JPS62219949A - Soldering - Google Patents

Abstract

PURPOSE:To solder a heat sink at a predetermined position on a substrate stably and with high accuracy by a method wherein the heat sink is held between 1st and 2nd jigs and soldered in that state and the 1st jig has the high dimensional accuracy. CONSTITUTION:As 1st jig 24 is abutted on a recessed part 29 to keep a certain relative position to a stem substrate 21, a heat sink 22 which is held between the 1st jig 24 and 2nd jig 25 is kept at a predetermined position defined by the front surface (a) of the 1st jig 24 and soldered to the stem substrate 21 in that state. Therefore, if the 1st jig 24 has the high dimensional accuracy, the heat sink 22 is always soldered to the predetermined position on the stem substrate 21 stably and with high accuracy without discrepancy or inclination even if the dimensional accuracies of other jigs 25-28 are inferior a little.

Description

[Detailed Description of the Invention] The present invention relates to a brazing method used in the manufacture of laser stems (hermetic terminals), etc., and particularly relates to a method for positioning a rectangular heat sink with high precision on a metal substrate. Concerning how to braze.

Conventionally, a laser stem used for a laser light source that irradiates laser light onto a laser disk, etc. is constructed by brazing a heat sink for mounting a laser element onto a stem substrate whose lead wires are sealed in glass. . For this laser stem, a laser element [diode] is attached to the vertical wall of the heat sink.
is fixed, the laser element and the lead wire are electrically connected, and then a cap with a lens is fixed on the peripheral edge of the stem substrate to form a laser light source. This laser light source is used for writing information on laser disks, etc., and the tolerance for axis deviation of the emitted laser beam is extremely small, and the positional accuracy of the heat sink that fixes the laser element on the stem board is on the order of microns. High quality is required.

Therefore, in order to meet the above requirements, various attempts have been made to form heat sink positioning means on the stem substrate and to devise jigs used when brazing the heat sink onto the stem substrate. Specifics of this attempt
An example will be described with reference to FIGS. 4 to 7, together with an example of the structure of a laser stem (see Japanese Patent Application Laid-open No. 172256/1983).

In the laser stem (1) in FIGS. 4 and 5, (
2) Kovar (Fe-N in Fe-Ni-Co alloy)
A circular stem substrate such as i-alloy (3) (3) is formed in two places on the stem substrate (2), and a sealing hole (4) (
(4) is the lead wire inserted into the glass (5) and sealed with glass (5), (6) is the grounding lead wire whose end face is welded to the bottom surface of the stem board (2), and (7) is the stem board ( , 1) A prismatic fl! fixed in position above with brazing material (8)!
This is an iJ heatsink. The heat sink (7) is attached to a vertical step (9) formed linearly on the stem substrate (2).
By bringing the surfaces into contact, it is positioned on the stem substrate (2) and brazed.

In this stem (1), a laser element (lO) is fixed to the front vertical wall surface (ml) of the heat sink (7), as shown by the chain line in FIG. A monitor light receiving element (12) is fixed to an inclined surface (11) formed directly below the laser element (10).
0) and the light receiving element (12) are connected to the lead wires (3) (3) with fully bent thin wires (not shown), and then the cap with lens (13) is fixed on the periphery of the stem board (2). be done. When the laser element (10) is energized to emit light, a portion of the light passes through the lens (14) of the cap (13) and is emitted to the outside as a laser beam.
A part of the light is received by a light receiving element (12), and the presence or absence of light emission from the laser element (10) is monitored based on the output signal of this light receiving element (12).

The heat sink (7) is brazed on the stem board (2) using three jigs (15) (
16) Using (17), it is done as follows. However, (15) is a lower jig, (16) is an upper jig, and (17) is a lower jig, each of which is a carbon jig to which the brazing material does not adhere.

The lower jig (15) has a recess (18) in which the stem board (2) is stored on the upper surface and a stem board (2) in the bottom of the recess (18).
) Three lead wires (3) (3) (6) extending from the bottom of the
Lead insertion hole (19) (19)...
has. The upper jig (16) has a guide hole (20) into which the heat sink (7) is inserted with sufficient margin.

The sleeping jig (17) has a wedge-shaped cross section with a tapered lower surface (n), and is inserted into the guide hole (20) from above and falls under its own weight.

The stem board (2) is stored in the recess (18) of the lower jig (15), and the upper jig (16) is placed on the lower jig (15) so that its guide hole (20) is on the stem board (2). Position and cover the area where the heat sink is to be fixed. Next, the brazing material (8) is supplied from the guide hole (20) to the portion of the stem board (2) where the heat sink is to be fixed, and then this brazing material (
8) Provide a heat sink (7) on top. After that, insert the weight jig (17) into the guide hole (20) so that the tapered surface (n) of the lower surface of the weight jig (17) touches the front ridgeline of the upper end of the heat sink (7). Then, the heat sink (7) becomes a sleeping jig (
The vertical stage (9) on the stem board (2) is pressed onto the stem board (2) by the gravity of ) and held in place against the vertical step (9).

In this state, the brazing material (8) is heated and melted, and the heat sink (7) is brazed and fixed onto the stem substrate (2).

In the brazing method using such jigs (15) to (17), the heat sink (7) and the stem board (2)
Even if the weight jig (17) expands due to the heat during brazing and contracts when cooled after brazing, the weight jig (17)
moves up and down, and the weight jig (17) uses its horizontal component of gravity to move the heat sink (7) to the stem base f! (2) Since the heat sink (7) is pressed against the upper vertical stage (9) and continues to be positioned, the heat sink (7) can be brazed onto the stem substrate (2) with high precision.

By the way, a vertical stage (9) for positioning the heat sink is provided on the stem board (2), and the heat sink (7) is placed on this vertical stage (9) by the horizontal component of the gravity of the weight jig (17). In order to press it constantly with force, it is necessary to provide a slight gap (g) between the back vertical wall surface (m2) of the heat sink (7) and the guide hole (20) of the upper jig (6). Yes. Therefore,
A weight jig (17
) When the tapered surface (n) of the heat sink (7) is pressed, there is a possibility that the heat sink (7) will be tilted by the gap (g) as shown by the chain line in FIG. 7) is inconveniently fixed onto the stem substrate (2) by brazing. A heat sink like this (7
Although the amount of positional deviation due to the inclination of the ( .

The present invention satisfies the above-mentioned demand, and is based on a fixed position on a substrate.
A method of brazing a heat sink having vertical wall surfaces on both sides, in which the heat sink is placed on the substrate held in a substantially horizontal position via a brazing material, and one of the vertical wall surfaces on both sides of the heat sink is attached to the substrate. The other vertical wall face is opposed to a first jig held in a fixed position on the substrate, and the other vertical wall face is opposed to a second jig movably arranged on the substrate, and this second jig is connected to another weight. Press the jig against the heat sink using the horizontal component of gravity, and move the heat sink to the first position. jig and the second
The present invention provides a brazing method characterized in that the brazing material is heated and melted while being held between two jigs.

In the method of the present invention, a first plate positioned with respect to a substrate is provided.
The heat sink is pressed onto the substrate by a second jig that is movable against the substrate, and is brazed onto the substrate while being held between the first and second jigs. By using a heat sink with high dimensional accuracy, the heat sink can be stably and accurately brazed in a fixed position on the board.

Next, the method of the present invention will be explained below with reference to the specific embodiment of the apparatus shown in FIGS. 1 to 3.

Figures 1 and 2 show the stem substrate (21) of the laser stem.
) shows a partial plan view and a cross-sectional view taken along the line A-A of a device for brazing a rectangular heat sink (22) in a fixed position on the top of the top (23), (24) and (25). are a first jig and a second jig for positioning the heat sink,
(26) is the first weight jig that applies a load in the horizontal direction to the second jig (25), (27) is the third jig for positioning the five-steer system, and (28) is the third jig. A second weight jig that applies a load in the horizontal direction to the jig (27), and each of these jigs (23) to
(28) is a carbon jig.

The lower jig (23) has a circular stem substrate (21) on its upper surface.
For example, a rectangular recess (2
9), and the bottom of this recess (29) has a stem substrate (
21) Two leads passed through and sealed with glass! (
30) (30) and lead insertion holes (32) (32)... are formed into which the grounding lead wire (31) whose end face is welded is inserted into the lower surface of the stem board (21).

The first jig (24) is inserted into one end of the recess (29), and has a step (33) at the lower front surface into which a part of the periphery of the stem board (21) fits. The front surface (a) of the jig (24) is formed as a vertical wall surface rising vertically from the stem substrate (21). The second jig (25) is a triangular prism with a right triangle cross section, one of its two perpendicular surfaces is placed on the stem substrate (21), and the other surface (b) is placed on the first jig (24). is installed parallel to and facing the front surface (a) of the

A stem board (21) is provided on the bottom surface of this second jig (25).
Lead wire (30) protruding upward (30) relief groove (
34) (34) is formed. First weight jig (26
) has a trapezoidal cross section with the tapered surface (d) facing downward and is placed on the tapered back surface (c) of the second jig (25), and the back surface facing the tapered surface (d) is (e) is a vertical wall surface.

Further, the third jig (27) is inserted into the recess (29) at one end opposite to the first jig (24), and its front surface (f) is a vertical wall surface. At the bottom of the stem board (
It has a step (35) into which a part of the periphery of the back (
h) has a tapered shape. The second weight jig (28) connects the tapered back surface (h) of the third jig (27) with the recess (29).
) is inserted between the inner wall surface of the third jig (2
It has a tapered surface (i) that contacts the tapered back surface (h) of 7) and a vertical back surface (j) that contacts the inner wall surface of the recess (29).

Using each of the above jigs (23) to (28), use the stem board (
21) Attach the heat sink (22) to the upper position in the following manner.
The stem board (2) supplied to the four parts (29) of the lower jig (23) is
1) Supply the brazing material (36) and the heat sink (22) to the area where the heat sink is to be fixed on the stem board (21).
) at both ends of the first jig (24) and third jig (27).
into the third jig (27) and the heat sink (22).
) A second jig (25) is supplied onto the stem substrate (21) between the two. In this state, for example, first the second weight smell (28
) is placed on the tapered back surface (h) of the third jig (27). Then, the horizontal component of the gravity of the second weight jig (28) pushes the third jig (27) to the left in the drawing of FIG.
The jig (24) is pressed against the inner wall surface of the recess (29) and held at a fixed position. Next, the second weight jig (26)
is inserted between the second jig (25) and the third jig (27). Then, the horizontal component of gravity of the second weight jig (26) presses the second jig (25) toward the heat sink (22), pushing the heat sink (22) towards the first jig (24).
). This state is shown in FIG. 2, and at this time, the heat sink (22)
Since the stem (m2) is held between the opposing front surfaces (a) and (b) of the first and second jigs (24) and (25), it does not tilt on the stem board (21), and the 1 jig (
24) are in contact with the recesses (two) and are in a fixed position relative to the stem board (21), so the first and second jigs (2
4) The heat sink (22) held by (25) is held at a fixed position determined by the front surface (a) of the first jig (24), and brazed onto the stem substrate (21) as it is. Therefore, if the first jig (24) is of good dimensional accuracy, even if the other jigs (25) to (28) have somewhat poor dimensional accuracy, the heat sink (22) can be attached to the stem board (2).
1) Brazing is always performed in a stable position with high accuracy without shifting or tilting.

Note that the present invention is not limited to the method of brazing a heat sink onto the stem substrate of a laser stem, but is also applicable to a jig for holding the heat sink, or a horizontal direction The shape of the weight jig that applies the load has been changed in various ways.

According to the present invention, the heat sink on the board during brazing can be held between the first jig on the fixed side and the second jig on the movable side even if some thermal expansion or contraction occurs. Since the first jig is used to accurately position and braze the heat sink to the substrate without tilting, the positioning accuracy of the heat sink row is highly and stable, and the laser requires micron precision. It is possible to provide a brazing method that is effective for the stem manufacturing process.

[Brief explanation of drawings]

FIG. 1 is a partial plan view showing an example of a specific implementation apparatus for the method of the present invention, and FIGS. 2 and 3 are sectional views taken along the line A--A in FIG. 1 in various states. Figure 4 is a plan view of the laser stem, Figure 5 is B of Figure 4.
- It is a sectional view along the B line. 6 and 7 are for explaining the conventional brazing method, and FIG. 6 is a partial vertical sectional view of the brazing device, and FIG.
The figure is a partially enlarged view of FIG. 6. (21) -・Substrate, (22) −・Heat sink. (24) - first jig, (25) - second jig, (
26> --1-- Weight jig. Figure 1 (Plan view 2! 2vl! (A-A4J'rli diagram) Figure 3 (A-
A47・h*rlj/)*Lu)Figure 4Figure 6Figure 5Figure 7

Claims (1)

[Claims] (1) A method of brazing a heat sink having vertical wall surfaces on both sides at a fixed position on a substrate, the heat sink being placed on the substrate positioned and held substantially horizontally via a brazing material, and One of the vertical wall surfaces on both sides of the heat sink is opposed to a first jig held in a fixed position relative to the substrate, and the other vertical wall surface is opposed to a second jig movably arranged on the substrate, This second jig is pressed against the heat sink side by the horizontal component of gravity of another weight jig, and with the heat sink being sandwiched between the first jig and the second jig, the brazing material is A brazing method characterized by heating and melting.