JPS5834951A - Manufacture of double heat sink type semiconductor device - Google Patents

Abstract

PURPOSE:To enable mass production, by pinching a mount body wherein electrode surfaces on both surfaces of a semiconductor element are sandwiched between a pair of flat electrode plates serving as heat sinks by a mold retainer and exfoliating the retainer after molding. CONSTITUTION:A mount body 17 wherein both electrodes 12a, 12b of the diode element 12 are junction-fixed in a sandwich form between a pair of flat plate electrodes 13, 14 serving as heat sinks is tightly fixed in a plurality with clearances between mold retainers 18, 21. The clearances between the retainers 18, 21 are filled with a molded resin member 16 resulting in an integral body. The mold reatiners 18, 21 are exfoliated and cut-separated for every element. Thus, a mounting on a printed substrate or the handling is facilitated resulting in mass production.

Description

[Detailed Description of the Invention] This invention relates to a method for manufacturing a molded semiconductor device, particularly a semiconductor device with a double heat sink structure in which heat sinks are disposed on both sides of a semiconductor element with a two-terminal structure such as a diode or a rectifier, and heat is dissipated from both electrode surfaces. (Regarding.

Conventionally, diodes and rectifiers are small, have excellent heat dissipation characteristics, and have a relatively large current capacity, so the DHD structure in which electrode plates are attached to both sides of the element electrode has been the mainstream. For example, FIG. 1 is a cross-sectional view of this kind of DHD type glass-sealed diode 1, in which both electrodes 2a and '2b of the diode element 2 are connected to a pair of lead conductors 3 made of Dumet material.
．． 8, and the glass tube 4 covers the periphery thereof and is sealed on the side surface of the outlet conductor 8. A pair of lead wires 5, 5 are welded to the outside of the outlet conductor 8.

The heat generated inside the diode element 2 is transferred to the large diameter outlet conductor 8.
It is configured to lead out to both sides of the element through the tube. By the way, in order to mount such a diode 1 on a printed circuit board or the like, the lead wires 5 are molded to match the pitch of the mounting holes of the printed circuit board, and the molded lead wires 5 are attached to the printed circuit board. This is done by inserting elastically into the mounting hole and then soldering, but this is a complicated process and requires a large amount of man-hours. For this reason, as shown in FIG.
. (DHD type diode application number 51-118208 August 2, 1973
8) This diode 9 is connected to the large diameter portion 7 of the outlet conductor 8.
Since it is plate-shaped and does not use a lead wire 5 that is easily bent like the diode described above, it is easy to handle and has excellent effects such as being able to apply automation to the mounting of printed circuit boards.

However, even though Dionide 9 has such excellent characteristics in terms of use, in terms of manufacturing, it becomes difficult to manufacture the Hiji conductor 8 which has a small diameter part 6 and a large diameter part 7, and to perform glass sealing work. There were drawbacks. That is, the sunrise conductor 8 is obtained by joining a small-diameter cylindrical Dumet part and a large-diameter plate-like part by welding or the like, but it is difficult to obtain one with a predetermined dimensional accuracy. Further, the glass sealing work is carried out by using a carbon jig or the like to align and mount the sealing parts such as the diode element 2, the lead conductor 8, and the glass tube 4, and then heat and melt the glass tube 4 at a high temperature. However, mounting the irregularly shaped sun conductor 8 takes many minutes and increases the number of man-hours, making it expensive, and it is difficult to obtain a semiconductor device with a double heat sink structure that satisfies both manufacturing and usage aspects. It has not been done.

The present invention has been proposed in view of the above points, and provides a method for manufacturing a semiconductor device with a double heat sink structure that is easy to attach to a printed circuit board and handle, and can be mass-produced at low cost.

The semiconductor device according to the present invention is mounted in a sandwich structure between a pair of flat electrode plates, with the electrode surface formed on the main surface of the semiconductor element serving as a heat sink. The mount body in which the semiconductor element is fixed between these electrode plates is one in which the main parts of the semiconductor element and both electrode plates except for the outer end surfaces are covered with a molding material. Since it uses a plate, manufacturing is extremely easy, and
Since the chip structure does not use thin lead wires, excellent effects such as ease of use of the semiconductor device can be obtained. A semiconductor device having such a structure is manufactured through at least the following steps. That is, 1. a semiconductor element mounting step in which the electrode surfaces formed on both main surfaces of the semiconductor element are fixed between a pair of electrode plates; 2. a plurality of mount bodies to which the semiconductor element is fixed are mounted on both sides of each electrode plate; 8. Covering the outer end surface of the electrode plate by placing the main surface of the mount body in close contact with a holder, for example, a pair of bases, the main surface of which is larger than the electrode plates; 8. Covering the end surface of the electrode plate; a step of filling a mold member into the gap between each mount body of the holder and integrally molding the semiconductor element and the electrode plate, 4 a step of solidifying the filled mold member, 5
a step of removing the solidified layer of the mold member and the set of bases from the end faces of the pair of electrode plates, and 6 a step of cutting and separating the solidified mold member between semiconductor elements to obtain individual semiconductor devices. The electrode member, which serves as a pair of heat sinks that fixes both electrode surfaces of the semiconductor element,
The double electrode has excellent features in terms of both manufacturing and use, such as using a flat electrode member that is easy to manufacture, and being a mold type, making the sealing work easier and easier to mass-produce than conventional glass-sealed types. A semiconductor device having a heat sink structure can be manufactured inexpensively and efficiently.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 shows an embodiment of a semiconductor device having a double heat sink structure obtained by the method of the present invention, in which a resin-sealed type 81 diode 11 is shown. In 1-1, 12 is a diode element with a planar structure, and although not shown on both main surfaces, an anode electrode 12a1 and a cathode electrode 12b corresponding to the internal P-N junction are made of metal with good ohmic contact, such as Au, It is formed by Aq vapor deposition or the Nobuki method. 13 and 14 are these two electrodes 1272,
12b, each of which is a flat plate electrode bonded with a solder material 15 such as silver paste, serves as an electrode lead-out terminal of the element 12 and a heat sink. 16 is the element 12 and the flat electrode 18.1
This is a molded member made of epoxy resin or the like, which covers the main parts of 4 except for the outer end surfaces 13a and 14a. In the diode 11 having such a structure, the element 12 is sandwiched between a pair of flat plate electrodes 18 and 14, and the heat generated inside the element 12 is transferred to both sides through these flat plate electrodes giA13 and 14. The heat is radiated to .In addition, a pair of flat plate electrodes F!i!, 18,1
Since the outer end surfaces 1112, 14a of 4 are exposed and sealed with resin, these end surfaces 18a, 14a can be attached to conductive lands of a printed circuit board, etc. (not shown) by soldering, etc., without using leads. Since it has a chip structure, it is easy to handle.

Next, a method of manufacturing the 81 diode 11 having the above structure will be described. First, as shown in FIG.
Both electrodes 12a and 12b of 2 are connected to a pair of flat electrodes 18.14.
They are joined and fixed in a sandwich manner with a solder material 15 such as Ap paste interposed therebetween.

Although not shown, the diode element 12 can be easily attached to the flat plate electrode 18.14 using a conventional semiconductor mounting apparatus, such as a method of passing the diode element 12 through a conveyor furnace using a carbon jig or the like. Further, as the solder material 15 to be used, a solder material having good adhesion to the A9 paste conductor element 12 and the flat plate electrodes 18, 1.4, such as gold-tin solder or silver complex solder, can be used. Next, both sides of the semiconductor element 12% 12
As shown in FIG.
A plurality of side outer end surfaces 14a are fixed to the flat base 18 using an adhesive 19 or the like at predetermined intervals. As the adhesive 9, a resinous adhesive is used which has enough adhesive strength to sufficiently cover the electrode end face 14a during molding of the semiconductor element 12, which will be described later, and which can be easily peeled off after assimilation of the mold member. Further, 20 is a partition plate provided between each mount body 17 of the flat base 18, which, although not necessarily necessary, facilitates cutting and separation after the mold member has solidified. Next, the electrode end surface 13a of the flat base 21 is similarly tightly fixed from above the other flat electrode 13 using the adhesive 19. That is, the flat bases 18 and 21 are connected to the respective electrode end surfaces 1412 . j8a is a mold holder for the mount body 17 to which the mount body 17 is closely fixed, and it is not necessarily necessary to fix it to this as a flat base with adhesive. Any structure may be used as long as the electrode end faces 14a and 13a of the mount body 17 are covered.

Next, both electrode plates 18.14 are attached to the flat plate base 18 in this way.
．． As shown in FIG. 6, a plurality of mount bodies 17, which are fixed between the two bases 18 and 21 and whose outer end surfaces 13a and 14a of both electrodes are covered, are filled with epoxy,
Mold member 1 made of resin material such as silicone or glass material
6, the semiconductor element 12 and both-handed plate electrodes 13 and 14 are integrally molded. Mold member 1
Various methods such as a dip method, a spray method, and an injection method are used for filling the electrodes 18 and 14.
, 14a are covered with a base 18.24, so that this part is not covered with the molding member 16. Next, after solidifying the mold member 16 at a predetermined temperature, the molded mount body 17 is immersed in a cleaning solution for the adhesive 19. As shown in FIG.
At the same time as the electrodes are removed from the flat electrodes i13 and 14, the adhesive 19 is peeled off and the outer end surfaces laa and 14a of the electrodes on both hands are exposed. Thereafter, by cutting and separating the mold member 16 between each element 12 as shown by the arrows, a large number of S1 diodes 11 having the double heat sink structure shown in FIG. 3 are manufactured at the same time.

Various methods such as a dicing method and a press cutting method can be used for this cutting and separation.
By providing the mold member 16 and a non-adhesive partition plate 20 in the area where one mold member 16 is to be cut, cutting and separation becomes easy. Furthermore, if the mold member 16 is filled in each individual element 12 and a gap is provided between each element 12, as shown in FIG. 8, cutting work after the mold member 16 is solidified becomes unnecessary. .

FIGS. 9 and 10 show another embodiment of the present invention, in which a flat plate electrode i13.14 of the above embodiment is provided with mounting portions for a plurality of semiconductor elements 12 serving as individual electrode plates, and these mounts. A frame body is used, which is made up of connecting parts that connect the parts, and the state after the semiconductor element 12 is mounted is shown in each frame body. That is, the frame body 22 shown in FIG. 9 has a plurality of adjacent mount parts 23 connected vertically and horizontally by connecting pieces 24, and the frame body 25 shown in FIG.
A plurality of mount parts 28 are constructed by forming vertical and horizontal grooves 27 in a wide electrode plate 26 of -, t by pressing or cutting. 28 are connected in a plate shape, which has the advantage of being easy to handle and suitable for automation. Similarly, in the frame body 22.25, the back sides of the mount parts 28 and 28, which serve as individual electrode plates, are covered by a pair of bases 18.21 (not shown), and the base '18
．． The mold member 16 is filled between the spaces 21.

After solidification, they are cut and separated, as shown in FIGS. 11 and 12, respectively.
Diode 29.8 with double heat sink structure shown in the figure
0 is obtained. These diodes 29,! 30 has a structure in which not only the outer end surface of the flat plate electrode mounting portion 28.28 is exposed from the mold member 16, but also the connecting piece 24 on the side surface and the cut surface 81 of the groove 26 are exposed, and this exposed cut surface 31 can be conveniently used for attaching printed circuit boards, etc.

As described above, the present invention fixes both electrodes of a semiconductor element between a pair of flat electrode bodies serving as a heat sink, and attaches each electrode body to the mold of each mount body. After tightly fixing the electrode body to the holder and covering the end face of the electrode body, fill the molding material between both claw stands to mold the semiconductor element and the electrode body together, and remove the cover ring after solidifying the molding material. Since the semiconductor device is constructed so as to obtain individual semiconductor devices, it is possible to provide a double heat sink type semiconductor device having a chip structure that is easy to manufacture, easy to mount on a printed circuit board, and easy to handle.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a conventional double heat sink type semiconductor device, FIG. 3 is a cross-sectional view of a double heat sink type semiconductor device according to the present invention, and FIGS. 4 to 7 are manufacturing steps shown in FIG. 3. FIG. 8 is a cross-sectional view of parts showing one embodiment of FIG. 3, and FIGS. 9 to 12 are perspective views of parts and products showing other embodiments of the present invention. 11.29.80...Double heat sink type semiconductor device, 12...Semiconductor element, 18
．． 14,22.25... Flat electrode body, 13aI
14a...End face, 16...Mold member, 17...Mount body, 18.21...Holder (base). 1st country 14 years

Claims (1)

[Claims] A plurality of semiconductor elements clamped by a pair of flat electrode bodies are spaced apart, and the pair of flat electrode bodies are brought into close contact with a holder, and a molding member is filled into the gap in the holder, so that the semiconductor elements are Manufacturing a double heat sink type semiconductor device, characterized in that a molded body is formed, the holder is removed from the pair of flat electrode bodies, and the mold member of the molded body is cut and separated between the semiconductor elements. Method.