JPH0634256U - Semiconductor module - Google Patents

Abstract

(57) [Abstract] [Purpose] In a resin-sealed semiconductor module, the characteristics of the resin-sealed semiconductor module are improved by preventing cracks in the sealing resin layer. [Structure] When a power semiconductor chip 4 and a control component 5 are mounted and a resin board is enclosed by surrounding a circuit board to which external lead-out terminals 6 are attached, the upper cover 11a, a side wall 11b, and an inner wall 11c are formed. A resin case 11 having an opening 11d and having a protrusion 16 integrally formed on the lower edge of the opening of the upper lid 11a is used.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor module obtained by mounting a power semiconductor chip and a control component for controlling the semiconductor chip on the same metal substrate and sealing them with resin.

[0002]

[Prior art]

 Conventionally, as a semiconductor module, for example, one having a structure shown in the sectional view of FIG. 2 is known. FIG. 3 is a plan view showing the circuit board of this semiconductor module before mounting to the case. In the figure, reference numeral 1 is a metal substrate having an insulating layer (not shown) on the entire surface, and a convex copper circuit 2 is adhesively soldered from the substantially central portion of the metal substrate 1 to one end, and the other end is also provided. A concave printed wiring board 3 having a copper circuit pattern printed on the insulating plate is adhered onto the insulating layer by an adhesive sheet or the like.

Then, cream solder is printed on the copper circuit 2 and the printed wiring board 3 of the metal substrate 1 at the required positions, the power semiconductor chip 4 is mounted on the copper circuit 2, and the surface mount component is mounted on the printed wiring board 3. Control parts 5 such as resistors, ICs, capacitors, etc. are mounted, and external lead-out terminals 6 are mounted on necessary parts on the metal substrate 1, and then all parts are soldered in a reflow furnace, and then the circuit is completed. The connection 7 between them is performed to obtain a circuit board as shown in FIG.

Next, the periphery and upper part of the circuit board are covered with a resin case 11 integrally formed with the upper lid 11a, the side wall 11b and the inner wall 11c, and the side wall 11b is bonded to the metal substrate 1 with an adhesive such as silicon rubber. At this time, the inner walls 11c and 11c provided in predetermined positions so as to surround the power semiconductor chip 4 and the control component 5 in advance are also bonded onto the metal substrate 1. Then, silicone rubber is filled into the inner walls 11c, 11c through the opening 11d provided in the upper lid 11a of the case 11 and heat-cured at 120 to 150 ° C to form the silicone rubber layer 12. Next, by filling the epoxy resin through the opening 11d between the upper side of the silicone rubber layer 12 and between the side wall 11b and the inner wall 11c, and heat curing at 120 to 150 ° C. to form the epoxy resin layer 13, as shown in FIG. A semiconductor module such as Instead of mounting the copper circuit and the printed wiring board on which the pre-control parts are surface-mounted on the metal board having the above-mentioned insulating layer, place the copper circuit on the metal board via an insulator, and place the power on the copper circuit. Sometimes semiconductor chips and control parts are mounted and soldered.

[0005]

[Problems to be solved by the device]

 However, when the semiconductor module as described above is obtained, conventionally, when the epoxy resin is filled on the silicone rubber layer, the high-viscosity epoxy resin does not uniformly enter, and as shown in FIG. An air layer 14 is often formed in the lower part of the resin, and when the filled epoxy resin is cured by heating, the silicone rubber layer 12 previously formed may also be heated and expanded. For this reason, the epoxy resin layer 13 between the expanding silicon rubber layer 12 and the air layer 14 has a smaller thickness than other parts, and the force due to the expansion of the silicone rubber layer during the heat curing causes the epoxy resin layer 13 to move. There is a drawback that cracks 15 will enter the thin portion.

Further, the semiconductor module thus obtained is becoming thinner due to the miniaturization of equipment such as an air conditioner in which it is used. When such a thin semiconductor module is attached to equipment, In addition, when a force is applied to the opening 11d, the crack 15 seen in the epoxy resin layer 13 in FIG. 4 may become larger, or the crack may cause the epoxy resin layer to be completely separated. There were problems that the characteristics would deteriorate and the creepage distance of the external wiring terminal member would become shorter, resulting in a lower withstand voltage.

[0007]

[Means for Solving the Problems]

 In view of the above, the present invention is made by integrally molding a protrusion at the lower edge of the upper lid opening, the side wall, and the inner wall when the resin is sealed on the circuit board on which the power semiconductor chip and the control component are mounted. It was found that the problems of the conventional semiconductor module can be solved by using the formed resin case.

That is, the present invention mounts and fixes a power semiconductor chip and a control component on a copper circuit laminated on a metal substrate having an insulating layer or a metal substrate to which an insulating substrate is adhered, and further, one end is a case. A circuit board obtained by mounting the other end of the terminal member that is pulled out outward on the metal board is composed of an upper lid, a side wall, and an inner wall, has an opening in the upper lid, and projects to the lower edge of the opening of the upper lid. Provided is a semiconductor module in which a portion is covered with a resin case formed by integral molding, and the inside of the case is sealed with resin.

[0009]

[Action]

 As described above, when the circuit board on which the power semiconductor chip and the control component are mounted is resin-sealed as described above, the protrusion is integrally formed on the lower edge of the opening of the upper lid, the side wall, and the inner wall. By using the resin case formed by molding, when filling the epoxy resin for forming the epoxy resin layer on the silicone rubber layer, the epoxy resin hits the protrusion at the edge of the opening and drops, so the filling speed is low. As a result, the air layer generated on the lower surface of the upper lid can be reduced, and thus cracks can be prevented from entering the epoxy resin layer between the air layer and the silicone rubber layer.

[0010]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. In the figure, the same reference numerals as those of the conventional example indicate the same parts. In FIG. 1, a resin case 11 is integrally formed with a case upper lid 11a, a side wall 11b, and an inner wall 11c, has an opening 11d in the upper lid 11a, and a protrusion 16 is also integrally formed in the lower edge of the opening 11d of the upper lid 11a. Has been. The resin case 11 having such a structure is mounted with the power semiconductor chip 4 and the control component 5, external lead terminals are attached, and the wiring 7 between the circuits is connected. The side wall 11b is adhered to the outer edge of the metal substrate 1 of the circuit board. By doing so, the lower end of the inner wall 11c is also bonded onto the metal substrate 1 at the same time. Then, silicone rubber is filled on the power semiconductor chips 4 and the control component 5 in the inner walls 11c, 11c from the opening 11d of the case upper lid 11a and heat-cured to form the silicone rubber layer 12.

Next, an epoxy resin is filled on the formed silicon rubber layer 12 through the opening 11d and heat-cured to form the epoxy resin layer 13. Thus, the semiconductor module of the present invention can be obtained. Since the protrusion 16 is formed on the lower edge of the opening 11d of the upper lid 11a of the resin case 11, when the epoxy resin is filled from the opening 11d, the epoxy resin hits the protrusion 16 at the edge of the opening 11d. Since it drops, the filling speed is moderated, and even if a force is applied to the epoxy resin in the opening 11d, the force can be received by the protruding portion 16, and as a result, the air layer 14 generated on the lower surface of the upper lid is reduced. Even if the epoxy resin layer 13 between the air layer 14 and the silicone rubber layer 12 is thin, the epoxy resin layer is cracked or cracked. Can be prevented. Therefore, when this semiconductor module is attached to equipment, there is no fear of cracking or separation of the epoxy resin layer, so that the moisture resistance characteristic does not deteriorate and the withstand voltage does not decrease.

In the resin case used in the present invention, the protrusion 16 formed on the lower edge of the opening 11d of the upper lid 11a is a portion corresponding to the lower surface of the upper lid opening of the mold used for molding the resin case. It can be easily obtained by integral molding. Further, although the circuit board having the power semiconductor chip and the control component on the same substrate has been described above, it goes without saying that the present invention can also be applied to a circuit board having only the power semiconductor chip.

[0013]

[Effect of device]

 As described above, according to the present invention, when the power semiconductor chip and the control component are mounted, the external lead terminals are attached, and the circuit board in which the circuits are connected is surrounded with the resin case and sealed with the resin. By using a resin case in which a protrusion is integrally formed on the lower edge of the upper lid opening, it is possible to prevent cracking in the sealing epoxy resin layer and prevent deterioration of characteristics.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor module of the present invention.

FIG. 2 is a sectional view of a conventional semiconductor module.

FIG. 3 is a plan view of a circuit board that constitutes a semiconductor module.

FIG. 4 is an enlarged partial sectional view of a conventional semiconductor module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal board 2 Copper circuit 3 Printed wiring board 4 Power semiconductor chip 5 Control component 6 External extraction terminal 11 Resin case 11a Upper lid 11b Side wall 11c Inner wall 11d Opening 12 Silicon rubber layer 13 Epoxy resin layer 14 Air layer 15 Cracked part 16 Protrusion

Claims (1)

[Scope of utility model registration request] 1. A power semiconductor chip and a control component are mounted and fixed on a copper circuit laminated on a metal substrate having an insulating layer or a metal substrate to which an insulating substrate is adhered, and one end of the power semiconductor chip and the control component are located outside the top of the case. A circuit board obtained by mounting the other end of the drawn-out terminal member on the metal board is composed of an upper lid, a side wall, and an inner wall, has an opening in the upper lid, and integrally forms a protrusion at the lower edge of the opening of the upper lid. A semiconductor module which is covered with the resin case formed in 1. and the inside of the case is sealed with resin.