JPS6212187A - Soldering of lead - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for brazing lead wires to a metal substrate such as a stem substrate.

Conventionally, brazing of two parts has been carried out in various fields, and as a specific example, the brazing of the ground lead wire of a SAW stem will be described below with reference to Figs. 4 to 7. explain.

First, Fig. 4 is a plan view of the SAW stem, and Fig. 5 is a plan view of the SAW stem.
In the figure, which shows a cross-sectional view along line A-A in
) is a rectangular stem board with a flange (2) on the periphery for positioning and fixing the cap, three through holes (3) (3) (3) for sealing the leads, and a ground lead fixing on the bottom. It has one recess (4) for Each of the through holes (3) (3
) (3) have lead wires (6) (6) (6) hermetically insulated sealed through glass (5) (5) (5), respectively, and a ground lead in the recess (4). (7) are electrically and mechanically connected and fixed by eutectic silver solder (8).

Conventionally, the ground lead (7) is brazed in the following manner. First, using a carbon brazing jig, place the ground lead (7) in the recess (4) of the stem board (1) as shown in Fig. 6, and then attach the ring-shaped silver solder (8a). or, as shown in Figure 7, place a rod-shaped or granular silver solder (8b), and then place an earth lead (7) on top of this silver solder (8b) to make the whole neutral. Or by heating to about 830°C in a weakly reducing atmosphere to melt the silver wax (8a) or (8b),
The ground lead (7) is brazed to the stem board (1) (Japanese Patent Laid-Open No. 50-56879).

However, in the above brazing method, it is difficult to automatically supply the silver solder (8a) or (8b), and workability is extremely poor because it is done manually, and furthermore, the same recess (4
) It is easy to place multiple pieces of silver solder or forget to add silver solder (in the former case, molten silver solder spreads around the area and causes a poor appearance, and in the latter case, brazing is impossible) become.

Therefore, the applicant of the present invention has previously proposed a brazing method that solves the above problems, which will be described below with reference to FIGS. 8 to 14 (Japanese Patent Application No. 59-23900). In this brazing method, first, the wt of silver-copper binary alloy shown in FIG.
In the phase diagram based on %, the range shown in (a) or the range shown in (b), which has a solid phase/liquid phase coexistence region, is 9o to 80w.
t%, copper 10-20wt% or l! 60-20wt%,
A silver-copper alloy having a composition of 40 to 80 wt% copper is used. Then, using an assembly jig, for example, place the earth lead (7) on a rod-shaped silver solder (lla) having a length (D2) larger than the diameter (Dl) of the earth lead (7), and place the earth lead (7) on the solid phase.・
When heated at a temperature in the liquid phase coexistence region, only a part of the silver solder (lla) turns into a liquid phase, and as shown in Figure 9, a rod-shaped silver solder (11a) is formed at the lower end of the earth lead (7). Temporarily fixed T-shaped earth lead/silver solder combination (12a)
Then, a large number of earth lead/silver solder composites (12a) are added to the obtained zero order, for example, "Syntron" (registered trademark).
When placed in a vibrating device known under the trade name of , and subjected to vibration, the earth lead/silver solder combination (12a) comes out in line in the axial direction. Therefore, at the outlet end of the device, as shown in Fig. 1θ, its dimension (D3) is larger than the external dimension (Dl) of the earth lead (7), and the length dimension (D2) of the silver solder (11a) is If a sorting shade (14) with a small opening (13) is provided, the earth lead (7) will pass through the opening (13) and the silver solder (11a) will pass through the opening (13) as shown in the figure.
> remains on the sorting chute (14) and slides in a so-called suspended state, and the side to which the silver solder (lla) is fixed is aligned in a certain direction. At this time, if there is any earth lead (7) to which the silver solder (11a) is not fixed, it will fall through the opening (13), and such a piece will be selectively removed.

The earth lead/silver solder combination (12a), in which the silver solder (11a) is aligned in a certain direction as described above, is cut out one by one from the sorting chute (14) and passed through a chute such as a vinyl tube to the 11th The upper sealing jig shown in the figure (
On the other hand, each through-hole (
3) Stem substrate (1) with leads m (6) (6) (6) sealed to (3) (3) via glass (5) (5) (5).
) (the figure is simplified), and the above earth lead/silver solder combination (
12a) inserted into the upper sealing jig (15), and
As shown in Figure 2, a silver solder (11a) is placed in the recess (4) of the stem substrate (1). In this state, the whole is 8
When heated at about 50 to 950°C, the silver solder (12a) is melted and the earth lead (7) is brazed to the recess (4), as shown in FIG. However, at this time, when the silver solder (lla) is placed in the recess (4), the ground lead (7) is placed in the silver solder (lla) as shown in FIG.
1a) is raised from the bottom of the recess (4) by a thickness H). Therefore, if the ground lead (7) is heated as it is, even though it is desirable to attach it to the bottom of the recess (4), the ground lead (7) may be brazed in a floating state away from the bottom. It is necessary to press the earth lead (7) as shown by the arrow in FIG. 12. This pressing of the earth lead (7) is carried out by placing the silver solder (11a) in the recess (4) and positioning the earth lead (7) with the positioning jig (17), as shown in Fig. 14. A common holding jig (
In step 18), pressure and load are applied all at once.

When B < °, the above-mentioned earth lead/silver solder combination (12
The brazing method using method a) requires heating and pressing of the ground lead (7), and a presser jig (18) is attached to the sealing jig.
) must be added, and an earth lead (7) must be added.
It is necessary to move the holding jig (18) so that a desired load is applied to the holding jig (18), which complicates the apparatus. Furthermore, in order to press a large number of earth leads (7) at once using a common holding jig (18), the earth leads (7) can be pressed at once.
) unless the pressing surfaces of the ground leads (7) are located at the same height, the same load will not be applied to each ground lead (7), and due to variations in lead length, some ground leads (7) may be underloaded and the reliability of the brazing strength may be reduced. It was declining.

In the present invention, a brazing agent is temporarily fixed to the side surface near the fixed end of the lead wire in advance, and after the fixed end of the lead wire is brought into contact with a metal substrate, the soldering material is heated and melted. It is characterized in that the lead wire is brazed to the stem.

False - Temporarily fix brazing agent to the side of the child lead so that the fixed end of the lead wire comes into contact with the metal substrate, and in this state heat the brazing agent.
melt.

1. A method for brazing lead wires according to the present invention will be described below with reference to specific examples of its use shown in FIGS. 1 to 3. First, in FIG. 1, (1) is a stem substrate which is an example of a metal substrate, (15) is an upper sealing jig, and (19) is a lead wire/brazing agent combination. The lead wire/brazing agent combination (19) has a fixed end (20a) on the side surface of the lead wire (20).
) A bar-shaped brazing agent (21) such as silver solder is temporarily fixed in the vicinity of the solder. Here, when the brazing agent (21) is silver solder, in the phase diagram by wt% of the silver-copper binary alloy shown in FIG. b) range, i.e. 90 to sowt% silver, 10 to sowt% copper
2Qwt% or 60-20wt% silver, 40-sowt copper
By using a silver-copper alloy with a composition of

Then, using an assembly jig, stick a bar-shaped brazing agent (21) on the side surface of the lead wire (20) in the same manner as in the past.
Temporarily fix the lead wire/brazing agent combination near a) (19)
′, the lead wires and
The solder bond (19) is inserted into the hole (1) of the upper sealing jig (15).
5a). On the other hand, the lower sealing jig (first
Place the stem board (1) into the hole (see Figure 1), and attach the lead wire/brazing agent combination (19) to the lower sealing jig.
As shown in Fig. 1, the upper sealing jig (15) inserted with
'''''-1''m (20) 'tri''CT4nW
+ L h 4:°′″″15″″. 1°1°′”01
When heated for 1 inch, as shown in Figure 3, the waxing agent (21)
is melted and the lead wire (20) is brazed to the recess (4). At this time, with the lead wire (20) positioned in the recess (4) of the stem board (1), the fixed end (2
0a) is in contact with the bottom of the recess (4), so there is no need to press the lead wire (20) as in the conventional case during heating, and the conventional holding jig (18) becomes unnecessary. Therefore, the reliability of the brazing strength is stabilized even if the lead wire (20) is under insufficient load during pressing.

Next, Fig. 2 shows a spherical brazing agent (22) connected to a lead wire (20
) In the case of this embodiment, which shows an embodiment in which the fixing end (20a) is temporarily fixed to the side surface near the fixing end (20a), brazing can be performed in the same manner as described above.

In addition, in the above embodiment, each through hole (3) of the stem substrate (1)
(3) After sealing the lead wires (6) (6) (6) to (3) through the glass (5) (5) (5), solder the ground lead (7) to the recess (4). We have explained the case where the waxing agent (21) (22) has a melting point of glass (
5) If the melting point is similar to (5) (5), the ground lead (7) can be brazed at the same time as the glass sealing of the lead wires (6) (6) (6). .

According to the present invention, when brazing a lead wire to a metal substrate, a brazing agent is temporarily fixed to the side surface near the fixed end of the lead wire in advance, and the fixed end of the lead wire is attached to the metal substrate. Because the brazing agent is heated and melted while in contact, brazing is performed.
There is no need to press the lead wire during heating, and a holding jig is no longer required, making the sealing jig a simple device. Furthermore, there is no shortage of load on the lead wire during pressing, and the reliability of the brazing strength is stable.

[Brief explanation of drawings]

1 and 2 are enlarged cross-sectional views of main parts showing the state before brazing of different embodiments of the lead wire brazing method according to the present invention, and FIG. 3 is an enlarged sectional view of the main part obtained by implementing the method of the present invention FIG. 4 is a plan view of a SAW stem which is an example of a brazing structure for lead wires, and FIG.
6 and 7 are enlarged cross-sectional views of main parts in an assembled state for brazing the ground lead to the recess of the stem board in Figure 4, and Figure 8 is a silver-copper cross-sectional view. wt% of binary alloy
FIG. 9 is a perspective view of a conventional earth lead/silver solder combination, FIG. 10 is a partial perspective view of the sorting shade for the earth lead/silver solder combination shown in FIG. 9, and FIG.
A partial sectional view of the upper and lower sealing jigs using the earth lead/silver solder combination shown in the figure, and Figure 12 shows the main assembly state for brazing using the earth lead/silver solder combination shown in Figure 9. 13 is an enlarged sectional view of the main part of the ground lead brazed in the assembled state shown in FIG. 12, and FIG. 14 shows the ground lead/silver solder combination shown in FIG. 9 assembled in the assembled state shown in FIG. 12. FIG. 3 is a cross-sectional view of a main part of the ground lead in a pressed state by a pressing jig when heating in the state. (1) -----metallic substrate [stem substrate], (4)
- recess, (20) --- lead wire [earth lead],
(20a) - Fixed end, (21) (22) - Brazing agent. τ−−

Claims (1)

[Claims] (1) When brazing a lead wire to a metal substrate, temporarily fix a brazing agent to the side surface near the fixed end of the lead wire, and after bringing the fixed end of the lead wire into contact with the metal substrate, apply the brazing agent to the side surface near the fixed end of the lead wire. A lead wire brazing method characterized in that the lead wire is brazed to a metal substrate by heating and melting the lead wire.