JPS58176957A - Glass molded type semiconductor device - Google Patents

Abstract

PURPOSE:To form the titled product excellent in moisture resistance without deterioration of characteristics, noncombustible, and high in operating critical temperature by a method wherein a glass serves both as a surface stabilizing material and a molding material, then tungsten or molybdenum is used as an electrode, and a solder wherein aluminum is the main constituent is used as a solder. CONSTITUTION:Those wherein copper leads 14a and 14b provided with Ni and Sn plated metals 15a, 15b, 16a, and 16b are welded to the Mo electrodes 13a and 13b by percussion are prepared, then respectively the electrodes 13a and 13b are contacted with the Al solders 12a and 12b of an Si pellet 11 by using a jig, and accordingly formed into an integral body by being passed through a furnace. Next, a glass slurry obtained by adding water, etc. to the extremely fine powder of the glass is wound around this integral body, and then the glass is sintered as a mold glass 17 by passing through the furnace. For the mold glass 17, wherein ZnO-B2O3-SiO2 is the main constituent is used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glass molded semiconductor device, and particularly to a companion diode that uses glass to stabilize the surface of a semiconductor pellet and hermetically seal it.

Conventionally, diodes have been made using resin to stabilize the surface of the semiconductor pellet and hermetically seal it.

Figure 1 shows a conventional resin-molded diode of this type, in which 1 is a silicon pellet with a p1n structure, and electrode films 2a, 2b7 of nickel or the like are formed on the amphibodi surfaces of the silicon pellet.
the law of nature! ERF'jbfLChD, ro5. Leads 4a and 4b are connected by materials 3m and 3b. Brazing filler metal 3m, 3
For lead b, lead-1 solder or lead-tin solder combining gold or silver is used, and for leads 4g and 4b, copper is used. The leads 4m and 4b have a nail header structure to facilitate connection. The outer surfaces of the leads 4a, 4b are connected to an external circuit by solder, and the brazing metals 3a, 3b are connected to the external circuit by solder.
In order to facilitate the connection with the Crycon pellet 1,
Silver plating layers 5g and 5b are provided. In order to stabilize the surface of the silicone pellet 1, a silicone-based rubber ring or face is provided as a surface stabilizer 6 around the entire outer surface of the silicone pellet 1, and the silicone pellet 1t is sealed with epoxy resin. The silicon pellet portion and part of the lead 4m, 4b are molded with the molding material 7.

A diode with such a structure is made by, for example, diffusing a certain impurity into a silicon wafer to form a pin structure, adding gold or other metal during its lifetime as necessary, and then depositing a nickel film by vapor deposition or plating. After providing a brazing material foil, a circular pellet 1 is punched out, and a nail header portion is provided on the copper wire, and a silver plating layer is applied to the lead 4 m.

4b, and using a jig, connect the nail header part of lead 41°4b to 3m of brazing material of silicon pellet 1, 3m.
brcm*t, -crtat,, mouth 5 material 3 a.

3b connects the leads 4m and 4b to the silicon pellet 1, and then the surface stabilizing material 6 is provided, and finally, the molding material 7 is provided in a cylindrical shape using a screwdriver to complete the process.

In such a resin-molded hot-temperature semiconductor device, since organic materials are used as the surface stabilizing material 6 and the molding material 7, deterioration over time is unavoidable, and the characteristics of the next semiconductor device, especially, Electrical characteristics tend to deteriorate. The deterioration of properties is particularly noticeable in the reverse property deterioration due to moisture penetration.

Also, the organic material is combustible, 69, brazing material 3a.

Since solder is used as 3b, the limit temperature WL for use as a semiconductor device is limited to a low value, and there is also the drawback that a large current cannot flow.

An object of the present invention is to provide a glass molded semiconductor device that has excellent moisture resistance and does not suffer from deterioration in characteristics.

Another object of the present invention is to provide a glass-molded semiconductor device that is non-flammable and has a high operating temperature limit.

The present invention is characterized in that the surface stabilizing material and the molding material are made of glass.

In conjunction with the glass mold, tungsten and molybdenum are used as electrodes, and leads are welded to these electrodes, and a brazing material whose main component is aluminum is used as the brazing material.

@2 Figure shows a glass molder diode which is an embodiment of the present invention.

In Fig. 2, 11 is the silicon wafer shown in Fig. 1)
It is a circular silico/pellet with a pin structure similar to 1. Here, the term "circular" includes square pellets with rounded corners. 121° 12b is a brazing material whose main component is aluminum, and pure aluminum is used. Reference numerals 13M and 13b are molybdenum electrodes, which are obtained by sintering and cut out from rods. Electrode 13a.

13bK is made of copper. 148 and 14b are provided by welding. Steel lead 11, 14bK has a thickness of 10 to 30
Nickel plating layers 15M and 15b of xm are provided. This is provided to protect the bath contact area from the external environment since it is difficult to form an alloy layer when molybdenum and steel are melted and the welded area has poor moisture resistance. Nickel plating layer 15a
, 15b minimum thickness 10/1mti molypude/pole 13
The maximum thickness is 30 μm, which is the thickness necessary to cover the bath contact portions of j1, 13b and steel leads 14M, 14b, and the protective effect does not increase even if the thickness is increased beyond this value.

A tin plated layer 161.1-6b having a thickness of 4 to 10 .mu.m is further provided on the nickel plating layer 158.15b to facilitate soldering with an external circuit. 17 is placed from one electrode 1311 to the other electrode 13b with a special molded glass for surface stabilization and airtight sealing of the silicon pellet 11. This molded glass 17 is
A glass containing zno-B, O, -810, as a product is used. In addition to surface stabilization, the molded glass 17 must have mechanical strength, chemical resistance, wettability with the electrodes 13a and 13b, and a coefficient of thermal expansion close to that of silicon, molybdenum, and tungsten. is 69, therefore,
57-70% Zn 0.18-32% BnO by weight%
A composition having an essential component of S.sub.iO of sm7 to 13% and, if necessary, 0 to several percent of other oxides, is effective.

The thermal expansion coefficient of this glass is 7 gusts/C, and the thermal expansion coefficient of molybdenum is 40~50 x 10-'/C (50~35
0C), and the thermal expansion coefficient of silico/35
X10"'/C (30-400C)! 6 with a slightly larger value.

Next, the manufacturing method will be explained. Silicon pellets 11 are made in the same manner as the silicon pellets 1 shown in FIG. Next, there is no nickel layer, and the aluminum solder 121.12b is directly provided. On the other hand, electrode 13Ji
, nickel on 13b.

mm gold layers 151, 15b, 16m, 16b are Bff et al.
Copper leads 14a and 14b are percussion welded to 7', and a silicon pellet 1 is attached using a jig.
The electrodes 131 and 13b are brought into contact with the waxes 12M and 12b of No. 1, respectively, and the glass is passed through a furnace to be integrated again.
A glass is wrapped around this integrated product and passed through a furnace to fire the glass as a molded glass 17. The melting point of pure aluminum is 660G, and it is heated to Fd600-7SOU. When removed from the furnace, the glass molded diode shown in FIG. 2 is obtained.

The glass mold type semiconductor device of the present invention has the following advantages.

Breath and mold gas hardly change over time and have good wettability with electrodes, so they have excellent moisture resistance and hardly cause any deterioration in the characteristics of semiconductor devices.

b. It is non-flammable because no organic materials are used.
The critical temperature for enclosures has been significantly improved.

Nine, the thermal resistance of glass is lower than that of organic materials, so
Excellent heat dissipation.

C. Since the thermal expansion coefficients of the silicon pellet, electrode, and glass are almost the same, no thermal stress is applied to the silicon pellet and the glass does not break. Therefore, extremely stable properties are maintained over a long period of time.

d. When molybdenum is used as the electrode, if a nickel film is provided on the copper lead, there is almost no deterioration in the moisture resistance of the weld between the WIL pole and the lead.

e. The tensile stress applied to the WII4 lead is not transmitted to the glass, but is borne by the glass, so the silicon pellet will not be damaged by the tensile stress.

The present invention can also be implemented with the following shapes.

(a) Not one silicon pellet, but two or three silicon pellets are layered in series in the same manner as in the next step (t).

b. The brazing material is not pure aluminum brazing, but an alloy brazing of aluminum and silicon.

C, @toku is made of tungsten, this we, the nickel film 15M, 15b is not necessary to be installed at times. Nine Vhs use copper leads.

[Brief explanation of the drawing]

Figure Is1 is a vertical sectional view of a conventional register/mold diode, and Figure 2 is a vertical sectional view of a glass molded diode showing an embodiment of the present invention. 11... Silicon pellet, 1211, 12b...
Brazing material, 13J1.13b-・Electrode, 11.14b・
...Reed, 151, 15b-J Kel plating layer, lel.

Claims (1)

[Claims] 1. A crow-molded pear semiconductor device constructed as follows. a, at least one silicone pellet of the remains of pins, b) an electrode made of either tungsten or sled located on the above-mentioned silicone pellet; C, the above-mentioned silicon pellet on each main surface q!r'wt and the like; d, copper lead bath-welded to each of the above electrodes; e; provided from one electrode to the other; n; the silicon pellets mentioned above. ′
4r surface stabilization and hermetic sealing Z n O
A glass molding material whose main components are -BtO and -810x. λ In claim 1, ν, the glass is % by weight.
57-70% znot is ~32% Bt in
O,,810 of 7-13%. A glass mold guard conductor device having a composition consisting of: λ % Eaves Claim W In paragraph 1, 9, the steel lead has a thickness of lO~30. A glass mode semiconductor device provided with a nickel layer of mm. 4% Permissible The glass mold type semiconductor device according to claim 3, wherein a tin layer (4 to 104 mf thick) is provided on the nickel layer.