JP3539826B2 - Thermocompression tools - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thermocompression bonding tool used when bonding a semiconductor chip to various circuit boards such as a liquid crystal substrate.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various types of thermocompression bonding tools used for bonding a semiconductor chip to various circuit boards such as a liquid crystal substrate are known.
[0003]
As one of them, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-86341, a lower end surface of a ceramic holder attached to a lower end of a tool body and an upper end surface of a heater are joined together. There is a thermocompression bonding tool formed by joining a lower end surface of a heater and an upper end surface of a ceramic indenter.
[0004]
Note that such a heater has a heating pattern sandwiched between a pair of ceramic thin plates as an electrical insulating material, and both ceramic thin plates are joined and sealed, or a heating pattern printed on the upper end surface of an indenter is formed of an electrical insulating material. What is sealed with a certain glass is used.
[0005]
[Problems to be solved by the invention]
However, since this type of thermocompression bonding tool uses an adhesive to join each part, the difference in thermal expansion due to the variation in the applied thickness of the adhesive and the difference between the thermal expansion of the adhesive and that of the electrical insulation material Due to the influence of the difference and the like, the parallelism of the lower end surface of the indenter (the surface pressed against the bonding portion) is liable to change with time and has a disadvantage that it is not constant.
[0006]
In addition, such a parallelism is regarded as a problem particularly in bonding that requires accuracy of a micron unit, and if it is not kept constant, chip displacement or the like occurs during bonding, and it becomes difficult to perform high-precision bonding. .
[0007]
The present invention has been made in view of such drawbacks, and as a result of intensive studies to solve it, as one of them, it is mounted on the upper end surface of a ceramic indenter in a recess formed on the lower end surface of the holder. It is necessary to attach the indenter to the holder by non-adhesive fixing means so as to position the heater, and as another, the indenter with the heater attached to the lower end side face is attached to the lower end of the holder. It has been found that the same problem can be solved also by mounting with non-adhesive fixing means.
[0008]
[Means for Solving the Problems]
That is, one of the thermocompression bonding tools according to the present invention includes a holder attached to the lower end of the tool body, a ceramic indenter attached to the lower end of the holder, and a holder for the holder which is opposed to each other. A thermocompression bonding tool comprising a lower end face and a heater disposed between the upper end face of the indenter, and the heater is mounted on the upper end face of the indenter in a thermocompression bonding tool having a heat generation pattern sealed with an electrical insulating material. The indenter is attached to the holder by a non-adhesive fixing means so that the heater is positioned in a recess formed in a lower end surface of the holder.
[0009]
Further, another one of the thermocompression bonding tools according to the present invention is, as described in claim 2, in the thermocompression bonding tool according to claim 1, wherein the holder is penetrated so as to be communicated with the recess. It is characterized in that it has a hole for exclusive use of air suction and has a chip suction hole penetrated so that the indenter can communicate with the recess.
Further, another one of the thermocompression bonding tools according to the present invention is, as described in claim 3, in the thermocompression bonding tool according to claim 1, wherein the holding tool is penetrated so as to be communicated with the recess. The air suction and supply hole and the air discharge hole have at least an air suction and supply hole, and the indenter has a chip suction hole penetrated so as to communicate with the recess. Things.
[0010]
Another aspect of the thermocompression bonding tool according to the present invention is, as described in claim 4, in the thermocompression bonding tool according to claim 1, wherein the holding tool is penetrated so as to be communicated with the recess. It has a hole dedicated to air supply and an air discharge hole.
[0011]
Further, another one of the thermocompression bonding tools according to the present invention is, as described in claim 5, in the thermocompression bonding tool according to claim 1, an air penetrated so that the holder does not communicate with the recess. It is characterized by having a supply exclusive hole.
[0012]
Further, another one of the thermocompression bonding tools according to the present invention is, as described in claim 6, a holder attached to a lower end of the tool body, and attached to a lower end of the holder by non-adhesive fixing means. A ceramic indenter, and a heater mounted on a lower side surface of the indenter, wherein the heater is formed by sealing a heating pattern with an electric insulator.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
In FIG. 1 showing the tip of the thermocompression bonding tool, a ceramic holder 2 is bolted to a lower end of a tool body 1 made of a metal material having low heat conductivity, and a ceramic holder is provided. At the lower end of 2, a ceramic indenter 3 is mounted.
[0014]
That is, the indenter 3 is fixed to the holder 2 with the bolts and nuts 4, and the upper end surface 3 a thereof is pressed against the lower end surface 2 a of the holder 2. It is made of aluminum nitride having good conductivity, high heat generation efficiency per unit area, and strong against thermal shock due to rapid heating.
[0015]
On the other hand, the holder 2 is made of a ceramic material having poor heat conductivity (for example, mullite). The latter (indenter 3) is selected to have a coefficient of thermal expansion that is as close as possible to the former (indenter 3).
[0016]
In addition, a heater 5 is mounted on the upper end surface 3a of the indenter 3, and this heater 5 generates a heating pattern 6 screen-printed on the upper end surface 3a of the indenter 3, as shown in FIG. It is configured by sealing with an electric insulating material 7.
[0017]
In this sealing, molten glass (electric insulating material) is thinly applied on the heat generating pattern 6 (for example, platinum palladium) and cured. However, other suitable electrical insulators 7 other than glass can be used.
[0018]
The heating pattern 6 is connected to a power supply (not shown), and the heater 5 is located in a recess 8 formed on the lower end surface 2 a of the holder 2. The peripheral wall is formed in a mode surrounded by the peripheral wall, that is, the peripheral wall is also formed in the front-rear direction (not shown).
[0019]
Further, the indenter 3 has a chip suction hole 9 formed in the lower end surface 3b thereof and the wall surface of the concave portion 8, and the holder 2 has an air hole formed in the side surface 2b thereof and the wall surface of the concave portion 8. An exclusive suction hole 10 is provided.
[0020]
Further, a pressure-resistant hose 11 for air suction is attached to the side surface 2b of the holder 2 so that one end thereof is connected to the air suction hole 10. The other end, not shown, of the air suction pressure-resistant hose 11 is connected to a vacuum pump.
[0021]
Therefore, since the vacuum pump can be operated to suck air from the chip suction hole 9, the semiconductor chip can be held by suction, and the tool body 1 is moved downward while the semiconductor chip is held by suction. Bonding.
[0022]
The tool body 1 is mounted so as to be movable in three axial directions via an XYZ table (not shown). At the time of bonding, the holder 2 and the indenter 3 are heated by the heater 5.
[0023]
However, since the heater 5 is located in the recess 8 and the indenter 3 is attached to the holder 2 by bolting, the parallelism of the lower end surface 3b of the indenter 3 (the surface pressed against the bonding portion) is reduced. It can be prevented from changing over time.
[0024]
That is, at the time of heating, the glass (electric insulating material) sealing the heat generating pattern 6 thermally expands, but since it is located in the concave portion 8, the influence is exerted on the holder 2 and the indenter 3. In addition, since the indenter 3 is attached to the holder 2 by bolting, it is possible to prevent uneven thermal expansion from occurring at this location, and to achieve a synergistic effect of these. In addition, the parallelism of the lower end surface 3b of the indenter 3 (the surface pressed against the bonding portion) can be prevented from changing over time.
[0025]
Since the heater 5 is located in the recess 8, it is possible to prevent the pressing force from acting on the sealing portion (the portion covered with the electrical insulating material) of the heat generating pattern 6 during bonding. Therefore, disconnection of the heating pattern 6 can also be prevented.
[0026]
When the indenter 3 does not hold the semiconductor chip by suction, the air can be sucked into the recess 8 from the chip suction hole 9 and can be cooled, so that it is effective from this point. In addition, heat conduction to the upper side of the holder 2 can be suppressed by the heat insulating effect of the air in the concave portion 8 and high-speed cooling can be performed.
[0027]
The indenter 3 may be attached to the holder 2 not only by bolting but also by an appropriate clamp or the like. In short, the indenter 3 may be attached by fixing means that does not use an adhesive, that is, non-adhesive fixing means.
[0028]
The heater 5 is preferably formed by sealing a heating pattern 6 printed on the upper end surface 3a of the indenter 3 with an electric insulating material 7, but the heating pattern is formed by a pair of ceramic thin plates (electric insulating material). It may be one in which both ceramic thin plates are adhered and sealed.
[0029]
However, it is preferable that the heat generating pattern 6 is screen-printed on the upper end surface 3a of the indenter 3 because it is excellent in heat conductivity and can be made compact. In addition, air may be any of room temperature air and cooling air, and is selected as needed.
[0030]
Next, another embodiment shown in FIG. 3 will be described. In this embodiment, the holder 2 is provided with the air suction / supply hole 15 and the air discharge hole 14 and the three-way switching valve 13. A pressure-resistant hose 11 for air suction and a pressure-resistant hose 12 for air supply are mounted via the.
[0031]
Therefore, the three-way switching valve 13 can be controlled to open and close in a predetermined manner to suck air from the chip suction hole 9 or discharge air from the chip suction hole 9 and the air discharge hole 14.
[0032]
That is, the air supply from the air supply pressure-resistant hose 12 is performed as needed, and thereby the holder 2 and the indenter 3 can be cooled to prevent overheating.
[0033]
In addition, when performing bonding at a lower temperature subsequent to the preceding bonding at a higher temperature, the temperature can be forcibly controlled to a lower temperature, and therefore, the temperature control of the tool can be speeded up.
[0034]
The air is exhausted from the air discharge hole 14 through a pressure-resistant hose (not shown) for air discharge attached to the holder 2 so as to be connected thereto. A valve (not shown) to which the pressure-resistant hose is connected is opened, and this valve is closed when air is sucked from the chip suction hole 9.
[0035]
Thus, it is preferable to form the air suction / supply hole 15 and the air discharge hole 14. However, only the air suction and supply hole 15 may be formed without forming the air discharge hole 14.
[0036]
In this case, since the air is discharged only from the chip suction holes 9, the cooling effect is inferior to the case where the air is discharged from both the air discharge holes 14 and the chip suction holes 9. Therefore, either one may be selected as needed.
[0037]
Next, the embodiment shown in FIG. 4 will be described. In this embodiment, a hole 16 dedicated to air supply and an air discharge hole 14 are formed in the holder 2, but a chip suction hole is formed in the indenter 3. Not drilled.
[0038]
Therefore, the semiconductor chip cannot be suction-held, but since the tool body 1 is mounted so as to be movable in three axial directions via the XYZ table, the thermocompression bonding shown in FIGS. Bonding (thermocompression bonding) can be performed similarly to the tool.
[0039]
Further, FIG. 5 also shows an embodiment in which a chip suction hole is not formed in the indenter 3, but in this case, air is provided so that the holder 2 does not open to the peripheral wall surface of the recess 8. The supply exclusive hole 16 is penetrated and provided. Therefore, even with this tool, a cooling effect can be obtained.
[0040]
As described above, the non-adhesive fixing means for fixing the indenter 3 to the holder 2 so that the heater 5 mounted on the upper end surface 3a of the indenter 3 is positioned in the recess 8 formed in the lower end surface 2a of the holder 2. In the following, another embodiment different from them, that is, the embodiment shown in FIG. 6 will be described. In this embodiment, the heater 5 is provided on the lower end side surface 20 of the indenter 3. It is mounted, and the indenter 3 is mounted on the holder 2 by bolts and nuts 21 (non-adhesive fixing means).
[0041]
Therefore, even when the glass (electric insulating material) sealing the heat generating pattern 6 thermally expands during heating, the parallelism of the lower end surface 3b (the surface pressed against the bonding portion) of the indenter 3 is affected by the influence thereof over time. Can be prevented. It should be noted that the indenter 3 may be one in which the chip suction hole 9 is formed or one in which the chip suction hole 9 is not formed, and is selected as necessary.
[0042]
【The invention's effect】
As described above, according to the first and sixth aspects of the present invention, there is provided a thermocompression bonding tool capable of preventing the parallelism of the lower end surface 3b (the surface pressed against the bonding portion) of the indenter 3 from changing with time. can get.
[0043]
According to the second, third, fourth and fifth aspects of the present invention, it is possible to forcibly cool the heated portion, and it is more effective that the parallelism of the lower end face 3 b of the indenter 3 changes with time. Thus, a thermocompression bonding tool that can be prevented is obtained.
[Brief description of the drawings]
FIG. 1 is a front view of a distal end portion of a thermocompression bonding tool.
FIG. 2 is a perspective view of an indenter.
FIG. 3 is a front view of a tip portion of another thermocompression bonding tool.
FIG. 4 is a front view of a distal end portion of another thermocompression bonding tool.
FIG. 5 is a front view of a tip portion of another thermocompression bonding tool.
FIG. 6 is a front view of a tip portion of another thermocompression bonding tool.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tool main body 2 Holder 2a Lower end face 2b of holder 3 Side face of holder 3 Indenter 3a Upper end face of indenter 3b Lower end face of indenter 5 Heater 6 Heating pattern 7 Electrical insulating material 8 Depression 9 Chip suction hole 10 Air suction hole 14 Air discharge hole 15 Air suction / supply hole 16 Air supply dedicated hole 20 Lower side of indenter

Claims (6)

A holder mounted on the lower end of the tool body, a ceramic indenter mounted on the lower end of the holder, and a heater disposed between a lower end surface of the holder and an upper end surface of the indenter opposed to each other. Wherein the heater is mounted on an upper end surface of the indenter on a lower end surface of the holder in a thermocompression bonding tool in which a heating pattern is sealed with an electrical insulating material. A thermocompression bonding tool, wherein the indenter is attached to the holder by non-adhesive fixing means so as to be positioned in the recess. 2. The thermocompression bonding tool according to claim 1, wherein the holder has a hole dedicated to air suction penetrated to communicate with the recess, and the tip suction penetrates the indenter so as to communicate with the recess. A thermocompression bonding tool having holes. 2. The thermocompression bonding tool according to claim 1, wherein the holding tool has at least an air suction / supply / hole among the air suction / supply / hole and the air discharge / hole which are pierced so as to communicate with the recess. Has a chip suction hole penetrated so as to be communicated with the concave portion. 2. The thermocompression bonding tool according to claim 1, wherein the holder has an air supply exclusive hole and an air exhaust hole penetrated so as to communicate with the recess. 2. The thermocompression bonding tool according to claim 1, wherein the holder has a hole dedicated to air supply penetrated so as not to communicate with the recess. A holder attached to a lower end of the tool body, a ceramic indenter attached to a lower end of the holder by non-adhesive fixing means, and a heater attached to a lower end side surface of the indenter; Wherein the heat generating pattern is sealed with an electrical insulator.

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