JP2004296645A - Method for curing adhesive and curing jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the curing time of an adhesive by efficiently heating by remarkably reducing the escape of a heat from a heater by transferring the heat from the heater efficiently to the adhesive by directly heating the adhesive by the heater. <P>SOLUTION: A method for curing the adhesive includes a step of adhering a heat sink plate 1 to be connected with a substrate 3 on which a heating element 4 is mounted to the housing 2 of the heating plate 1. The method further includes the steps of coating the adhesive 5 on the heat sink plate 1 or the housing 2, then superposing the heat sink plate 1 and the housing 2, and heating to cure the adhesive 5 in the heater 12 disposed locally at the position corresponding to the coating region of the adhesive 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a curing method and a curing jig for an adhesive for bonding a heat sink to which a substrate on which an element is mounted is bonded and a housing of the heat sink.
[0002]
[Prior art]
In a power module having a control function such as an inverter gate bipolar transistor (IGBT) module for an inverter, a substrate on which a heating element is mounted is joined to a heat radiating plate due to a problem such as heat radiation. A housing for covering and protecting the substrate is bonded to the heat sink with an adhesive. A thermosetting adhesive is used as an adhesive for bonding the heat sink to the housing.
Then, when bonding the housing to the heat sink, a method of heating and curing the adhesive through the heat sink by superimposing the housing on the heat sink coated with the adhesive, and then placing the heat sink on the hot plate. Was taking.
[0003]
Further, as a method of bonding the heat radiating plate and other members, for example, in order to improve the bonding strength between the heat radiating plate and the substrate bonded with an adhesive tape, a thermosetting adhesive is applied to the substrate longitudinal end portion. There is known a technique in which a thermosetting adhesive is cured by applying heat to a portion of a thermosetting adhesive without increasing the warpage of a heat sink (see Patent Documents 1 and 2).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 7-32629 [Patent Document 2]
JP-A-7-40566
[Problems to be solved by the invention]
As described above, when bonding the housing to the heat sink, when the heat sink is placed on the hot plate and the adhesive is cured, not only the adhesive application area but also the entire heat sink having a large heat capacity is heated. Therefore, there has been a problem that it is difficult for the adhesive to rise in temperature and it takes a long time to be cured.
In view of the above, the present invention provides a method for curing an adhesive that can be cured in a short time by shortening the curing time of the adhesive for bonding the heat sink and the housing.
[0006]
[Means for Solving the Problems]
An adhesive curing method and a curing jig of the present invention that solves the above problems have the following features.
That is, in the first aspect, there is provided a bonding method for bonding a heat radiating plate to which a substrate on which an element is mounted is joined and a housing of the heat radiating plate. The plate and the housing are overlapped, a heater is locally disposed at a location corresponding to the adhesive application area, and the adhesive is locally heated and cured by the heater.
As a result, it is possible to heat only the vicinity of the adhesive application region by the heater, and it is possible to greatly reduce the amount of heat from the heater that escapes to an unnecessary portion. Then, heat from the heater can be efficiently transmitted to the adhesive, and the curing time of the adhesive can be reduced.
[0007]
In the second aspect, the heating and curing of the adhesive by the heater are performed by setting the superposed radiator plate and the housing while positioning the radiating plate and the housing on a curing jig provided with the heater.
Thereby, the relative position between the radiator plate and the housing and the heating range by the heater can be accurately aligned with a simple configuration, and the adhesive can be more efficiently cured.
[0008]
According to a third aspect of the present invention, the heater is removably inserted in the vicinity of the adhesive application area between the heat sink or the housing or the stacked heat sink and the housing, and after the adhesive is cured, the heater is turned on. It is a thing to extract.
As a result, the adhesive can be locally and directly heated by the heater, so that the escape of heat from the heater can be greatly reduced, and efficient heating can be performed.
In addition, since a base for supporting the heater or mounting the radiator plate is not required, the heating equipment can be simplified.
[0009]
According to a fourth aspect of the present invention, the adhesive curing jig protrudes from the base for positioning the heat sink and the housing on which the superposed heat sink and the housing are set. A positioning member, a heater embedded in the base in accordance with an application area of the adhesive applied to the heat sink or the housing, and an urging member for urging the heater in a direction protruding from the base. is there.
Thereby, the heater and the heat radiating plate can be brought into close contact with each other at the time of heating, heat can be more efficiently transmitted to the adhesive, and the curing time of the adhesive can be reduced.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a heat radiating plate and a housing and a curing jig bonded by the method of curing an adhesive of the present invention. FIG. 2 is a perspective view showing a state where the heat radiating plate and the housing are set in the curing jig. FIG. 3 is a side sectional view showing a curing jig in a state where a heat sink and a housing are set, FIG. 4 is a view showing a curing step of an adhesive, and FIG. 5 is a heat sink and a housing and a heater in a second embodiment. FIG. 6 is a perspective view showing a state where a heater is inserted with a radiator plate and a housing overlapped. FIG. 7A is formed by a lower heater groove of the radiator plate and an upper heater groove of the housing. FIG. 4B is a partially enlarged perspective view showing a state where a heater is inserted into a hole formed by the heater, and FIG. 4B is a partially enlarged perspective view showing a state where a heater is removed from a hole formed by a lower heater groove of a heat sink and an upper heater groove of a housing. FIG. 8 and FIG. It is a perspective view showing a heat radiating plate formed with holes.
[0011]
The method of curing an adhesive according to the present invention is a method of setting a heat sink to which a substrate having elements mounted thereon and a housing bonded to the heat sink in a superimposed state on a curing jig, and setting the heat sink or the housing. Is locally heated and cured by a heater provided in a curing jig.
[0012]
First, a first embodiment of a method for curing an adhesive will be described.
As shown in FIG. 1, a substrate 3 on which a heating element 4 is mounted is joined to an upper surface of a heat sink 1 to which a housing 2 is adhered by soldering or the like. The heat radiating plate 1 is for efficiently radiating the heat generated during the operation of the heating element 4.
The adhesive 5 for bonding the heat radiating plate 1 and the housing 2 is applied to a portion of the upper surface of the heat radiating plate 1 corresponding to the bonding region with the housing 2. The coating is performed by a known coating method such as coating by a dispenser or coating by screen printing.
[0013]
The curing jig 7 has a base 11 on which the heat radiating plate 1 and the housing 2 in an overlapped state are set, and projects upward from the base 11 to position the heat radiating plate 1 and the housing 2 to be set with respect to the base 11. Positioning pins 13, 13, which are positioning members for performing the above, a heater 12 buried in the base 11, and a push-up member 15 as a biasing member for biasing the heater 12 in a direction protruding from the base 11. I have.
[0014]
As shown in FIG. 2, the heater 12 embedded in the base 11 applies the adhesive 5 applied to the substrate 1 or the housing 2 while the heat sink 1 and the housing 2 are set on the curing jig 7. It is arranged at a position corresponding to the area.
The positioning pins 13 are provided at a plurality of positions, and the heat sink 1 and the housing 2 are provided with positioning holes 1a and 2a into which the positioning pins 13 can be inserted, in accordance with the number and the positions of the positioning pins 13, respectively. Is formed.
[0015]
As shown in FIG. 3, a heater embedding hole 11a is formed in the base 11 of the curing jig 7 at a position where the heater 12 is arranged, and a heater lifting block 14 is provided in the heater embedding hole 11a. It is fitted slidably up and down.
A heater embedding groove 14 a is formed on the upper surface side of the heater lifting block 14, and the heater 12 is embedded in the heater embedding groove 14 a via a heat insulating material 16. The upper end of the heater 12 is located above the upper surface of the heater push-up block 14 in a natural state in which a force from above is not applied to the heater 12.
[0016]
Further, a push-up member 15 for urging the heater push-up block 14 upward to be pushed up is provided at the bottom of the heater embedding hole 11a. In the present embodiment, the lifting member 15 uses a disc spring. However, the lifting member 15 may elastically urge the heater lifting block 14 upward, such as another spring member such as a compression spring or a leaf spring, or a heat-resistant rubber member. Anything should do.
The heater push-up block 14 is pushed up by the push-up member 15, and in a natural state where no force is applied from above, the upper end of the heater 12 is located above the upper surface of the base 11.
[0017]
Using the curing jig 7 configured as described above, the adhesive 5 for bonding the heat sink 1 and the housing 2 is cured by the following method.
First, an adhesive 5 is applied to a predetermined area of the upper surface of the heat radiating plate 1 to which the housing 2 is bonded, and the housing 2 is overlaid on the heat radiating plate 1 to which the adhesive 5 has been applied from above. At this time, it is desirable that the relative position between the heat radiating plate 1 and the housing 2 is adjusted to a position where the heat sink 1 and the housing 2 are finally bonded.
[0018]
The heat radiating plate 1 and the housing 2 are placed and set on the curing jig 7 while the positioning holes 1a and 2a of the superposed heat radiating plate 1 and the housing 2 are inserted into the positioning pins 13 and 13.
By inserting the positioning holes 1a and 2a into the positioning pins 13 and 13, the relative position between the heat sink 1 and the housing 2 and the relative position between the applied adhesive 5 and the heater 12 are accurately positioned.
[0019]
A load is applied to the radiator plate 1 and the housing 2 placed on the base 11 from above.
In this state, the heater 12 is pressed against the lower surface of the radiator plate 1 and has a temperature sufficient for the adhesive 5 to be cured, and the adhesive is heated and cured by the heater 12 via the radiator plate 1. .
[0020]
In this case, the heater 12 is pushed upward by the push-up member 15 and the heat sink 1 and the housing 2 are in a state where a downward load is applied. Heat from 12 is efficiently transferred to adhesive 5.
Further, since the heater 12 is disposed only below the area where the adhesive 5 is applied, and does not heat unnecessary areas, the heating area of the radiator plate 1 is reduced and heat is efficiently applied to the adhesive 5. And the temperature can be increased to shorten the curing time and reduce the energy required for curing.
[0021]
When the adhesive 5 is hardened and hardened by the heating of the heater 12, the load applied to the heat sink 1 and the housing 2 is released, and the heat sink 1 and the housing 2 are removed from the hardening jig 7.
[0022]
After the adhesive 5 is applied to the heat sink 1 or the housing 2 as described above, the heat sink 1 and the housing 2 are overlapped with each other, and the heater 12 is locally arranged at a position corresponding to the application area of the adhesive 4. By heating and hardening the adhesive 5 by the heater 12, it becomes possible to heat only the vicinity of the application area of the adhesive 4 by the heater 12, and the heat from the heater 12, which escapes to an extra portion, is removed. Can be significantly reduced.
Thereby, the heat from the heater 12 can be efficiently transmitted to the adhesive 5, and the curing time of the adhesive 5 can be shortened.
[0023]
The heating and curing of the adhesive material 5 by the heater 12 is performed by setting the superposed heat radiating plate 1 and the housing 2 while positioning the heat radiating plate 1 and the housing 2 on the curing jig 7 provided with the heater 12. 2 and the heating range of the heater 12 can be accurately positioned with a simple configuration, and the adhesive 5 can be more efficiently cured.
[0024]
Further, the curing jig 7 includes a base 11 on which the heat sink 1 and the housing 2 are set, and positioning pins 13 projecting from the base 11 for positioning the heat sink 1 and the housing 2 with respect to the base 11. A heater 12 buried in the base 11 in accordance with an application area of the adhesive 5 applied to the radiator plate 1 or the housing 2 and a push-up member 15 for urging the heater 12 in a direction for pushing the heater 12 upward. At the time of heating, the heater 12 and the heat radiating plate 1 can be brought into close contact with each other, so that heat can be more efficiently transmitted to the adhesive 5 and the curing time of the adhesive 5 can be reduced.
[0025]
Next, an example in which the adhesive curing method of the present embodiment is applied to an adhesive curing step for the heat sink 1 and the housing 2 will be described.
In the adhesive curing step, first, as shown in FIG. 4A, the housing 2 is supplied from above the heat sink 1 on which the adhesive has been applied to a predetermined area by a dispenser or the like.
As shown in FIG. 4B, the housing 2 is superimposed on the heat radiating plate 1 on the conveyor 21, and is conveyed by the conveyor 21 to a position where the curing jig 7 is arranged.
[0026]
The curing jig 7 is disposed below the conveyor 21, and a receiving stand 23 is disposed above the conveyor 21 at the position where the curing jig 7 is disposed. The curing jig 7 is supported on the support base 22 via the cylinders 22a, and can be moved up and down by expansion and contraction of the cylinders 22a.
When the heat radiating plate 1 and the housing 2 that have been superimposed are conveyed to the position of the curing jig 7, the cylinders 22a are extended to raise the curing jig 7.
[0027]
As shown in FIG. 4C, the positioning of the heat radiating plate 1 and the housing 2 with the heater 12 is performed by the positioning pins 13 and 13 when the curing jig 7 is raised, and the heat radiating plate 1 and the housing 2 are separated. The heater 12 can be brought into close contact with the lower surface of the heat sink 1 by being sandwiched between the curing jig 7 and the receiving stand 23.
This state is maintained for a predetermined time until the adhesive 5 is cured.
[0028]
As shown in FIG. 4D, when the adhesive 5 is hardened by the heating of the heater 12 closely attached to the heat sink 1, the cylinders 22a are reduced to lower the hardening jig 7, and the bonded heat sink is heated. 1 and the housing 2 are carried out by the conveyor 21.
As described above, the application of the adhesive 5, the superposition of the heat sink 1 and the housing 2, the curing of the adhesive 5, and the unloading of the heat sink 1 and the housing 2 after the adhesive has been cured are automated and made into a line. Can be.
[0029]
Next, a second embodiment of the method for curing the adhesive will be described.
As shown in FIG. 5, the substrate 3 on which the heating element 4 is mounted is joined to the center of the upper surface of the heat sink 51. .. Are formed along the respective sides in the vicinity of the peripheral portion on the upper surface of the heat radiating plate 51, and are bonded to both sides of each of the lower heater grooves 51a. Agent 5 is applied.
[0030]
On the lower surface of the housing 52 bonded to the heat radiating plate 51, upper heater grooves 52a, 52a,... Are formed in accordance with the positions of the lower heater grooves 51a, 51a,.
When the radiator plate 51 and the housing 52 are overlapped, the lower heater grooves 51a, 51a... Of the radiator plate 51 and the upper heater grooves 52a, 52a. A circular hole will be formed.
[0031]
When bonding the radiator plate 51 and the housing 52 formed in this manner, first, the adhesive 5 is applied to both sides of the lower heater grooves 51a, 51a,. A heater 62 is placed on each of the heaters 51a.
As shown in FIG. 6, after the heater 62 is set in the lower heater grooves 51a, the housing 52 is overlaid on the heat sink 51, and a load is applied from above. In this state, as shown in FIG. 7A, the heater 62 is in a state of being inserted into a hole formed by the lower heater groove 51a and the upper heater groove 52a.
[0032]
The heater 62 is heated while being inserted into the hole, and the heated state is maintained until the adhesive 5 hardens.
As shown in FIG. 7B, after the adhesive 5 is cured, the heater 62 is removed from the hole, and the bonded heat sink 51 and housing 52 are completed.
[0033]
As described above, the heater 62 is inserted into the vicinity of the adhesive application area between the heat radiating plate 51 and the housing 52 which are superimposed, and the adhesive is hardened. Heating can be performed directly, and heat can be efficiently released by greatly reducing the escape of heat from the heater 62.
In addition, since a base for supporting the heater 62 and mounting the radiator plate 1 is not required, the heating equipment can be simplified.
[0034]
As shown in FIG. 8, heater insertion holes 71a, 71a,... Located below the application area of the adhesive 5 are formed from the side surfaces of the heat sink 71, and the heater 62 is inserted into the heater insertion holes 71a. Then, the adhesive 5 can be locally heated and cured.
Similarly, the adhesive 5 may be applied to the lower surface of the housing 52, and a hole for inserting the heater 62 may be formed in the housing 62 in the vicinity of the application area of the adhesive 5, and the bonding may be performed. .
[0035]
【The invention's effect】
As described above, according to the present invention,
The adhesive can be directly heated by the heater, and the heat from the heater can be efficiently transmitted to the adhesive.
This makes it possible to perform efficient heating by greatly reducing the escape of heat from the heater, thereby shortening the curing time of the adhesive.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a heat radiating plate and a housing bonded by a method for curing an adhesive of the present invention, and a curing jig.
FIG. 2 is a perspective view showing a state in which a heat sink and a housing are set on a curing jig.
FIG. 3 is a side sectional view showing a curing jig in a state where a heat radiating plate and a housing are set.
FIG. 4 is a view showing a curing step of an adhesive.
FIG. 5 is a perspective view illustrating a radiator plate, a housing, and a heater according to a second embodiment.
FIG. 6 is a perspective view showing a state in which a heater is inserted with a heat sink and a housing overlapped.
7A is a partially enlarged perspective view showing a state in which a heater is inserted into a hole formed by a lower heater groove of a heat sink and an upper heater groove of a housing, and FIG. FIG. 4 is a partially enlarged perspective view showing a state where a heater is removed from a hole formed by a heater groove and an upper heater groove of a housing.
FIG. 8 is a perspective view showing a radiator plate having a hole into which a heater is inserted.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat sink 2 Housing 3 Substrate 5 Adhesive 7 Curing jig 11 Base 12 Heater 13 Positioning pin 15 Push-up member

Claims (4)

A bonding method for bonding a heat sink and a housing to which a substrate on which elements are mounted is bonded,
After applying the adhesive to the heat sink or the housing, the heat sink and the housing are overlapped,
A method for curing an adhesive, comprising locally disposing a heater at a position corresponding to an adhesive application area, and locally heating and curing the adhesive with the heater. The method for curing an adhesive according to claim 1, wherein the heating and curing of the adhesive by the heater are performed by setting the superposed radiator plate and the housing while positioning them on a curing jig provided with the heater. . The heater, the heat sink or the housing, or between the stacked heat sink and the housing, removably inserted near the adhesive application area,
The method for curing an adhesive according to claim 1, wherein the heater is removed after the adhesive is cured. A base on which the superposed heat sink and the housing are set,
A positioning member protruding from the base, which performs positioning with respect to the base of the heat sink and the housing to be set,
A heater buried in the base according to the application area of the adhesive applied to the heat sink or the housing;
And a biasing member for biasing the heater in a direction protruding from the base.

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