JPS6234153B2 - - 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 compact, 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 a diode element 2 are clamped by a pair of lead conductors 3 and 3 made of a composite material. A glass tube 4 covers the periphery and is sealed on the side surface of the outlet conductor 3. Exit conductor 3
A pair of lead wires 5, 5 are welded to the outside of the
The structure is such that the heat generated inside the diode element 2 is led out to both sides of the element through the large-diameter lead conductor 3. By the way, in order to mount such a diode 1 on a printed circuit board or the like, the lead wire 5 is molded by aligning it with the mounting hole of the printed circuit board (not shown), and the molded lead wire 5 is inserted into the mounting hole of 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. Therefore, as shown in Figure 2,
a pair of outlet conductors 8 having a small diameter portion 6 and a large diameter portion 7;
8, the electrodes 2a and 2b of the diode element 2 are clamped between the end faces of the small diameter part 6, and the diode element 2 is surrounded and sealed with the glass tube 4 on the side of the small diameter part 6 of the outlet conductor 8. A shaped glass-sealed diode 9 has also been proposed. (Refer to DHD type diode application number 53-118203 dated August 28, 1973) In this diode 9, the large diameter portion 7 of the outlet conductor 8 is plate-shaped.
Since the lead wire 5, which is easy to bend as in the case of the diode, is not used, it is easy to handle and has excellent effects such as being able to automate the mounting of printed circuit boards.

However, even though the diode 9 has such excellent features in terms of use, in terms of manufacturing, it becomes difficult to manufacture the lead conductor 8 having the small diameter part 6 and the large diameter part 7, and to perform glass sealing work. There were flaws. That is, although the lead conductor 8 is obtained by joining a small-diameter cylindrical piece and a large-diameter plate-like part by welding or the like, it is difficult to obtain one with a predetermined dimensional accuracy. In addition, the glass sealing work uses a carbon jig, etc. to seal the diode element 2, the lead conductor 8, and the glass tube 4.
This is done by aligning and attaching the sealing parts such as, and heating and melting the glass tube 4 at a high temperature, but it takes a lot of time and effort to attach the lead conductor 8, which has an irregular shape, and increases the number of man-hours. For these reasons, it is expensive, and a semiconductor device with a double heat sink structure that can satisfy both manufacturing and usage aspects has not been obtained.

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, in which electrode surfaces formed on both main surfaces of the semiconductor element serve as heat sinks. 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, and the flat electrodes are attached to a pair of lead conductors. Since it uses a plate, manufacturing is extremely easy, and 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 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. 3. Covering the outer end surface of the electrode plate by tightly fixing the main surface between the holders of the mount body, such as a pair of bases, which are formed larger than the electrode plates; 3. Covering the end surface of the electrode plate; Filling the void between each mount body of the holder with a mold member,
4. Solidifying the filled mold member; 5. After solidifying the mold member, removing the set of bases from the end faces of the pair of electrode plates. The process of
and 6. Cutting and separating the solidified mold member between semiconductor elements to obtain individual semiconductor devices. The double heat sink structure has excellent characteristics in terms of both manufacturing and use, such as using a flat electrode member and being a mold type, which makes the sealing work easier and easier to mass-produce than conventional glass-sealed types. A semiconductor device can be manufactured at low cost 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 with a double heat sink structure obtained by the method of the present invention, in which a resin-sealed Si diode 11 is shown. In the figure, 12 is a diode element with a planar structure, and an anode electrode 12a and a cathode electrode 12b, which are not shown in the figure, correspond to the internal PN junction on both main surfaces.
metals with good ohmic contact, e.g.
It is formed by Au, Ag vapor deposition or plating method. 13 and 14 are these two electrodes 12a, 12
A flat plate electrode is bonded to b by a solder material 15 such as silver paste, and serves as an electrode lead-out terminal and a heat sink for the element 12. 16 is a molded member made of epoxy resin or the like that covers the main parts of the element 12 and the flat electrodes 13 and 14 except for the outer end surfaces 13a and 14a. The diode 11 having such a structure has the element 1
2 is connected between a pair of flat plate electrodes 13 and 14 in a sandwiched state, and heat generated inside the element 12 is radiated to both sides through both of these flat plate electrodes 13 and 14. Furthermore, since the outer end surfaces 13a and 14a of the pair of flat plate electrodes 13 and 14 are exposed and sealed with resin, these end surfaces 13a and 14a can be soldered to conductive lands on a printed circuit board or the like (not shown). It is easy to install and has a chip structure that does not use leads, so it is easy to handle.

Next, a method for manufacturing the Si diode 11 having such a structure will be described. First, as shown in FIG. 4, both electrodes 12a and 12b of the diode element 12 are bonded with a solder material 1 such as Ag paste between the pair of flat electrodes 13 and 14.
5, and are joined and fixed in a sanderch style.
Although not shown, the diode element 12 can be easily attached to the flat plate electrodes 13 and 14 using a conventional semiconductor mounting device, such as a method of passing the diode element 12 through a conveyor furnace using a carbon jig or the like. In addition, the soldering material 15 used is not only Ag paste but also the semiconductor element 1.
2 and the flat plate electrodes 13, 14, a solder material having good adhesion, such as gold-tin solder or silver-tin solder, can be used. Next, both electrodes 12a, 1 of the semiconductor element 12
As shown in FIG. 5, the mount body 17 in which the electrodes 2b are attached to the flat electrodes 13 and 14 is first attached to the outer end surface 14a of one of the flat electrodes 14 on the flat base 18 using an adhesive 19 or the like. Separate and fix for a specified period of time. As the adhesive material 19, the semiconductor element 1 to be described later is used.
2, a resin adhesive is used that has enough adhesive strength to sufficiently cover the electrode end face 14a and can be easily peeled off after the mold member has solidified.
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 the respective electrode end surfaces 14a and 13 of the mount body 17.
a is a holder for the mold of the mount body 17 that is closely fixed, and it is not necessarily necessary to fix it to this as a flat base with adhesive; in short, each mount body 17 is 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 13 and 14 are fixed between the flat plate bases 18 and 21 in this way, and both electrode outer end surfaces 13 and 14 are fixed between the flat plate bases 18 and 21.
As shown in FIG.
The semiconductor element 12 and both flat electrodes 1 are filled with a molding member 16 made of a resin material such as epoxy or silicone, or a glass material.
3 and 14 are integrally molded. Various methods can be used to fill the mold member 16, such as a dip method, a spray method, and an injection method.
The outer end surfaces 13a, 14a of are covered with the bases 18, 21, so that these portions are not covered with the mold 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.
is removed from the flat electrodes 13 and 14, and at the same time,
The adhesive material 19 is peeled off and the outer end surfaces 13 of both flat electrodes are removed.
a, 14a are exposed. Thereafter, by cutting and separating the mold member 16 between each element 12 as shown by the arrows, a large number of Si diodes 11 having the double heat sink structure shown in FIG. 3 are simultaneously manufactured. Various methods such as a dicing method and a press cut method are adopted for this cutting and separation.
If this is provided, cutting and separation will be facilitated. Further, the filling of the mold member 16 is performed as shown in FIG.
If this is done for each individual element 12 and a gap is provided between each element 12, cutting work after solidifying the mold member 16 becomes unnecessary.

9 and 10 show another embodiment of the present invention, in which the flat electrodes 13 and 14 of the above embodiment are provided with mounting portions for a plurality of semiconductor elements 12 serving as individual electrode plates, and mounting portions for 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 22 shown in FIG.
5, a plurality of mount parts 28 are constructed by forming vertical and horizontal grooves 27 in one wide electrode plate 26 by pressing or cutting. A large number of 23 and 28 are connected in a plate shape, which has the advantage of being easy to handle and suitable for automation. In the case where these frame bodies 22 and 25 are used, the back side of the same number of mount parts 23 and 28, which serve as individual electrode plates, is covered by a pair of bases 18 and 21 (not shown).
A mold member 16 is filled between the bases 18 and 21. After solidification, they are cut and separated to obtain diodes 29 and 30 having a double heat sink structure as shown in FIGS. 11 and 12, respectively. These diodes 29 and 30 are connected to the mounting portion 23 of the flat electrode,
A structure is obtained in which not only the outer end surface of 28 is exposed from the mold member 16, but also the connecting piece 24 on the side surface and the cut surface 31 of the groove 26 are exposed, and this exposed cut surface 31 is used for attaching a printed circuit board, etc. It is convenient to do this.

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 it to the holder and covering the end face of the electrode body, fill the space between the two bases with a molding member to mold the semiconductor element and the electrode body together, and remove the cover ring after solidifying the molding member. Since the semiconductor device is constructed so that individual semiconductor devices are obtained, 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, 30...Double heat sink type semiconductor device, 12...Semiconductor element, 13, 14, 2
2, 25... Flat electrode body, 13a, 14a...
End face, 16...mold member, 17... mount body, 18, 21... holder (base).

Claims (1)

[Claims] 1. Separate a plurality of semiconductor elements clamped by a pair of flat electrode bodies, bring the pair of flat electrode bodies into close contact with a holder, and fill the void in the holder with a molding member to remove the semiconductor elements. A method for manufacturing a double heat sink type semiconductor device, comprising forming a mold body, removing the holder from the pair of flat electrode bodies, and cutting and separating the mold members of the mold body between the semiconductor elements. .