JPS606542B2 - Manufacturing method of hermetically sealed body - Google Patents

Description

Detailed Description of the Invention [1' Field of Application of the Invention This invention uses an eyelet having an electroless scale nickel plating layer formed on its surface to hermetically seal at least glass inside the eyelet, and at the same time seals the outside of the eyelet. The present invention relates to a method of manufacturing an airtightly sealed body in which another metal member is brazed to the body.

More specifically, the present invention relates to a method of manufacturing a stem for a semiconductor device, in which a lead wire is hermetically and insulatively sealed inside an eyelet via glass, and a copper stem substrate or a heat sink is brazed to the outside of the eyelet. '2i Prior Art As a stem for a semiconductor device such as a power transistor for high power use, there is a structure shown in FIGS. 1 and 2.

In the figure, 1 is a steel stem board, which has mounting holes 2, 2 at both longitudinal ends for fixing to heat dissipation fins, etc., an annular groove 3 for fixing a welding ring, and an eccentric groove in the annular groove 3. It has through holes 4, 4 for eyelet competition at the positions. 5,5
is an iron eyelet which is iron-fitted and brazed to the through holes 4, 4, and lead wires 7, 7 are hermetically and insulatively sealed in the eyelets 5, 5 via glasses 6, 6. .

8 is an iron welding ring brazed to the annular groove 3.

Conventionally, this type of stem has been manufactured as follows.

First, an airtight state is manufactured in which the lead wire 7 is hermetically and insulatively sealed inside the eyelet 5 through the glass 6. This airtight terminal is iron-fitted to the through holes 4, 4, a welding ring 8 is inserted into the annular groove 3, and an annular silver solder is placed around each eyelet 5, 5 and around the welding ring 8, and the whole The silver solder was heated to melt each silver solder, and the eyelets 5 were soldered to the stem substrate 1, and the welding ring 8 was soldered to the annular groove 3. However, such a manufacturing method requires a heating process for glass sealing to manufacture an airtight terminal and a heating process for brazing silver soldering, which increases the number of processes and increases processing costs. In addition, since the heating process for glass sealing and the heating process for brazing have different operating temperatures, separate heating furnaces are required, leading to an increase in equipment costs. Therefore,
An electroless nickel plating layer with a thickness of about 20 mm is formed on the surfaces of the eyelets 5, 5 in advance, and the eyelets 5
, 5 into the through holes 4, 4, and temporarily fixed by caulking from the bottom side, using a graphite sealing jig,
Glass tablets are inserted into the eyelets 5, 5, lead wires 7, 7 are placed through the glass tablets, and an electroless film with a thickness of about 20 mm is also placed on the surface of the annular groove 3. By inserting and arranging the welding ring 8 on which a nickel plating layer has been formed and heating the whole, the glass tablet is melted, and the glass tablets 6, 6 are attached to the eyelets 5, 5.
At the same time, the electroless nickel plating layer on the surface of the eyelets 5, 5 and welding ring 8 is melted to connect the eyelets 5, 5 and welding ring 8 to the stem board. 1 has been proposed.

According to such a manufacturing method, glass sealing and brazing can be performed at the same time in a single heating process, which has the advantage of significantly reducing manufacturing man-hours and lowering equipment costs.

However, according to such a method, the third
As shown in the figure, a phosphorous-containing nickel brazing layer 9 to which an electroless nickel plating layer is welded is interposed at the sealing interface between the eyelet 5 and the glass 6, thereby improving the sealing properties between the eyelet 5 and the glass 6. A new problem arises in that the glass 6 tends to fall off the eyelet 5 during an impact test because the airtightness deteriorates and the sealing strength is weak. In order to solve these problems, it is conceivable to form an electroless nickel plating layer only on the outer surface of the eyelet 5, but partial plating is very complicated and the above-mentioned advantages are offset. Put it away.

[3'Object of the Invention Accordingly, the main object of the present invention is to provide a method for manufacturing an airtight sealed body in which at least glass is sealed within the airlet of this type and at the same time other metal members are brazed to the outside of the airt. An object of the present invention is to provide a method for producing an airtightly sealed body in which the thickness of a wax layer inside an eyelet can be made sufficiently thin without using a partial plating method.

'4} General Description of the Invention To summarize, the present invention provides at least one step on the inner wall surface of the airlet, forms an electroless nickel plating layer on the entire surface, and performs glass sealing as in the conventional method.

By performing this at the same time as soldering, when the electroless nickel plating layer melts, the molten brazing material aggregates at the step part due to surface tension, and the thickness of the remaining brazing layer becomes thinner. The present invention is characterized in that it improves the sealing properties between the eyelet and the glass, and improves the sealing strength and impact resistance. {5- Embodiments The above objects and other objects and features of the present invention will become more apparent from the detailed description given below with reference to the drawings.

FIG. 4 is a plan view of the stem for a semiconductor device of the first embodiment manufactured by the manufacturing method of the present invention, and FIG.
FIG. 6 is a vertical sectional view taken along the line V-V in the figure, and FIG. 6 is an enlarged vertical sectional view of the main part of FIG. 5.

The feature of this embodiment is that an eyelet ring 10 is formed by integrally press-molding iron eyelets 5, 5 and an iron welding ring 8, and step portions 51, 51 are formed on the inner wall surface of the lower end of the eyelets 5, 5. It is. Since the other parts are the same as those in FIGS. 1 and 2, the same parts are given the same reference numerals and the explanation thereof will be omitted. Next, the manufacturing method will be described. First, an eyelet ring 10 is manufactured in which the eyelets 5, 5 and the welding ring 8 are integrated, and which has stepped portions 51, 51 on the inner wall surface of the lower end of the eyelets 5, 5. An electroless nickel plating layer having a thickness of about 20 mm is formed on the surface.

The eyelets 5, 5 of the eyelet ring 10 are fitted into the through holes 4, 4 of the stem substrate 1, and fine powder of sealing glass is inserted into the eyelets 5, 5 using a sealing pick made of graphite. A press-molded and bonded glass tablet is inserted, and the lead wires 7, 7 are passed through the glass tablet.
The whole body is heated for about 1 hour in a neutral or weakly reducing atmosphere.
Heat to 000°C. Then, the glass tablet melted and the lead wires 7, 7 were hermetically and insulatively sealed to the eyelets 5, 5 via the glasses 6, 6, and the electroless scale nickel plating layer on the surface of the eyelet ring 10 melted. Eyelets 5, 5 and welding ring 8 by brazing metal
is hermetically soldered to the stem substrate 1. By the way, if the step portions 51, 51 are formed on the inner wall surfaces of the eyelets 5, 5, when the electroless scale nickel plating layer on the surface melts, the molten brazing material will bend to the corners of the step portions 51, 51 due to surface tension. agglomerates into Therefore, the thickness of the wax layer 91 on the inner wall surface of the eyelets 5, 5 becomes sufficiently thinner than the wax layer 92 on the outer wall surface, and the sealing property between the eyelets 5, 5 and the glasses 6, 6 is improved. In other words, impact resistance is improved. Note that when the eyelets 5, 5 and the welding ring 8 are integrally press-molded as in this embodiment, not only the material utilization rate of the press-molding is improved, but the number of parts is reduced, and the transparency of the eyelets 5, 5 is reduced. The iron joints to the holes 4, 4 and the positioning of the welding ring 8 can be done at the same time, and the caulking process between the stem board 1 and the eyelets 5, 5 can be omitted, which reduces assembly processing costs, reducing costs. is also possible.

Furthermore, by fitting the airlets 5, 5 into the through holes 4, 4 of the stem base plate 1, the positioning of the welding ring 8 can be automatically performed. The annular groove 3 is also no longer necessary, the press mold of the stem substrate 1 is simplified, and the cost can be further reduced. Furthermore, the stepped portions 51, 51 do not necessarily have to be perpendicular to the inner wall surface of the eyelet.

Next, specific examples will be described.

1 Plating thickness variation test As shown in Figures 4 and 5, the eyelets 5, 5 and the welding ring 8 are integrally molded, and the outer diameter of the eyelets 5, 5 is on the 6.6 side, and the inner diameter is on the 6.6 side. By using an eyelet ring which is not according to the present invention and has no stepped portion on the inner wall surface of the lower end with ◇ on the 3 side, and an eyelet ring according to the present invention which has stepped portions 51, 51 of 0.5 mm on the inner wall surface of the lower end, An electroless nickel plating layer of a predetermined thickness was formed on the surface, and a stem for a semiconductor device was manufactured by the same method as described above, and the thicknesses of the wax layers 91 and 92 on the inner and outer surfaces of the eyelets 5 and 5 were measured. The results shown in the table below were obtained.

The reason why the thickness of the solder layer after sealing and brazing decreases compared to the initial electroless nickel plating thickness on both the inner and outer wall surfaces is because the molten brazing material invades the grain boundaries of the eyelet. This is because the wax layer on the inner wall surface is thinner than the wax layer on the outer wall surface because the wax layer on the inner wall surface is pressed by the molten glass and the eyelet 5,
This is because they are attracted to the brazing material at the interface between 5 and the stem substrate 1.

Airtightness Test and Shock Resistance Test When 100 stems for semiconductor devices were manufactured for each thickness of the electroless scale nickel plating layer and an airtightness test was conducted, no particular difference was observed.

In addition, after conducting the airtightness test, we dropped a 15-meter weight in the axial direction of the lead wire 7 from a height of 1 m to check the number of times airtightness failures occur, and the number of times the airtightness failure occurrence rate exceeds 50%. When we conducted an impact resistance test, we obtained the results shown in the table below.

FIG. 7 shows an enlarged vertical cross-sectional view of a main part of a stem for semiconductor bag counterfeiting according to another embodiment of the present invention.

A feature of this embodiment is that stepped portions 52, 52 are formed at the center of the inner wall surfaces of the eyelets 5, 5 in the height direction.
In the case of this embodiment, agglomeration of the molten brazing material occurs at both the upper and lower corners of the step portions 52, 52, and the thickness of the brazing layer 91 on the inner wall surfaces of the eyelets 5, 5 becomes even thinner, resulting in a more excellent effect. can get. FIG. 8 shows a longitudinal sectional view of a stem for a semiconductor device according to still another embodiment of the present invention. In this embodiment, the present invention is applied to a stem having the structure shown in FIGS. 1 and 2, and the eyelet 5,
Step portions 51, 51 are formed on the inner wall surface of the lower end of 5. In this embodiment as well, step portions 52, 52 may be formed at the center portions of the eyelets 5, 5 in the height direction, as in FIG. FIG. 9 shows a plan view of a stem for a semiconductor device according to still another embodiment of the present invention, and FIG. 10 shows a longitudinal sectional view taken along the line X--X in FIG. 9. In the figure, reference numeral 11 denotes an iron flange, which has mounting holes 12, 12 at both ends in the longitudinal direction for attaching heat radiating fins, etc., and a round hole 13 for assembling a heat radiating plate in the center. Reference numeral 14 denotes a heat sink made of copper, which is brazed to the round hole 13 and has through holes 15, 15 at eccentric positions for forming eyelet formations.

Reference numerals 16 and 16 indicate iron eyelets that are brazed to the through holes 15 and 15, and these eyelets 16 and
Lead wires 18, 18 are inserted into the inside of the glass 17, 17 through the glasses 17, 17.
is sealed in an airtight and insulating manner.

Here, on the inner wall surface of the lower end of the eyelets 16, 16, a fifth
Step portions 51, 51 are formed similarly to the figure. Next, the manufacturing method will be explained.

First, an electroless nickel plating layer with a thickness of about 20 mm is formed on the surfaces of the flange 11 and the eyelets 16, 16, and the heat sink plate 14 is iron-bonded to the round hole 13 of the flange 1. After joining the eyelets 16, 16 to the eyelets 15, 15 and temporarily fixing them by caulking the respective iron parts, insert the glass tablet into the eyelets 16, 16 using a sealing tool made of graphite. , the lead wires 18, 18 are inserted into the glass tablet and heated under the same conditions as described above. Then, the glass tablet melts and the lead wires 18, 18 are hermetically and insulatively sealed to the eyelets 16, 16 via the glasses 17, 17, and the electroless scale nickel plating on the surfaces of the flange 11 and the eyelets 16, 16 is completed. The flange amount 1, the heat sink 14, the eyelet 16,
16 are brazed together. In this embodiment as well, the same effect as described above can be obtained by causing the step portions 51, 51 to aggregate the molten brazing material. Incidentally, in the above embodiments, the stem for a semiconductor device was explained.
It can also be applied to the production of other hermetically sealed bodies, and in particular to the production of hermetic windows, etc., in which transparent glass plates without lead wires are hermetically sealed within the eyelet.

'6' Summary As described above, in this invention, the inner wall surface of the eyelet forms at least one step, an electroless nickel plating layer is formed on the surface, at least glass is disposed inside the eyelet, and the outer wall surface of the eyelet is formed with at least one step. By placing another metal member on the surface and heating it, the glass is sealed inside the eyelet, and at the same time, another metal member is brazed on the outside of the eyelet, so the electroless nickel plating layer is melted. The solder material aggregates at the corners of the step and the thickness of the solder layer on the inner wall of the eyelet becomes thinner, improving the sealing strength between the eyelet and the glass and improving the impact resistance between the eyelet and the glass. do.

Furthermore, compared to a method in which only the outer surface of the eyelet is partially plated, the workability is very good and it is suitable for mass production.

[Brief explanation of drawings]

FIG. 1 is a plan view of a conventional stem for a semiconductor device, FIG. 2 is a longitudinal sectional view taken along the Rolo line in FIG. 1, and FIG. 3 is a stem for a semiconductor device manufactured by the manufacturing method that is the background of the present invention. FIG. 4 is a plan view of a stem for a semiconductor device according to an embodiment of the present invention, and FIG.
The figure is a vertical sectional view taken along the line V-V in FIG. 4, FIG. 6 is an enlarged vertical sectional view of the portion shown in FIG. 5, and FIG. 7 is a stem for a semiconductor device according to another embodiment of the present invention. FIG. 8 is a vertical cross-sectional view of still another stem for a semiconductor device manufactured according to the present invention, and FIG. 9 is a vertical cross-sectional view of still another embodiment of the stem for a semiconductor device manufactured according to the present invention. FIG. 10 is a vertical sectional view taken along the line X--X in FIG. 9. 1, 14...Other metal parts (stem board, heat sink)
, 5, 16...eyelet, 51, 52...stepped portion, 6,
17...Set glass, 7,18...Lead wire,
8...Welding ring, 91, 92...Raw layer, 1
0... Eyelet ring, 11... Flange. Younger brother '1 Gensei zl Single younger brother 3 figure 4 Younger brother Ta figure 3 figure Purple 7 figure 8 Ax q figure Younger brother' River Gen

Claims (1)

[Claims] 1. An electroless nickel plating layer is formed on the surface of an eyelet having at least one step on the inner wall surface, at least a sealing glass is disposed inside the eyelet, and other metal members are placed outside the eyelet. The method is characterized in that the sealing glass is melted and sealed to the eyelet by placing and heating the sealing glass, and at the same time, the electroless nickel plating layer is melted and the eyelet and other metal members are brazed together. Method for manufacturing a sealed body. 2. The hermetically sealed body according to claim 1, wherein the sealing glass is a glass tablet formed by press-molding fine glass powder, and a lead wire is further disposed through the glass tablet. Production method. 3. The air vent according to claim 1 or 2, wherein the eyelet is made of iron, the other metal member is a stem substrate made of copper, and an iron welding ring is further brazed to the stem substrate. Method for manufacturing a sealed body. 4. The eyelet and the welding ring are integrally formed.
A method for manufacturing a hermetically sealed body according to claim 3. 5. Manufacturing the hermetically sealed body according to claim 1 or 2, wherein the other metal member is a copper heat sink, and an iron flange is further brazed to the outside of the heat sink. Method.