JP2624586B2 - Welding device and welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding apparatus and a welding method, and more particularly to a welding apparatus and a welding method for welding a component such as a semiconductor chip to a stem using a bonding agent.

[0002]

2. Description of the Related Art Generally, components whose performance is affected by temperature are bonded to a stem (radiation base member) by using a bonding agent containing a metal to release heat. For example, in the case of a semiconductor laser chip, as shown in FIGS. 4A and 4B, first, the stem 105 is held on the stem holder 101 by the stem chucking plate 102 (the entire configuration of the welding apparatus is shown in FIG. 3). Shown). Header 105 of stem 105
Indium 106 is previously attached to 05a as a bonding agent. Then, the semiconductor laser chip 107 is mounted on the indium 106, and the ceramic heater 104 is brought into pressure contact with the stem 105. In this state, the temperature of the ceramic heater 104 is controlled so that the indium 10
6 and melt the semiconductor laser chip 10 on the stem 105.
7 are joined. Conventionally, as shown in FIG. 5, the temperature control of the ceramic heater 104 includes a rising time until the actual heating temperature is increased to an appropriate temperature and an appropriate heating time for maintaining the heating temperature at an appropriate temperature (within an appropriate temperature range). And a cooling time in which the heating temperature is forcibly lowered by air blowing, and a leaving time in which the device is left naturally until it reaches room temperature.

[0003]

However, in the above-mentioned conventional welding method, the stem 105 is attached to the stem holder 101.
There is a problem that the time from attaching to removing (hereinafter, referred to as “tact time”) is long, and productivity is not good. This is because rapid heating and rapid cooling cannot be performed because the heat capacity of the ceramic heater 104 is large. In particular, rapid heating (increase the rate of temperature rise during the rise time) is regulated to keep the overshoot (difference between the actual heating temperature and the appropriate temperature) immediately after entering the appropriate heating time within the appropriate temperature range. Is done.

An object of the present invention is to provide a welding apparatus and a welding method capable of shortening the tact time and improving the productivity.

[0005]

In order to achieve the above object, a welding apparatus according to the present invention is provided with a disk-shaped turntable, and a plurality of the turntables are radially attached to the periphery of the turntable at predetermined angles. A stem holder capable of holding the stem toward the outside of the turntable, and a plurality of heat baths provided radially around the turntable for each of the angles and capable of maintaining a predetermined temperature are provided.

It is preferable that a stem mounting portion for mounting a stem on the stem holder is provided at one position where the heat bath is to be provided around the turntable.

The temperature of each of the heat baths is preferably set to a high temperature, an appropriate temperature, and a low temperature in order from the side closer to the stem mounting portion.

It is desirable that each of the heat baths has a ceramic heater which can move in a radial direction with respect to the turntable and is brought into pressure contact with a stem attached to the stem holder.

The welding method according to the present invention is also directed to a disk-shaped turntable, a plurality of stem holders radially attached to the periphery of the turntable at a predetermined angle, and a plurality of stem holders around the turntable. Using a plurality of radially provided heat baths,
A welding method of welding a predetermined component to a stem via a bonding agent, wherein the stem holder holds a stem on which a component to be bonded to the bonding agent is mounted in advance toward the outside of the turntable. , To each of the above hot baths in order, high temperature, appropriate temperature,
Rotating the turntable at each of the angles while maintaining the low temperature, sequentially contacting the stem with each of the heat baths to melt and solidify the bonding agent on the stem. .

[0010]

The welding apparatus of the present invention is driven as follows.
First, the stem on which the parts to be joined with the joining agent are placed in advance is held by the stem holder toward the outside of the turntable. Further, the heat baths around the turntable are maintained at, for example, a high temperature, an appropriate temperature, and a low temperature in this order. In this state, the turntable is rotated at each angle, and the stem is sequentially brought into contact with each of the heat baths. Thereby, the bonding agent on the stem is rapidly heated and melted in the high-temperature heat bath (rapid heating section), and after the necessary time has passed in the appropriate temperature heat bath (appropriate temperature heating section), It is rapidly cooled by a low-temperature heat bath (cooling section) and solidifies (however, the cooling rate is within a range where crystal distortion during solidification does not matter). After this, the stem is removed from the stem holder. As described above, since the welding apparatus includes a plurality of heat baths, the heat baths can be set to different temperatures in advance. Therefore, there is no need to provide a time for raising and lowering the temperature of the heat bath during the joining step, and as a result, the tact time is shortened as compared with the related art. Moreover, since a plurality of stem holders are provided, for example, when one stem (and stem holder) moves from the rapid heating section to the appropriate temperature heating section, the next stem holder is moved to the rapid heating section, and The joining of the next stem can begin while joining is in progress. That is, the joining operations can be sequentially performed in parallel by the number of heat baths. Therefore, the tact time is greatly reduced, and the productivity is improved. In addition, since each of the heat baths only needs to maintain a constant temperature, temperature control is easily performed. Note that when the stem holder moves between the heat baths, the heating temperature is expected to decrease instantaneously, but is suppressed to a level (within an appropriate temperature range) that does not actually cause any problem.

In a case where a stem mounting portion for mounting a stem on the stem holder is provided around the turntable at one position where the heat bath is to be provided, the turntable is rotated so that the stem holder becomes a stem mount portion. The stem can be mounted when it comes to the position. That is, the operation of mounting the stem and the operations of heating and cooling in each heat bath can be synchronized with the rotation cycle of the turntable. Therefore, productivity is further improved.

When each of the heat baths has a ceramic heater which can move in a radial direction with respect to the turntable and has a ceramic heater which is brought into pressure contact with a stem attached to the stem holder, the turntable is rotated so that each of the stem holders is heated. Upon reaching the bath position, the stem quickly reaches the temperature of the ceramic heater. Therefore, the tact time is reduced. In addition, since the temperature of the ceramic heater can be set at a constant current, temperature control is easily performed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The welding apparatus and the welding method according to the present invention will be described below in detail with reference to embodiments.

FIG. 1 shows a welding apparatus according to an embodiment of the present invention as viewed from above. This welding apparatus comprises a disk-shaped turntable 13 and six stem holders 1, 2, and 6 mounted radially every 60 degrees around the turntable 13.
3, 4, 5, and 6 are provided. Each stem holder 1,…, 6
Consists of a main body 21 and a stem chucking plate 22,
Each of the stems can be held toward the outside of the turntable 13. Five heat baths 8, 9, 10, 11, and 12 are provided radially every 60 degrees around the turntable 13, and a stem mounting arm (stem mounting portion) 7 is provided at the remaining one position. ing. The stem mounting arm 7 can move to the position 7a shown by the broken line when the stem holders 1,..., 6 come to the close position, and mount the stem 15 on the stem holders 1,. Each of the heat baths 8,..., 12 includes a ceramic heater 23 and a heater holder 24 for holding the ceramic heater 23, and can maintain a predetermined temperature by supplying a constant current to the ceramic heater 23, respectively. Actually, the heat bath (rapid heating section) 8 is set at a high temperature, the heat baths (appropriate temperature heating sections) 9 and 10 are set at an appropriate temperature, and the heat bath (cooling section) 11 is set at a low temperature in order from the side near the stem mounting arm 7. ing. Reference numeral 12 denotes a spare heat bath. Each of the heat baths 8,...
3 can move radially. Thus, when the turntable 13 is rotated to bring the stem holders 1,..., 6 to the close position, the ceramic heater 23 is brought into pressure contact with the stems 17 attached to the respective stem holders. Then, when the turntable 13 is to rotate next time, the turntable 13 is separated.

This welding device is driven as follows. First, the stem holder 1 holds a stem 15 on which a component (for example, a semiconductor laser chip) 17 to be bonded to a bonding agent is mounted in advance. In this state, the turntable 13 is rotated clockwise by 60 degrees to bring the stem 15 into contact with the ceramic heater 23 of the rapid heating unit 8. Thereby, the bonding agent on the stem 15 is rapidly heated and melted. As shown in FIG. 2, the actual heating temperature (indicated by a solid line A in the figure)
When the temperature reaches the appropriate temperature, the ceramic heater 23 is separated from the stem 15 at time T1. In the figure, T indicates the movement time, and CT indicates the cycle time. A broken line B indicates the conventional heating temperature shown in FIG. Subsequently, the turntable 13 shown in FIG. 1 is rotated by 60 degrees, and the stem 15 is brought into contact with the ceramic heater 23 of the appropriate temperature heating unit 9 to maintain the temperature at the appropriate temperature. After a predetermined time T2 elapses in the appropriate temperature heating unit 9, the appropriate temperature heating unit 10 similarly holds the stem 15 at the appropriate temperature for the time T3. Subsequently, the turntable 13 is rotated by 60 degrees, and the cooling unit 11 rotates the stem 15.
Is brought into contact with the ceramic heater 23. As a result, the stem 15 is rapidly cooled, and the above-mentioned bonding agent solidifies (however, the cooling rate is set so that crystal distortion during solidification does not matter). Thereafter, the stem 15 is removed from the stem holder 1.

Since the welding apparatus includes a plurality of heat baths 8,..., 12, the heat baths 8,. Therefore, there is no need to provide time for raising and lowering the temperature of the heat baths 8,..., 12 during the cycle time, and as a result, the tact time can be shortened as compared with the related art. Moreover, since a plurality of stem holders 1,..., 6 are provided, for example, when one stem 15 and the stem holder 1 move from the rapid heating section 8 to the appropriate temperature heating section 9, the next stem holder is moved to the rapid heating section 8. It can be moved to start joining the next stem while joining the one stem 15. That is, the joining operations can be sequentially performed in parallel by the number of heat baths. Therefore, the solid line A and the broken line B are shown in FIG.
As shown by the difference, the tact time can be greatly reduced, and the productivity can be improved. Moreover, since each of the heat baths 8,..., 12 only needs to maintain a constant temperature, the temperature can be easily controlled. Although it is expected that the temperature of the stem will instantaneously decrease during the time T during which the stem holder moves between the heat baths, it can be suppressed to a level (within an appropriate temperature range) that does not cause any problem in practice.

Further, since the stem mounting arm 7 is provided at a position around the turntable 13 where the heat bath is to be provided, the stem can be mounted when the turntable 13 is rotated and the stem holder comes to the close position. it can. That is, the work of mounting the stem and the heating and cooling work in each heat bath,
It can be synchronized with the rotation cycle of the turntable 13. Therefore, productivity can be improved.

[0018]

As is apparent from the above description, the welding apparatus according to the present invention is provided with a disk-shaped turntable, and a plurality of radially attached to the periphery of the turntable at predetermined angles, each of which has a stem. A stem holder that can be held toward the outside of the
A plurality of heat baths are provided radially around the rotary table at each of the angles and can maintain a predetermined temperature, respectively. There is no need to provide time to raise and lower the temperature of the bath. In addition, the joining operation can be sequentially performed in parallel by the number of heat baths. Therefore, the tact time can be significantly reduced, and the productivity can be improved.

In the case where a stem mounting portion for mounting a stem on the stem holder is provided at one position where the heat bath is to be provided around the rotary table, the operation of mounting the stem and the heating and heating in each heat bath are performed. The cooling operation can be synchronized with the rotation cycle of the turntable, and the productivity can be improved.

When each of the heat baths has a ceramic heater which can move radially with respect to the turntable and is brought into pressure contact with a stem attached to the stem holder, the stem can be rapidly heated or cooled. It is possible to shorten the tact time. In addition, since the temperature of the ceramic heater can be set at a constant current, the temperature can be easily controlled.

The welding method according to the present invention further comprises a disk-shaped turntable, a plurality of stem holders radially attached to the periphery of the turntable at a predetermined angle, and a plurality of stem holders around the turntable. Using a plurality of radially provided heat baths,
A welding method of welding a predetermined component to a stem via a bonding agent, wherein the stem holder holds a stem on which a component to be bonded to the bonding agent is mounted in advance toward the outside of the turntable. , To each of the above hot baths in order, high temperature, appropriate temperature,
By rotating the turntable at each of the angles while maintaining a low temperature, the step of sequentially contacting the stem with each of the heat baths to melt and solidify the bonding agent on the stem, Tact time can be greatly reduced, and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a welding apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a lapse of a heating temperature when a component is mounted on a stem using the welding device.

FIG. 3 is a diagram showing the overall configuration of a conventional welding device.

FIG. 4 is a view showing a main part of the conventional welding apparatus.

FIG. 5 is a diagram showing a progress of a heating temperature when a component is mounted on a stem using the conventional welding apparatus.

[Explanation of symbols]

 1, 2, 3, 4, 5, 6 stem holder 7 stem mounting arm 8, 9, 10, 11, 12 heat bath 15 stem 17 parts 21 stem holder main body 22 stem chucking plate 23 ceramic heater 24 heater holder

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-169159 (JP, A) JP-A-61-63357 (JP, A) JP-A-56-17180 (JP, A) JP-A 55-180 161565 (JP, A) JP-A-63-237448 (JP, A) Japanese Utility Model Laid-Open No. 1-96256 (JP, U)

Claims (5)

(57) [Claims] 1. A disk-shaped turntable, a plurality of stem holders attached radially to the periphery of the turntable at predetermined angles and capable of holding stems to the outside of the turntable, respectively; A welding device, comprising: a plurality of heat baths provided radially around the periphery for each of the angles and capable of maintaining a predetermined temperature. 2. A stem mounting portion for mounting a stem on the stem holder at one position where the heat bath is to be provided around the turntable.
The welding device according to claim 1. 3. The welding apparatus according to claim 2, wherein the temperature of each of the heat baths is set to a high temperature, an appropriate temperature, and a low temperature in order from a side closer to the stem mounting portion. 4. The heat bath according to claim 1, wherein each of the heat baths has a ceramic heater which is movable in a radial direction with respect to the turntable and is brought into pressure contact with a stem mounted on the stem holder. The welding device according to any one of the above. 5. A disk-shaped turntable, a plurality of stem holders radially attached to the periphery of the turntable at predetermined angles, and a plurality of stem holders radially provided at each angle around the turntable. A welding method for welding a predetermined component to a stem via a bonding agent using a heat bath, wherein the stem on which a component to be bonded to the bonding agent is mounted in advance on the stem holder, to the outside of the turntable. The step of holding the heat bath in order, the high temperature, the appropriate temperature, and the low temperature are maintained in order, and the rotating table is rotated at each of the angles while the stem is in contact with each of the heat baths. A welding method comprising a step of melting and solidifying a bonding agent on a stem.