JP3247636B2 - Bonding tool and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bonding tool and a method for manufacturing the same. More specifically, the present invention has a good adhesion between the polycrystalline diamond film constituting the tool working surface and the substrate, and is free from cracks and peeling.
AB (Tape Automated Bondin)
g) A bonding tool for a process and a manufacturing method thereof.

[0002]

2. Description of the Related Art In a TAB process, electrodes of an LSI chip and leads of a film carrier are connected. FIG.
FIG. 4 is an explanatory view of a TAB step. On the thermal insulator 2 on the heating stage 1, the film carrier 6 having the inner lead 5 is moved via the tape guide 7 to the chip 4 positioned by the chip guide 3, and the position of the inner lead and the electrode 8 are brought to coincide. In this state, the heated bonding tool 9 is pressed down by the pressing cylinder 10 to press the inner lead against the electrode, and to form an Au-Sn eutectic alloy between the inner lead and the electrode, or Is bonded to the inner lead by thermocompression bonding. In order to perform good TAB, it is important to maintain the uniformity of the height of the electrode, and also to ensure the flatness of the working surface of the bonding tool, the wear resistance, and the uniform temperature distribution. As a material for the working surface of the bonding tool, a polycrystalline diamond film having excellent wear resistance and high thermal conductivity has been developed. Generally, Si is used as a substrate for forming a polycrystalline diamond film.
A sintered body such as C, Si ₃ N ₄ , or AlN is used. However, the sintered substrate contains a binder element and an impurity element. For example, in the case of a SiC sintered body, Al, F
e, B, etc. are present at the grain boundaries or are dissolved in the crystal. Such impurity elements and binder elements have an adverse effect on the deposition of the polycrystalline diamond film, reduce the adhesion between the polycrystalline diamond film and the substrate, and cause cracks in the polycrystalline diamond film during tool manufacturing and use. Or the polycrystalline diamond film is separated from the substrate. For this reason, there is a demand for a bonding tool that has good adhesion between the substrate and the polycrystalline diamond film and can be used stably without cracking or peeling.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a bonding tool for a TAB process, which has good adhesion between a polycrystalline diamond film constituting a tool working surface and a substrate and is free from cracks and peeling, and a method of manufacturing the same. The purpose of this is to provide.

[0004]

The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems.
It has been found that the provision of the iC intermediate layer improves the adhesion, and the present invention has been completed based on this finding. That is, the present invention provides: (1) a 10-mm thick SiC sintered body formed on a substrate by CVD.
An SiC intermediate layer having a thickness of 20 to 10 μm is formed, and the surface of the SiC intermediate layer is roughened.
A bonding tool characterized in that a tool tip formed by coating a polycrystalline diamond film having a surface roughness of 0 μm or less and Rmax of 0.1 μm or less by a CVD method is brazed to a shank; On the substrate of thickness 1 by the CVD method.
After forming a 0-100 μm SiC intermediate layer, the SiC
The surface of the C intermediate layer is roughened, a polycrystalline diamond film having a thickness of 20 to 100 μm is deposited on the roughened surface by a CVD method, and the surface of the polycrystalline diamond film is polished to have a surface roughness of Rmax 0.1 μm or less. And (3) roughening the surface of the intermediate layer by scratching with diamond powder or by removing diamond from the surface of the intermediate layer. 3. The method of manufacturing a bonding tool according to claim 2, wherein the method is performed by performing blasting with soft abrasive grains or grinding with a diamond grindstone.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The bonding tool of the present invention
A SiC intermediate layer is formed on a substrate by a CVD method, and the tip of the tool, the surface of which is covered with a polycrystalline diamond film, is brazed to a shank. FIG.
1 is a perspective view of one embodiment of the bonding tool of the present invention. The bonding tool of the present invention
A SiC intermediate layer 12 is formed by a CVD method, and a tool tip whose surface is covered with a polycrystalline diamond film 13 is brazed to a shank 15 by a brazing material 14. In the present invention, the material of the substrate is not particularly limited, and examples thereof include a SiC sintered body, a Si ₃ N ₄ sintered body, and an AlN sintered body. Among them, SiC
The sintered body has a coefficient of thermal expansion close to that of the SiC intermediate layer or the polycrystalline diamond film formed by the CVD method, so that cracking and peeling due to repeated heating and cooling of the bonding tool hardly occur, and the workability is good. It has excellent mechanical strength, little thermal deformation, and physical properties close to those of diamond, so that it can be used particularly preferably.

In the present invention, a SiC intermediate layer is formed on a substrate by a CVD method. There is no particular limitation on the method of forming the SiC intermediate layer. For example, a known synthesis method such as a thermal CVD method using silane SiH ₄ and propane C ₃ H ₈ as raw materials can be used. The SiC intermediate layer deposited by the CVD method has a higher adhesion to the substrate than the SiC intermediate layer formed by the PVD method. When the substrate is a SiC sintered body, the SiC sintered body and the Si
Particularly excellent adhesion is obtained between the C intermediate layers. In the present invention, by forming the SiC intermediate layer on the substrate, the polycrystalline diamond film can be bonded to the SiC intermediate layer with strong adhesion without being affected by the binder element or the impurity element contained in the substrate. . The thickness of the SiC intermediate layer is preferably from 10 to 100 μm,
More preferably, it is 0 to 80 μm. If the thickness of the SiC intermediate layer is less than 10 μm, it may be difficult to completely prevent the influence of a binder element or an impurity element in the substrate. It is sufficient that the thickness of the SiC intermediate layer is 100 μm or less, and if the thickness exceeds 100 μm, the adhesion of the intermediate layers tends to decrease due to a slight difference in thermal expansion between each other. In the present invention, S
After forming the iC intermediate layer, a polycrystalline diamond film is deposited and coated on the surface. The method for depositing a polycrystalline diamond film on the surface of the SiC intermediate layer is not particularly limited, and examples thereof include a hot filament method, a microwave plasma method, a high-frequency plasma method, a DC discharge plasma method, an arc discharge plasma jet method, and a combustion flame method. And the like.

In the present invention, forming an SiC intermediate layer;
The deposition of the polycrystalline diamond film can be performed continuously using the same apparatus, or the substrate on which the SiC intermediate layer is formed is once taken out, the surface is roughened, and then the polycrystalline diamond film is deposited. Can be precipitated. By continuously forming the SiC intermediate layer by the CVD method and depositing the polycrystalline diamond film by the CVD method using the same apparatus, the process is streamlined,
The contamination of the surface of the SiC intermediate layer can be prevented, and the adhesion between the SiC intermediate layer and the polycrystalline diamond film can be improved.
If the formation of the SiC intermediate layer by the CVD method and the deposition of the polycrystalline diamond film by the CVD method cannot be performed continuously, the purpose is mainly to remove the surface layer contaminated by oxidation and to roughen the surface. The surface can be scratched with diamond powder, blasted with abrasive grains softer than diamond, or ground with a diamond grindstone. Examples of abrasive grains softer than diamond include Al ₂ O ₃ and SiC. Si
By roughening the surface of the C intermediate layer, the contact area between the SiC intermediate layer and the polycrystalline diamond film can be increased, and the adhesion between the SiC intermediate layer and the polycrystalline diamond film can be increased. In the present invention, the thickness of the polycrystalline diamond film is preferably 20 to 100 μm, and 40 to 8 μm.
More preferably, it is 0 μm. If the thickness of the polycrystalline diamond film is less than 20 μm, the durability of the working surface of the tool is insufficient, and a sufficient number of shots may not be obtained. The thickness of the polycrystalline diamond film is usually 100μ
Even if the thickness exceeds 100 μm, the bonding tool does not extend its life in proportion to the increase in the thickness of the polycrystalline diamond film, and adheres due to the difference in thermal expansion. Power tends to decrease.

In the present invention, after depositing and coating a polycrystalline diamond film on the surface of the SiC intermediate layer, the surface of the polycrystalline diamond film is polished. There is no particular limitation on the method of polishing the surface of the polycrystalline diamond film. For example, the surface can be polished by a dry lapping machine. By polishing the surface of the polycrystalline diamond film, the surface roughness of the film surface is reduced to Rma.
x 0.1 μm or less. This is necessary in order to join the lead wires by uniform heating. In the present invention, after the polishing of the surface of the polycrystalline diamond film is completed, the tip of the tool is brazed to the shank. However, there is no problem if polishing is performed after brazing. There is no particular limitation on the brazing material for brazing the shank and the tool tip, and examples thereof include gold brazing, silver brazing, palladium brazing, copper brazing, brass brazing, phosphor copper brazing, nickel brazing, and aluminum alloy brazing. be able to. Among these,
Activated silver brazes can be used particularly preferably. After brazing, lapping is performed so that the working surface has a flatness of 1 μm or less at the temperature used (400 to 600 ° C.). Since the bonding tool of the present invention has the SiC intermediate layer formed by the CVD method between the substrate and the polycrystalline diamond film constituting the tool working surface, the adhesion between the substrate and the polycrystalline diamond film is good, and the bonding process can be performed for a long time in the TAB process. Even when used, there is no risk of cracking or peeling.

[0009]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 A 40 μm thick SiC intermediate layer was formed on a 4 mm thick, 10 mm × 10 mm SiC sintered substrate by a thermal CVD method using a mixed gas of silane and propane. Next, the SiC substrate was heated to 900 ° C., a mixed gas of methane 0.8% by volume and hydrogen 99.2% by volume was introduced under a reduced pressure of 50 Torr, and diamond was vapor-phase synthesized by a hot filament method for 20 hours. A polycrystalline diamond film having a thickness of 40 μm was formed on the SiC intermediate layer, and further subjected to skiff polishing to obtain a tool tip. This tool tip is made of austenitic low thermal expansion cast iron [Enomoto Casting Co., Ltd., CN
-5] with an activated silver braze.
A bonding tool was obtained. This bonding tool was attached to a bonder, the temperature of the tool was maintained at 500 ° C, and a tool load of 5 kg and a pressure cycle of 3 were applied to the heating stage.
500,000 shot tests were performed at 0 times / minute. When the state of the working surface of the tool after the test was completed was observed for changes in the surface with a differential interference microscope, no abnormality was observed. Example 2 A 40 μm thick SiC intermediate layer was formed on a 4 mm thick, 10 mm × 10 mm SiC sintered substrate by a thermal CVD method using a mixed gas of silane and propane. Next, the SiC substrate is heated to 900 ° C., a mixed gas of methane 0.8% by volume and hydrogen 99.2% by volume is introduced under a reduced pressure of 50 Torr, and diamond gas phase synthesis is performed for 20 hours by a microwave plasma method. 40 μm thick on SiC intermediate layer
A polycrystalline diamond film having a thickness of m was formed, and skif polishing was further performed to obtain a tip portion of the tool. Using this tool tip, a bonding tool was produced in the same manner as in Example 1, and a 500,000 shot test was performed. When the state of the working surface of the tool after the test was completed was observed for changes in the surface with a differential interference microscope, no abnormality was observed. Example 3 An 80 μm thick SiC intermediate layer was formed on a 4 mm thick, 10 mm × 10 mm SiC sintered substrate by a thermal CVD method using a mixed gas of silane and propane, and the surface thereof was diamond powder. Was scratched. Then, S
The iC substrate was heated to 900 ° C., and a gaseous mixture of 0.8% by volume of methane and 99.2% by volume of hydrogen was introduced under a reduced pressure of 50 Torr. An 80 μm-thick polycrystalline diamond film was formed on the layer, and skif polishing was performed to obtain a tool tip. Using this tool tip,
A bonding tool was prepared in the same manner as in Example 1, and 5
Ten thousand shot tests were performed. When the state of the working surface of the tool after the test was completed was observed for changes in the surface with a differential interference microscope, no abnormality was observed. Example 4 As a substrate, Si ₃ N ₄ having a thickness of 4 mm and a size of 10 mm × 10 mm was used.
The same operation as in Example 1 was repeated, except that a sintered substrate was used. The state of the working surface of the tool after the completion of the 500,000 shot test was observed for changes in the surface with a differential interference microscope, and no abnormalities were observed. Example 5 The same operation as in Example 1 was repeated, except that an AlN sintered body substrate having a thickness of 4 mm and a size of 10 mm × 10 mm was used as the substrate. The state of the working surface of the tool after the completion of the 500,000 shot test was observed for changes in the surface with a differential interference microscope, and no abnormalities were observed. Example 6 The thickness of the SiC intermediate layer formed by the thermal CVD method was 10 μm.
The same operation as in Example 1 was repeated, except that m was used. 5
When the state of the tool working surface after the completion of the 100,000 shot tests was observed for changes in the surface with a differential interference microscope, no abnormality was observed. Comparative Example 1 The same operation as in Example 1 was repeated, except that a 10 μm-thick SiC intermediate layer was formed on a SiC sintered body substrate by a sputtering method, which is a PVD method. When the state of the tool working surface after the completion of the 500,000 shot test was observed for changes in the surface with a differential interference microscope, peeling was observed between the intermediate layer and the diamond film. Comparative Example 2 The same operation as in Example 1 was repeated, except that a polycrystalline diamond film having a thickness of 50 μm was directly formed on the SiC sintered body substrate without forming an SiC intermediate layer. The state of the working surface of the tool after 500,000 shot tests was completed was observed with a differential interference microscope for changes in the surface, and slight cracks were observed. Comparative Example 3 The same operation as in Example 4 was repeated, except that a polycrystalline diamond film having a thickness of 50 μm was directly formed on the Si ₃ N ₄ sintered body substrate without forming an SiC intermediate layer. When the state of the tool working surface after the completion of the 500,000 shot test was observed for changes in the surface with a differential interference microscope, corner wear and partial peeling were observed. Comparative Example 4 The same operation as in Example 5 was repeated, except that a polycrystalline diamond film having a thickness of 50 μm was directly formed on the AlN sintered body substrate without forming the SiC intermediate layer. When the state of the tool working surface after the completion of the 500,000 shot test was observed for changes in the surface with a differential interference microscope, many cracks were observed. Table 1 shows the results of Examples 1 to 6 and Comparative Examples 1 to 4.

[0010]

[Table 1]

From the results shown in Table 1, it can be understood that Si
In the bonding tools of Examples 1 to 6 provided with the C intermediate layer, no abnormality was observed on the working surface of the tool after 500,000 shot tests were completed, and the adhesion of the polycrystalline diamond film of the bonding tool of the present invention was confirmed. Is good. On the other hand, in the bonding tool of Comparative Example 1 in which the SiC intermediate layer was formed by the sputtering method, peeling was observed on the tool working surface after 500,000 shot tests were completed. It can be seen that the intermediate layer formed by the method has weaker adhesion to the polycrystalline diamond film than the intermediate layer formed by the thermal CVD method. Also,
In the bonding tools of Comparative Examples 2 to 4 having no SiC intermediate layer, cracks and corner wear were observed on the tool working surface after 500,000 shot tests, and the adhesion of the polycrystalline diamond film was poor. .

[0012]

The bonding tool according to the present invention has good adhesion between the polycrystalline diamond film constituting the tool working surface and the substrate, does not cause cracking or peeling even when used for a long time, and is particularly suitable for the TAB process. Can be suitably used as a bonding tool.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a TAB step.

FIG. 2 is a perspective view of one embodiment of the bonding tool of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating stage 2 Thermal insulator 3 Chip guide 4 Chip 5 Inner lead 6 Film carrier 7 Tape guide 8 Electrode 9 Bonding tool 10 Pressure cylinder 11 Substrate 12 SiC intermediate layer 13 Polycrystalline diamond film 14 Brazing material 15 Shank

Claims (3)

(57) [Claims] 1. A method according to claim 1, wherein a thickness of the SiC sintered body is formed on a substrate by a CVD method.
Is SiC intermediate layer is formed of the 10 to 100 [mu] m, the Si
C The surface of the intermediate layer has been roughened,
１００100 μm, surface roughness of Rmax 0.1 μm or less
Polycrystalline diamond film coated by CVD method
A bonding tool characterized by brazing a tool tip to a shank. 2. The method according to claim 1, wherein the SiC sintered body is formed on a substrate by a CVD method.
After forming a 10-100 μm thick SiC intermediate layer,
The surface of the SiC intermediate layer is roughened, and C
Polycrystalline diamond having a thickness of 20 to 100 μm by VD method
Depositing a polycrystalline diamond film and polishing the surface of the polycrystalline diamond film.
It is obtained by forming a surface having a surface roughness of Rmax 0.1 μm or less.
Specially brazing the tool tip to the shank
Characteristic bonding tool manufacturing method. 3. The method of claim 1 , wherein the surface of the intermediate layer is treated with diamond.
Scratched by powder or softer than diamond
Blasting with diamond grains or diamond grinding stone
3. The bondy according to claim 2, wherein the bonding is performed by performing a grinding process.
Method of manufacturing tools.