JP2012119488A - Manufacturing method of semiconductor device and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device and the semiconductor device which improves heat radiation by using a metal mold that does not need presser pins.SOLUTION: A manufacturing method of a semiconductor device 11 has: a process in which an assembly intermediate body, in which a power element 4 is placed on one surface of a metal plate 3 having a lead terminal 2 and an insulation resin layer 5 having a feature that thermal expansion is caused by heating is secured between the other surface of the metal plate and an upper surface of a metal layer, is prepared; a process in which the assembly intermediate body is placed so that a lower surface of the metal layer of the assembly intermediate body faces a bottom surface of a lower metal mold recessed part 24 in a resin sealing metal mold; a process in which a mold resin filling space 28 is formed with recessed parts of a lower metal mold 22 and an upper metal mold 21; a process in which the insulation resin layer is heated, the thickness of the insulation resin layer is increased, and the metal layer is pressed toward the bottom surface of the recessed part of the lower metal mold; and a process in which the mold resin filling space is filled with a mold resin.

Description

The present invention relates to a method for manufacturing a semiconductor device and a semiconductor device, and more particularly to a method for manufacturing a semiconductor device having a high heat dissipation structure on which a power element is mounted, and the semiconductor device.

Regardless of household appliances or industrial products, high-voltage three-phase motor drive semiconductor devices are used for drive control of motors incorporated in air conditioner compressors, washing machine drums, pumps, and the like. It is also used for motor drive control of hybrid vehicles, electric vehicles and the like. This type of semiconductor device has a structure in which a high-side (H-side) driving circuit and a low-side (L-side) driving circuit are integrated into a set of three phases, that is, three circuits. The high-side drive circuit includes a high-side switching element inserted between a power supply voltage and a motor-side output and an integrated circuit for driving the switching element. The low-side drive circuit includes a low-side switching element inserted between the motor-side output and the reference power supply and an integrated circuit for driving the switching element. In general, both driving integrated circuits are integrated as one semiconductor chip. As a result, the semiconductor device includes a total of six switching elements and a total of three driving integrated circuits. A transistor having the same polarity is used for each of the high-side switching element and the low-side switching element, and both transistors are electrically connected in series to form a half-bridge circuit. Moreover, the heat sink is attached to metal at the resin sealing body. Such a semiconductor device is also called a power intelligent module (IPM).

In recent years, this semiconductor device is required to have a high voltage, and the demand for high heat dissipation has become a problem. As in the following Patent Document 1, as a semiconductor device having a high heat dissipation structure, a power element provided on a die pad of a frame via an adhesive such as solder, a lead terminal having one end provided on the frame, There is a structure having a metal foil provided on the lower surface via a resin sheet, and a mold resin that covers at least the other end of the lead terminal and at least a part of the lower surface of the metal layer.

As one of countermeasures, a semiconductor device in which a resin sealing mold is provided with a pressing pin and a die pad is fixed to the inner surface of the mold and resin molding is known as a conventional technique (see, for example, Patent Document 1 and FIG. 4). ). Thereby, the resin sheet joined to the die pad and the metal foil can be satisfactorily fixed.

JP 2005-123495 A

Furthermore, the power module is required to be used in a high temperature environment. At this time, in order to efficiently release the heat generated in the semiconductor device, it is necessary to strengthen the adhesion between the internal structure and the heat sink and expose the surface of the heat sink.

However, since the conventional technique requires a pressing pin, there is a problem that the resin-sealed mold becomes complicated. There is also a problem of further improving heat dissipation.

Accordingly, the present invention has been made to solve the above-described problems, and a semiconductor device manufacturing method and a semiconductor device that can further improve heat dissipation using a mold that does not require a pressing pin. The purpose is to provide.

In order to solve the above-described problems, the present invention is configured as follows.
In the method for manufacturing a semiconductor device of the present invention, a power element is placed on one surface of a metal plate having lead terminals, and is fixed between the other surface of the metal plate and the upper surface of the metal layer, and is heated. A lower mold in a resin-sealed mold having a step of preparing an assembly intermediate including an insulating resin layer having a thermal expansion property, a lower surface of a metal layer of the assembly intermediate, a lower mold, and an upper mold Placing the assembly intermediate body in the lower mold recess so as to place the lead terminal on the upper surface of the lower mold lead sandwiching portion of the lower mold and facing the bottom surface of the recess, and sandwiching the lower mold lead Forming the mold resin filling space between the lower mold recess and the upper mold recess, and applying heat to the insulating resin layer, Increasing the thickness, pressing the metal layer toward the bottom surface of the lower mold recess, and heating A step of filling the molding resin filling space formed mold resin under die and upper die, characterized by having a.
Further, the lead terminal and the metal plate of the assembly intermediate body are characterized by a deformed strip lead frame.
Further, the insulating resin layer has a laminated structure of an insulating resin and an adhesive layer.
A semiconductor device of the present invention is manufactured by any one of the above-described manufacturing methods.

According to the present invention, since the thickness of the insulating resin layer is increased, it is possible to provide a method of manufacturing a semiconductor device and a semiconductor device that can be molded while pressing a metal layer and can be manufactured using a mold that does not require a pressing pin. There is an effect. In addition, since a metal plate is used, the metal layer is further pressed against the sealing mold, heat dissipation is increased, and generation of resin burrs on the metal layer can be suppressed. Therefore, a method for manufacturing a semiconductor device capable of improving heat dissipation and There is an effect that a semiconductor device can be provided.

It is manufacturing process sectional drawing of the semiconductor device which concerns on Example 1 of this invention. It is sectional drawing of the semiconductor device which concerns on Example 1 of this invention. It is sectional drawing of the semiconductor device which concerns on Example 2 of this invention. It is sectional drawing of the semiconductor device which concerns on Example 3 of this invention.

Hereinafter, embodiments of the present invention will be described in detail. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the dimensional relationship ratios and the like are different from the actual ones. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

A method for manufacturing the semiconductor device 11 according to the first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a manufacturing process sectional view showing a manufacturing process of a semiconductor device 1 according to a first embodiment of the present invention. (A) is an intermediate assembly preparation step, (B) is an intermediate assembly placement step, (C) is a step of forming a mold resin filling space and a metal layer is pressed against the bottom surface of the lower mold recess. (D) is a step of filling the mold resin filling space.

First, as shown in FIG. 1A, the intermediate assembly preparation step is the intermediate assembly 1 in the form before mold resin sealing of the semiconductor device 11 according to the first embodiment.

The intermediate assembly 1 includes a lead terminal 2, a metal plate 3, a power element 4, an insulating resin layer 5, and a metal layer 6.

The lead terminal 2 is used as an electrical input / output unit of the semiconductor device. For example, press punching or chemical etching is applied, and copper or layer alloy is often used as the material. Further, it is joined to the circuit surface of the metal plate 3 by solder or the like.

The metal plate 3 is an aluminum substrate, and an aluminum plate is insulated on one surface, and a circuit pattern is formed on the insulating surface. The lead terminal 2 and the power element 4 are placed on the circuit pattern. Alternatively, a copper substrate may be used for the metal plate 3.

The power element 4 is a transistor or the like of a switching element, and is joined to the circuit surface of the metal plate 3 by solder or the like. For example, it is manufactured by a die bonder device. The power element 4 and the lead terminal 2 are wired and electrically coupled by a wire bonder device.

The insulating resin layer 5 is fixed between the metal layer 6 and the surface of the metal plate 3 facing the circuit pattern surface. In addition, the insulating resin layer 5 having a property of increasing the thickness of the insulating resin layer 5 by applying heat is used. For example, the material of the insulating resin layer 5 is a highly expandable insulating adhesive or a highly expandable resin tape by heating.

The metal layer 6 is a plate-shaped heat sink. One surface of the metal layer 6 is fixed to the metal plate 3 via the insulating resin layer 5. The other surface becomes an exposed surface after resin sealing with mold resin. For example, copper or a copper alloy can be used as the material.

Next, as shown in FIG. 1B, the intermediate assembly placement step is a state in which the intermediate assembly 1 according to the first embodiment is placed in the resin molding die 27.

The resin-sealed mold 27 is a metal member, and is an upper mold 21, a lower mold 22, an upper mold recess 23, a lower mold recess 24, an upper mold lead clamping unit 25, and a lower mold lead clamping unit 26. It consists of

The upper die 21 is an upper portion of a portion that forms a pair with the resin-sealed die 27, the upper die recess 23 is processed, and an upper die lead holding portion 25 is provided.

The lower mold 22 is a lower portion of a portion that forms a pair with the resin-sealed mold 27, the lower mold recess 24 is processed, and a lower mold lead holding part 26 is provided.

The upper mold recess 23 is a processing space dug into the upper mold 21 and is also called an upper mold cavity. This space is filled with mold resin to mold the outer shape of the semiconductor device.

The lower mold recess 24 is a processing space dug into the lower mold 22 and is also called a lower mold cavity. The intermediate assembly 1 is disposed in the lower mold recess 24. At this time, the other surface of the metal layer 6 of the intermediate assembly 1 is brought into contact with the bottom surface of the lower mold recess 24. Similar to the upper mold recess 23, this space is filled with mold resin, and the outer shape of the semiconductor device is formed.

The upper mold lead clamping portion 25 is the lower surface of the upper mold 21 and is processed into a flat surface. The upper surface of the lead terminal 2 is pressed with this surface.

The lower mold lead clamping portion 26 is the upper side surface of the lower mold 22 and is processed (not shown) so that the lead terminal 2 of the intermediate assembly 1 can be disposed.

Next, as shown in FIG. 1 (C), the step of forming the mold resin filling space 28 and the step of pressing the metal layer toward the bottom surface of the recess of the lower mold are the resin-sealed metal mold according to the first embodiment. This is a state before the mold 27 is filled with resin.

Here, the upper die 21 is lowered, and the lead terminal 2 is sandwiched between the upper die lead sandwiching portion 25 and the lower die lead sandwiching portion 26. The upper mold concavity 23 and the lower mold concavity 24 form a mold resin filling space 28 for filling the mold resin. The upper mold 21 and the lower mold 22 are heated by a cartridge heater, and the metal foil 6 is in contact with the lower surface of the concave portion of the lower mold concave portion 24 through the lead terminal 2 and the metal plate 4. From these, heat is also transmitted to the insulating resin layer 5. For example, the mold temperature is set to 190 ° C.

As a result, the insulating resin layer 5 is heated, the thickness is increased by thermal expansion, the metal plate 3 is pressed in the upper surface direction, and the metal layer 6 is pressed against the bottom surface of the lower mold recess 24 in the lower surface direction.

Next, as shown in FIG. 1D, the process intermediate assembly placement process for filling the mold resin filling space is a state in which the resin sealing mold 27 according to the first embodiment is filled with the mold resin 29.

The mold resin 29 becomes a resin sealing body that forms a semiconductor device. The upper mold recess 23 and the lower mold recess 24 fill the formed mold resin 29 into the formed space. For example, an epoxy resin is filled and molded by a transfer mold apparatus.

Thereafter, the intermediate assembly 1 and the mold resin 29 are taken out from the resin sealing mold 27. Thereby, the semiconductor device 11 shown in FIG. 2 in which the intermediate assembly 1 according to the first embodiment of the present invention is resin-sealed with the mold resin 29 is completed.

Next, the manufacturing method of the semiconductor device 11 according to the first embodiment and the effects of the semiconductor device 11 will be described.

As described above, in the method of manufacturing the semiconductor device 11 according to the first embodiment, the lead terminal 2 is sandwiched between the pair of the upper mold 21 and the lower mold 22 at the time of resin molding and is heated by the resin molding. The thickness of the insulating resin layer 5 increases due to thermal expansion. Further, the metal layer 6 is pressed toward the bottom surface of the lower mold recess 24. As a result, the resin molding die 27 does not require a pin structure for pressing the member, and it is possible to manufacture a semiconductor device with a die having a simple structure.

Moreover, since the metal plate 3 is used, it is possible to improve heat dissipation and to improve heat dissipation. Furthermore, even if there is a gap between the metal layer 6 and the bottom surface of the lower mold recess 24 at the stage where the intermediate assembly 1 is disposed in the lower mold recess 24 of the lower mold 22, the lower surface of the metal layer 6 is It is possible to strongly adhere to the bottom surface of the lower mold recess 24, and it is possible to suppress the occurrence of resin burrs in the exposed portions of the metal layer 6 after resin molding and improve the heat dissipation.

In the second embodiment, a deformed lead frame 7 can be used instead of the metal plate 3 and the lead terminal 2 as shown in FIG. Since other manufacturing methods are the same as those of the first embodiment, the description thereof is omitted.

In the second embodiment, the same effect as in the first embodiment can be obtained. Furthermore, since the metal plate and the lead terminal can be integrally formed, the joining work between the metal plate and the lead terminal can be omitted.

From the above Example 1 and Example 2, the method for manufacturing a semiconductor device according to the present invention increases the thickness of the insulating resin layer, so that the resin layer can be molded while pressing the metal layer, and there is no need for a pressing pin. It can be manufactured in molds. In addition, since a metal plate is used and the metal layer is pressed against the sealing mold to increase heat dissipation and the generation of resin burrs on the metal layer can be suppressed, heat dissipation can be improved.

Although the embodiment of the present invention has been described as described above, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques should be apparent to those skilled in the art.

For example, as Example 3, as illustrated in FIG. 4, a laminated structure in which an adhesive layer 8 is attached to one surface and the other surface of the insulating resin 9 and the insulating resin 9 may be employed. For example, the material of the insulating resin 9 and the adhesive layer 8 is a high expansion material by heating.

Further, the size of the insulating resin layer 5 and the metal layer 6 may be the same size as the metal plate 3.

The material of the metal layer 6 may be aluminum or an aluminum alloy.

A combination of the second embodiment and the third embodiment is also possible.

DESCRIPTION OF SYMBOLS 1, Intermediate assembly 2, Lead terminal 3, Metal plate 4, Power element 5, Insulating resin layer 6, Metal layer 7, Deformed lead frame 8, Adhesive layer 9, Insulating resin 11, 12, 13, Semiconductor device 21, Upper mold 22, lower mold 23, upper mold recess 24, lower mold recess 25, upper mold lead clamping part 26, lower mold lead clamping part 27, resin sealing mold 28, mold resin filling space 29 , Mold resin

Claims (4)

An insulating resin layer having a characteristic that a power element is mounted on one surface of a metal plate having lead terminals, is fixed between the other surface of the metal plate and the upper surface of the metal layer, and is thermally expanded by heating. A lower surface of the metal layer of the intermediate assembly, and a bottom surface of a lower mold recess in a resin-sealed mold having a lower mold and an upper mold. And disposing the assembly intermediate body in the lower mold recess so as to arrange the lead terminal on the upper surface of the lower mold lead holding part of the lower mold, and the lower mold lead holding part, A step of sandwiching the lead terminal with the upper mold lead sandwiching portion and forming a mold resin filling space with the lower mold concave portion and the upper mold concave portion, applying heat to the insulating resin layer, Increase the thickness of the insulating resin layer and place the metal layer on the bottom surface of the lower mold recess. A step of selfish pressing method of manufacturing a semiconductor device characterized by having the steps of filling the molding resin filling space formed a heated mold resin at the upper mold and the lower mold.
2. The method of manufacturing a semiconductor device according to claim 1, wherein the lead terminal and the metal plate of the assembly intermediate body are deformed strip lead frames.
The method for manufacturing a semiconductor device according to claim 1, wherein the insulating resin layer has a laminated structure of an insulating resin and an adhesive layer.
  A semiconductor device manufactured by the manufacturing method according to claim 1.

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