JP2854785B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to an improvement in a terminal for electrically connecting a circuit component such as a semiconductor chip to an external device.

[0002]

2. Description of the Related Art FIGS. 6 to 8 show sectional structures of a conventional semiconductor device. FIG. 6 is a front cross-sectional view of the semiconductor device before bending the plate-shaped terminal, and FIG. 7 is an enlarged cross-sectional view near the bent portion of the plate-shaped terminal in the semiconductor device after bending the plate-shaped terminal. FIG. 8 is a front sectional view of the semiconductor device after bending the plate-shaped terminal.

As shown in FIGS. 6 to 8, this conventional semiconductor device 50 includes the following components. That is, in FIG. 6, 1 is an insulating case, 2 is a conductive plate terminal for electrically connecting a circuit component such as a semiconductor chip and an external device, and 5 is a part of the plate terminal 2. A protrusion for fixing the plate-like terminal 2, a hole 7 formed in the plate-like terminal 2, a conductive nut 8 embedded in the upper surface of the case 1, and a conductive nut 10 on the upper main surface. An insulating substrate having a wiring pattern; 9, a lower end surface of the plate-like terminal 2 joined to the wiring pattern; 11, a heat sink bonded to a lower main surface of the insulating substrate 10; 12, mounted on an upper main surface of the insulating substrate 10 Semiconductor chip 13 is silicone gel and 14 is epoxy resin.

As shown in FIG. 6, a lower portion of the plate-like terminal 2 is bent in an S-shape. The bent portion is provided for the purpose of absorbing thermal deformation or the like of the plate-like terminal 2 to prevent an unnecessary thermal stress from being applied to a semiconductor chip or the like. When assembling the semiconductor device 50, the S-shaped bent portion (S vent) causes the plate-like terminal 2 to move upward from below while keeping the shape of the upper portion straight as shown in FIG. Case 1 (in the direction of the arrow in FIG. 6)
Inserted into When the plate-like terminal 2 is inserted, the plate-like terminal 2 is fixed to the case 1 by the action of the protrusion 5. Thereafter, as shown in FIGS. 7 and 8, the semiconductor device 50 is completed by bending the portion of the plate-shaped terminal 2 exposed to the outside of the case 1. At this time, the hole 7 formed in the plate terminal 2 substantially faces the female screw of the nut 8. For this reason, an electrode (not shown) of the external device and the plate-like terminal 2 can be fastened by inserting a bolt (not shown) through the hole 7 and further screwing it into the nut 8.

[0005]

Since the conventional apparatus is configured as described above, it has the following problems.

First, after the plate-like terminal 2 is inserted into the case 1, the upper end is bent to form the hole 7.
And the screw hole of the nut 8 face each other. For this reason, as shown in FIG. 7, a gap 6 is generated between the plate-shaped terminal 2 and the surface of the case 1 by the action of the spring-back of the plate-shaped terminal 2, so that the gap between the plate-shaped terminal 2 and the nut 8 is formed. However, there has been a problem that the contact resistance becomes high, which causes excessive heat generation. Further, there is a problem that the positions of the screw holes of the hole 7 and the nut 8 may be shifted from each other due to a variation in the finish in the bending. At this time, it is difficult or impossible to penetrate the bolt through the hole 7 and further screw it into the nut 8. Further, there is a problem that the bending process after the insertion of the plate-shaped terminal 2 is not easy, and the production cost is increased. In addition, when the plate-like terminal 2 has a certain thickness or more, for example, when the semiconductor device 50 is a device for controlling a large current, an annealing process is required after the bending process. However, there was a problem that it further increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and prevents heat generation at the end of a plate-like terminal, has good positional accuracy, is easy to process, and has a small number of manufacturing steps. It is an object of the present invention to provide a semiconductor device capable of reducing costs and a method for manufacturing the same.

[0008]

According to a first aspect of the present invention, there is provided a semiconductor device comprising: an electrically insulating insulating substrate having a wiring pattern on an upper main surface and having a semiconductor chip mounted thereon; A heat sink that is bonded to a lower main surface of the semiconductor chip and dissipates heat loss in the semiconductor chip; a lower end portion is attached to an outer peripheral edge of the heat sink to surround the semiconductor chip, and an upper end portion projects in an inner circumferential direction. A cylindrical case having a protruding portion, a conductive screw terminal embedded in the upper end portion, a female screw hole opened on the surface of the upper end portion, and an outer end surface exposed on the surface of the upper end portion; An outer end surface of the screw terminal having a bent portion, having an S-shaped bent portion between the fitting bent portion and the insulating substrate, being fitted and fixed to the protrusion at the fitting bent portion; One end is in contact with Plane and a plate-shaped terminal of conductive joining to the wiring pattern.

According to a second aspect of the present invention, in the semiconductor device according to the first aspect, an outer end surface of the screw terminal protrudes from a surface of the upper end portion.

According to a third aspect of the present invention, in the semiconductor device according to the first aspect, the surface of the plate-shaped terminal is brought into contact with the protruding portion of the plate-shaped terminal by abutting the peripheral end surface of the terminal. It further includes a stopper that regulates the fitting position.

According to a fourth aspect of the present invention, in the semiconductor device according to the first aspect, the fitting is press-fitted by elastic biasing force of the fitting bent portion.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: preparing an electrically insulating insulating substrate having a wiring pattern disposed on an upper main surface; An electrically insulating terminal having a protruding protrusion, a female screw hole is opened on the surface of the upper end, and a conductive screw terminal whose outer end surface is exposed on the surface of the upper end is embedded in the upper end. A step of preparing a cylindrical case, having a fitting bent portion, and when fitted to the protrusion at the fitting bent portion, the upper end surface contacts the outer end surface of the screw terminal, and the lower end surface is A step of preparing a conductive plate-shaped terminal which comes into contact with the wiring pattern and has an S-shaped bent portion between the lower end surface and the fitting bent portion; and mounting a semiconductor chip on an upper main surface of the insulating substrate. And a heat sink on the lower main surface of the insulating substrate. A step of bonding, a step of fitting and fixing the plate-shaped terminal to the projection of the cylindrical case, and a step of radiating the lower end of the cylindrical case so that the cylindrical case surrounds the semiconductor chip. A step of fixing the lower end face of the plate-shaped terminal to the wiring pattern.

[0013]

In the semiconductor device according to the present invention, the case is cylindrical and the plate terminals are fixed by fitting into the cylindrical case. Therefore, before the plate-shaped terminal is attached to the cylindrical case, a predetermined bending process can be performed on the plate-shaped terminal in a single state. For this reason, processing is easy, the number of manufacturing steps is reduced, and heat generation is suppressed due to improvement in bonding with the screw terminal.

<Operation of the invention according to claim 2> Since the outer end surface of the screw terminal protrudes from the surface of the upper end portion of the cylindrical case, the contact between the plate terminal and the screw terminal is reliably performed.

<Operation of the invention according to claim 3> By the action of the stopper, movement such as rotation of the plate-like terminal is prevented, so that the positional accuracy between the plate-like terminal and the screw terminal is improved.

<Effect of the invention according to claim 4> When the plate-like terminal is fitted into the cylindrical case, the plate-like terminal does not come off from the cylindrical case due to the action of the elastic urging force. Workability in the manufacturing process of the device is improved.

<Operation of the invention according to claim 5> In the manufacturing method according to the present invention, before the plate-like terminal is attached to the cylindrical case, the plate-like terminal that has been subjected to a predetermined bending process in a single state is prepared. Is done. Therefore, the bending accuracy of the plate-shaped terminal is good. In addition, since the attachment of the plate-like terminal to the cylindrical case is realized by fitting the plate-like terminal to the projection, manufacturing is facilitated.

[0018]

<First Embodiment> A first embodiment of the present invention will be described below. 1 and 2 are a front sectional view and a plan view, respectively, of a semiconductor device 100 in this embodiment. FIG. 3 is a bottom view of the case 21 constituting the semiconductor device 100 and its attached members. In these figures, 21 is a cylindrical case (cylindrical case) made of an insulating resin, and 22 is a conductive plate for electrically connecting a circuit component such as a semiconductor chip and an external device. Terminal,
23 is a screw for fixing the plate terminal 22 to the case 21;
Is a stopper provided on the case 21 in a projecting shape, and regulates the rotation of the plate-like terminal 22.
28 is a conductive nut (screw terminal) embedded in the upper surface of the case 21, 27 is a hole formed in the plate-like terminal 22, and 30 has a conductive wiring pattern on the upper main surface. An electrically insulating insulating substrate, 29 is a lower end surface of the plate-like terminal 22 joined to the wiring pattern, 31 is a heat sink bonded to a lower main surface of the insulating substrate 30, and 32 is mounted on an upper main surface of the insulating substrate 30. Semiconductor chip 33, silicone gel,
34 is an epoxy resin.

The case 21 has a cylindrical shape, and its lower end is attached to the outer peripheral edge of the heat sink 31. As a result, the case 21 houses the semiconductor chip 32 therein. The case 21 further has a protruding portion whose upper end protrudes in the inner circumferential direction. The nut 28 is embedded in the upper surface of the projection. The upper side surface (outer side surface) of the nut 28 is located on the same plane as the upper surface, and is exposed to the outside.

Since the hole 27 provided in the plate-like terminal 22 is located opposite to the female screw hole of the nut 28 opened on the upper surface of the case 21, a conductive bolt (not shown) penetrates the hole 27. Then, by screwing to the nut 28, the electrode (not shown) of the external device and the plate-like terminal 22 are connected.
Can be concluded.

The plate-like terminal 22 is fitted and attached to a projection at the upper end of the case 21. FIG.
It is a perspective view of. As shown in FIG. 4, the plate-shaped terminal 22 has a “U-shaped” fitting bent portion on the upper portion, and this bent portion fits on the inner peripheral side of the protrusion of the case 21. In addition to the hole 27, the plate-shaped terminal 22 has a hole 42 for positioning in the vertical direction.
And a hole 43 for screw fixing. Plate terminal 22
Is fixed to the protrusion of the case 21 by the screw 23 (FIGS. 1 and 3) penetrating the hole 43. The position of the upper part of the plate-like terminal 22 is regulated by fitting the hole 42 into a small protrusion (FIG. 1) provided on the inner side surface of the protrusion of the case 21.

As shown in FIG. 4, a "V-shaped" cutout 44 is formed in the plate-shaped terminal 22 so as to open in the same direction as the direction in which the "U-shaped" fitting bent portion opens. I have.
This notch 44 is formed by a stopper 24 provided on the bottom surface of the projection of the case 21, that is, a small wedge-shaped projection (FIG. 3).
Abut. When the notch 44 comes into contact with the stopper 24, the rotation of the plate-like terminal 22 in the horizontal plane with the screw 23 as a fulcrum is regulated. An S-vent (S-shaped) bent in an “S-shape” is provided below the fitting bent portion of the plate-like terminal 22.
A bent portion 45 is formed. This S vent 45
Are formed for the purpose of absorbing thermal deformation of the plate-like terminals 22 caused by the operation of the device, thereby preventing unnecessary thermal stress from being applied to a semiconductor chip or the like.

As described above, in the apparatus of this embodiment, the case 21 has a cylindrical shape with both ends opened, and the plate-like terminal 22 is fixed by fitting into the cylindrical case 21. . Therefore, before the plate-like terminal 22 is attached to the case 21, a predetermined bending process can be performed on the plate-like terminal 22 in a single state. As a result, the plate terminals 22
Can be easily processed and the processing accuracy can be improved.
Furthermore, since the springback which is inevitable in the conventional device can be eliminated, the problem associated with the springback is also solved. Further, the rotation of the plate-like terminal 22 is restricted by the contact between the stopper 24 and the notch 44 and the like, and the plate-like terminal 22 can be fixed to the case 21 with only one screw 23. It can be easily incorporated into That is, the apparatus 100 of this embodiment has an advantage that the manufacturing process can be simplified and the accuracy of the product can be improved.

The semiconductor device 100 can be manufactured in the following manner. First, an insulating substrate 30 having a wiring pattern disposed on an upper main surface thereof, a case 21 having a nut 28 embedded therein, a case 21 processed into a predetermined shape, and the like are prepared in advance. Next, circuit components such as the semiconductor chip 32 are mounted on the upper main surface of the insulating substrate 30. Subsequently, a heat sink is bonded to the lower main surface of the insulating substrate 30. The plate-like terminal 22 is fitted to the projecting portion of the case 21, and is fixed with the screw 23. Next, the lower end of the case 21 is fixedly attached to the outer peripheral edge of the heat sink 31. Before or after this, the lower end surface 29 of the plate-like terminal 22 is joined to the wiring pattern on the insulating substrate 30. Thereafter, a silicone gel 33 is applied to the upper main surface of the insulating substrate 30 so as to cover circuit components such as the semiconductor chip 32. Next, the epoxy resin 34 is applied to the case 2
1 is filled. Through the above steps, the semiconductor device 1
00 is completed.

In this manufacturing method, since the plate-like terminal 22 is processed into a predetermined shape in advance and then attached to the case 21, the problem associated with springback as described above is solved. Further, in this method, since the plate-like terminal 22 is attached to the case 21 by fitting and is fixed with only one screw 23, the process is simple.

<Second Embodiment> FIG.
However, the present invention is not limited to the above. For example, even if a plate-like terminal 22a having the shape shown in FIG. 5 is used, the same effect as described above can be obtained. In the plate-like terminal 22a shown in FIG. 5, the hole 62, the hole 63, the notch 64, and the S vent 65 are respectively provided in the hole 42, the hole 4 in the plate-like terminal 22.
It functions similarly to 3, notch 44, and S vent 45.

Instead of fixing the plate-like terminal with one screw 23, for example, two screws may be fixed to two places on the bottom surface of the projection of the case 21. In this case, since the rotation of the plate-like terminal 22 is regulated by these two screws, the cut 44 and the stopper 24 may not be provided.

<Third Embodiment> In the above embodiment, the upper surface of the nut 28 is located on the same plane as the upper surface of the case 21. However, the upper surface of the nut 28 projects above the upper surface of the case 21. The nut 28 may be embedded in the case 21 so as to perform the operation. In this case, there is an advantage that the contact between the plate terminal 22 and the nut 28 is reliably performed.

<Fourth Embodiment> In the "U-shaped" fitting bent portion of the plate-shaped terminal 22, for example, the plate-shaped terminal is previously set so that the right-angled bent portion of the "U-shaped" has a somewhat acute angle. 22 can be processed in advance. In this case, the plate-like terminal 22 is press-fitted to the projection of the case 21 by the elastic biasing force of the fitting bent portion. For this reason, when the plate-like terminal 22 is fitted into the case 21, the plate-like terminal 22 is
Therefore, there is an advantage that workability in the manufacturing process of the device is improved.

[0030]

<Effect of the Invention> According to the semiconductor device of the present invention, the plate-like terminal is processed into a predetermined shape in a unitary state before the plate-like terminal is attached to the cylindrical case. be able to. For this reason, first, since the springback can be eliminated, the joining property between the plate-shaped terminal and the screw terminal is improved. As a result, excessive heat generation at this joint can be prevented. Second, since the processing of the plate-shaped terminals can be mechanized, the positional accuracy can be easily increased. Third, the processing is easy, and the annealing process can be mechanized. Therefore, the number of manufacturing steps is reduced, and the manufacturing cost is reduced accordingly. Fourth,
Since bending is not required after attaching the plate-shaped terminal to the cylindrical case, unnecessary stress is not added to the cylindrical case, and therefore there is no danger of damaging the cylindrical case. Improvements, resulting in a further reduction in manufacturing costs.

<Effect of the invention according to claim 2> Since the outer end surface of the screw terminal protrudes from the surface of the upper end portion of the cylindrical case, the contact between the plate terminal and the screw terminal is reliably performed. It works.

<Effect of the Invention> Since the movement of the plate terminal is prevented by the action of the stopper, the positional accuracy between the plate terminal and the screw terminal is improved. In addition, the stopper merely comes into contact with the stopper, and does not require screwing or the like for rotation control, so that the manufacturing process of the device can be simplified.

<Effect of the invention according to claim 4> When the plate-like terminal is fitted into the cylindrical case, the plate-like terminal does not come off from the cylindrical case due to the action of the elastic urging force, and thus does not fall off. Workability in the manufacturing process of the device is improved.

<Effect of the Invention According to Claim 5> In the manufacturing method according to the present invention, before the plate-like terminal is attached to the cylindrical case, a plate-like terminal that has been subjected to a predetermined bending process in a single state is prepared. Is done. Therefore, the bending accuracy of the plate-shaped terminal is good. In addition, since the attachment of the plate-like terminal to the cylindrical case is realized by fitting the plate-like terminal into the projection, there is an effect that the device can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of the apparatus according to the embodiment of the present invention.

FIG. 3 is a bottom view of the inside of the apparatus according to the embodiment of the present invention.

FIG. 4 is a perspective view of a plate terminal according to the embodiment of the present invention.

FIG. 5 is a perspective view of a plate-like terminal according to another embodiment of the present invention.

FIG. 6 is a front sectional view of a conventional device.

FIG. 7 is a partially enlarged front sectional view of a conventional device.

FIG. 8 is a front sectional view of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Case (tubular case) 22 Plate-shaped terminal 23 Screw 24 Stopper 28 Nut (Screw terminal) 27 Hole 30 Insulating board 29 Lower end surface of plate-shaped terminal 31 Heat sink 32 Semiconductor chip

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 23/48 H01L 25/07 H01L 25/18

Claims (5)

(57) [Claims] 1. An electrically insulating insulating substrate having a wiring pattern on an upper main surface and having a semiconductor chip mounted thereon, and a heat radiator bonded to a lower main surface of the insulating substrate to dissipate heat loss in the semiconductor chip. A plate, a tubular case having a lower end attached to an outer peripheral edge of the heatsink and surrounding the semiconductor chip, and having a protruding portion having an upper end protruding in an inner circumferential direction; A female screw hole is opened on the surface of the portion, and a conductive screw terminal having an outer end surface exposed on the surface of the upper end portion, and a fitting bent portion, and the fitting bent portion is fitted to the protrusion. And an S-shaped bent portion between the fitting bent portion and the insulating substrate, one end of which abuts the outer end surface of the screw terminal, and the other end surface of which is joined to the wiring pattern. And a plate terminal of Semiconductor device. 2. The semiconductor device according to claim 1, wherein an outer end surface of said screw terminal protrudes from a surface of said upper end portion. 3. The semiconductor device according to claim 1, further comprising a stopper that restricts a fitting position of the plate-shaped terminal to the protrusion by making surface contact with a peripheral end surface of the plate-shaped terminal. 4. An elastic urging force of the fitting bent portion,
The semiconductor device according to claim 1, wherein the fitting is a press fitting. 5. A step of preparing an electrically insulating insulating substrate having a wiring pattern disposed on an upper main surface thereof, wherein the upper end portion has a projection projecting in an inner circumferential direction, and a female surface is provided on a surface of the upper end portion. A step of preparing an electrically insulating tubular case in which a conductive screw terminal having a screw hole opened and an outer end surface exposed on the surface of the upper end portion is embedded in the upper end portion; When the fitting bent portion is fitted to the protrusion, the upper end surface contacts the outer end surface of the screw terminal, and the lower end surface contacts the wiring pattern, and the lower end surface and the fitting bent portion. A step of preparing a conductive plate-like terminal having an S-shaped bent portion with the portion; a step of mounting a semiconductor chip on an upper main surface of the insulating substrate; and a heat sink on a lower main surface of the insulating substrate. The step of bonding, and the plate on the protrusion of the cylindrical case. Fitting the terminal and fixing the terminal; fixing the lower end of the cylindrical case to the outer peripheral edge of the heat sink so that the cylindrical case surrounds the semiconductor chip; Joining the lower end face to the wiring pattern.