JP2007165747A - Semiconductor chip contact mechanism for system-in-package (sip) - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact mechanism for economically and stably connecting the terminals of semiconductor chips in the upper and lower layers arranged by a closed pitch in an SiP(system-in-package) where a plurality of semiconductor chips are laminated in thickness direction. <P>SOLUTION: In an SiP including a plurality of semiconductor chips, electric connection between upper and lower laminated semiconductor chips, between the semiconductor chip and a packet direct material and/or direct materials on which the semiconductor chips are set is carried out by holding a contact layer configured by putting a contact member(ring) formed of conductive metallic thin wires through a through-hole formed in an insulating layer constituted of a heatproof insulating film or the like between the upper layer and lower layer to be connected, and electrically connecting the terminals of the upper and lower laminated layers by the contact member put through the contact layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor chip contact mechanism in a system-in-package (hereinafter simply referred to as “SiP”) in which a plurality of semiconductor chips are mounted. More specifically, a stack type SiP in which a plurality of semiconductor chips are stacked in the vertical direction (including the one in which a semiconductor chip is set on a substrate and the entire substrate is stacked, the same applies hereinafter) or the semiconductor chip on a package direct material The present invention relates to a novel contact mechanism for performing electrical connection between vertically stacked semiconductor chips, between a semiconductor chip and a package direct material, and / or between a direct material on which a semiconductor chip is set in a horizontally juxtaposed SiP.

In recent years, a technique called SiP has been attracting attention in order to reduce the size of a semiconductor package (for example, see Non-Patent Document 1).
Such SiP technology is effective as a means for downsizing a plurality of semiconductor chips such as memories and CPUs as an integrated package, and is a type in which a plurality of semiconductor chips are directly stacked in the thickness direction to form a stack or a single direct material There are a type in which a plurality of semiconductor chips are juxtaposed on a (substrate), a type in which semiconductor chips set on a direct material (substrate) are superposed together with the direct material, and the like.
In either case, the connection between the stacked semiconductor chips or between the semiconductor chip and the direct material is a problem, and at present, the connection is made with a thin metal wire (wire) by solder.

  However, the connection by soldering is limited in the distance between adjacent connection points, and it is difficult to replace some semiconductor chips constituting the package after they are connected once. When there was, there was a problem that the whole package had to be defective.

  In addition, in SiP in which a plurality of semiconductor chips are stacked, it is also known that input / output pads in upper and lower semiconductor chips are stacked so as to face each other (see, for example, Patent Document 1).

However, with such a contact mechanism, it is necessary to create the semiconductor chip so that the positions of the input / output pads of the upper and lower semiconductor chips to be stacked are in accurate contact, and the manufacturing process is complicated.
'Electric Journal' September 2003, pp. 98-101 JP 2005-109239 A

  The main object of the present invention is to solve the above-described problems in the conventional SiP contact mechanism, connect terminals arranged at narrower intervals, and part of a semiconductor chip constituting the package. When a defect is found, an attempt is made to provide an SiP contact mechanism that can replace the chip.

  As a result of diligent research to solve various problems in the conventional SiP contact mechanism, the present inventors have found that a stack type Si SiP and / or a semiconductor chip in which a plurality of semiconductor chips are stacked in a vertical direction are mounted on a package direct material. In the horizontally juxtaposed SiP, the electrical connection between the stacked upper and lower semiconductor chips, between the semiconductor chip and the package direct material, and / or between the package direct materials is between the upper layer and the lower layer to be connected. The present invention has been conceived by interposing a specific contact layer and electrically connecting the stacked upper and lower terminals with the contact layer.

That is, the invention according to claim 1 of the present invention is a system-in-package (SiP) in which a plurality of semiconductor chips are stacked in a vertical direction and / or a system in which semiconductor chips are juxtaposed horizontally on a package direct material. In the package (SiP), the electrical connection between the stacked upper and lower semiconductor chips, between the semiconductor chip and the package direct material and / or between the package direct materials is performed between the upper layer and the lower layer to be connected. A semiconductor chip or a direct material disposed above and below the contact layer by the contact member of the contact layer with a contact layer provided with a contact member formed in a shape elongated in the vertical direction from a wound conductive metal fine wire System-in-package (SiP) contact mechanism, characterized by electrically connecting the terminals of each other
The “direct package material” referred to in the present invention is a generic term for members other than the semiconductor chip (IC chip) among the members constituting the semiconductor package, and includes a wide range including, for example, “package substrate” and “lead frame”. Means a member.

  The invention of claim 2 is characterized in that, in the system SiP contact mechanism, the contact member is a flexible member whose vertical dimension can be changed by a load from the upper and lower layers. The contact member is configured to reliably and stably contact the upper and lower layer terminals.

  According to a third aspect of the present invention, in the contact mechanism for SiP, the contact layer includes an insulating layer made of a synthetic resin film or a synthetic resin sheet, and a contact member inserted into each of the plurality of through holes of the insulating layer. It is characterized by. The invention according to claim 4 is characterized in that the contact member is a ring formed by forming a wound conductive metal wire into an ellipse having a major axis in the thickness direction of the contact layer. The invention is characterized in that the contact member is formed by forming a wound conductive metal fine wire into a shape such as a rectangle, a rhombus, or a mushroom that extends in the thickness direction of the contact layer. By providing such a contact member, a more practical contact mechanism is obtained.

  According to a sixth aspect of the present invention, in the contact mechanism for SiP, the contact member is inserted into the through hole so that a part of the outer periphery thereof is in pressure contact with an inner wall of the through hole formed in the insulating layer. In addition, the upper and lower ends of the contact member protrude from the upper and lower surfaces of the insulating layer so as to contact the upper and lower terminals, respectively, and provide a low-cost and highly practical contact mechanism. Is.

  Furthermore, the invention according to claim 7 is the contact mechanism for SiP, wherein the contact member made of a thin conductive metal wire is inserted into a through hole provided in the insulating layer between the upper layer and the lower layer to be connected. A contact layer is interposed, and the contact members inserted through the contact layer are used to electrically connect the terminals of the upper and lower layers, and the space between the upper and lower layers including the contact layer is made of an insulating heat conductive material. It is characterized in that the heat generated and accumulated in the system in package (SiP) is effectively dissipated to the outside.

  The present invention can be applied to both stack-type SiPs in which a plurality of semiconductor chips are stacked in the vertical direction and / or SiPs in which semiconductor chips are juxtaposed horizontally on a package direct material. In SiP, electrical connection is made between stacked semiconductor chips, between a semiconductor chip and a package direct material, and / or between package direct materials (for example, substrates on which semiconductor chips are set). Therefore, a specific contact layer described in detail below is interposed between the upper layer and the lower layer to be connected, and the stacked upper and lower layer terminals are electrically connected by the contact member provided on the contact layer. Is.

  In the present invention, the contact layer is preferably formed from an insulating layer made of a synthetic resin film or a synthetic resin sheet, and a conductive metal thin wire inserted through each of a plurality of through holes formed in the insulating layer. It is comprised with the contact member formed.

A specific example of the insulating layer is a synthetic resin film or sheet having a thickness of about 25 to 200 μm. The film or sheet is preferably made of a heat-resistant synthetic resin. “Heat resistance” as used herein means having a heat distortion temperature of about 180 ° C. or higher, and examples of such synthetic resins include polyimide, polyamideimide, aramid (fully aromatic polyamide) and the like. I can do it. Especially, the film or sheet | seat of a polyimide is excellent in practicality as an insulating layer which comprises the contact mechanism of this invention in various points, and is suitable. However, in the present invention, it is preferable to use a film or sheet made of a heat-resistant synthetic resin as the insulating layer, but it may be composed of other materials having an insulating function.
As already described, the insulating layer is provided with a plurality of small holes penetrating in the thickness direction. The number, position, layout, and the like of the through holes in the insulating layer are appropriately selected according to the number and positions of connection terminals such as semiconductor chips to be connected. The contact layer in the contact mechanism of the present invention is configured by inserting one contact member, which will be described later, into each of these through holes.

  The contact member is obtained by forming a wound conductive metal wire into a predetermined shape, and as a specific example, an annular body formed by winding the conductive metal wire in one or a plurality of loops is elliptical. Examples include a member formed into a shape such as a shape, a rectangle, a rhombus, or a mushroom. These contact members have a form in which an ellipse, a rectangle, a rhombus, a mushroom or the like is drawn on a plane with thin metal wires, and these are raised in a substantially vertical direction. These are inserted through the through-holes of the insulating layer and held in that position. As the contact member, when an elliptical ring in which a conductive fine metal wire is wound in one or a plurality of loops is used, an elliptical ring having a major axis of 60 to 150 μm is preferable. Moreover, in the case where the annular body of the thin metal wire is formed into a rectangle, a rhombus, or other predetermined shape, it is preferable that the dimension in the length direction is 60 to 150 μm. In the case of an elliptical ring, the minor axis of the ellipse should be substantially equal to the inner diameter of the through hole of the insulating layer, and in the case of other shapes, the dimension of the portion perpendicular to the length direction is set near the center. The inner diameter of the through hole should be approximately equal. Each of these members is formed into a predetermined shape from an annular body wound with a conductive thin metal wire, so that it has flexibility with respect to loads from above and below, and the members are elastically deformed by the load. And since the dimension of the up-and-down direction changes moderately, it contacts with the terminal located up and down of this contact member reliably.

  However, the contact member constituting the contact mechanism of the present invention is formed by forming an annular body wound with a conductive thin metal wire, and in the vertical direction according to the load while being inserted into the through hole of the insulating layer As long as it is a flexible member that changes in size, it is not limited to one formed into the above shape, for example, an arrow shape or a single rod shape in which the upper end or lower end of the member is enlarged and the other tip is sharpened What was shape | molded etc. may be sufficient. Moreover, you may arrange | position the contact member of 2 or more types of different shapes in one insulating layer.

  The material of the conductive fine metal wire that forms the contact member is not particularly limited, but aluminum, copper, silver, gold, iron, or an alloy containing these, which are generally low-hardness metals, are suitable. Stainless steel wires, piano wires, etc. are useful as the fine wires made of iron.

  In the case where the contact member is formed into any shape, it is preferable that a conductive metal fine wire is wound a plurality of times, particularly 2 to 10 times, and formed into a predetermined shape. Thus, by forming the contact member with an annular body in which the conductive thin wire is wound a plurality of times, the contact area between the contact member and the upper and lower connection terminals is increased, and the conductivity stability is greatly improved. That is, a contact member formed of a plurality of turns of the annular thin metal wire into a predetermined shape (for example, an elliptical ring) has a large contact area with the upper and lower terminals to be connected and has an appropriate flexibility. Therefore, when a load is applied from above and below, it is deformed so that it is slightly crushed and slightly flattened, and the dimensions in the up-and-down direction are changed. It can be carried out.

  In the present invention, the contact member is usually inserted into a through hole formed in the insulating layer, and the cross section of the through hole has an appropriate shape such as a circle, an ellipse, a rectangle, a polygon, and a slit. A portion of the outer periphery of the contact member formed of a conductive metal thin wire inserted through the through hole is pressed against the inner wall of the through hole to grip the position of the contact member; and The upper end portion and the lower end portion are disposed so as to protrude upward and downward from the upper and lower surfaces of the insulating layer, respectively. Each contact member only needs to be held in the through hole of the insulating layer, and in some cases, the contact member may be provided so as to be movable (slidable) up and down in the through hole.

  In the contact structure of the present invention, as described above, the contact member formed between the upper layer and the lower layer to be electrically connected with SiP and formed of a conductive thin metal wire in a through hole provided in the insulating layer is movable. In this case, the stacked upper and lower layer terminals are electrically connected to each other by the contact member formed so as to be movable up and down. The section including the contact layer between the lower layers is preferably filled with an insulating heat transfer material. By filling the conductive material in this way, the heat generated from the semiconductor chip can be efficiently discharged to the outside by the heat conductive material.

  Examples of such insulating heat transfer materials include organic materials such as heat-dissipating silicone grease, heat-dissipating silicone adhesive, and epoxy-based high heat conductive adhesive, and insulating inorganic heat conductive fillers such as silicon oxide and aluminum oxide. I can do it.

  As described above, the contact structure of the present invention includes a stack type SiP in which a plurality of semiconductor chips are stacked to form a package, a SiP in which a plurality of semiconductor chips are arranged in parallel on a package direct material, or a semiconductor chip as a substrate. As a means for electrical connection between the stacked upper and lower semiconductor chips, between the semiconductor chip and the package direct material and / or between the direct materials on which the semiconductor chip is set, in the SiP in which the substrate set is stacked together with the substrate Can be used effectively. That is, the terminal to be connected by the contact structure according to the present invention is, for example, a stack type SiP in which a plurality of semiconductor chips are vertically stacked (a semiconductor chip directly stacked or a semiconductor chip set on a direct material). And / or upper and lower terminals in SiP in which semiconductor chips are juxtaposed horizontally on the package direct material. That is, it may be terminals such as electrode pads or bumps facing each other on the upper and lower sides of the semiconductor chip, or may be a connection between a terminal on the lower surface of the semiconductor chip and a terminal on the upper surface of the substrate on which it is set. In addition, in a semiconductor package of a type in which semiconductor chips set on a direct material (substrate) made of insulating synthetic resin, glass, ceramics, etc. are stacked together with the direct material, the upper direct material bottom terminal and the lower semiconductor It may be connected to a terminal provided on the upper surface of the chip.

  The SiP having the connection structure of the present invention as described above may be entirely or partially sealed with an insulating resin.

  As described above, in the contact structure of the present invention, in the SiP, the upper and lower ends of the flexible contact member that can be dimensionally changed in the vertical direction are formed of the conductive metal fine wires provided in the insulating layer as means for electrically connecting the layers. Since it protrudes from the upper and lower surfaces of the insulating layer, it can be kept in good contact with the electrode terminals such as semiconductor chips stacked up and down by the contact member and can be stably conducted. Moreover, when the contact member made of a conductive metal thin wire is interposed between the terminals of the semiconductor chip and pressed from above, the deformation is sufficient to bring the terminals into contact with each other while absorbing the flatness of the semiconductor chip and the like. In addition, the terminals can be connected to each other while the contact member maintains uprightness. As a result, even terminals of semiconductor chips having complicated shapes can be electrically connected reliably.

  In addition, if the contact member formed of the conductive metal fine wire in the above-mentioned shape is arranged so that the longitudinal direction thereof is along the thickness direction of the insulating film or sheet, the contact member is smaller than the spherical conductive member such as a solder ball. In addition to being able to be installed in an insulating film at a narrow interval (fine pitch), for example, a ring formed in an elliptical loop or the like has moderate spring elasticity against loads from above and below, so that a semiconductor chip It is possible to prevent the terminals such as from being damaged.

  Moreover, the contact structure of the present invention is low in manufacturing cost and excellent in economy. This is a particularly important advantage when applied industrially.

  Further effects and advantages of the present invention will become apparent from the following description of preferred embodiments. In this embodiment, the case where the contact member is mainly an elliptical ring made of a conductive metal thin wire inserted through a through hole of an insulating layer made of a synthetic resin film is described. It is not limited to the embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
FIG. 1 is a simplified cross-sectional view showing the structure of a stacked semiconductor package according to an embodiment of the present invention. FIG. 2 is a simplified cross-sectional view showing an example of a contact layer, which shows an example of a heat-resistant insulating film having a plurality of through-holes each inserted with a contact member formed of a thin conductive metal wire into an elliptical ring. It is. FIG. 3 is a side view illustrating various contact members formed by forming conductive metal fine wires.

  FIG. 1 shows an example of the overall configuration of a SiP (system in package) of a semiconductor chip having a contact structure according to the present invention. FIG. 1 is a simplified cross-sectional view of a SiP in which semiconductor chips having different functions (specifically, a memory 2 and a CPU 3) are stacked and set on a ceramic substrate 1 in FIG. In FIG. 1, a memory 2 is stacked on a CPU 3, and the stacked body is placed on a ceramic substrate 1 to form a SiP that is entirely sealed with a resin (not shown). .

  That is, in this SiP, the position of the electrode pad (terminal) 21 on the lower side of the memory 2 and the position of the electrode pad (terminal) 31 on the upper side of the CPU 3 are arranged to face each other. Further, the positions of the electrode pads (terminals) 31 below the CPU 3 and the terminals 11 of the substrate 1 also face each other. In the SiP of FIG. 1, these electrode pads or terminals are electrically connected to each other by a contact layer 4 disposed between the memory 2 and the CPU 3 and another contact layer 4 disposed between the CPU 3 and the substrate. Has been.

  Each of the contact layers 4 used here has an insulating layer 41 made of a heat-resistant insulating film as a base, and a plurality of through-holes 43 drilled through the contact layer 42 made of conductive thin metal wires. It is composed of things. That is, as shown in FIG. 2, the contact layer 4 has a large number of through-holes 43 formed in an insulating layer 41 made of a heat-resistant insulating synthetic resin film such as polyimide, and a thin conductive metal wire is elliptically formed in each through-hole. The contact member 42 formed in the shape ring is inserted, and the upper and lower ends of the contact member 42 are protruded from the upper and lower surfaces of the insulating layer 41 made of a film.

  In FIG. 1 and FIG. 2, an elliptical ring formed by winding a conductive metal wire is used as the contact member 42. However, in the present invention, those formed into various other shapes can be used. . For example, as shown in FIG. 3, in addition to the elliptical ring (A), a rectangular ring (B), a diamond-shaped ring (C), or a mushroom-shaped ring (D) may be used. These may have a shape that is longer than that illustrated, or one or both of the upper and lower ends may be pointed. In the present invention, as shown in FIGS. 2 and 3, a conductive metal fine wire is wound a plurality of times (about 2 to 10 times) to form an annular body (loop), which is formed into a predetermined shape. Is preferred. Further, a similar annular body may be formed by aligning a plurality of thin conductive metal wires.

  As shown in FIGS. 1 and 2, these connecting members 42 have a longitudinal direction along a direction orthogonal to the surface of the insulating layer 41 made of a synthetic resin film or the like, that is, vertically into the through hole 43. The upper end and the lower end of the member 42 are inserted so as to protrude from the upper and lower openings of the through hole 43. Each connection member 42 is in pressure contact with the inner wall of the through hole 43 on both outer sides thereof, and is stably held in each through hole.

  In the contact layer 4 of the contact structure according to the present invention, the contact member 42 formed by forming a conductive metal fine wire into a predetermined shape is disposed with its longitudinal direction along the thickness direction of the insulating layer 41. Therefore, the number of installations per unit area can be increased as compared with conventional solder balls and the like, and as a result, it is possible to connect a semiconductor chip with terminals provided at a fine pitch, and a fine metal wire Since the contact member as a whole has moderate flexibility and elasticity, the upper and lower terminals can be electrically connected stably.

  In the contact structure of the present invention, the contact layer 4 is further included between the upper and lower semiconductor chips, or between the semiconductor chip and the direct material, for example, between the memory 2 and the CPU 3 in FIG. The space may be filled with an insulating heat transfer material (not shown). By filling with such a heat transfer material, the heat generated in the semiconductor chip can be dissipated to the outside. Further, the whole or a part of SiP may be sealed with an insulating resin or the like.

  Since the SiP having the contact structure of the present invention becomes a small and high-performance semiconductor package, it is widely used not only in mobile phone terminals in which a stack type semiconductor package (stacked MPC) has been used, but also in all fields of SiP. It can be used, and is useful in realizing downsizing of electronic devices.

1 is a simplified cross-sectional view of a stacked semiconductor package illustrating SiP according to an embodiment of the present invention. FIG. 4 is a simplified cross-sectional view illustrating a contact layer formed by using a heat-resistant insulating film as an insulating layer and winding a ring formed in an elliptical loop by winding a heat insulating conductive metal fine wire around the through hole. It is a side view which illustrates the contact member which shape | molds a conductive metal fine wire in shapes other than an elliptical ring, (A) is an ellipse, (B) is a rectangle, (C) is a rhombus, (D) is a mushroom. An example of molding into a shape is shown.

Explanation of symbols

1 Board 11 Board Terminal 2 Memory (Semiconductor Chip)
21 Memory electrode pad 3 CPU (semiconductor chip)
31 Electrode pad 4 of CPU 4 Contact layer 41 Insulating layer 42 made of heat-resistant insulating film Connection member 43 formed of conductive metal fine wire Through-hole provided in insulating layer

Claims (7)

  In a stacked system in package (SiP) in which a plurality of semiconductor chips are stacked vertically and / or in a system in package (SiP) in which semiconductor chips are juxtaposed horizontally on a package direct material, Between the upper layer and the lower layer to be connected between the semiconductor chip and the package direct material and / or between the package direct materials, the wound conductive metal fine wire is long in the vertical direction A contact layer provided with a contact member formed in the contact layer is interposed, and the contact members of the contact layer are used to electrically connect the semiconductor chips or the straight material terminals arranged above and below the contact layer. A system-in-package (SiP) contact mechanism.   The system-in-package (SiP) contact mechanism according to claim 1, wherein the contact member is a flexible member whose vertical dimension can be changed by a load from the upper and lower layers.   The said contact layer consists of an insulating layer which consists of a synthetic resin film or a synthetic resin sheet, and the contact member penetrated to each of the several through-hole provided in this insulating layer, The Claim 1 or Claim characterized by the above-mentioned. The contact mechanism for system in package (SiP) of 2.   The said contact member is what shape | molded the wound electroconductive metal fine wire in the elliptical ring which has a long diameter in the thickness direction of a contact layer, The Claim 1 characterized by the above-mentioned. Contact mechanism for system in package (SiP).   The said contact member is what shape | molded the shape of rectangles, a rhombus, or a mushroom shape etc. which extended the electroconductive metal fine wire wound in the thickness direction of the said contact layer. The contact mechanism for system in package (SiP) in any one of.   The contact member is inserted into the through hole so that a part of the outer periphery thereof is in pressure contact with the inner wall of the through hole formed in the insulating layer, and the upper end and the lower end of the contact member are the upper surface of the insulating layer, respectively. The system-in-package (SiP) contact mechanism according to claim 1, wherein the contact mechanism protrudes from the lower surface and contacts the upper and lower layer terminals.   Between the upper layer and the lower layer to be connected, a contact layer formed by inserting the contact member made of a conductive metal wire in a through hole provided in the insulating layer is interposed, and the contact member is inserted into the contact layer The upper and lower layers of the stacked terminals are electrically connected to each other, and the space between the upper and lower layers including the contact layer is filled with an insulating heat transfer material. Contact mechanism for system-in-package (SiP) described in 1.

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