JPH0468558A - Semiconductor module - Google Patents

Abstract

PURPOSE:To permit resin material to harden so as to be a locking piece for a frame and a metal substrate, improve bonding strength of the frame with the metal substrate and prevent the frame from peeling off from the metal substrate by injecting the resin material in a locking hole provided corresponding to the bonding area of the metal substrate with the frame under the condition that the frame is bonded with the metal substrate. CONSTITUTION:An anode electrode plate 4 is bent at a bending part 4a so as to permit a top edge 4B to stand, the bonding area E of a cathode electrode plate 1 is coated with adhesive 12 and a frame 2 is bonded. Corresponding to the bonding area E, four locking holes 13 which penetrate the electrode plate 1 are formed at the four corners of the frame 2 for the cathode electrode plate 1, epoxy resin is injected to the locking holes 13 by turning the whole module and the injected resin is bonded at the bottom of the frame 2 to be locking pieces 14. the locking pieces 14 are also bonded with the locking holes 13, a level difference 13a is operated to prevent the locking pieces 14 from falling out and the bonding strength of the cathode electrode plate 1 with the frame 2 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a semiconductor module, and particularly to its structure.

[Prior Art] Conventionally, as this type of semiconductor module, a module in which a plurality of semiconductor chips are housed in a package is known.

That is, this module, as shown in Figure 11.12,
A cathode electrode plate 21 is provided as a metal substrate, and two molybdenum plates 22 are soldered to the upper surface of the cathode electrode plate 21, and a plurality of diode chips 23 as semiconductor chips are bonded to the upper surface of each molybdenum plate 22. Both molybdenum plates 2
2, the base end side of a band-shaped anode electrode plate 25 is soldered to the upper surface of the cathode electrode plate 21 with an insulating plate 24 interposed therebetween. This anode electrode plate 25 and each diode chip 23 are electrically connected via aluminum wires 26.

Further, a rectangular frame-shaped frame 27 made of an insulating material such as resin is adhered to the outer peripheral edge adhesion area E of the cathode electrode plate 21 with an adhesive, and an inner coating material 28 made of gel is placed inside the frame 27. and mold resin material 29 are filled in layers. Furthermore, the upper surface of the frame body 27 is covered with a cover 30. The distal end side of the anode electrode plate 25, which extends upwardly through the inner coating material 28 and the mold resin material 29, is provided so as to penetrate through the cover 30 and protrude from the upper surface thereof.

[Problems to be Solved by the Invention] However, in the conventional semiconductor module, the frame 27
was only adhered to the cathode electrode plate 21 by the adhesive applied to the adhesive area E of the cathode electrode plate 21. For this reason, as the module is used for a long period of time, there is a risk that the bonded portion will deteriorate due to stress caused by changes in temperature and humidity. Furthermore, as the temperature of the module itself rises during energized use, the inner coating material 28 and molded resin material 29 inside the frame body 27 thermally expand, causing the bonded portion between the frame body 27 and the cathode electrode plate 21 to be peeled off. There was a possibility that the frame 27 would be easily peeled off from the cathode electrode plate 21 due to the shearing force exerted thereon. As a result, there was a risk that the reliability of the module itself would be impaired.

This invention was made in view of the above-mentioned circumstances, and its purpose is to increase the adhesive strength between the frame and the metal substrate, and to prevent the frame from peeling off from the metal substrate. The objective is to provide a semiconductor module that is possible.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a metal substrate having a semiconductor chip bonded to its upper surface, and a metal substrate bonded to the upper surface of the metal substrate and electrically connected to the semiconductor chip. A semiconductor module comprising a connected electrode plate, a frame bonded to a metal substrate so as to surround the semiconductor chip and the electrode plate, and a molding resin material filled in the frame and covering the semiconductor chip, A locking hole is provided through the metal substrate corresponding to the bonding area with the frame of the metal substrate, and when the frame is bonded to the metal substrate, injection is injected into the locking hole and the frame is bonded to the frame. A locking piece made of a resin material to be bonded is provided.

[Function] According to the above configuration, when the frame is bonded to the metal substrate, by injecting the resin material into the locking hole provided in the bonding area of the metal substrate with the frame, The resin material is injected into the locking hole and hardens to form a locking piece that adheres to the frame and the metal substrate. Therefore, the adhesive bond between the frame and the metal substrate may deteriorate, or the molded resin material inside the frame may thermally expand, creating shearing force that attempts to separate the bond between the frame and the metal substrate. Even if
Since the adhesive force between the locking piece and the frame is maintained and the locking piece is adhesively locked in the locking hole of the metal substrate, the adhesiveness between the frame and the metal substrate is ensured.

[Example] Hereinafter, an example embodying the present invention will be described in detail based on FIGS. 1 to 6.

Fig. 1 is a partially cutaway side view of the semiconductor module of this embodiment, Fig. 2 is a plan view of the same semiconductor module, Fig. 3 is a plan view of its mounting state, and Fig. 4 is the same. FIG. 5 is a side view showing the mounted state, and FIG. 5 is a side sectional view showing the inside of the semiconductor module.

As shown in FIGS. 1 and 2, this semiconductor module has a cathode electrode plate 1 as a metal substrate and a PB as an insulating material provided on the upper surface of the cathode electrode plate 1.
It includes a frame 2 made of T (polybutylene terephthalate), a cover 3 covering the upper side of the frame 2, and an anode electrode plate 4 penetrating the cover 3.

To explain the inside thereof, as shown in FIGS. 3 to 5, two molybdenum plates 5 are soldered to the upper surface of the cathode electrode plate 1. A total of six diode chips 6 as semiconductor chips are soldered to the upper surface of each molybdenum plate 5.

FIGS. 3 and 4 show the anode electrode plate 4 in an expanded state, and the band-shaped anode electrode plate 4 has a narrow base end 4A and a wide distal end 4B. This anode electrode plate 4 has three thin bent portions 4a,
4b is formed. Further, an elongated hole 4c is formed in the wide tip side 4B of the anode electrode plate 4. The base end 4A of the anode electrode plate 4 is joined to the upper surface of the cathode electrode plate 1 between both molybdenum plates 5 via an insulating plate 7. Also, the tip side 4 of this anode electrode plate 4
B is bent upward at its bent portion 4 a and is erected with respect to the cathode electrode plate 1 . Further, at the joint portion between the anode electrode plate 4 and the cathode electrode plate 1, each diode chip 6 and the anode electrode plate 4 are electrically connected via aluminum wires 8 by wire bonding.

As shown in FIG. 5, inside the frame 2, a gel-like inner coating material 9 and a mold resin material 10 made of epoxy resin are filled in layers. or,
A cover 3 covering the upper surface of the frame 2 is formed with a hole 3a through which the tip end 4B of the anode electrode plate 4 passes. Then, inner coating material 9 and mold resin material 10
A distal end side 4B of the anode electrode 4 extending upwardly through the hole 3a is provided so as to protrude upwardly through the hole 3a.

Further, the tip side 4B of the protruding anode electrode plate 4 is folded back to the upper surface of the cover 3 at a bent portion 4b.

A nut insertion recess 3b is formed on the upper surface of the cover 3, and a hexagonal nut 11 is mounted in the recess 3b. Then, with the tip side 4B of the anode electrode plate 4 folded back, the elongated hole 4c of the tip side 4B is inserted into the hexagonal nut 11.
It is arranged corresponding to the screw hole 11a of.

As shown by the two-dot chain line in FIG. 3, the diode chip 6 and the anode electrode plate 4
The area surrounding the joint with the frame body 2 is the adhesive area E with the frame 2. Prior to adhesion to the frame 2, an adhesive 12 is applied to this adhesive area E as shown in FIG.

In this embodiment, a locking hole 13 is formed in the cathode electrode plate 1 to correspond to the bonding area E and pass through the cathode electrode plate 1. As shown in Figures 1 to 5, this locking hole 1
A total of four numerals 3 are formed so as to correspond to the four corners of the frame 2. As shown in an enlarged view in FIG.
3a is formed. As shown in FIGS. 1 and 6, a locking piece 14 made of epoxy resin is provided in the locking hole 13 in a state where the frame 2 and the cathode electrode plate l are adhered. The end surface of this locking piece 14 is adhered to the bottom surface of the frame 2 when the epoxy resin is injected.

Next, a procedure for assembling this semiconductor module will be explained.

First, as shown in FIGS. 3 and 4, the diode chip 6 is soldered onto the cathode electrode plate 1 via the molybdenum plate 5. Moreover, the base end side 4 of the anode electrode plate 4 in the extended state
A is soldered to the cathode electrode plate l through the insulating plate 7. Then, each diode chip 6 and the base end 4A of the anode electrode plate 4 are connected with an aluminum wire 8.

Next, the anode electrode plate 4 is bent at its bent portion 4a to stand up the tip side 4B, and the frame 2 is bonded by applying an adhesive 12 to the bonding area E of the cathode electrode plate 1.

After bonding the frame 2, the entire module is turned over, epoxy resin is injected to provide the locking pieces 14 in the locking holes 13, and the resin and adhesive 12 are waited for to harden. On this occasion,
The injected resin firmly adheres to the bottom surface of the frame body 2 while hardening to form the locking piece 14. Further, the locking piece 14 is also bonded and locked in the locking hole 13, and the stepped portion 13a acts as a stop for the locking piece 14 to be removed.

Thereafter, when the locking pieces 14 and the adhesive 12 have hardened, the entire module is turned over again and the inner two-tink material 9 is injected into the inside of the frame 2.

After the inner coating material 9 is cured, a molding resin material 1O is further injected and cured.

Subsequently, the cover 3 is attached to the upper side of the frame 2 while passing the tip side 4B of the anode electrode plate 4 through the hole 3a, and after fitting the hexagonal nut 11 into the recess 3b of the cover 3, the tip side of the anode electrode plate 4 is inserted. 4B at the bending portion 4b to complete the assembly of the semiconductor module.

In the semiconductor module assembled as described above, the adhesion between the locking piece 14 and the frame body 2 is firmly maintained, and the locking piece 14 is adhered to the locking hole 13 of the cathode electrode plate l. Since removal is prevented, the adhesive strength between the cathode electrode plate 1 and the frame 2 can be increased.

Therefore, as the module is used for a long period of time, the bonded area between the cathode electrode plate 1 and the frame body 2 by the adhesive 12 deteriorates due to the stress caused by changes in temperature and humidity, and the adhesive force decreases. Also, the adhesive force of the locking piece 14 can prevent both parts 1 and 2 from peeling off.

Furthermore, as the temperature of the module itself increases during energized use, the inner coating material 9 and mold resin material 10 within the frame body 2 will thermally expand, and the bonded portion between the frame body 2 and the cathode electrode plate l will likely be peeled off. Even when shearing force is applied, the adhesive force between the locking piece 14 and the frame body 2 is maintained, and the locking piece 14 is adhesively locked in the locking hole 13 of the cathode electrode plate 1. Therefore, both 1. 2 can be prevented from peeling off.

In other words, the adhesive 12 between the cathode electrode plate 1 and the frame 2
Even if the adhesive strength of both 1 and 2 decreases, the adhesive strength of both 1 and 2 can be maintained due to the strong adhesion of the locking piece 14 and the prevention of the locking piece 14 from coming out in the locking hole 13. Both as 1. It is possible to increase the adhesive strength of both 1. 2 can be prevented from peeling off.

Note that this invention is not limited to the above embodiments (
The present invention can be implemented as follows by changing a part of the structure as appropriate without departing from the spirit of the invention.

(1) In the above embodiment, as shown in FIG. 6, the locking piece 14 is provided by injecting epoxy resin into the locking hole 13 formed only in the cathode electrode plate 1, and the tip surface of the locking piece 14 is As shown in FIG. The locking piece 14A may be provided by injecting a resin material to increase the adhesive area of the locking piece 14A to the frame body 2 and provide a locking action.

In this case, the adhesive force by the locking piece 14A can be further increased, and the shear stress at the bonded portion can be increased.

(2) In the above embodiment, as shown in FIG. 6, the locking piece 14 is provided by injecting epoxy resin into the locking hole 13 formed only in the cathode electrode plate l, and the tip surface of the locking piece 14 is As shown in FIG. The locking pieces 14B and 14c are formed by forming a screw 16 or by forming a stepped portion 17 in the recess 15 as shown in FIG. 9, and injecting a resin material into the recess 15 and the locking hole 13. It is also possible to increase the adhesion area of each of the locking pieces 14B and 14C to the frame body 2 and to provide a locking effect.

In this case, the adhesive force of each locking piece 14B, 14C can be further increased, and the shear stress and tensile stress at the bonded portion can be increased.

(3) In the above embodiment, as shown in FIG.
A step part 13a is formed in 3, and a locking piece 14 is provided by injecting epoxy resin.As shown in FIG. hole 18
The locking piece 19 may be provided by injecting a resin material into the plate.

[Effects of the Invention] As detailed above, according to the present invention, the adhesive strength between the frame and the metal substrate can be increased, and the peeling of the frame from the metal substrate can be prevented. be effective.

[Brief explanation of the drawing]

1 to 6 are drawings of an embodiment embodying the present invention, in which FIG. 1 is a partially cutaway side view of a semiconductor module, and FIG. 2 is a plan view showing the same semiconductor module. Figure 3 is a plan view showing the mounting state, and Figure 4 is a plan view showing the mounting state.
5 is a side sectional view showing the inside of the semiconductor module, and FIG. 6 is an enlarged sectional view showing a locking piece in a locking hole. FIGS. 7 to 1O are enlarged sectional views showing a locking piece in a locking hole in another embodiment embodying the present invention. FIG. 11 is a plan view showing the mounting state of the semiconductor module in the conventional example;
FIG. 2 is a side sectional view showing the inside of the semiconductor module in the same conventional example. In the figure, 1 is a cathode electrode plate as a metal substrate, 2 is a frame, 4 is an anode electrode plate, 6 is a diode chip as a semiconductor chip, IO is a molded resin material, 13.18 is a locking hole, 14.14A , 14B, 14C, 19 are locking pieces,
E is the adhesive area. Patent applicant Toyota Industries Corporation representative
Patent Attorney On 1) Hironobu (and 1 other person) Figure 2 Figure 9 14c 13 +3a 61st! ! 3a 181! ! 14B 1313a Figure 4! i-, 4B and -4b 'r-4 No. 51!1

Claims (1)

[Scope of Claims] 1. A metal substrate having a semiconductor chip bonded to the top surface, an electrode plate bonded to the top surface of the metal substrate and electrically connected to the semiconductor chip, and the semiconductor chip and the electrode plate A semiconductor module comprising: a frame adhered to the metal substrate so as to surround the frame; and a molding resin material filled in the frame and covering the semiconductor chip, wherein an adhesive area of the metal substrate with the frame A locking hole is provided through the metal substrate corresponding to the above, and a resin material is injected into the locking hole and adhered to the frame when the frame is adhered to the metal substrate. A semiconductor module equipped with a locking piece.