JP3602763B2 - Method for manufacturing power semiconductor module - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
This invention relates to a method of manufacturing a power semiconductor module, and more particularly to a method of manufacturing a power semiconductor module which output terminal connected to the semiconductor or the like is formed integrally with the resin case.
[0002]
[Prior art]
BACKGROUND ART Conventionally, for example, there is a power semiconductor module having a structure in which an output terminal is embedded in a resin case by integral molding with the resin case, as shown in FIG. In FIG. 1, reference numeral 2 denotes a metal substrate made of iron, copper, aluminum, or the like, on which an insulating substrate 4 having patterned copper circuits 6a to 6d formed on the surface is adhered. The insulating substrate 4 is made of alumina or aluminum nitride. Semiconductor chips 8a and 8b and other chips 8c are soldered on the copper circuits 6a to 6c on the insulating substrate 4.
[0003]
One end protruding from the bottom wall portion 10b of the output terminal 12 embedded in the L-shape in one side wall portion 10a of the resin case 10 and the bottom wall portion 10b connected thereto on the copper circuit 6d. The bent end surface portion 12c is soldered. The resin case 10 is filled with a gel-like sealing material 24 to a height exceeding the height of the semiconductor chips 8a and 8b and the like, thereby protecting the semiconductor chips 8a and 8b and the like. A printed wiring board 26 is arranged above the sealing material 24 in the resin case 10, and components 28a to 28e for controlling and protecting the semiconductor chips 8a and 8b are mounted thereon. Have been. A lid 30 is placed over the upper part of the resin case 10 to maintain the airtightness of the case 10.
[0004]
In the power semiconductor module having the configuration of FIG. 1 described above, a conventional aspect of the output terminal 12 formed to be embedded in one of the side wall portions 10a of the resin case 10 and the bottom wall portion 10b connected thereto will be described. As shown in FIG. 5A, the output terminal 12 pulls out a copper plate 40 having a required width wound in a coil shape, cuts the copper plate 40 into a required length L, and cuts the hatched portions 42a, 42b, 42c, 42d. By punching, a plurality of output terminals 12, 14, 16 having one side (upper side) as a common band-shaped support 18 as shown in FIG. 5B are obtained. The plurality of output terminals 12, 14, 16 supported by the band-shaped support portion 18 are simultaneously provided with the vertical portions 12a, 14a, 16a and the horizontal portions 12b, 14b, 16b at predetermined positions as shown in FIG. The ends of the horizontal portions 12b, 14b, 16b are further bent so that they can be soldered to the copper circuit 6d in FIG. 1 and bent end surfaces 12c, 14c, 16c. Is formed.
[0005]
Next, the plurality of output terminals 12, 14, 16 supported by the belt-shaped support portions 18 having the shape shown in FIG. 6 are connected to one side wall of a resin case molding mold (not shown) having a predetermined shape. Part into the bottom wall portion, and a thermosetting resin liquid such as polyphenylene sulfide or polybutylene terephthalate is poured into the mold, and the vertical portions 12a, 14a, and 16a of the output terminals are left slightly below the belt-like support portion 18. The horizontal portions 12b, 14b, and 16b are embedded in the vertical portions 10a of the resin case 10 so that their bent end surfaces 12c, 14c, and 16c are exposed, and these are connected to the side wall portions 10a of the resin case 10. By embedding in the surface of the bottom wall 10b to be heated and hardening, an output terminal is simultaneously formed in the resin case 10 as shown in FIG. It is possible to perform the embedding of 2,14,16. Thereafter, the strip-shaped support portions 18 to which the vertical portions 12a, 14a, 16a of the output terminals 12, 14, 16 projecting above the resin case 10 are connected are cut.
[0006]
As shown in FIG. 1, a semiconductor chip and other components 8a, 8b, 8c are mounted on copper circuits 6a to 6c via a solder layer, and an insulating substrate 4 on which a solder layer is formed also on the copper circuit 6d is provided. Silicone rubber is applied to the edge of the metal substrate 2, and the resin case 10 obtained by cutting the band-shaped support 18 obtained above on the silicone rubber is exposed from the bottom wall 10 b of the case 10. The bent end faces 12c, 14c, 16c of the output terminals 12, 14, 16 are mounted on the copper circuit 6d so as to be mounted thereon, and are heated in a reflow furnace, whereby the copper circuits 6a to 6c Soldering of semiconductor chips and other components 8a, 8b, 8c, soldering of bent end faces 12c, 14c, 16c of output terminals 12, 14, 16 onto copper circuit 6d, and edge of metal substrate 2 at the same time To resin case Adhesion of 0 is performed, it is the configuration power semiconductor module shown in FIG. 1 is obtained.
[0007]
[Problems to be solved by the invention]
However, the output terminals 12, 14, and 16 are formed with bent end surfaces 12 c, 14 c, and 16 c at the other ends, and the output terminals are formed as shown in FIG. 6 by heat molding of a thermosetting resin using a mold. When the output terminals 12, 14, 16 are buried in the resin case 10 at the same time as the molding of the resin case 10 as shown in FIG. 7, cooling after heat molding with a thermosetting resin such as polyphenylene sulfide or polybutylene terephthalate is performed. In this case, there is a problem that the bottom wall portion 10b of the obtained resin case 10 is curved inward as shown in FIG. 8, for example, because the cooling rate is different inside the thick portion of the resin. When the resin case 10 thus curved is applied to the metal substrate 2, the copper terminals 6 d ₁ , 6 d ₂ , 6 d ₃ are exposed from the output terminals 12, 14, 16 embedded in the resin case 10. each bent end face portion 12c to be soldered onto, 14c, among 16c, for example, 14c are not in contact with the solder layer 20b, therefore only the output terminal 14 that is not soldered on the copper circuit 6d ₂ As a result, the reliability of soldering is impaired, and the resulting semiconductor module cannot perform its function sufficiently.
[0008]
In view of the above, the present invention considers the formation of a bent end surface portion of an output terminal to be soldered on a copper circuit, and heats the output terminal during molding of the output terminal embedded in the resin case and integrally formed with the resin case. Alternatively, the reliability of the soldering of the bent end face of the output terminal to the copper circuit is improved by preventing the influence from being affected in the subsequent cooling process.
[0009]
[Means for Solving the Problems]
The method for manufacturing a power semiconductor module according to claim 1, wherein the power semiconductor chip mounted on a copper circuit on a surface of an insulating substrate provided on a metal substrate via a solder layer, and the output terminal are formed of the metal. In the method of manufacturing a power semiconductor module, in which a thermosetting resin case is bonded to a peripheral edge of a board and soldered at the same time, one end of the output terminal is formed into a band-shaped support portion using a copper plate, and a lower portion thereof is punched to a required width. In forming the strip portion integrally with the thermosetting resin case by embedding the strip portion in the side wall portion and the bottom wall portion of the thermosetting resin case covered by the periphery of the metal substrate. the other end of the output terminal is exposed from the bottom wall portion of the thermosetting resin case, the exposed other end after thermosetting resin case molded by folding so as to be connected to the copper circuitry, the copper It is obtained by the connecting Orikyokutan face portion of the road.
[0010]
According to a second aspect of the present invention, there is provided a method of manufacturing a power semiconductor module according to the first aspect of the present invention , wherein one end of the power semiconductor module is formed into a band-shaped support portion using a copper plate, and a lower portion is punched into a required width. After being formed integrally with the thermosetting resin case so as to be embedded in the side wall portion and the bottom wall portion of the thermosetting resin case, the output terminal was exposed from the thermosetting resin case. Each of the bent end faces formed at the other ends is formed at the same height so as to be able to contact the copper circuit provided on the surface of the insulating substrate.
[0011]
According to the first aspect of the present invention, a strip-shaped output terminal is formed by using a copper plate, one end of which is a band-shaped support portion, and a lower portion thereof is punched to have a required width. In forming integrally with the thermosetting resin case so as to be embedded in the side wall portion and the bottom wall portion of the resin case covered by the peripheral edge of the resin case, the other end of the output terminal is protruded from the bottom wall portion of the resin case, After the resin case is molded, the exposed other end is bent to form a bent end surface, so that when the thermosetting resin case is molded at the same time as the embedding of the output terminal, the heat and cooling processes cause heat to be generated. even if the deformation curable resin case occurs, since the bent end face portion of the output terminal to be soldered on the copper circuit is formed by bending after the resin case molded, the thermosetting resin Ke Scan without being affected at all deformation, can be formed to be in contact with the copper circuit, it is possible to greatly improve the soldering reliability of the copper circuit of the output terminal bent end face portion.
[0012]
According to the second aspect of the present invention, in the first aspect, a plurality of strip-shaped output terminals formed by punching a copper sheet at one end to a band-shaped support portion and a required width below the copper plate. even, so as to be embedded in the sidewall portion of the thermosetting resin case after integrally formed with the thermosetting resin case, the respective other ends projecting from the thermosetting resin case and bent end face portion Therefore, even if there are a plurality of output terminals, the bent end face portions can be formed at the same height so as to be in contact with the copper circuit provided on the surface of the insulating substrate.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail. Note that the main configuration of the power semiconductor module according to the present invention is the same as that of FIG. 1 described above, and thus description thereof will be omitted. In the drawings shown below, the same parts as those in FIG. 1 are denoted by the same reference numerals.
[0014]
2 to 4 show a process of manufacturing an output terminal used in obtaining a power semiconductor module having the same main configuration as that of FIG. 1 in the present invention. First, FIG. 2 is a perspective view of an output terminal group A embedded in the resin case 10 when the resin case 10 is molded using a thermosetting resin by a mold having a required shape. As shown in FIG. 5A, the output terminal group A draws out a copper plate 40 of a required width wound in a coil shape, cuts it into a required length L, and then diagonally shades 42a, 42b, 42c, 42d. A plurality of strip-shaped output terminals 12, 14, 16 of a required size having one side (upper side) as a common band-shaped support 18 as shown in FIG. After the above-described punching process, they are bent at predetermined positions S into vertical portions 12a, 14a, 16a and horizontal portions 12b, 14b, 16b in an L-shape.
[0015]
As described above, the output terminal group A which is bent in an L shape and one end of which is connected by the band-shaped support portion 18 is, as described above, one of the molds (not shown) of a required shape for molding the resin case. It is placed at a predetermined position in the bottom wall from the side wall. At this time, the output terminal group A is arranged such that the vertical portions 12a, 14a, 16a of the plurality of output terminals 12, 14, 16 are slightly exposed below the strip-shaped support portion 18 to which they are connected, outside the side wall portion of the mold. Place on. The horizontal portions 12b, 14b, and 16b bent in an L-shape at the positions of S of the output terminals 12, 14, and 16 are embedded in a resin case, contacted with a copper circuit after being molded, and soldered to the copper circuit. The required length required to form the bent end face to be formed is exposed outside the bottom wall of the mold, and the resin case 10 is placed so as to be positioned on the upper surface of the bottom wall 10b.
[0016]
After the output terminal group A is placed in the mold as described above, a thermosetting resin liquid such as polyphenylene sulfide or polybutylene terephthalate is poured into the mold, and is cured by heating, as shown in FIG. As described above, the vertical portions 12a, 14a, and 16a slightly below the belt-like support portions 18 of the output terminals 12, 14, and 16 are embedded, and the horizontal portions 12b, 14b, and 16b that are bent in an L shape expose their ends. As a result, an output terminal group A surrounded by the resin case 10 such that the middle portion is located on the upper surface of the bottom wall portion 10b is obtained.
[0017]
Then, the output terminal group A shown in FIG. 3A obtained above separates the band-like support portion 18 and exposes outward from the bottom wall portion 10b of the resin case 10 as shown in FIG. The end faces of the horizontal parts 12b, 14b, 16b of the output terminals 12, 14, 16 are bent to form bent end faces 12c, 14c, 16c. At this time, the bent end portions 12c, 14c, and 16c are at the same height where they are sufficiently in contact with a copper circuit having a solder layer such as cream solder or solder foil as shown in FIG. Can be adjusted.
[0018]
When the output terminal group A is placed at a required position in the mold as described above and the resin case is molded with the thermosetting resin, the inside of the thick portion of the resin is replaced with another portion at the time of cooling after heating. Since the cooling rate is different from that of FIG. 3, the bottom wall 10b of the resin case 10 may be curved inward as shown in FIG. Along with this curvature, the dimensions of the exposed portions of the horizontal portions 12b, 14b, 16b of the output terminals 12, 14, 16 are different. However, in the output terminal group A of the present invention, as described above, In order to form the bent end faces 12c, 14c, 16c when the output terminal group A is soldered onto a copper circuit having a solder layer such as solder or solder foil, as shown in FIG. 4, after forming the resin case. Even if the dimensions of the exposed portions of the horizontal portions 12b, 14b, 16b of the output terminals 12, 14, 16 are somewhat different, the bent end face portions 12c, 14c, 16c of the output terminals 12, 14, 16 Can be adjusted to the same height so as to contact the copper circuit having the solder layer 20 such as cream solder or solder foil.
[0019]
【The invention's effect】
As described above, in the method of manufacturing a power semiconductor module of the present invention, be an output terminal which has been made integral with the thermosetting resin case can be soldered securely and internal copper circuit Therefore, the reliability of soldering is improved, and the function as a semiconductor module can be sufficiently performed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a main configuration of a power semiconductor module.
FIG. 2 is an explanatory diagram showing an example of a shape of an output terminal used in the present invention.
FIG. 3 is an explanatory view showing one example of a process of manufacturing an output terminal integrally formed with a resin case used in the present invention.
FIG. 4 is an explanatory view showing one example of a production process of an output terminal integrally formed with a resin case used in the present invention.
FIG. 5 is an explanatory view showing an example of a production process of an output terminal.
FIG. 6 is an explanatory diagram showing a conventional output terminal.
FIG. 7 is an explanatory view showing an output terminal integrally formed with a conventional resin case.
FIG. 8 is an explanatory view showing a state when a conventional output terminal integrally formed with a resin case and a copper circuit are soldered.
[Explanation of symbols]
2 Metal substrate 4 Insulating substrate 6a, 6b, 6c, 6d Copper circuit 8a, 8b, 8c Semiconductor chip 10 Resin case 12, 14, 16 Output terminal 12c, 14c, 16c Bend end portion 18 of output terminal 18 Band support 20 Solder layer

Claims (2)

A power semiconductor chip and an output terminal mounted via a solder layer on a copper circuit on a surface of an insulating substrate provided on a metal substrate are soldered simultaneously with bonding of a thermosetting resin case to a peripheral edge of the metal substrate. In the method for manufacturing a power semiconductor module to be attached, the output terminal is formed in a strip shape by using a copper plate, one end of which is a band-shaped support portion, and a lower portion thereof is punched to a required width, and the strip portion is formed of the metal substrate. In forming integrally with the resin case so as to be embedded in the side wall portion and the bottom wall portion of the thermosetting resin case that is wrapped around the periphery, the other end of the output terminal is exposed from the bottom wall portion of the resin case, A method for manufacturing a power semiconductor module , wherein the other end exposed after forming the resin case is bent so as to be connectable to the copper circuit to form a bent end face for connection to the copper circuit . 2. The method for manufacturing a semiconductor module according to claim 1, wherein a plurality of output terminals are formed by using a copper plate, one end of which is formed as a strip-shaped support portion, and a lower portion thereof is formed as a strip having a predetermined width . After being formed integrally with the thermosetting resin case so as to be embedded in the side wall portion and the bottom wall portion of the resin case, all of the bent end surfaces formed at the other ends exposed from the thermosetting resin case are insulated. A method of manufacturing a power semiconductor module , wherein the power semiconductor module is formed at the same height as to be capable of contacting a copper circuit provided on a surface of a substrate.

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