-sectional view) of a part of the cross-sectional view shown in FIG. 2 ; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; 2A to 2C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 1; It is a top view of the semiconductor device concerning 2nd Embodiment. 21 is a cross-sectional view along line XXI-XXI of FIG. 20; FIG. 21 is a cross-sectional view for explaining a manufacturing process of the semiconductor device shown in FIG. 20; FIG. 21 is a cross-sectional view for explaining a manufacturing process of the semiconductor device shown in FIG. 20; FIG. 21 is a cross-sectional view for explaining a manufacturing process of the semiconductor device shown in FIG. 20; FIG. 21 is a cross-sectional view for explaining a manufacturing process of the semiconductor device shown in FIG. 20; FIG. 21 is a cross-sectional view for explaining a manufacturing process of the semiconductor device shown in FIG. 20; FIG. 21 is a cross-sectional view for explaining a manufacturing process of the semiconductor device shown in FIG. 20; FIG. It is a top view of the semiconductor device concerning the modification of 2nd Embodiment. It is a top view of the semiconductor device concerning 3rd Embodiment. FIG. 30 is a cross-sectional view along line XXX-XXX in FIG. 29; 30A to 30C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 29; 30A to 30C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 29; 30A to 30C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 29; 30A to 30C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 29; 30A to 30C are cross-sectional views for explaining a manufacturing process of the semiconductor device shown in FIG. 29; FIG. 11 is a cross-sectional view of a semiconductor device according to a modification of the third embodiment; It is a cross-sectional view of a semiconductor device according to a modification. It is a cross-sectional view of a semiconductor device according to a modification.

Preferred embodiments of the semiconductor device of the present disclosure and the method of manufacturing the semiconductor device of the present disclosure will be specifically described below with reference to the drawings.

[First Embodiment]
A semiconductor device A10 according to the first embodiment will be described with reference to FIGS. 1 to 4. FIG. The semiconductor device A10 includes a substrate 1, an insulating layer 15, a wiring portion 20, a columnar body 25, an electrode pad 26, a semiconductor element 31, a bonding layer 32, a sealing resin 4, a first heat dissipation layer 51, and a second heat dissipation layer 52. It has

FIG. 1 is a plan view of the semiconductor device A10. For convenience of understanding, the sealing resin 4 and the insulating layer 15 are omitted in FIG. FIG. 2 is a cross-sectional view along line II-II of FIG. FIG. 3 is an enlarged view (partially enlarged cross-sectional view) of a part of the cross section shown in FIG. be. FIG. 4 is an enlarged view (partially enlarged cross-sectional view) of a part of the cross section shown in FIG. FIG. 4 is a diagram mainly for explaining cross-sectional structures of the wiring portion 20 and the second heat dissipation layer 52. As shown in FIG.

The semiconductor device A10 shown in these figures is a device that is surface-mounted on circuit boards of various electronic devices. Here, for convenience of explanation, the thickness direction of the substrate 1 is referred to as the thickness direction z. Further, the longitudinal direction (horizontal direction in the plan view) of the semiconductor device A10 orthogonal to the thickness direction z is called a first direction x. A lateral direction of the semiconductor device A10 (vertical direction in the plan view) orthogonal to both the thickness direction z of the substrate 1 and the first direction x is called a second direction y. As shown in FIG. 1, the semiconductor device A10 has a rectangular shape when viewed in the thickness direction z (hereinafter referred to as "plan view"). In this embodiment, the dimension in the thickness direction z of the semiconductor device A10 is approximately 300 to 400 μm, the dimension in the first direction x is approximately 200 to 300 μm, and the dimension in the second direction y is approximately 200 to 300 μm. be. In addition, each dimension is not limited.

The substrate 1 is a supporting member on which the semiconductor element 31 is mounted and serves as the base of the semiconductor device A10. The shape of the substrate 1 in a plan view is, as shown in FIG. 1, a rectangular shape with long sides along the first direction x. In this embodiment, the substrate 1 is plate-shaped and has a dimension in the thickness direction z of about 200 to 300 μm. Note that the shape and dimensions of the substrate 1 are not limited. The substrate 1 is mainly composed of a single-crystal intrinsic semiconductor material, and in this embodiment, is mainly composed of Si. In addition, the material of the substrate 1 is not limited. The substrate 1 has a substrate main surface 11 , a substrate back surface 12 and a plurality of substrate side surfaces 13 .

As shown in FIG. 2, the substrate main surface 11 and the substrate back surface 12 face opposite sides and are separated from each other in the thickness direction z. The substrate main surface 11 faces the thickness direction z, as shown in FIG. The substrate main surface 11 is flat. Further, the shape of the substrate main surface 11 in plan view is rectangular. In this embodiment, the substrate main surface 11 faces the circuit board when the semiconductor device A10 is mounted on the circuit board. In this embodiment, the substrate main surface 11 includes covered regions 111 and exposed regions 112 . The covered region 111 is a region covered with an insulating layer 15, which will be described later. The exposed region 112 is a region exposed from the insulating layer 15 that is not covered with the insulating layer 15 to be described later. In this embodiment, the substrate main surface 11 corresponds to the "mounting surface" of the invention.

The substrate rear surface 12 faces the side opposite to the substrate principal surface 11 in the thickness direction z. The substrate back surface 12 is flat. Further, the shape of the substrate back surface 12 in plan view is rectangular. The substrate back surface 12 is exposed to the outside. Each of the plurality of substrate side surfaces 13 is sandwiched between the substrate main surface 11 and the substrate back surface 12, as shown in FIG. In this embodiment, the substrate 1 has four substrate side surfaces 13 facing either the first direction x or the second direction y. Each substrate side surface 13 is flat and perpendicular to the substrate main surface 11 and the substrate back surface 12 .

As shown in FIG. 2, the insulating layer 15 is an electrically insulating coating formed so as to cover a portion (covering region 111) of the main surface 11 of the substrate 1. As shown in FIG. The insulating layer 15 electrically insulates the substrate 1 and the wiring portion 20 . In this embodiment, the insulating layer 15 is made of SiO ₂ and formed by thermally oxidizing the substrate 1 . In this embodiment, the thickness (dimension in the thickness direction z) of the insulating layer 15 is, for example, approximately 0.7 to 2.0 μm. The material, thickness, and formation method of the insulating layer 15 are not limited.

As shown in FIGS. 1, 2 and 4, the wiring portion 20 is a conductor formed on the substrate 1 and electrically connected to the semiconductor element 31 . As shown in FIG. 4, the wiring section 20 is composed of an underlying layer 201 and a plated layer 202 which are laminated to each other. The underlying layer 201 is formed on the substrate 1 and electrically insulated from the substrate 1 by the insulating layer 15 . The underlying layer 201 is composed of a Ti layer and a Cu layer laminated to each other, and has a thickness of about 200 to 800 nm. The plating layer 202 is formed on the outside of the underlying layer 201 (on the side opposite to the substrate 1) so as to be in contact with the underlying layer 201. As shown in FIG. The plated layer 202 is made of Cu, and its thickness is set to be thicker than that of the base layer 201, and is about 3 to 20 μm. In this embodiment, the underlying layer 201 is formed by a sputtering method. Also, the plating layer 202 is formed by electrolytic plating. The material, film thickness, and forming method of the wiring portion 20 are not limited. The wiring portion 20 according to this embodiment is composed of a plurality of main surface wirings 21 .

Each of the plurality of main surface wirings 21 is arranged on the substrate main surface 11 as shown in FIGS. In this embodiment, the semiconductor device A10 has four main surface wirings 21 . Each main surface wiring 21 has a strip shape extending in the first direction x. Note that the number, shape, and arrangement of the main surface wiring 21 are not limited.

Each of the plurality of columnar bodies 25 is a conductor that connects the wiring portion 20 and the electrode pad 26 . In this embodiment, the semiconductor device A10 has four columnar bodies 25. As shown in FIG. In this embodiment, each columnar body 25 has a prismatic shape with a rectangular cross section on the xy plane. The shape of the columnar body 25 is not limited, and may be, for example, a columnar shape. In each columnar body 25, one end (lower end shown in FIG. 2) in the thickness direction z is connected to the wiring portion 20 (main surface wiring 21) and protrudes from the wiring portion 20 in the thickness direction z. The other end (upper end shown in FIG. 2) of the columnar body 25 in the thickness direction z is exposed from the sealing resin 4 and connected to the electrode pad 26 . Each columnar body 25 also has a top surface 251 and a plurality of side surfaces 252, respectively. In each columnar body 25 , a top surface 251 corresponds to the other end, is exposed from the sealing resin 4 , and is in contact with each electrode pad 26 . The multiple side surfaces 252 are parallel to the thickness direction z. In this embodiment, each columnar body 25 has four side surfaces 252, and each of the four side surfaces 252 faces either the first direction x or the second direction y. Each side surface 252 and the plurality of side surfaces 252 are all covered with the sealing resin 4 . In this embodiment, each columnar body 25 is made of Cu, for example, and formed by electrolytic plating. The number, material, and forming method of the columnar bodies 25 are not limited. In this embodiment, as shown in FIG. 2, each columnar body 25 and each wiring portion 20 (each main surface wiring 21) are integrated by being coupled at their boundaries. Note that they do not have to be integrated without being combined.

A plurality of electrode pads 26 are terminals for surface-mounting the semiconductor device A10 on a circuit board of an electronic device. In this embodiment, the semiconductor device A10 has four electrode pads 26. As shown in FIG. Each of the plurality of electrode pads 26 is a conductor rectangular in plan view. Each electrode pad 26 is configured to contact the entire top surface 251 of each columnar body 25 exposed from the sealing resin 4 . Each electrode pad 26 partially overlaps each of the main surface wirings 21 and the sealing resin 4 in plan view. In this embodiment, each electrode pad 26 is composed of, for example, a Ni layer 261, a Pd layer 262, and an Au layer 263 laminated together, as shown in FIG. In this embodiment, the Ni layer 261 is in contact with the columnar wiring, the Au layer 263 is exposed to the outside, and the Pd layer 262 is interposed between the Ni layer 261 and the Au layer 263 . As shown in FIG. 1, the plurality of electrode pads 26 are all positioned on the outer periphery of the first heat dissipation layer 51 in plan view. In this embodiment, the thickness (dimension in the thickness direction z) of each electrode pad 26 is, for example, about 3 to 15 μm. In this embodiment, the electrode pads 26 are formed by electroless plating. The number, thickness, material, shape, and forming method of the electrode pads 26 are not limited.

The wiring portion 20 (the plurality of main surface wirings 21), the plurality of columnar bodies 25, and the plurality of electrode pads 26 form conductive paths between the circuit board on which the semiconductor device A10 is mounted and the semiconductor element 31. FIG. 1 and 2 is merely an example, and the wiring portion 20, the plurality of columnar bodies 25 and the plurality of electrode pads 26 in the actual semiconductor device A10 are shown in FIGS. The arrangement form of the electrode pads 26 is not limited to this.

The semiconductor element 31 is electrically connected to the wiring portion 20 as shown in FIG. The semiconductor element 31 has a rectangular shape in plan view. The semiconductor element 31 is flip-chip mounted. In the present embodiment, a plurality of columnar bodies 25 constitute a housing space for the semiconductor element 31 . The semiconductor element 31 according to this embodiment is an integrated circuit (IC) in which a circuit for driving a switching element such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is formed. Note that the semiconductor element 31 is not limited to this, and may be an element in which various circuits are formed. Also, the semiconductor element 31 can be a Hall element, for example. The semiconductor element 31 has an element main surface 311 , an element back surface 312 and a plurality of element side surfaces 313 .

As shown in FIG. 2, the element main surface 311 and the element back surface 312 face opposite sides and are separated from each other in the thickness direction z. The element main surface 311 faces the substrate main surface 11 . A plurality of electrode bumps 31 a are formed on the element main surface 311 . Each electrode bump 31a is composed of, for example, an alloy solder containing Sn, an alloy solder layer containing Sn/Ni layer/Cu layer, an alloy solder layer containing Sn/Cu layer, or an Au layer/Pd layer/Ni layer. . The element back surface 312 faces the same direction (thickness direction z) as the main surface 11 of the substrate. The element rear surface 312 is exposed from the sealing resin 4 . Each of the plurality of element side surfaces 313 is parallel to the thickness direction z. The semiconductor element 31 in this embodiment has four element side surfaces 313, and the four element side surfaces 313 each face either the first direction x or the second direction y. Each element side surface 313 is covered with the sealing resin 4 .

Each of the plurality of bonding layers 32 is a conductor interposed between each electrode bump 31a of the semiconductor element 31 and each main surface wiring 21, as shown in FIGS. Each bonding layer 32 connects the semiconductor element 31 to each main surface wiring 21 by adhesion, and ensures conduction between the semiconductor element 31 and each main surface wiring 21 (wiring portion 20). The bonding layer 32 according to the present embodiment is composed of a Ni layer and an alloy layer containing Sn that are laminated to each other. The alloy layer is, for example, lead-free solder such as Sn--Ag alloy or Sn--Sb alloy. In this form, the Ni layer is in contact with the main surface wiring 21, and the alloy layer is in contact with the electrode bumps 31a. Note that the material of the bonding layer 32 is not limited. For example, a Cu layer may be interposed between the Ni layer and the main surface wiring 21, the Ni layer may be omitted, or the alloy layer may not be used.

The sealing resin 4 is an electrically insulating synthetic resin containing, for example, a black epoxy resin as a main component. The sealing resin 4 covers part of the semiconductor element 31 and the columnar body 25 as shown in FIG. In this embodiment, the sealing resin 4 overlaps the substrate 1 in plan view and has a rectangular shape in plan view. The material and shape of the sealing resin 4 are not limited. The sealing resin 4 has a resin main surface 41 and a plurality of resin side surfaces 43 . The resin main surface 41 and the plurality of resin side surfaces 43 are all exposed surfaces in the semiconductor device A10.

The resin main surface 41 faces the same direction as the substrate main surface 11 (thickness direction z). The resin main surface 41 is flat. The resin main surface 41 is flush with the top surface 251 of the columnar body 25 and the element back surface 312 of the semiconductor element 31, as shown in FIG.

Each of the plurality of resin side surfaces 43 is sandwiched between the resin main surface 41 and the insulating layer 15 . Each resin side surface 43 is parallel to the thickness direction z. The sealing resin 4 in this embodiment has four resin side surfaces 43, and each of the four resin side surfaces 43 faces either the first direction x or the second direction y. In this embodiment, each resin side surface 43 has a first resin side surface 431 and a second resin side surface 432, as shown in FIG. The first resin side surface 431 is flat, and one edge in the thickness direction z is connected to the resin main surface 41 . The second resin side surface 432 is flat, and one edge in the thickness direction z is connected to the insulating layer 15 . The first resin side surface 431 is arranged inside the semiconductor device A10 relative to the second resin side surface 432 in plan view. Therefore, each resin side surface 43 has two stages. The second resin side surface 432 is flush with the substrate side surface 13 of the substrate 1 . Note that the configuration of the resin side surface 43 is not limited to this. For example, the first resin side surface 431 may be arranged outside the semiconductor device A10 relative to the second resin side surface 432 in plan view. Alternatively, each resin side surface 43 may be one flat surface instead of two steps.

The first heat dissipation layer 51 is for radiating heat generated from the semiconductor element 31 . The first heat dissipation layer 51 covers the element rear surface 312 of the semiconductor element 31, as shown in FIGS. Therefore, the semiconductor element 31 overlaps the first heat dissipation layer 51 in plan view. The first heat dissipation layer 51 is exposed from the sealing resin 4 and exposed to the outside of the semiconductor device A10. The first heat dissipation layer 51 substantially coincides with the electrode pad 26 in the thickness direction z. That is, the first heat dissipation layer 51 overlaps each electrode pad 26 when viewed from the direction orthogonal to the thickness direction z. The first heat dissipation layer 51 is spaced apart and insulated from each of the electrode pads 26 . The thickness of the first heat dissipation layer 51 is, for example, about 3 to 15 μm.

The first heat dissipation layer 51 according to this embodiment is composed of a Ni layer 511, a Pd layer 512, and an Au layer 513, which are laminated to each other, as shown in FIG. First heat dissipation layer 51 is formed by, for example, electroless plating. That is, the first heat dissipation layer 51 in this embodiment is made of the same material as the electrode pad 26 and is formed by the same formation method. The material and formation method of the first heat dissipation layer 51 are not limited. In the first heat dissipation layer 51, the Ni layer 511 is in contact with the semiconductor element 31 (element rear surface 312), and the Au layer 513 is exposed to the outside. A Pd layer 512 is interposed between the Ni layer 511 and the Au layer 513 . In the present embodiment, as shown in FIG. 3, the planar view edge of the Ni layer 511 substantially coincides with the plurality of element side surfaces 313 .

The second heat dissipation layer 52 is for releasing heat generated from the semiconductor element 31 . As shown in FIG. 2, the second heat dissipation layer 52 is arranged in a direction in which the element main surface 311 faces the semiconductor element 31 in the thickness direction z. In this embodiment, the second heat dissipation layer 52 is arranged between the semiconductor element 31 (element main surface 311) and the substrate 1 (substrate main surface 11). The second heat dissipation layer 52 is separated from the semiconductor element 31 in the thickness direction z. A sealing resin 4 is filled between the second heat dissipation layer 52 and the semiconductor element 31 . The second heat dissipation layer 52 contacts the substrate 1 in the exposed region 112 of the substrate main surface 11 of the substrate 1 . As shown in FIG. 1, at least a portion (entirely in the present embodiment) of the second heat dissipation layer 52 overlaps the semiconductor element 31 in plan view. In the present embodiment, the second heat dissipation layer 52 extends from one edge to the other edge in the second direction y of the substrate principal surface 11 in plan view. In addition, in the present embodiment, the upper surface of the second heat dissipation layer 52 shown in FIG. 4 is substantially the same as the upper surface of the wiring portion 20 shown in FIG. 4 in the thickness direction z. The upper surface of the second heat dissipation layer 52 shown in FIG. 4 and the upper surface of the wiring portion 20 shown in FIG. 4 may be different in the thickness direction z.

As shown in FIG. 4, the second heat dissipation layer 52 according to this embodiment is composed of a base layer 521 and a plated layer 522 which are laminated to each other. Base layer 521 is composed of a Ti layer and a Cu layer laminated to each other, and is formed, for example, by a sputtering method. Also, the plated layer 522 is made of Cu and formed, for example, by electroplating. That is, the second heat dissipation layer 52 in this embodiment is made of the same material as the wiring part 20 and is formed by the same formation method. The material and formation method of the second heat dissipation layer 52 are not limited. In the present embodiment, the second heat dissipation layer 52 is electrically conductive, and is spaced apart from the wiring section 20 . It should be noted that the ground (reference potential) portion of the wiring portion 20 and the second heat dissipation layer 52 may be electrically connected, and the second heat dissipation layer 52 may be used as a ground wiring.

Next, an example of a method for manufacturing the semiconductor device A10 will be described with reference to FIGS. 5 to 19. FIG. Note that these figures show cross sections in the yz plane along line II-II in FIG. The thickness direction z, the first direction x and the second direction y of the base material 81 (described later) shown in these figures are the thickness direction z and the first direction of the substrate 1 shown in FIGS. It is the same as the direction indicated by x and the second direction y.

First, as shown in FIG. 5, a base material 81 is prepared. The base material 81 corresponds to the substrate 1 of the semiconductor device A10. The substrate 81 is made of a single-crystal intrinsic semiconductor material, and in this embodiment, is a Si single crystal. The base material 81 has a size that allows a plurality of substrates 1 of the semiconductor device A10 described above to be obtained. That is, the subsequent manufacturing process is based on the assumption that a plurality of semiconductor devices A10 are manufactured collectively. The base material 81 has a front surface 811 and a rear surface 812 facing opposite sides in the thickness direction z, as shown in FIG. The surface 811 is a portion that becomes the main surface 11 of the substrate later.

Then, as shown in FIGS. 5-7, an insulating layer 815 is formed. The insulating layer 815 corresponds to the insulating layer 15 of the semiconductor device A10. In the step of forming the insulating layer 815 (insulating layer forming step), the surface 811 of the base material 81 is thermally oxidized to form the insulating layer 815 over the entire surface 811 as shown in FIG. The thickness of insulating layer 815 is, for example, about 0.7 to 2.0 μm. Then, as shown in FIG. 6, a resist layer 801 is formed. Photolithography is used to form the resist layer 801 . For example, a resist layer 801 is formed so as to cover the entire surface of the insulating layer 815 by a spin coating method using a spin coater (rotary coating device) or the like, and then the resist layer 801 is exposed and developed to form a pattern. to form The resist layer 801 forming the pattern has an opening 801a through which a portion of the insulating layer 815 is exposed. By removing a portion of the insulating layer 815 exposed from the resist layer 801, an insulating layer 815 having an opening 815a is formed as shown in FIG. Partial removal of the insulating layer 815 is performed, for example, by dry etching using a fluorine-based gas. As a result, a region 811a covered with the insulating layer 815 and a region 811b exposed from the insulating layer 815 through the opening 815a are formed on the surface 811 of the base material 81 . A region 811a covered with the insulating layer 815 corresponds to the covered region 111 of the semiconductor device, and a region 811b exposed from the insulating layer 815 corresponds to the exposed region 112 of the semiconductor device.

Next, as shown in FIG. 8, a foundation layer 820z is formed. A part of the underlying layer 820z (a later-described underlying layer 820a) corresponds to the underlying layer 201 of the wiring portion 20 of the semiconductor device A10, and a part of the underlying layer 820z (a later-described underlying layer 852a) corresponds to the underlying layer 201 of the semiconductor device A10. 2 corresponds to the base layer 521 of the heat dissipation layer 52 . The underlying layer 820z is formed by a sputtering method. The underlying layer 820z according to the present embodiment is composed of a Ti layer and a Cu layer laminated to each other, and has a thickness of about 200 to 800 nm. In the step of forming the base layer 820z (base layer forming step), after forming a Ti layer in contact with the insulating layer 815 and the base material 81, a Cu layer is formed in contact with the Ti layer.

Next, as shown in FIGS. 9 and 10, plating layers 820b and 852b are formed. The plating layer 820b corresponds to the plating layer 202 of the wiring portion 20 of the semiconductor device A10, and the plating layer 852b corresponds to the plating layer 522 of the second heat dissipation layer 52 of the semiconductor device A10. In this embodiment, the plating layer 820b and the plating layer 852b are formed collectively. Both of the plating layers 820b and 852b are formed by pattern formation by photolithography and electroplating. In the step of forming the plating layers 820b and 852b (plating layer forming step), first, a resist layer 802 for forming the plating layers 820b and 852b shown in FIG. 9 is formed by photolithography. In forming the resist layer 802, a photosensitive resist is applied by spin coating so as to cover the entire surface of the underlying layer 820z. Then, patterning is performed by exposing and developing the photosensitive resist. Thereby, as shown in FIG. 9, a resist layer 802 forming a pattern is formed. Then, plating layers 820b and 852b are formed in contact with the base layer 820z exposed from the resist layer 802. Next, as shown in FIG. The plating layers 820b and 852b are made of Cu. The plating layers 820b and 852b are formed by electroplating using the base layer 820z as a conductive path. After that, as shown in FIG. 10, the resist layer 802 is removed.

Next, as shown in FIGS. 11 and 12, a bonding layer 832 is formed. The bonding layer 832 corresponds to the bonding layer 32 of the semiconductor device A10. The bonding layer 832 is formed by pattern formation by photolithography and electroplating. In the step of forming the bonding layer 832 (bonding layer forming step), first, a resist layer 803 for forming the bonding layer 832 shown in FIG. 11 is formed. The method of forming the resist layer 803 is the same as that of the resist layer 802 . As shown in FIG. 11, the resist layer 803 forming the pattern has an opening 803a through which a portion of the plating layer 820b is exposed. The shape of the opening 803a according to this embodiment is a rectangular parallelepiped. Then, a bonding layer 832 is formed in contact with the plating layer 820b exposed from the resist layer 803. Next, as shown in FIG. The bonding layer 832 is composed of a Cu layer, a Ni layer, and an alloy layer containing Sn, which are laminated together. The alloy layer is, for example, lead-free solder such as Sn--Ag alloy or Sn--Sb alloy. The bonding layer 832 is formed so as to fill the opening 803a of the resist layer 803 by electroplating using the base layer 820z and the plating layer 820b as conductive paths. After that, as shown in FIG. 12, the resist layer 803 is removed.

Next, as shown in FIGS. 13 and 14, pillars 825 are formed. The columnar body 825 corresponds to the columnar body 25 of the semiconductor device A10. The columnar body 825 is formed by pattern formation by photolithography and electroplating. In the step of forming the columnar body 825 (columnar body forming step), first, a resist layer 804 for forming the columnar body 825 shown in FIG. 13 is formed. The resist layer 804 is formed by attaching a dry film resist suitable for thick films, for example. Note that the resist layers 802 and 803 may be formed in the same manner as the resist layers 802 and 803 . As shown in FIG. 13, the resist layer 804 forming the pattern has an opening 804a through which a portion of the plating layer 820b is exposed. The thickness of the resist layer 804 is determined according to the height of the columns 825 to be formed. The shape of the opening 804a according to this embodiment is a rectangular parallelepiped. Then, a columnar body 825 is formed in the opening 804a of the resist layer 804 so as to be in contact with the plating layer 820b. The columnar bodies 825 are made of Cu. The columnar body 825 is formed so as to fill the opening 804a by electroplating using the underlying layer 820z and the plating layer 820b as a conductive path. After that, as shown in FIG. 14, the resist layer 804 is removed.

Next, as shown in FIG. 15, all unnecessary base layers 820z that are not covered with the plating layer 820b are removed from the base material 81. Next, as shown in FIG. This unnecessary base layer 820z is removed by wet etching, for example. Wet etching uses, for example, a mixed solution of H ₂ SO ₄ (sulfuric acid) and H ₂ O ₂ (hydrogen peroxide). By the step of removing a portion of the base layer 820z (base layer removal step), the insulating layer 815 is exposed from the removed portion of the base layer 820z, as shown in FIG. In addition, the base layer 820z has a portion at least partially in contact with the base material 81 (a portion located in the left-right center in FIG. 15) and a portion in which the entirety is in contact with the insulating layer 815 (a portion located on both left and right sides in FIG. 15). is divided into For convenience of understanding, a portion of the base layer 820z at least partially in contact with the base material 81 is referred to as a base layer 852a, and a portion in contact with the insulating layer 815 entirely is referred to as a base layer 820a. Therefore, through this process, the wiring portion 820 composed of the foundation layer 820a and the plating layer 820b is formed, and the second heat dissipation layer 852 composed of the foundation layer 852a and the plating layer 852b is formed. That is, the wiring part 820 and the second heat dissipation layer 852 are formed collectively. The wiring portion 820 corresponds to the wiring portion 20 (main surface wiring 21) of the semiconductor device A10, and the second heat dissipation layer 852 corresponds to the second heat dissipation layer 52 of the semiconductor device A10. From the above, the step of forming the wiring portion 820 (wiring portion forming step) and the step of forming the second heat dissipation layer 852 (second heat dissipation layer forming step) are both the base layer forming step and the plating layer forming step. , and an underlayer removal step.

Next, as shown in FIG. 16, a semiconductor element 831 is mounted on the wiring portion 820 . The semiconductor element 831 corresponds to the semiconductor element 31 of the semiconductor device A10. The process of mounting the semiconductor element 831 (semiconductor element mounting process) is performed by FCB (Flip Chip Bonding). After applying flux to the electrode bumps 839 of the semiconductor element 831 , the semiconductor element 831 is temporarily attached to the bonding layer 832 with the element main surface 831 a facing the base material 81 using a flip chip bonder. At this time, the bonding layer 832 is sandwiched between both the wiring portion 820 and the semiconductor element 831 . Next, after the bonding layer 832 is melted by reflow, the bonding layer 832 is solidified by cooling, thereby completing the mounting of the semiconductor element 831 .

Next, as shown in FIG. 17, a sealing resin 84 covering the semiconductor element 831 is formed. The sealing resin 84 corresponds to the sealing resin 4 of the semiconductor device A10. The sealing resin 84 according to the present embodiment is a synthetic resin having electrical insulation, for example, a black epoxy resin as a main component. In the step of forming the sealing resin 84 (sealing resin forming step), the sealing resin 84 is formed so as to cover the semiconductor element 831, the wiring portion 820 and the columnar bodies 825 without exposing them. Therefore, the surface 84a of the sealing resin 84 is positioned above the semiconductor element 831 and the columnar body 825 in FIG. 17 in the thickness direction z.

Next, as shown in FIG. 18, the columnar body 825 and the semiconductor element 831 are exposed from the sealing resin 84. Next, as shown in FIG. In this embodiment, the step of exposing the columnar body 825 (columnar body exposing step) and the step of exposing the semiconductor element 831 (semiconductor element exposing step) are collectively performed by, for example, mechanical grinding. In the columnar body exposing process and the semiconductor element exposing process, the sealing resin 84 is mechanically ground from the surface 84 a side, thereby exposing the columnar body 825 and the semiconductor element 831 from the sealing resin 84 . As a result, an element rear surface 831b of the semiconductor element 831 and an exposed surface 825a of the columnar body 825, which are exposed from the sealing resin 84, are formed. Also, a resin main surface 841 of the sealing resin 84 is formed. Element rear surface 831b of semiconductor element 831, exposed surface 825a of columnar body 825, and resin main surface 841 of sealing resin 84 are all flat and flush. The element back surface 831b of the semiconductor element 831 corresponds to the element back surface 312 of the semiconductor element 31 of the semiconductor device A10, the exposed surface 825a of the columnar body 825 corresponds to the top surface 251 of the columnar body 25 of the semiconductor device A10, and the sealing resin 84 corresponds to the resin main surface 41 of the semiconductor device A10.

Next, as shown in FIG. 19, electrode pads 826 and a first heat dissipation layer 851 are formed. The electrode pad 826 corresponds to the electrode pad 26 of the semiconductor device A10, and the first heat dissipation layer 851 corresponds to the first heat dissipation layer 51 of the semiconductor device A10. In the present embodiment, the step of forming the electrode pads 826 (electrode pad forming step) and the step of forming the first heat dissipation layer 851 (first heat dissipation layer forming step) are collectively performed by electroless plating. In this embodiment, the Ni layer, the Pd layer, and the Au layer are deposited in this order by electroless plating. At this time, a Ni layer is formed so as to be in contact with and cover the element rear surface 831b of the semiconductor element 831, and a Pd layer is formed on the Ni layer and an Au layer is formed on the Pd layer. A heat dissipation layer 851 is formed. Further, a Ni layer is formed so as to be in contact with and cover the exposed surface 825 a of the columnar body 825 , a Pd layer is formed on the Ni layer, and an Au layer is formed on the Pd layer. is formed. In this embodiment, the electrode pads 826 and the first heat dissipation layer 851 are formed at the same time. Both the electrode pad 826 and the first heat radiation layer 851 have a thickness of about 3 to 15 μm, for example. It should be noted that in forming the electrode pad 826 and the first heat radiation layer 851, even if the formation speed and degree of formation are slightly different, they are formed at the same time. Since the element back surface 831b, the exposed surface 825a, and the resin main surface 841 are flush as described above, the electrode pad 826 and the first heat dissipation layer 851 are aligned in the thickness direction z.

Next, a portion of the base material 81 is ground by mechanical grinding, for example, from the rear surface 812 side of the base material 81 shown in FIG. The step of grinding the base material 81 may be performed as required. After that, the base material 81 and the sealing resin 84 are cut along the first direction x, and the base material 81 and the sealing resin 84 are cut along the second direction y, thereby corresponding to the substrate 1 of the semiconductor device A10. Divide into individual pieces for each range. For cutting, the base material 81 and the sealing resin 84 are cut by blade dicing, for example. In this embodiment, the sealing resin 84 is cut from the resin main surface 841 side by step cutting. Thereby, as shown in FIG. 2, a first resin side surface 431 and a second resin side surface 432 are formed on the resin side surface 43 . The individual pieces divided in the process become the semiconductor devices A10. Through the above steps, the semiconductor device A10 is manufactured.

Next, the effects of the semiconductor device A10 and its manufacturing method will be described.

The semiconductor device A10 includes a first heat dissipation layer 51. As shown in FIG. The first heat dissipation layer 51 is in contact with the semiconductor element 31 (element rear surface 312) and exposed to the outside. By adopting such a configuration, heat generated from the semiconductor element 31 when the semiconductor device A10 is energized is released to the outside via the first heat radiation layer 51 . Therefore, according to the semiconductor device A10, the heat generated from the semiconductor element 31 can be efficiently released to the outside.

The semiconductor device A10 further includes a second heat dissipation layer 52 . The second heat dissipation layer 52 is arranged between the semiconductor element 31 (element main surface 311) and the substrate 1 (substrate main surface 11) in the thickness direction z. By adopting such a configuration, heat generated from the semiconductor element 31 when the semiconductor device A10 is energized is released to the outside via the second heat dissipation layer 52 and the substrate 1 . Therefore, according to the semiconductor device A10, the heat generated from the semiconductor element 31 is not only radiated from the element back surface 312 side by the first heat radiation layer 51, but also radiated from the element main surface 311 side by the second heat radiation layer 52. becomes possible. That is, the heat of the semiconductor element 31 can be released to the outside more efficiently.

In the semiconductor device A10, the substrate main surface 11 of the substrate 1 includes an exposed region 112 exposed from the insulating layer 15, and the second heat dissipation layer 52 covers at least part of the exposed region 112 (all of it in this embodiment). ) is in contact with the substrate 1 . With such a configuration, heat is more easily conducted from the second heat dissipation layer 52 to the substrate 1 than when the insulating layer 15 is interposed between the second heat dissipation layer 52 and the substrate 1 . Therefore, the heat dissipation of the semiconductor device A10 can be improved.

In the semiconductor device A10, the top surface 251 of the columnar body 25, the resin main surface 41, and the element back surface 312 are flush. By adopting such a configuration, the dimension of the semiconductor device A10 in the thickness direction z can be set short, and the height of the device can be reduced. Moreover, since the electrode pad forming process and the first heat dissipation layer forming process can be collectively performed by electroless plating, the electrode pad 26 (826) and the first heat dissipation layer 51 (851) can be formed simultaneously.

In the semiconductor device A10, the wiring portion 20 and the second heat dissipation layer 52 are made of the same material. By adopting such a configuration, the wiring section 20 (820) and A second heat dissipation layer 52 (852) is formed. That is, since the wiring portion forming step and the second heat dissipation layer forming step can be performed collectively, the wiring portion 20 (820) and the second heat dissipation layer 52 (852) can be formed at the same time.

Although the semiconductor device A10 includes the substrate 1 in the first embodiment, the semiconductor device A10 may not include it. For example, in the manufacturing process described above, in the step of grinding the back surface 812 of the base material 81 , not only part of the base material 81 but also the entire base material 81 is ground, thereby manufacturing a semiconductor device without the substrate 1 . Note that the insulating layer 815 may be ground at the same time to expose the wiring portion 820 (20). However, since the exposed wiring portion 20 may cause an unintended short circuit, it is preferable to leave the insulating layer 815. FIG. Note that the exposed wiring portion 20 may be covered with an insulating film different from the insulating layer 815 .

[Second embodiment]
A semiconductor device A20 according to the second embodiment will be described with reference to FIGS. 20 and 21. FIG. In these figures, elements that are the same as or similar to those of the semiconductor device A10 described above are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 20 is a plan view of the semiconductor device A20, omitting the sealing resin 4 and the insulating layer 15 for convenience of understanding. 21 is a cross-sectional view taken along line XXI-XXI of FIG. 20. FIG. Although FIG. 21 shows the case where each resin side surface 43 is one flat surface, it may be two steps as in the first embodiment. The semiconductor device A20 according to this embodiment is different from the semiconductor device A10 in that the recess 14 is formed in the substrate 1 .

The substrate 1 according to this embodiment has a substrate principal surface 11 , a substrate rear surface 12 , a plurality of substrate side surfaces 13 , and recesses 14 . In this embodiment, the (100) plane, in which the crystal orientation of the substrate 1 is (100), is used as the substrate main surface 11 . Further, as shown in FIG. 1, the substrate main surface 11 has a frame shape surrounding the concave portion 14 in plan view.

Recess 14 is formed so as to be recessed from substrate main surface 11 . The concave portion 14 does not penetrate the substrate 1 in the thickness direction z of the substrate 1 . In this embodiment, the concave portion 14 has a rectangular shape in plan view. In this embodiment, as shown in FIG. 21, the semiconductor element 31 is arranged so that a part thereof is accommodated in the recess 14 . Recess 14 has a bottom surface 141 and a plurality of communicating surfaces 142 .

The bottom surface 141 is a surface on which the semiconductor element 31 is mounted. The bottom surface 141 is orthogonal to the thickness direction z of the substrate 1 and has a rectangular shape in plan view. The bottom surface 141 is flat. In this embodiment, the bottom surface 141 corresponds to the "mounting surface" of the invention.

Each of the plurality of connecting surfaces 142 is a surface connecting to the main surface 11 and the bottom surface 141 of the substrate, as shown in FIGS. 20 and 21 . 21 of each connecting surface 142 is connected to the main surface 11 of the substrate, and the lower end of each connecting surface 142 shown in FIG. Each communicating surface 142 is inclined with respect to the bottom surface 141 . In this embodiment, the recess 14 has four communication surfaces 142 , and a plurality of communication surfaces 142 are formed along the four sides of the bottom surface 141 . Here, in the present embodiment, since the main surface 11 of the substrate is the (100) plane, all of the plurality of connecting surfaces 142 are (111) planes. Therefore, the inclination angles of the plurality of connecting surfaces 142 with respect to the bottom surface 141 are all the same, and the angle is approximately 55° (eg, 54.7°). In this embodiment, the recess 14 is formed by anisotropic etching.

The wiring section 20 according to the present embodiment includes a plurality of main surface wirings 21, a plurality of connecting surface wirings 22, and a plurality of bottom surface wirings 23. FIG.

Each of the plurality of main surface wirings 21 is part of the wiring portion 20 formed on the substrate main surface 11 of the substrate 1 . Each main surface wiring 21 is connected to each communication surface wiring 22 at an intersection line between the substrate main surface 11 and each communication surface 142 along the second direction y, and extends from the intersection line along the first direction x. there is Each main surface wiring 21 is connected to each columnar body 25 .

Each of the plurality of connecting surface wirings 22 is part of the wiring portion 20 formed on each connecting surface 142 of the substrate 1 . Each communication surface wiring 22 is formed on one of a pair of communication surfaces 142 spaced apart in the first direction x, and has a rectangular shape in plan view. In this embodiment, each connecting surface wiring 22 is formed so as to be parallel to the first direction x. 21 is connected to each main surface wiring 21, and the lower end of each communication surface wiring 22 shown in FIG. there is

Each of the plurality of bottom wirings 23 is part of the wiring section 20 formed on the bottom surface 141 of the substrate 1 . In the present embodiment, each bottom surface wiring 23 is connected to each communication surface wiring 22 at an intersection line between the bottom surface 141 and each communication surface 142 along the second direction y, and extends toward the inner side of the bottom surface 141 from the intersection line. procrastinating. As shown in FIG. 21, a semiconductor element 31 is electrically connected to each bottom wiring 23 via each bonding layer 32 .

Next, an example of a method for manufacturing the semiconductor device A20 will be described with reference to FIGS. 22 to 27. FIG. The description of the parts common to the manufacturing method of the semiconductor device A10 according to the first embodiment will be omitted. These figures are cross-sectional views for explaining the manufacturing process of the semiconductor device A20, and show cross-sections in the yz plane along line XXI-XXI in FIG.

First, as shown in FIGS. 22 to 24, a base material 81 is prepared and recesses 814 are formed in the base material 81 . The recess 814 corresponds to the recess 14 of the semiconductor device A20. Specifically, as shown in FIG. 22, a base material 81 is prepared as in the first embodiment. The base material 81 according to the present embodiment employs a (100) plane having a crystal orientation of (100) as the surface 811 .

Next, as shown in FIG. 22, a mask layer 805 made of SiO ₂ is formed by thermally oxidizing the surface 811 . At this point, mask layer 805 covers the entire surface 811 . The thickness of mask layer 805 is, for example, about 0.7 to 2.0 μm.

Next, as shown in FIG. 23, the mask layer 805 is patterned by etching. Specifically, a resist is formed on the mask layer 805 by photolithography, the mask layer 805 is etched, and then the resist is removed. This forms an opening in mask layer 805 . The shape and size of this opening are set according to the shape and size of the concave portion 814 to be finally obtained. In this embodiment, the opening is rectangular.

Next, as shown in FIG. 24, recesses 814 are formed in the base material 81 . In the step of forming the recesses 814 (recess formation step), for example, anisotropic etching using KOH is performed. KOH is an example of an alkaline etching solution that can achieve good anisotropic etching for Si single crystals. By performing this anisotropic etching, a recess 814 having a bottom surface 814a and a connecting surface 814b shown in FIG. 24 is formed. In this embodiment, since the (100) plane is adopted as the surface 811, each connecting surface 814b is a (111) plane, and the angle formed by the connecting surface 814b with respect to the surface 811 (xy plane) is , about 55° (eg 54.7°). In this embodiment, the depth (dimension in the thickness direction z) of the recess 814 is approximately 50 to 80 μm. The etching solution is not limited to KOH, and may be an alkaline solution such as TMAH (tetramethylammonium hydroxide) or EDP (ethylenediaminepyrocatel). Alternatively, isotropic etching may be performed using a hydrofluoric-nitric acid (mixed acid of HF and HNO ₃ ) solution as an etching solution.

Mask layer 805 is then removed. The mask layer 805 is removed by etching using HF, for example. Through the recess forming process described above, a recess 814 is formed in each opening formed in the mask layer 805 .

Next, as shown in FIG. 25, an insulating layer 815, a foundation layer 820z, plating layers 820b and 852b, a bonding layer 832, and columnar bodies 825 are formed. These steps are performed in the same manner as the insulating layer forming step, base layer forming step, plating layer forming step, bonding layer forming step, and columnar body forming step according to the first embodiment. However, in the present embodiment, the formation of the resist layer 802 in the plating layer forming step and the formation of the resist layer 803 in the bonding layer forming step are performed by a spray coating method or an electrodeposition method instead of the spin coating method described above. be done. A spin coating method may be used as in the first embodiment. Also, the formation order of these is the same as in the first embodiment.

Next, as shown in FIG. 26, after removing the unnecessary base layer 820z that is not covered with the plating layers 820b and 852b, the semiconductor element 831 is mounted on the base material 81, and the sealing resin 84 is formed. These steps are performed in the same manner as the base layer removing step, the semiconductor element mounting step, and the sealing resin forming step according to the first embodiment. However, in the semiconductor element mounting process of the present embodiment, the semiconductor element 831 is mounted on the bottom surface 814 a of the recess 814 so that a portion of the semiconductor element 831 is accommodated in the recess 814 .

Next, as shown in FIG. 27, after exposing the columnar body 825 and the semiconductor element 831 from the sealing resin 84, the electrode pad 826 and the first heat dissipation layer 851 are formed. These formations are performed in the same manner as the pillar exposing process, the semiconductor element exposing process, the electrode pad forming process, and the first heat dissipation layer forming process according to the first embodiment. 27, the base layer 820a and the plated layer 820b are described as the wiring portion 820, and the base layer 852a and the plated layer 852b are described as the second heat dissipation layer 852. As shown in FIG.

Then, similarly to the first embodiment, the base material 81 is ground from the rear surface 812 side as necessary. After that, by blade dicing, the base material 81 and the sealing resin 84 are cut along the first direction x and the second direction y, thereby dividing into individual pieces corresponding to the substrate 1 of the semiconductor device A20. Through the above steps, the semiconductor device A20 is manufactured.

Next, the effects of the semiconductor device A20 and its manufacturing method will be described.

According to this embodiment, the semiconductor device A20 includes the first heat dissipation layer 51, like the semiconductor device A10. Therefore, the heat generated from the semiconductor element 31 can be released to the outside from the element rear surface 312 side. In other words, the same effects as in the first embodiment can be obtained in this embodiment as well.

According to this embodiment, the semiconductor device A20 includes the second heat dissipation layer 52, like the semiconductor device A10. Therefore, the heat generated from the semiconductor element 31 can be radiated not only from the element back surface 312 side by the first heat radiation layer 51 but also from the element main surface 311 side by the second heat radiation layer 52 . In other words, the same effects as in the first embodiment can be obtained in this embodiment as well.

In addition, in the present embodiment, those configured in the same manner as in the first embodiment have the same effects as in the first embodiment.

In the second embodiment, the case where the shape of the wiring part 20 in a plan view is the shape shown in FIG. 20 has been described, but the shape is not limited to this. For example, the shape of the wiring portion 20 in plan view may be a shape as shown in FIG. FIG. 28 shows a semiconductor device A20' according to such a modification. FIG. 28 is a plan view showing the semiconductor device A20' and corresponds to FIG.

The semiconductor device A20' differs from the semiconductor device A20 in the shape of the wiring portion 20. FIG. The semiconductor element 31 in the semiconductor device A20' differs from the semiconductor element 31 in the semiconductor device A20 in the arrangement of the electrode bumps 31a. It is The bottom wiring 23 formed on the bottom surface 141 of the substrate 1 extends to the vicinity of the center of the bottom surface 141 so as to be connected to these electrode bumps 31a. Further, the width (dimension in the second direction y) of the connecting surface wiring 22 formed on the connecting surface 142 of the substrate 1 increases from the main surface 11 of the substrate toward the bottom surface 141 . In the semiconductor device A20′, as shown in FIG. 28, the inner side of the contact surface wiring 22 (the center side of the semiconductor device A20′ in the second direction y) is parallel to the first direction x, but the contact surface The outer side of the wiring 22 (the side opposite to the center side of the semiconductor device A20' in the second direction y) is inclined with respect to the first direction x.

The semiconductor device A20' configured as described above can also achieve the same effect as the semiconductor device A20.

The shape of the connecting surface wiring 22 is not limited to the one described above (see FIG. 28). The outer side of the connecting surface wiring 22 may be parallel to the first direction x, and the inner side of the connecting surface wiring 22 may be inclined with respect to the first direction x. Also, both the inner side and the outer side of the connecting surface wiring 22 may be inclined with respect to the first direction x. Further, the width of the connecting surface wiring 22 may be reduced from the main surface 11 of the substrate toward the bottom surface 141 .

In this modified example, the case where the second heat dissipation layer 52 is not provided is shown, but the present invention is not limited to this, and the second heat dissipation layer 52 may be provided.

[Third Embodiment]
A semiconductor device A30 according to the third embodiment will be described with reference to FIGS. 29 and 30. FIG. In these figures, elements that are the same as or similar to those of the semiconductor devices A10 and A20 described above are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 29 is a plan view of the semiconductor device A30, omitting the sealing resin 4 and the insulating layer 15 for convenience of understanding. 30 is a cross-sectional view taken along line XXX-XXX in FIG. 29. FIG. Although FIG. 30 shows the case where each resin side surface 43 is one flat surface, it may be two steps as in the first embodiment. The semiconductor device A30 according to the present embodiment is different from the semiconductor device A10 in that it does not have the columnar bodies 25 and the plurality of electrode pads 26 are arranged on the substrate rear surface 12 side of the substrate 1 .

The substrate 1 according to this embodiment has a substrate principal surface 11 , a substrate rear surface 12 , a plurality of substrate side surfaces 13 , and a plurality of through holes 16 . In the present embodiment, as with the substrate 1 according to the second embodiment, the (100) plane, in which the crystal orientation of the substrate 1 is (100), is adopted as the substrate main surface 11 . Also, the semiconductor element 31 is mounted on the main surface 11 of the substrate, as shown in FIG. In this embodiment, the main surface 11 of the substrate corresponds to the "mounting surface" of the invention.

As shown in FIG. 30, each of the plurality of through holes 16 penetrates from the main surface 11 of the substrate 1 to the back surface 12 of the substrate 1 in the thickness direction z. In this embodiment, as shown in FIG. 29, the substrate 1 has four through-holes 16, and each through-hole 16 is provided near four corners of the substrate 1, respectively. In the present embodiment, each through-hole 16 has a rectangular shape in plan view. The opening dimension of each through-hole 16 on the side of the main surface 11 of the substrate is about 200 to 300 μm. The number, arrangement, shape and dimensions of the through-holes 16 are not limited. The insulating layer 15 is also formed on the inner surface of each through-hole 16, as shown in FIG.

The wiring portion 20 according to this embodiment includes a plurality of main surface wirings 21 and a plurality of through wirings 24 . Each of the plurality of through-wirings 24 is formed to penetrate through the substrate 1 . Each through wire 24 is formed inside each through hole 16 so as to fill each through hole 16 . Each through wire 24 is exposed from the substrate main surface 11 and the substrate back surface 12 of the substrate 1 respectively. One end of each through wire 24 exposed from the substrate main surface 11 is connected to the main surface wire 21 . The other end of each through-wiring 24 exposed from the back surface 12 of the substrate is connected to each electrode pad 26 . In this embodiment, each through wire 24 is prismatic and has an exposed surface 241 . Each exposed surface 241 is a surface on the other end side of each through wire 24 exposed from the substrate back surface 12 and is flush with the substrate back surface 12 . The shape of each through wire 24 is not limited, and may be, for example, a cylindrical shape. In this embodiment, the plurality of main surface wirings 21 and the plurality of through wirings 24 are integrally formed of the same material. Note that the plurality of main surface wirings 21 and the plurality of through wirings 24 may be separately formed of different materials.

In this embodiment, each electrode pad 26 is formed so as to be in contact with the entire exposed surface 241 of each through wire 24 exposed from the substrate rear surface 12 .

In this embodiment, the semiconductor device A30 includes a resin film 6. As shown in FIG. The resin film 6 is formed on the back surface 12 of the substrate. The resin film 6 covers the entire surface of the substrate rear surface 12, and covers the entire surface of the semiconductor device A30 on the substrate rear surface 12 side, excluding the portions where the plurality of electrode pads 26 are formed. The resin film 6 serves to electrically insulate the electrode pads 26 from each other.

Next, an example of a method for manufacturing the semiconductor device A30 will be described with reference to FIGS. 31 to 35. FIG. Note that the description of the parts common to the manufacturing method of the semiconductor device A10 and the manufacturing method of the semiconductor device A20 will be omitted. These figures are cross-sectional views for explaining the manufacturing process of the semiconductor device A30, and show cross-sections in the yz plane along line XXX-XXX in FIG.

First, as shown in FIG. 31, a substrate 81 is prepared, and recesses 813 are formed in the surface 811 of the substrate 81 . The recess 813 is a portion that will later become a through hole 816, and is formed in the same manner as the recess 814 according to the second embodiment (see FIGS. 22 to 24).

Next, as shown in FIG. 32, an insulating layer 815, a base layer 820z, plated layers 820b and 852b, and a bonding layer 832 are formed. These formations are performed in the same manner as the insulating layer forming process, base layer forming process, plating layer forming process, and bonding layer forming process according to the first embodiment. In the plating layer forming process according to the present embodiment, a suppressor and an accelerator are added to the plating solution. Plating deposits and grows on the surface. As a result, the plated layer 820b formed is thicker in the portions located in the recesses 813 than in the portions located on the surface 811 . A thick portion of the plating layer 820b formed in the recess 813 becomes the through wiring 24 of the semiconductor device A30.

Next, as shown in FIG. 33, after removing the unnecessary base layer 820z that is not covered with the plating layers 820b and 852b, the semiconductor element 831 is mounted on the base material 81, and the sealing resin 84 is formed. These steps are performed in the same manner as the base layer removing step, the semiconductor element mounting step, and the sealing resin forming step according to the first embodiment.

Next, as shown in FIG. 34, sealing resin 84 and a portion of base material 81 are ground, for example, by mechanical grinding. 34 and 35, the base layer 820a and the plated layer 820b are described as the wiring portion 820, and the base layer 852a and the plated layer 852b are described as the second heat dissipation layer 852. As shown in FIG. In this embodiment, the sealing resin 84 is ground from the surface 84a side (upper side in the drawing) to expose the semiconductor element 831 . By this grinding, the element main surface 831a of the semiconductor element 831 and the resin main surface 841 of the sealing resin 84 are both flat and flush. Further, the base material 81 is ground from the back surface 812 side (lower side in the drawing) to form the through holes 816 and the through wirings 824 . In this embodiment, grinding is performed until the overall dimension in the thickness direction z (the dimension from the back surface 812 to the upper surface of the sealing resin 84) reaches a desired dimension (for example, about 200 to 300 μm). Through this grinding, the through wiring 824 comes to have an exposed surface 824 a exposed from the back surface 812 of the base material 81 . Further, the concave portion 813 is penetrated by grinding the bottom portion thereof to become a through hole 816 . In this embodiment, the recess 813 with a depth of about 50 to 80 μm is ground to form a through hole 816 with a thickness (about 30 to 50 μm) of the base material 81 . That is, the through wiring 824 is also ground by about 20 to 30 μm. Further, the exposed surface 824a of the through wire 824 and the back surface 812 of the base material 81 are both flat and flush.

Next, as shown in FIG. 35, a resin film 86 is formed so as to cover the rear surface 812 of the base material 81 . An opening is formed in the resin film 86 so as to surround the exposed surface 824 a of the through wire 824 . Next, as shown in FIG. 35, electrode pads 826 are formed in the openings of the resin film 86 in contact with the exposed surfaces 824a of the through-wirings 824, and the first heat dissipation layer 51 is formed in contact with the device rear surface 831b of the semiconductor device 831. do.

Next, as in the first embodiment, by cutting the base material 81 and the sealing resin 84 along the first direction x and the second direction y by blade dicing, a range corresponding to the substrate 1 of the semiconductor device A30 is obtained. Separate into individual pieces. Through the above steps, the semiconductor device A30 is manufactured.

Next, the effects of the semiconductor device A30 and its manufacturing method will be described.

According to this embodiment, the semiconductor device A30 includes the first heat dissipation layer 51, like the semiconductor devices A10 and A20. Therefore, the heat generated from the semiconductor element 31 can be released to the outside from the element rear surface 312 side. In other words, the same effects as in the first embodiment can be obtained in this embodiment as well.

According to this embodiment, the semiconductor device A30 includes the second heat dissipation layer 52, like the semiconductor devices A10 and A20. Therefore, the heat generated from the semiconductor element 31 can be radiated not only from the element back surface 312 side by the first heat radiation layer 51 but also from the element main surface 311 side by the second heat radiation layer 52 . In other words, the same effects as in the first embodiment can be obtained in this embodiment as well.

In addition, in the present embodiment, those configured similarly to the first embodiment or the second embodiment have the same effects as those of the first embodiment or the second embodiment, respectively.

Although the case where the second heat dissipation layer 52 is formed on the substrate 1 has been shown in the third embodiment, the present invention is not limited to this. For example, the second heat dissipation layer 52 may be formed so as to penetrate the substrate 1 . FIG. 36 shows a semiconductor device A30' according to such a modification. FIG. 36 is a cross-sectional view showing the semiconductor device A30', corresponding to the cross-section shown in FIG.

The substrate 1 in the semiconductor device A30' further has a through hole 16' compared to the substrate 1 in the semiconductor device A30. The through-hole 16' overlaps the semiconductor element 31 in plan view. The through-hole 16' has a rectangular shape in plan view. Through hole 16 ′ is formed similarly to through hole 16 . The through hole 16' may be formed at the same time as the through hole 16 or may be formed at different timings. The number and shape of the through holes 16' are not limited. In this modification, the insulating layer 15 is also formed on the inner surface of the through hole 16', as shown in FIG.

In the semiconductor device A30', as shown in FIG. 36, the second heat dissipation layer 52 is formed inside the through hole 16' so as to partially fill the through hole 16'. The second heat dissipation layer 52 is exposed from the substrate main surface 11 and the substrate rear surface 12 of the substrate 1 respectively. A metal film 27 is formed on the surface of the second heat dissipation layer 52 exposed from the substrate rear surface 12 . The metal film 27 is made of the same material as the electrode pad 26, for example. That is, the metal film 27 is composed of a Ni layer in contact with the second heat dissipation layer 52, a Pd layer laminated on the Ni layer, and an Au layer laminated on the Pd layer. The Au layer is exposed to the outside. The metal film 27 is formed by electroless plating similarly to the electrode pad 26 . In this modified example, the resin film 6 (86) is formed so as to have an opening in order to cover the back surface of the second heat dissipation layer 52 with the metal film 27. As shown in FIG. Note that the resin film 6 may be formed instead of the metal film 27 in the semiconductor device A30'.

The semiconductor device A30' configured as described above can also achieve the same effect as the semiconductor device A30. Furthermore, according to the semiconductor device A30', the second heat dissipation layer 52 is formed so as to penetrate the substrate 1. As shown in FIG. The material of the second heat dissipation layer 52 is metal (mainly Cu), which has a higher thermal conductivity than Si, which is the material of the substrate 1 . Therefore, the semiconductor device A30' can release the heat of the semiconductor element 31 to the outside more efficiently than the semiconductor device A30.

In addition, in the above modified example, the case where the through hole 16' is added to the semiconductor device A30 is shown, but the through hole 16' is further added to the semiconductor devices A10 and A20, and the second heat dissipation layer 52 may be formed inside the through-hole 16' such that the through-hole 16' is partially filled. That is, the second heat dissipation layer 52 may be configured to penetrate through the substrate 1 in the semiconductor devices A10 and A20. In this case, the through hole 16' may or may not have an inner surface inclined with respect to the thickness direction z, similarly to the semiconductor device A30'. The method of forming the through holes 16' is not particularly limited.

In the first to third embodiments, the semiconductor devices A10, A20, A30 were provided with the second heat dissipation layer 52, but this need not be provided. For example, in the plating layer forming step (see FIGS. 9 and 10), by forming the resist layer 802 also at the position where the plating layer 852b is to be formed, a semiconductor device without the second heat dissipation layer 52 can be manufactured. .

In the first to third embodiments, in the semiconductor devices A10, A20, and A30, the semiconductor element 31 and the second heat dissipation layer 52 are separated, and the gap between the semiconductor element 31 and the second heat dissipation layer 52 is sealed. Although the case where the resin 4 is filled is shown, it is not limited to this. For example, the semiconductor element 31 and the second heat dissipation layer 52 may be joined by a conductor. FIG. 37 is a diagram for explaining such a modification, and is a cross-sectional view corresponding to FIG. This figure shows a case where the semiconductor element 31 and the second heat dissipation layer 52 are joined by a joining layer 32' in the semiconductor device A10, for example. In this modification, the bonding layer 32 ′ is made of the same material as the bonding layer 32 . Also, as shown in FIG. 37, the bonding layer 32' is formed so as to partially cover the surface of the second heat dissipation layer 52 facing the semiconductor element 31 (upper surface in the drawing). In addition, it may be formed so as to cover all of the facing surfaces. Also, the arrangement and shape of the bonding layer 32' are not limited to those shown in FIG. With such a configuration, heat generated from the semiconductor element 31 is transferred to the second heat dissipation layer 52 via the bonding layer 32'. Since the bonding layer 32 ′ is mainly made of a metal material, it has higher thermal conductivity than the sealing resin 4 . Therefore, it is possible to further improve the heat dissipation performance of the semiconductor device. In addition, when the semiconductor element 31 and the second heat dissipation layer 52 are bonded by the bonding layer 32', the second heat dissipation layer 52 may be used as an internal wiring. In this case, it is preferable to interpose an insulating material between the second heat dissipation layer 52 and the substrate 1 .

In the first to third embodiments, the semiconductor devices A10, A20, and A30 each have one semiconductor element 31. However, the present invention is not limited to this, and a plurality of semiconductor elements may be provided. FIG. 38 is a diagram for explaining such a modification, and is a cross-sectional view corresponding to FIG. This figure shows, for example, the case where the semiconductor device A10 further includes a semiconductor element 33 . In this modification, the semiconductor element 33 is a discrete semiconductor such as a diode. It should be noted that an integrated circuit, like the semiconductor element 31, may be used instead of a discrete semiconductor. The semiconductor element 33 is a surface mount type package. By adopting such a configuration, the semiconductor device can be made multi-functional.

The semiconductor device and the method for manufacturing the semiconductor device according to the present disclosure are not limited to the above embodiments. The specific configuration of each part of the semiconductor device according to the present disclosure and the specific method of each step of the method for manufacturing the semiconductor device according to the present disclosure can be changed in design in various ways.

A10, A20, A20', A30, A30': Semiconductor device 1: Substrate 11: Substrate main surface 111: Covered region 112: Exposed region 12: Substrate rear surface 13: Substrate side surface 14: Recess 141: Bottom surface 142: Communication surface 15: Insulating layers 16, 16': Through hole 20: Wiring part 201: Base layer 202: Plating layer 21: Main surface wiring 22: Communication surface wiring 23: Bottom surface wiring 24: Through wiring 241: Exposed surface 25: Columnar body 251: Top Surface 252 : Side surface 26 : Electrode pad 261 : Ni layer 262 : Pd layer 263 : Au layer 27 : Metal film 31 : Semiconductor element 31a : Electrode bump 311 : Element main surface 312 : Element back surface 313 : Element side surfaces 32, 32': Bonding layer 33 : Semiconductor element 4 : Sealing resin 41 : Resin main surface 43 : Resin side surface 431 : First resin side surface 432 : Second resin side surface 51 : First heat dissipation layer 511 : Ni layer 512 : Pd layer 513 : Au layer 52: Second heat dissipation layer 521: Base layer 522: Plating layer 6: Resin films 801, 802, 803, 804: Resist layers 801a, 803a, 804a: Opening 805: Mask layer 81: Base material 811: Surface 811a: Region 811b: Region 812: Back surface 813: Recessed portion 814: Recessed portion 814a: Bottom surface 814b: Communication surface 815: Insulating layer 815a: Opening 816: Through hole 820: Wiring portion 820a: Base layer 820b: Plating layer 820z: Base layer 824: Through wiring 824a: exposed surface 825: columnar body 825a: exposed surface 826: electrode pad 831: semiconductor element 831a: element main surface 831b: element back surface 832: bonding layer 839: electrode bump 84: sealing resin 84a: surface 841: resin main surface 851: first heat dissipation layer 852: second heat dissipation layer 852a: underlying layer 852b: plating layer 86: resin film

Claims (13)

a first semiconductor element having a first element main surface and a first element back surface facing opposite sides in a thickness direction;
a first heat radiating portion in contact with the back surface of the first element in the thickness direction;
a substrate having a substrate main surface and a substrate back surface facing opposite to each other in the thickness direction and facing the first element main surface in the thickness direction;
a second heat radiating portion provided on the main surface side of the substrate;
a wiring portion provided separately from the second heat radiation portion on the main surface of the substrate and made of the same material as the second heat radiation portion;
a sealing resin covering a portion of the first semiconductor element;
a conductive member extending in a direction away from the wiring portion and exposed from the sealing resin;
a first bonding layer that electrically connects the first semiconductor element and the wiring portion;
a second bonding layer disposed between the first semiconductor element and the second heat radiation part and in contact with the first semiconductor element and the second heat radiation part;
an insulating layer that covers a portion of the main surface of the substrate and insulates the substrate from the wiring portion;
with
the main surface of the substrate includes an exposed region exposed from the insulating layer;
The second heat radiation part covers a part of the insulating layer while being in contact with the exposed region.
semiconductor device. The conductive member is a columnar body,
A semiconductor device according to claim 1 . comprising a plurality of the conductive members,
3. The semiconductor device according to claim 1 or 2. The back surface of the substrate is exposed from the sealing resin,
4. The semiconductor device according to claim 1. At least a part of the second heat radiation part overlaps with the first semiconductor element when viewed from the thickness direction,
5. The semiconductor device according to claim 1. a second semiconductor element having a second element main surface facing the same direction as the first element main surface in the thickness direction and a second element back surface facing the same direction as the first element main surface in the thickness direction; ,
wherein the second semiconductor element is connected to the wiring portion;
6. The semiconductor device according to claim 1. Further comprising a third heat radiation part on the back surface of the second element,
7. The semiconductor device according to claim 6. wherein the second semiconductor element is a diode;
8. The semiconductor device according to claim 6 or 7. the substrate is composed of a semiconductor material;
9. The semiconductor device according to claim 1. wherein the semiconductor material is Si;
10. The semiconductor device according to claim 9. Both the second heat radiation part and the wiring part are composed of a laminated base layer and a plating layer,
11. The semiconductor device according to claim 1. The underlying layer is composed of a laminated Ti layer and a Cu layer,
The plating layer is composed of Cu,
12. The semiconductor device according to claim 11. The dimension of the substrate in the thickness direction is 200 μm or more and 300 μm or less.
13. The semiconductor device according to claim 1.

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