JP2011165903A - Semiconductor module and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor module that can more efficiently transmit the heat of built-in semiconductor element to a heat sink, and to provide its manufacturing method. <P>SOLUTION: A semiconductor module A1 has a substrate 1 where a semiconductor element 21 is mounted on its surface and a through hole 16a is placed, a heat sink 5 arranged so that it faces the backside of the substrate 1, and a heat transfer member 17 consisting of a filling part 171 which is charged into a through hole 16a and a swelling section 172 which swells to the backside of the substrate 1 from the filling part 171, wherein the swelling section 172 is formed so that the thickness in the z direction of the substrate 1 may decrease as it backs away from the filling part 171 in the x direction and it is in contact with the heat sink 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor module including a heat radiating plate for radiating heat generated from a heating element to the outside, and a method for manufacturing the same.

  For example, in a semiconductor module in which a plurality of semiconductor elements are incorporated and a heat generating element having a large heat generation amount is included in the semiconductor elements, there is a problem that heat generated by the heat generating elements adversely affects other semiconductor elements. In order to solve this problem, a method has been proposed in which a heat transfer path is formed between a heat generating element and a heat radiating plate using a heat transfer member such as solder (for example, see Patent Document 1). FIG. 15 shows an example of a conventional semiconductor module. The semiconductor module X includes a substrate 92 on which a plurality of circuit components including the heating elements 91 are mounted, and a heat radiating plate 93 fixed to the substrate 92 using eyelets. The heating element 91 includes an external electrode 91a connected to the wiring pattern 94 provided on the surface of the substrate 92, and a ground electrode 91b formed on the mounting surface. The ground electrode 91 b is in contact with the heat transfer member 95 filled in the through hole 92 a formed in the substrate 92. The heat transfer member 95 bulges from the lower end of the through hole 92 a and is in contact with the heat radiating plate 93. For this reason, in the semiconductor module X, the heat of the heat generating element 91 is easily transmitted to the heat radiating plate 93 through the heat transfer member 95.

  When manufacturing such a semiconductor module X, after the substrate 92 and the heat radiating plate 93 are fixed with eyelets, cream solder is applied to the surface side of the substrate 92. Thereafter, the substrate 92 and the heat radiating plate 93 are carried into a reflow furnace and heated to melt the cream solder. At this time, a part of the cream solder applied to the surface side of the substrate 92 flows into the gap between the substrate 92 and the heat radiating plate 93 through the through hole 92a, and the heat transfer member 95 as shown in FIG. 15 is formed.

  However, in such a semiconductor module X, when the amount of cream solder applied to the substrate 92 is insufficient, the heat transfer member 95 is unreasonably separated from the heat radiating plate 93, and heat transfer is performed well. Unexpected situations can occur. Further, in the case where wiring is provided on the back side of the substrate 92, if the amount of cream solder is too large, there may be a situation in which unreasonable conduction between wirings that should be separated from each other may be caused. In order to prevent such defects, for example, it was necessary to accurately adjust the amount of cream solder applied.

JP 2004-87594 A

  The present invention has been conceived under the circumstances described above, and it is an object of the present invention to provide a semiconductor module capable of more efficiently transferring heat of a built-in semiconductor element to a heat sink and a method for manufacturing the same. To do.

  A semiconductor module provided by the first aspect of the present invention includes a substrate having a semiconductor element mounted on the surface and having one or more through holes, and a heat sink disposed to face the back surface of the substrate. A heat transfer member comprising a filled portion filled in one of the one or more through holes and a bulging portion that bulges from the filling portion to the back side of the substrate. And the bulging portion is formed so that the thickness in the thickness direction of the substrate decreases as the distance from the filling portion increases in the in-plane direction of the substrate, and the heat sink and It is characterized by touching.

  In a preferred embodiment, the through hole filled with the filling portion is provided at a position overlapping the semiconductor element in the thickness direction of the substrate.

  In a more preferred embodiment, the substrate is formed on a base material, a first surface wiring pattern formed on the surface of the base material, and on which the semiconductor element is mounted, and on the back surface of the base material. And a first back surface wiring pattern that is electrically connected to the first front surface wiring pattern through the through hole filled with the filling portion, and the bulging portion includes the first back surface wiring pattern. It is formed so as to cover at least part of the backside wiring pattern.

  In a more preferred embodiment, the substrate is formed on the back surface of the base material, and includes a second back surface wiring pattern spaced from the first back surface wiring pattern, and the second back surface. The wiring pattern is insulated from the heat sink.

  In a more preferred embodiment, the substrate is formed on the surface of the base material, is separated from the first front surface wiring pattern, and is electrically connected to the second back surface wiring pattern. Two surface wiring patterns are provided.

  In a preferred embodiment, the heat transfer member is made of a solder material.

  In another preferred embodiment, the heat transfer member is made of resin.

  In a more specific embodiment, the semiconductor element is a DC voltage conversion control element, and is mounted on the substrate for input, output, and ground, and the DC voltage conversion control element and the output are mounted on the substrate. A coil connected to the terminal, mounted on the board, an input-side capacitor connected to the input terminal and the ground terminal, mounted on the board, the output terminal and the And an output-side capacitor connected to the ground terminal.

  More preferably, the input, output, and ground terminals protrude parallel to each other in the same direction, and the input, output, and input terminals are in a direction perpendicular to the protruding direction in which the ground terminal protrudes. The terminals for the output, the ground terminal, and the output terminal are arranged in this order.

  A method of manufacturing a semiconductor module provided by the second aspect of the present invention includes a step of mounting a semiconductor element on the surface of a substrate having one or more through holes, and a heat sink for cooling the semiconductor element on the substrate. A method of manufacturing a semiconductor module, comprising: a filling portion filled in one of the one or more through holes before the step of installing the heat sink; and A heat transfer member configured to bulge to the back surface side of the substrate and to be formed so that the thickness in the thickness direction of the substrate decreases as the distance from the filling portion increases in the in-plane direction of the substrate. In the step of installing the heat radiating plate, the heat radiating plate is installed in contact with the bulging portion.

  In a preferred embodiment, the substrate has a through hole at a position overlapping the semiconductor element in the thickness direction of the substrate, and in the step of forming the heat transfer member, the thickness direction of the substrate is viewed. The filling portion is formed so as to fill the through hole in a position overlapping with the semiconductor element.

  In a more preferred embodiment, the substrate is formed on a base material, a first surface wiring pattern formed on the surface of the base material, and on which the semiconductor element is mounted, and on the back surface of the base material. A first backside wiring pattern that is formed and has a region overlapping with the first surface wiring pattern in the thickness direction of the base material; and the first surface wiring pattern and the above in the thickness direction of the base material. A through hole formed in a region overlapping with both the first backside wiring pattern, and in the step of forming the heat transfer member, the filling portion is formed so as to fill the through hole. The bulging portion is formed so as to cover at least a part of the first backside wiring pattern.

  In a preferred embodiment, the heat transfer member is formed of a solder material.

  In a more preferred embodiment, the step of forming the heat transfer member includes bringing the substrate into a solder tank filled with the liquid solder material and attaching the solder material to the back surface of the substrate. This is done by the flow-type soldering operation.

  In another more preferred embodiment, the step of forming the heat transfer member is performed by a reflow type soldering operation in which the solder material in a paste form is applied and then heated.

  In another preferred embodiment, the heat transfer member is formed of resin.

  According to such a manufacturing method, after the bulging portion is formed, the substrate and the heat radiating plate are combined so that the heat radiating plate is in contact with the bulging portion. For this reason, the said heat sink necessarily contacts the said heat-transfer member. Therefore, according to the present invention, it is possible to more reliably ensure contact between the heat radiating plate and the heat transfer member, and to realize efficient heat transfer from the semiconductor element to the heat radiating plate. .

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

It is a front view which shows the semiconductor module in 1st Embodiment of this invention. It is a rear view which shows the semiconductor module shown in FIG. It is an enlarged view which shows the surface side of the board | substrate incorporated in the semiconductor module shown in FIG. It is the enlarged view which permeate | transmitted a part of surface side of the board | substrate incorporated in the semiconductor module shown in FIG. It is an enlarged view which shows the back surface side of the board | substrate incorporated in the semiconductor module shown in FIG. It is an expanded sectional view which follows the VI-VI line of FIG. It is sectional drawing which shows 1 process of the manufacturing method of the semiconductor module shown in FIG. FIG. 8 is a cross-sectional view showing a step that follows FIG. 7. FIG. 9 is a cross-sectional view showing a step that follows FIG. 8. FIG. 10 is a cross-sectional view showing a step that follows FIG. 9. It is sectional drawing which shows the process following FIG. It is sectional drawing which shows 1 process of another manufacturing method of the semiconductor module shown in FIG. FIG. 13 is a cross-sectional view showing a step that follows FIG. 12. It is sectional drawing which shows the semiconductor module in 2nd Embodiment of this invention. It is sectional drawing which shows an example of the conventional semiconductor module.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 to 6 show a semiconductor module according to the first embodiment of the present invention. The semiconductor module A1 of this embodiment includes a substrate 1, a plurality of electronic components 2, an input terminal 3A, a ground terminal 3B, an output terminal 3C, a resin package 4, and a heat sink 5. The semiconductor module A1 is used, for example, as a switching regulator for converting the received input voltage into a desired output voltage and supplying it to a device of an electronic device. The semiconductor module A1 has, for example, a width of about 13.6 mm, a height that does not include the input terminal 3A, the ground terminal 3B, and the output terminal 3C, and a thickness of about 5.2 mm. The width direction of the semiconductor module A1 is the x direction, the height direction is the y direction, and the thickness direction is the z direction.

  The substrate 1 is for supporting a plurality of electronic components 2 and is, for example, a printed substrate in which wiring is formed on a base material 11 made of glass epoxy resin by printing. A front surface wiring pattern 12 shown in FIG. 4 is formed on the surface of the base material 11, and a back surface wiring pattern 13 shown in FIG. 5 is formed on the back surface. In the present embodiment, the substrate 1 has a plan view size of about 12.8 mm × 13.5 mm and a thickness of about 0.8 mm.

  A plurality of through holes 15, 16a, 16b, and 16c are formed in the substrate 1. Each through hole 15 penetrates the base material 11 in the z direction and reaches both the front surface wiring pattern 12 and the back surface wiring pattern 13. For example, copper plating connected to both the front surface wiring pattern 12 and the back surface wiring pattern 13 is formed on the inner surface of each through hole 15. As shown in FIG. 6, the through holes 16 a, 16 b, and 16 c penetrate the base material 11 in the z direction and reach both the front surface wiring pattern 12 and the back surface wiring pattern 13. For example, copper plating connected to both the front surface wiring pattern 12 and the back surface wiring pattern 13 is formed on the inner surfaces of the through holes 16a, 16b, and 16c. The through holes 16a, 16b and 16c are filled with a heat transfer member 17, respectively. In the present embodiment, the through holes 16a and 16b have a radius of about 1.0 mm. The radius of each through hole 15 and through hole 16c is 0.3 to 0.5 mm. The number of through holes 15 can be changed as appropriate.

  As shown in FIG. 4, the surface wiring pattern 12 has blocks 12A, 12B, 12C, 12D, 12E, and 12F that are separated from each other. The surface wiring pattern 12 is provided with a plurality of pads 14 for mounting a plurality of electronic components 2 at appropriate positions. 3 to 5, the plurality of pads 14 correspond to the first surface wiring pattern in the present invention is the block 12D of the surface wiring pattern 12 and correspond to the second surface wiring pattern. Are blocks 12A, 12B, 12C, 12E, 12F.

  As shown in FIG. 5, the back surface wiring pattern 13 includes blocks 13A and 13B that are separated from each other. A ground terminal 3B is connected to the block 13A and functions as a so-called ground pattern. The block 13A covers most of the back surface of the substrate 1 near the input terminal 3A, the ground terminal 3B, and the output terminal 3C. A convex portion is formed in the block 13A. The convex portion protrudes on the opposite side to the input terminal 3A, the ground terminal 3B, and the output terminal 3C. The block 13B is substantially U-shaped, and is disposed so as to fit with the convex portion of the block 13A. In the present invention, the first back surface wiring pattern corresponds to the block 13A in the back surface wiring pattern 13, and the second back surface wiring pattern corresponds to the block 13B.

  The front surface wiring pattern 12 and the back surface wiring pattern 13 are made of, for example, copper and are formed to have a thickness of about 50 μm.

  Each of the three heat transfer members 17 includes a filling portion 171 filled inside the through holes 16 a, 16 b, and 16 c and a bulging portion 172 that bulges to the back side of the base material 11. The heat transfer member 17 is made of, for example, a solder material containing copper. As shown in FIG. 6, the bulging portion 172 is formed in a dome shape whose thickness in the z direction decreases as the distance from the filling portion 171 increases in the x direction. The bulging portion 172 is formed so as to cover a part of the block 13 </ b> A of the back surface wiring pattern 13. The thickness in the z direction of each bulging portion 172 connected to each filling portion 171 filled in each through hole 16a, 16b, 16c is 0.2 mm. The thickness of each bulging portion 172 is set so that the distance between the substrate 1 and the heat radiating plate 5 becomes an appropriate value in order to improve the insulation resistance in accordance with the specifications of the semiconductor module A1 described later. For example, when the voltage input / output to / from the semiconductor module A1 is changed, the thickness of each bulging portion 172 is desirably adjusted as appropriate.

  The input terminal 3A, the ground terminal 3B, and the output terminal 3C are so-called pin type terminals, and are attached to the substrate 1 as shown in FIGS. In the present embodiment, the input terminal 3A, the ground terminal 3B, and the output terminal 3C protrude in the same direction along the y direction as shown in FIGS. ing. More specifically, as shown in FIG. 3, the input terminal 3A, the ground terminal 3B, and the output terminal 3C are arranged in this order from the left side in the drawing. The input terminal 3A is connected to the block 12A. The output terminal 3C is connected to the block 12F. The ground terminal 3B is connected to the block 13A.

  The plurality of electronic components 2 are, for example, for realizing the function of the semiconductor module A1, and include an IC 21, a fuse 22, a coil 23, capacitors 24A to 24E, and resistors 25A to 25F, as shown in FIG. It is out. The plurality of electronic components 2 constitute a circuit that performs a DC voltage conversion function by being incorporated as shown in FIG.

  The IC 21 is an example of a semiconductor device according to the present invention, and is a one-chip type synchronous rectification step-down switching regulator with a built-in FET. The IC 21 can produce a step-down output of 1.2V, 1.8V, 3.3V, 5V, etc. from an input voltage of 5V or 12V. The IC 21 is mounted so as to overlap a portion of the block 12D that is closer to the side opposite to the ground terminal 3B. Through holes 16a and 16b are formed in regions of the block 12D that overlap with the IC 21 when viewed in the z direction. Further, five through holes 15 and through holes 16c are formed in a region of the block 12D that does not overlap with the IC 21. The IC 21 has eight terminals, and each terminal is connected to the surface wiring pattern 12.

  The lower surface of the IC 21 in the z direction is in contact with the filling portion 171 filled in both the through holes 16a and 16b.

  The fuse 22 is for preventing the IC 21 from being damaged by an overcurrent. The fuse 22 is disposed on the left side in FIG. 3 and is mounted so as to straddle the block 12A and the block 12B. Thereby, the fuse 22 is electrically connected to the input terminal 3A.

  The coil 23 is for smoothing the output voltage from the IC 21, and is disposed between the IC 21 and the ground terminal 3B. The coil 23 is mounted so as to straddle the portion connected to the coil connection terminal of the IC 21 in the surface wiring pattern 12 and the block 12F, and overlaps the portion near the ground terminal 3B in the block 12D.

  The capacitors 24A to 24E are for smoothing the output voltage from the IC 21. Among these, the capacitor 24D functions as an input side capacitor, and the capacitor 24E functions as an output side capacitor. Capacitors 24A to 24E are incorporated as shown in FIG.

  The capacitor 24E is disposed so as to straddle the block 12E and the block 12F, and is electrically connected to the output terminal 3C. The capacitor 24E is also electrically connected to the ground terminal 3B via the block 12E, the plating of the through hole 15, and the block 13A. The capacitor 24E is arranged alongside the coil 23 in a direction perpendicular to the protruding direction of the input terminal 3A, the ground terminal 3B, and the output terminal 3C, and is located on the output terminal 3C side.

  The capacitor 24D is arranged so as to straddle the block 12C and the block 12E. The capacitor 24D is adjacent to the capacitor 24E in the protruding direction of the input terminal 3A, the ground terminal 3B, and the output terminal 3C, and is located on the opposite side of the capacitor 24E from the output terminal 3C. The capacitor 24D is electrically connected to the input terminal 3A through the block 12C, the plating of the through hole 15, the block 13B, the block 12B, the fuse 22, and the block 12A. The capacitor 24D is also electrically connected to the ground terminal 3B via the block 12E, the plating of the through hole 15, and the block 13A.

  The resistors 25A to 25F are loads for balancing voltage conversion, and are incorporated as shown in FIG.

  Among these electronic components 2, the IC 21 has a relatively large amount of heat generation.

  The resin package 4 is for protecting the plurality of electronic components 2 and is made of, for example, a black epoxy resin. As shown in FIG. 1, the resin package 4 occupies most of the front surface of the semiconductor module A1 and wraps around to the side. The resin package 4 is provided with a gap, and a plurality of electronic components 2 are accommodated in the gap. A silicone resin 6 is provided between the resin package 4 and the plurality of electronic components 2.

  The heat sink 5 is made of, for example, aluminum, and is disposed so as to face the back surface of the substrate 1 as shown in FIG. In this embodiment, the heat sink 5 and the board | substrate 1 are joined by the adhesive agent 7 excellent in heat conduction. As shown in FIGS. 1 and 2, the heat sink 5 protrudes from the resin package 4 to the opposite side in the y direction from the input terminal 3A, the ground terminal 3B, and the output terminal 3C.

  As shown in FIG. 2, the resin package 4 has three protrusions 4a. The right projection 4 a in the drawing is fitted in the recess 1 a of the substrate 1 at a position where it does not overlap the heat sink 5. The two protrusions 4 a on the left side in the drawing are respectively fitted to the other recess 1 a of the substrate 1 and the recess 5 a of the heat sink 5.

  An example of the specification of the semiconductor module A1 is as follows. The input voltage is rated at 12V, the minimum is 6V, and the maximum is 14V. The output voltage has a rating of 5.00V, a minimum of 4.90V, and a maximum of 5.10V. The maximum output current is 500 mA, and when the heat sink is used in combination, the maximum output current is 800 mA. The line regulation is rated at 5 mV and the maximum is 50 mV, and the load regulation is rated at 10 mV and the maximum is 50 mV. The output ripple voltage has a rating of 5 mV and a maximum of 50 mV. The minimum startup time is 7.0 msec for the rating and 4.0 msec for the minimum, and the power conversion efficiency is 88% for the rating and 83% for the minimum.

  Next, an example of a method for manufacturing the semiconductor module A1 will be described with reference to FIGS.

  First, as shown in FIG. 7, a step of mounting a plurality of electronic components 2 on the substrate 1 is performed. In this step, the through holes 15, 16a, 16b, and 16c are formed in the substrate 11, and the front surface wiring pattern 12 and the back surface wiring pattern 13 are further formed. Thereafter, the plurality of electronic components 2 are mounted on the surface wiring pattern 12.

  Next, as shown in FIGS. 8 and 9, a step of forming the heat transfer member 17 is performed. First, as shown in FIG. 8, a process of applying solder paste 17A from the back side of the substrate 1 to a position overlapping with the through holes 16a, 16b, 16c is performed. This step can be performed using, for example, a solder printer. Next, the process of melting the solder paste 17A is performed by carrying the substrate 1 into a reflow furnace and heating it. As shown in FIG. 9, the melted solder paste 17A has a filling portion 171A that fills the through holes 16a, 16b, and 16c, and a bulging portion 172B that is dome-shaped due to surface tension. At this time, since the base material 11 repels the solder, the expanded range of the expanded portion 172A of the melted solder paste 17A is within the range where the block 13A is formed. Then, the heat-transfer member 17 which has the filling part 171 and the bulging part 172 is formed by cooling.

  Next, as shown in FIG. 10, a process of assembling the substrate 1 to the resin package 4 is performed. In this step, the silicone resin 6 is also formed.

  Next, as shown in FIG. 11, the process of installing the heat sink 5 is performed. In this step, for example, the heat sink 5 is brought close to the back surface of the substrate 1 with the adhesive 7 applied to the surface facing the back surface of the substrate 1 of the heat sink 5, and the heat sink 5 and the bulging portion 172 This is performed by fixing the heat radiating plate 5 and the substrate 1 at a position where the contact is made.

  The semiconductor module A1 shown in FIGS. 1 to 6 can be smoothly manufactured through the above steps.

  Next, the operation of the semiconductor module A1 will be described.

  According to the present embodiment, since the heat radiating plate 5 is installed so as to be in contact with the bulging portion 172 after the heat transfer member 17 is formed, the heat transfer member 17 and the heat radiating plate 5 are reliably in contact with each other. The filling portion 171 filled in the through holes 16 a and 16 b is in contact with the IC 21, and heat generated in the IC 21 is efficiently transmitted to the heat radiating plate 5 through the heat transfer member 17. For this reason, the semiconductor module A1 has a structure in which the heat generated by the IC 21 having a relatively large amount of heat is quickly cooled by the heat sink 5. Therefore, in the semiconductor module A1, the plurality of electronic components 2 are not easily affected by heat.

  Furthermore, in this embodiment, the semiconductor module A1 can be mounted on a circuit using the pin type input terminal 3A, the ground terminal 3B, and the output terminal 3C. When mounting using such pin-type terminals, in general, heat is less likely to be released than when surface mounting is performed, and heat tends to accumulate on the substrate. However, in this embodiment, since the structure in which heat is transmitted to the heat radiating plate 5 through the heat transfer member 17 as described above is provided, it is possible to favorably avoid such a problem.

  Furthermore, according to the present embodiment, the three heat transfer members 17 are installed so as to fill each of the through holes 16 a, 16 b, and 16 c, and the three bulging portions 172 are in contact with the heat radiating plate 5. For this reason, the heat sink 5 is not easily inclined, and the space between the block 13A of the backside wiring pattern 13 and the heat sink 5 is kept constant. Therefore, it is difficult for the heat sink 5 to come into contact with the block 13B of the backside wiring pattern 13, and unreasonable conduction between the blocks 13A and 13B can be prevented. Thus, the semiconductor module A1 has a structure suitable for providing wiring on the back side of the substrate 1.

  Further, according to the manufacturing method described above, the bulging portion 172 is naturally formed by the surface tension when the solder paste 17A is melted, and does not require a special method. For this reason, according to the manufacturing method described above, the semiconductor module A1 can be manufactured relatively easily.

  Hereinafter, another method for manufacturing the semiconductor module A1 will be described with reference to FIGS. However, the description of the steps common to the manufacturing method of the semiconductor module A1 shown in FIGS.

  The process shown in FIGS. 12 and 13 is a process of forming the heat transfer member 17, and corresponds to FIGS. 8 and 9 in the manufacturing method described above. In this step, first, a flux is applied to regions on the inner peripheral surfaces of the through holes 16a, 16b, and 16c and the back surface side of the substrate 1 that overlap with the through holes 16a, 16b, and 16c when viewed in the z direction. Thereafter, as shown in FIG. 12, the substrate 1 is carried into a solder tank F through which the solder material flows, and the solder material is attached to the back surface side of the substrate 1. At this time, as shown in FIG. 13, the liquid solder material 17B adheres to the area where the flux is applied. The solder material 17B includes a filling portion 171B that fills the through holes 16a, 16b, and 16c, and a bulging portion 172B that adheres to the back surface of the substrate 1. The bulging portion 172B has a dome shape with the center bulging due to surface tension. By solidifying the solder material 17B, a heat transfer member 17 as shown in FIG. 6 is formed.

  Also by such a manufacturing method, the semiconductor module A1 can be manufactured smoothly. Also in this manufacturing method, since the bulging portion 172B has a dome-like shape that naturally swells due to surface tension, the heat transfer member 17 can be easily formed.

  Hereinafter, another embodiment of the present invention will be described. In these drawings, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment, and description thereof will be omitted as appropriate.

  FIG. 14 shows a semiconductor module A2 in the second embodiment of the present invention. In the semiconductor module A2, the heat sink 5 is fixed to the resin package 4 using eyelets. For this reason, in the semiconductor module A2, the adhesive 7 as shown in FIG. 6 is not provided between the substrate 1 and the heat sink 5 as shown in FIG.

  In such a semiconductor module A2, the substrate 1 is fixed by being sandwiched between the heat sink 5 and the resin package 4, and the bulging portion 172 is in contact with the heat sink 5 with certainty. . For this reason, the semiconductor module A2 has a structure in which heat generated by the IC 21 having a relatively large amount of heat is quickly cooled by the heat radiating plate 5. Therefore, in the semiconductor module A2, the plurality of electronic components 2 are not easily affected by heat.

The semiconductor module according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the semiconductor module according to the present invention can be modified in various ways. For example, as a material for forming the heat transfer member 17, a solder material is used in the above embodiment.
A conductive resin such as an Ag paste may be used.

  In the above embodiment, the heat transfer members 17 are formed at three locations. However, even if the heat transfer members 17 are additionally formed in the through holes 15 provided in the region where the blocks 12D and 13A overlap when viewed in the z direction. I do not care. Further, the case where the heat transfer member 17 is installed only in one or both of the through holes 16a and 16b is also within the scope of the present invention.

  Furthermore, in the above embodiment, after mounting the plurality of electronic components 2 on the substrate 1, the solder paste 17A is installed and heated in the reflow furnace, but after the solder paste 17A is installed and heated in the reflow furnace, A plurality of electronic components 2 may be mounted.

A1, A2 Semiconductor module 1 Substrate 11 Base material 12 Front surface wiring pattern 13 Back surface wiring pattern 14 Pads 15, 16a, 16b, 16c Through hole 17 Heat transfer member 17A Solder paste 17B Solder materials 171, 171B Filling portions 172, 172B 2 Electronic components 21 IC (semiconductor element)
22 fuse 23 coil 24A-24C capacitor 24D (input side) capacitor 24E (output side) capacitor 25A-25F resistor 3A input terminal 3B ground terminal 3C output terminal 4 resin package 5 heat sink 6 silicone resin 7 adhesive

Claims (16)

A substrate on which a semiconductor element is mounted and having one or more through holes;
A heat sink arranged to face the back surface of the substrate;
A semiconductor module comprising:
A heat transfer member configured by a filling portion filled in one of the one or more through holes, and a bulging portion that bulges from the filling portion to the back side of the substrate;
The bulging portion is formed so that the thickness in the thickness direction of the substrate decreases as the distance from the filling portion increases in the in-plane direction of the substrate, and is in contact with the heat sink. A semiconductor module.   2. The semiconductor module according to claim 1, wherein the through hole filled with the filling portion is provided at a position overlapping the semiconductor element in a thickness direction view of the substrate. The substrate is formed on the surface of the base material, the first surface wiring pattern on which the semiconductor element is mounted, and the back surface of the base material, and the filling portion is filled. A first back surface wiring pattern that is electrically connected to the first front surface wiring pattern through the formed through hole,
The semiconductor module according to claim 1, wherein the bulging portion is formed so as to cover at least a part of the first back surface wiring pattern. The substrate is formed on the back surface of the base material, and includes a second back surface wiring pattern spaced from the first back surface wiring pattern,
The semiconductor module according to claim 3, wherein the second back surface wiring pattern is insulated from the heat sink.   The substrate includes the second surface wiring pattern formed on the surface of the base material, spaced from the first surface wiring pattern, and electrically connected to the second back surface wiring pattern. The semiconductor module according to claim 4.   The semiconductor module according to claim 1, wherein the heat transfer member is made of a solder material.   The semiconductor module according to claim 1, wherein the heat transfer member is made of resin. The semiconductor element is a DC voltage conversion control element,
Input, output, and ground terminals,
A coil mounted on the substrate and connected to the DC voltage conversion control element and the output terminal;
Mounted on the board, an input side capacitor connected to the input terminal and the ground terminal,
The semiconductor module according to claim 1, further comprising: an output-side capacitor mounted on the substrate and connected to the output terminal and the ground terminal. The input, output, and ground terminals protrude in parallel in the same direction,
9. The semiconductor according to claim 8, wherein the input terminal, the ground terminal, and the output terminal are arranged in this order in a direction perpendicular to a protruding direction in which the input terminal, the output terminal, and the ground terminal protrude. module. A method of manufacturing a semiconductor module, comprising: mounting a semiconductor element on a surface of a substrate having one or more through holes; and installing a heat sink for cooling the semiconductor element,
Prior to the step of installing the heat sink, the filling portion filled in any of the one or more through holes, and a bulge from the filling portion to the back side of the substrate, and in the in-plane direction of the substrate, And having a step of forming a heat transfer member constituted by a bulging portion formed so that the thickness in the thickness direction of the substrate decreases as it moves away from the filling portion,
In the step of installing the heat sink, the heat sink is installed so as to be in contact with the bulging portion. The substrate has a through hole at a position overlapping the semiconductor element in the thickness direction view of the substrate,
11. The semiconductor module according to claim 10, wherein, in the step of forming the heat transfer member, the filling portion is formed so as to fill the through hole in a position overlapping with the semiconductor element in a thickness direction view of the substrate. Production method. The substrate is formed on a base material, a surface of the base material, a first surface wiring pattern on which the semiconductor element is mounted, and a back surface of the base material. A first back surface wiring pattern having a region overlapping with the first front surface wiring pattern when viewed in the thickness direction, and a first surface wiring pattern and the first back surface wiring pattern when viewed in the thickness direction of the base material The through hole formed in a region overlapping with both, and
In the step of forming the heat transfer member, the filling portion is formed so as to fill the through hole, and the bulging portion is formed so as to cover at least a part of the first back surface wiring pattern. A method for producing a semiconductor module according to 10 or 11.   The method for manufacturing a semiconductor module according to claim 10, wherein the heat transfer member is formed of a solder material.   The step of forming the heat transfer member is carried out by a flow-type soldering operation in which the substrate is carried into a solder tank filled with the liquid solder material and the solder material is adhered to the back surface of the substrate. The manufacturing method of the semiconductor module of Claim 13 performed.   The method of manufacturing a semiconductor module according to claim 13, wherein the step of forming the heat transfer member is performed by a reflow soldering operation in which the solder material formed in a paste form is applied and then heated.   The semiconductor module according to claim 10, wherein the heat transfer member is formed of a resin.

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