JP2009073885A - Joining member joining method and joining apparatus - Google Patents

Abstract

The present invention provides a joining method and joining apparatus for joining members capable of shortening joining work time while suppressing warping of a workpiece.
In the joining method of the present invention, first, a workpiece 10 is accommodated in a space 2 that is insulated and sealed. Next, the piston 3 is moved downward, the inside of the space 2 is pressurized, and the temperature in the space 2 is set to a temperature higher than room temperature. By maintaining this atmosphere, the adhesive 18 of the workpiece 10 that is a thermosetting resin is cured, and the resin case 11 and the heat sink 12 are bonded. Next, the piston 3 is moved upward, the pressure in the space 2 is reduced, and the temperature in the space 2 is set to a temperature lower than the normal temperature. By maintaining this atmospheric state, the workpiece 10 is cooled.
[Selection] Figure 2

Description

  The present invention relates to a bonding method and a bonding apparatus for a bonding member for bonding a first bonding member and a second bonding member via a thermosetting resin adhesive.

  A hybrid vehicle is equipped with a power IC for high withstand voltage and large current. Since power ICs generate a large amount of heat during use, a configuration for improving the heat dissipation from the elements is required. Therefore, as a configuration of the power module, generally, a configuration is adopted in which a heat sink is bonded to the outside of a resin case that houses the power IC, and the heat generated from the power IC is efficiently released to the outside (for example, Patent Documents). 1).

  In the power module having such a configuration, a thermosetting resin such as polyimide, epoxy resin, or phenol resin is used as an adhesive for bonding the resin case and the heat sink. Conventionally, one of the following two methods has been adopted as a method of curing the thermosetting resin applied to the upper surface of the heat sink.

(A) Oven Heating Method In the oven heating method, as shown in FIG. 5, the resin case 11 is placed on the heat sink 12 with the adhesive 18 applied on the upper surface, and the resin case 11 and the heat sink 12 are brought into contact with each other. The jig 13 is assembled. Thereafter, the jig 13 is put into the oven, the adhesive 18 is cured, and the resin case 11 and the heat sink 12 are bonded.

(B) Hot plate heating method In the hot plate heating method, as shown in FIG. 6, the resin case 11 is placed on the heat sink 12 with the adhesive 18 applied on the upper surface, and the heat sink 12 contacts the hot plate 14. To be placed. Thereafter, the pressure cylinder 15 is brought into contact with the resin case 11 and the heat sink 12 is pressed against the hot plate 14. As a result, the heat sink 12 is heated, and the adhesive 18 is further cured to bond the resin case 11 and the heat sink 12 together.
JP 2002-203942 A

  However, the conventional heating method described above has the following problems. That is, in the oven heating method, the jig 13 has a large heat capacity and takes time for curing and cooling. Further, manual work is also required for assembling the jig 13. Therefore, it takes a long time to perform the joining work.

  In the hot plate heating method, heating time can be shortened by directly heating the heat sink 12. There is no need to assemble jigs. However, the heat sink 12 is more actively heated than the resin case 11. Therefore, the curing of the adhesive 18 starts in a state where a temperature difference is generated between the resin case 11 and the heat sink 12. As a result, the heat sink 12 contracts more than the resin case 11 when the workpiece 10 is cooled, and the workpiece 10 is greatly warped.

  The present invention has been made to solve the problems of the above-described conventional joining member joining methods. That is, the problem is to provide a joining member joining method and joining apparatus that can reduce the work time while suppressing the warpage of the workpiece.

  The joining member joining method made for the purpose of solving this problem is a joining member joining method using a joining member for joining a first joining member and a second joining member via a thermosetting resin adhesive as a workpiece. And a storage step for storing the workpiece in a thermally sealed space, a pressurizing step for pressurizing the space after the storing step, and a depressurizing step for depressurizing the space after the pressurizing step. It is characterized by that.

  Moreover, the joining apparatus of the joining member made | formed for the purpose of the solution of this subject is the joining member which makes the workpiece the joining member which joins the 1st joining member and the 2nd joining member through the thermosetting resin adhesive A joining device, which forms a heat-insulated and sealed space, accommodates a work in the space, pressurizing means for pressurizing the space, depressurizing means for depressurizing the space, pressurizing means, And control means for controlling the decompression means.

  In the present invention, first, the workpiece is accommodated in a thermally sealed space as an accommodation step. Next, as a pressurizing step, the inside of the space is pressurized to increase the internal pressure of the space. As the space is pressurized, the temperature in the space increases. By maintaining the state of this atmosphere, the work adhesive, which is a thermosetting resin, is cured, and the first joining member and the second joining member are joined. Next, as a depressurization step, the space is depressurized to reduce the internal pressure of the space. As the space is depressurized, the temperature in the space decreases. By maintaining this atmosphere, the workpiece is cooled quickly.

  In the joining method of the present invention, the internal pressure in the space in which the workpiece is accommodated is increased by adiabatic compression in the pressurizing step. This increase in the internal pressure causes a clamping effect to bring the first and second joining members of the workpiece into contact with each other. Therefore, a jig or the like for fixing the first joining member and the second joining member is not necessary. Therefore, there is no delay in joining time due to heating / cooling of the jig. In addition, there is no manual time for assembling the jig. Therefore, the time required for the joining process is short.

  In the pressurizing step, the ambient temperature in the space rises due to adiabatic compression of the space. Increasing the ambient temperature heats the entire workpiece uniformly. Therefore, the temperature difference between the first joining member and the second joining member during heating is small. As a result, workpiece warpage during cooling is small.

  In the pressurizing step of the present invention, it is better to pressurize the space by compressing the space, and in the depressurizing step, to decompress the space by expanding the space. That is, the internal pressure is changed by compressing / expanding the space. In this method, the energy used for compression / expansion of the space is purely converted into heating energy, which is energy efficient. Also, no energy source such as a pump or heater is required to adjust the internal pressure. Therefore, the equipment configuration is simple.

  In the pressurization step of the present invention, a pressurization condition in which the pressurization amount and pressurization time are set is acquired, and the space is pressurized according to the pressurization condition. In the depressurization step, the depressurization amount and the depressurization time are set. It is better to acquire the reduced pressure conditions and to reduce the pressure in the space according to the reduced pressure conditions. Thus, it is not necessary to detect the temperature in the space or the temperature of the work by setting the pressurizing condition and the depressurizing condition in advance and controlling the internal pressure of the space according to these conditions. Therefore, the equipment configuration is simple.

  Alternatively, in the pressurizing step of the present invention, the temperature of the workpiece housed in the space is detected, and the detected temperature reaches the first temperature that is higher than the curing temperature of the adhesive of the workpiece. In the depressurization step, the temperature of the work housed in the space is detected, and the space is depressurized until the detected temperature reaches a second temperature that is lower than the first temperature. Good. Thus, by acquiring the workpiece temperature directly and controlling the internal pressure of the space based on the temperature, more appropriate internal pressure control can be performed. Therefore, the joint work time can be shortened.

  ADVANTAGE OF THE INVENTION According to this invention, the joining method and joining apparatus of the joining member which shortened joining operation time were achieved, suppressing the curvature of a workpiece | work.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which a joining device for joining members according to the present invention is embodied will be described in detail with reference to the accompanying drawings. In the present embodiment, the present invention is applied to a joining device that joins a resin case housing a semiconductor module and a heat sink via a thermosetting resin adhesive.

[First embodiment]
[Configuration of joining device]
As shown in FIG. 1, a joining apparatus 100 according to a first embodiment houses a workpiece 10 that is an object to be joined, a cylinder 1 having one end as an open end and the other as a closed end, and an opening end of the cylinder 1. A piston 3 which is inserted and thermally insulated and sealed in the cylinder 1 and is movable in the vertical direction (the axial direction of the cylinder 1); a storage unit 8 in which operation settings of the piston 3 are stored; It has the control part 5 which acquires the setting information memorize | stored in the part 8, and controls the actuator 6 which moves the piston 3 to an up-down direction.

  In the joining apparatus 100, the position of the piston 3 is controlled by the control unit 5 based on the pressurization condition and the decompression condition stored in advance in the storage unit 8. As the pressurizing condition, the position of the piston 3 and the time for maintaining the position are set. As for the decompression condition, the position of the piston 3 and the time for maintaining the position are set as in the pressurization condition.

  Further, the piston 3 can be detached from the cylinder 1, and the workpiece 10 can be input from the opening end of the cylinder 1. The piston 3 is provided with a through hole 31 that can be opened and closed. A shutter mechanism that opens and closes the through hole 31 is also controlled by the control unit 5.

  The workpiece 10 is a joined body that is joined by a resin case 11 that houses a power IC, a metal heat sink 12, and a thermosetting resin adhesive 18. As the thermosetting resin, polyimide, epoxy resin, phenol resin, or the like that is generally used as an adhesive is applicable.

[Joint procedure]
Subsequently, an operation procedure of a bonding process using the bonding apparatus 100 of the present embodiment will be described with reference to FIGS. 2 and 3.

  First, as a “pre-curing process”, the piston 3 is removed, and the workpiece 10 is put into the cylinder 1 from the open end of the cylinder 1. That is, the workpiece 10 is placed at a predetermined position in the cylinder 1. At this time, the workpiece 10 is not fixed with a jig or the like, and the resin case and the heat sink are overlapped with an adhesive interposed therebetween. After the workpiece 10 is loaded, the piston 3 is attached and the piston 3 is moved downward to a predetermined position (hereinafter referred to as “initial position”) with the through hole 31 opened. After reaching a predetermined position, the through hole 31 is closed, and a space 2 that is insulated and sealed is formed in the cylinder 1. The atmosphere in the space 2 at this time is equivalent to the atmosphere outside the cylinder 1 and is at normal temperature and pressure.

  Next, as a “curing step”, the piston 3 is moved downward to compress the space 2 (compression process). At this time, the control unit 5 acquires the pressurizing condition from the storage unit 8. And the position of piston 3 is controlled according to the pressurization conditions. In the compression process, the space 2 is compressed by compressing the space 2 that is insulated and sealed, and the ambient temperature rapidly rises accordingly. As the temperature in the space 2 rises, the temperature of the workpiece 10 in the cylinder 1 also rises.

  After the position of the piston 3 is moved, the position of the piston 3 is maintained for a predetermined time set as a pressurizing condition (that is, a time when the adhesive of the work 10 is predicted to be hardened) and is compressed. (Compression maintenance process). In the compression maintaining process, heat exchange is performed between the atmosphere in the space 2 and the workpiece 10, the ambient temperature gradually decreases, the workpiece temperature gradually increases, and the entire workpiece 10 is heated uniformly. Thereby, an adhesive agent hardens | cures and a resin case and a heat sink are joined.

  During the curing process, the space 2 is in a high pressure state, and the resin case constituting the workpiece 10 and the heat sink are in contact with each other at a high pressure with an adhesive interposed therebetween. Therefore, a jig or the like for fixing the workpiece 10 is not necessary.

  Next, as a “cooling step”, the piston 3 is moved upward to expand the space 2 (expansion process). At this time, the control unit 5 acquires the decompression condition from the storage unit 8 as in the curing process. Then, the position of the piston 3 is controlled according to the decompression condition. Specifically, the piston 3 is moved until the vertical position of the piston 3 is higher than the initial position. In the expansion process, by expanding the space 2 that is insulated and sealed, the space 2 is depressurized, and the ambient temperature rapidly decreases accordingly. As the temperature in the space 2 decreases, the temperature of the workpiece 10 in the cylinder 1 also decreases.

  After the piston 3 is moved, the position of the piston 3 is maintained for a predetermined time set as a decompression condition (that is, a time when the workpiece 10 is expected to be sufficiently cooled), and the expanded state is maintained ( Expansion maintenance process). In the expansion maintenance process, heat exchange is performed between the atmosphere in the space 2 and the workpiece 10, the ambient temperature gradually increases, the workpiece temperature gradually decreases, and the entire workpiece 10 is uniformly cooled.

  Next, as the “curing / cooling completion process”, the piston 3 is moved to the initial position, and the space 2 is returned to the normal temperature and normal pressure as in the pre-curing process. After the movement of the piston 3, the through-hole 31 of the piston 3 is opened, the piston 3 is removed, and the workpiece 10 in the cylinder 1 is taken out. Thereby, the joining operation | work of the workpiece | work 10 is complete | finished.

[Second form]
[Configuration of joining device]
As shown in FIG. 4, the joining device 200 according to the second embodiment receives the signals from the cylinder 1, the piston 3, the temperature sensor 4 that detects the temperature of the workpiece 10, and the signal from the temperature sensor 4. And a controller 5 that controls an actuator 6 that moves the actuator in the vertical direction. In the joining device 200, the position of the piston 3 is controlled based on the signal from the temperature sensor 4. This is different from the first embodiment in which the temperature sensor 4 is not provided and the position control of the piston 3 is performed based on the pressurization condition or the decompression condition stored in the storage unit 8 in advance.

[Joint procedure]
Then, the operation | movement procedure of the joining process using the joining apparatus 200 of this form is demonstrated. First, as a pre-curing process, the piston 3 is removed, and the workpiece 10 is put into the cylinder 1 from the opening end of the cylinder 1.

  Next, as a curing step, the piston 3 is moved downward to compress the space 2 (compression process). In the compression process, the space 2 is compressed by compressing the space 2 that is insulated and sealed, and the ambient temperature rapidly rises accordingly. As the temperature in the space 2 rises, the temperature of the workpiece 10 in the cylinder 1 also rises.

  At this time, the control unit 5 acquires the temperature of the workpiece 10 by the temperature sensor 4. Then, the position of the piston 3 is controlled so that the temperature of the workpiece 10 becomes the first temperature (that is, the temperature at which the adhesive of the workpiece 10 starts to cure). After the temperature in the space 2 reaches the first temperature, the position of the piston 3 is maintained for a predetermined time (that is, the time until the adhesive of the workpiece 10 is completely cured), and the compression state is maintained (compression). Maintenance process). Thereby, an adhesive agent hardens | cures and a resin case and a heat sink are joined.

  Next, as a cooling step, the piston 3 is moved upward to expand the space 2 (expansion process). Specifically, the piston 3 is moved until the vertical position of the piston 3 reaches the initial position. In the expansion process, by expanding the space 2 that is insulated and sealed, the space 2 is depressurized, and the ambient temperature rapidly decreases accordingly. As the temperature in the space 2 decreases, the temperature of the workpiece 10 in the cylinder 1 also decreases.

  At this time, the controller 5 acquires the temperature of the workpiece 10 by the temperature sensor 4 as in the curing process. Then, the position of the piston 3 is controlled so that the temperature in the workpiece 10 becomes the second temperature (in this embodiment, a temperature lower than normal temperature). After the temperature of the workpiece 10 reaches the second temperature, the position of the piston 3 is maintained for a predetermined time (that is, the time until the workpiece 10 reaches the predetermined temperature) and the expanded state is maintained (expansion maintaining process). .

  Next, as a curing / cooling completion process, the piston 3 is moved to the initial position, and the space 2 is returned to the same room temperature and normal pressure as in the process before curing. After the movement of the piston 3, the through-hole 31 of the piston 3 is opened, the piston 3 is removed, and the workpiece 10 in the cylinder 1 is taken out. Thereby, the joining operation | work of the workpiece | work 10 is complete | finished.

  In the joining apparatus 200 according to the second embodiment, the temperature of the workpiece 10 is directly detected. Therefore, it is possible to quickly switch to the compression maintenance process when the workpiece 10 reaches the curing start temperature of the adhesive 18. Moreover, since the timing at which the curing start temperature is reached can be recognized, the margin for the time until the adhesive of the workpiece 10 is completely cured (the time for maintaining the compressed state) can also be set short. Therefore, compared with the first embodiment, the joining work time can be further shortened.

  On the other hand, in the joining device 100 of the first embodiment, the piston 3 is controlled without installing the temperature sensor 4. Therefore, compared to the second embodiment, the equipment structure and the control of the piston 3 are simple.

  As described above in detail, in the joining apparatus of the present embodiment, first, the workpiece 10 is accommodated in the space 2 that is heat-insulated and sealed. Next, the space 2 is pressurized by the downward movement of the piston 3 to raise the temperature in the space 2. By maintaining this atmosphere, the adhesive 18 of the workpiece 10 that is a thermosetting resin is cured, and the resin case 11 and the heat sink 12 are bonded. Next, the space 2 is depressurized by the upward movement of the piston 3, and the temperature in the space 2 is lowered. By maintaining this atmospheric state, the workpiece 10 is quickly cooled.

  In the joining device of the embodiment, the internal pressure in the space 2 is increased by adiabatic compression. The increase in the internal pressure causes a clamping effect to bring the resin case 11 of the workpiece 10 and the heat sink 12 into contact with each other. Therefore, a jig or the like for fixing the resin case 11 and the heat sink 12 is not required during the bonding process. Therefore, there is no delay in joining time due to heating / cooling of the jig. In addition, there is no manual time for assembling the jig. Therefore, the time required for the joining process is short.

  Further, the atmospheric temperature in the space 2 is raised by adiabatic compression of the space 2. Increasing the ambient temperature heats the entire workpiece 10 uniformly. Therefore, the temperature difference between the resin case 11 and the heat sink 12 during heating is small. As a result, the warpage of the workpiece 10 during cooling is small.

  In the joining device of the embodiment, the internal pressure is changed by compressing / expanding the space 2. In this method, the energy used for compression / expansion of the space 2 is purely converted into heating energy. Therefore, energy efficiency is good. Also, no energy source such as a pump or heater is required to adjust the internal pressure. Therefore, the equipment configuration is simple.

  Further, as a means for compressing / expanding the space, a piston mechanism in which the piston 3 moves up and down in the cylinder 1 is applied. By applying the piston mechanism, the space 2 can be compressed and expanded, that is, the workpiece 10 can be heated and cooled with a single facility, and the facility configuration is further simplified.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the compression / expansion may be performed by replacing the atmosphere with an inert gas such as nitrogen or a mixed gas of nitrogen and hydrogen.

  In the embodiment, the internal pressure of the space 2 is changed by moving the piston 3 up and down. However, the present invention is not limited to this. For example, a vacuum pump or a compressor may be connected to the cylinder 1, and the space 2 may be compressed or expanded by taking in and out the gas.

It is a schematic block diagram which shows the structure of the joining apparatus concerning a 1st form. It is a figure which shows the joining procedure of the joining apparatus concerning a 1st form. It is a graph which shows the atmospheric temperature and workpiece | work temperature in a cylinder during joining operation | movement. It is a schematic block diagram which shows the structure of the joining apparatus concerning a 2nd form. It is a figure which shows the example of adhesion | attachment by an oven heating system. It is a figure which shows the example of adhesion | attachment by a hotplate heating system.

Explanation of symbols

1 Cylinder (accommodating means)
2 Space in cylinder 3 Piston (pressurizing means, decompressing means)
4 Temperature sensor (temperature detection means)
5 Control unit (control means)
8 storage unit (storage means)
10 Workpiece 11 Resin case (first bonding member)
12 Heat sink (second bonding member)
18 Thermosetting resin adhesive 100 Joining device

Claims (8)

In the joining method of the joining member using the joining member that joins the first joining member and the second joining member via the thermosetting resin adhesive as a workpiece,
An accommodating step for accommodating the workpiece in a thermally sealed space;
A pressurizing step for pressurizing the space after the accommodating step;
A joining member joining method comprising: a decompressing step of decompressing the space after the pressurizing step. In the joining method according to claim 1,
In the pressurizing step, the space is pressurized by compressing the space,
In the depressurizing step, the space is depressurized by expanding the space, and the joining member joining method is characterized in that: In the joining method according to claim 1 or 2,
In the pressurization step, a pressurization condition in which a pressurization amount and a pressurization time are set is acquired, and the space is pressurized according to the pressurization condition,
In the depressurization step, a depressurization condition in which a depressurization amount and a depressurization time are set is acquired, and the space is depressurized in accordance with the depressurization condition. In the joining method according to claim 1 or 2,
In the pressurizing step, the temperature of the work housed in the space is detected, and the inside of the space is added until the detected temperature reaches a first temperature that is higher than the curing temperature of the adhesive of the work. Press,
In the depressurizing step, the temperature of the work housed in the space is detected, and the space is depressurized until the detected temperature reaches a second temperature that is lower than the first temperature. A joining method for joining members. In a joining device for a joining member using a joining member for joining the first joining member and the second joining member via a thermosetting resin adhesive as a workpiece,
A storage means for forming a heat-insulated and sealed space and storing the workpiece in the space;
Pressurizing means for pressurizing the space;
Decompression means for decompressing the space;
A joining device for joining members, comprising: a pressurizing means and a control means for controlling the decompressing means. The joining apparatus according to claim 5,
The pressurizing means compresses the space to pressurize the space,
The said decompression means decompresses the inside of the said space by expanding the said space, The joining apparatus of the joining member characterized by the above-mentioned. In the joining apparatus according to claim 5 or 6,
Storage means for storing a pressurizing condition in which a pressurizing amount and a pressurizing time are set, and a depressurizing condition in which a depressurizing amount and a depressurizing time are set;
The said control means controls the said pressurization means based on the said pressurization conditions, and controls the said pressure reduction means based on the said pressure reduction conditions, The joining apparatus of the joining member characterized by the above-mentioned. In the joining apparatus according to claim 5 or 6,
Having temperature detecting means for detecting the temperature of the work housed in the space;
The said control means controls the said pressurization means and the said pressure reduction means based on the signal from the said temperature detection means, The joining apparatus of the joining member characterized by the above-mentioned.

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