JP3299694B2 - Bonding tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a bonding tool. More specifically, the present invention provides good adhesion between the polycrystalline diamond film constituting the tool working surface and the substrate, excellent abrasion resistance on the side surface of the tool tip member, and generation of cracks and peeling in the polycrystalline diamond film. No TAB
The present invention relates to a bonding tool for a (Tape Automated Bonding) process.

[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. For example, Japanese Patent Publication No. 7-66930 and Japanese Patent No. 25209
No. 71 discloses Si or Si ₃ N ₄ , SiC or A
There has been proposed a bonding tool having a tool tip in which a polycrystalline diamond is precipitated by a vapor phase synthesis method using a sintered body mainly composed of 1N as a base. However, in the TAB process, when the adhered material adhering to the tip of the tool is cleaned using a tungsten wire brush or the like, the surface and the side of the tip of the tool are worn. There is a problem that the diamond film is cracked or dropped, and the lead and the electrode cannot be joined. In particular, when a substrate made of a SiC sintered body and / or a vapor-phase synthesized SiC is used, as the cleaning for removing the metal oxide attached to the tip of the tool is repeated, only the substrate is worn, and cracks in the polycrystalline diamond film occur. And peeling easily. Japanese Patent No. 2590113 proposes a bonding tool having a tool tip in which polycrystalline diamond is deposited on a base material made of a diamond sintered body by a vapor phase synthesis method. However, the diamond sintered body has a problem that the hardness is as high as Hv 8,000 to 10,000 and it takes time and labor to process. Also, Co is often used as a binder for the diamond sintered body,
Since Co prevents the adhesion between the polycrystalline diamond film and the diamond sintered body, there is a problem that the polycrystalline diamond film at the tip of the tool is easily cracked or peeled off. Therefore, there is a need for a long-life bonding tool that does not wear the side surfaces of the substrate, has good adhesion of the polycrystalline diamond film, and can be used stably without cracking or peeling.

[0003]

SUMMARY OF THE INVENTION The present invention provides a polycrystalline diamond film which has good adhesion between a polycrystalline diamond film constituting a tool working surface and a substrate, has excellent abrasion resistance on the side surface of a tool tip member, TAB without cracking or peeling
The purpose of the present invention is to provide a bonding tool for a process.

[0004]

Means for Solving the Problems The present inventor has conducted intensive studies to solve the above-mentioned problems, and as a result, a CBN sintered body has
As a substrate on which a polycrystalline diamond film is deposited by the CVD method, it has been found that the polycrystalline diamond film has excellent adhesion to the polycrystalline diamond film and excellent abrasion resistance on the side surfaces. Based on this finding, the present invention has been completed. That is, the present invention provides: (1) 60 volume% or more of CBN and 40 volume% or less of a binder, wherein the binder is aluminum boride, aluminum nitride, aluminum oxide, titanium carbide, titanium nitride, titanium carbonitride. , A thickness of more than 100 μm and less than 50 μm deposited on a CBN sintered body substrate which is one or more materials selected from the group consisting of hafnium carbide, tantalum nitride and tungsten carbide. A bonding tool having a tool tip on which a crystalline diamond film is formed. Further, as preferred embodiments of the present invention, (2) the bonding tool according to (1), wherein the CBN content of the CBN sintered body is 50% by volume or more; and (3) the surface roughness of the polycrystalline diamond film Rmax is 0.1
The bonding tool according to item (1), which is not more than μm, may be mentioned.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The bonding tool of the present invention
A polycrystalline diamond film deposited by a CVD method on a CBN sintered body substrate is formed. The CBN sintered body substrate used in the present invention is obtained by using a laser or the like from a CBN sintered body obtained by sintering CBN fine particles together with fine powder of a binder or under a high-temperature, high-pressure condition without adding a binder. It can be obtained by processing. The CBN content in the CBN sintered body used in the present invention is preferably 50% by volume or more, and more preferably 60% by volume or more. When the CBN content in the CBN sintered body is 50% by volume or more, the CBN particles are directly bonded to each other, and have excellent mechanical strength and heat resistance. In the present invention, the binder of the CBN sintered body is aluminum boride AlB ₂ , aluminum nitride AlN, aluminum oxide Al ₂ O ₃ , titanium carbide TiC, titanium nitride TiN,
It is preferable to use titanium carbonitride TiCN, hafnium carbide HfC, tantalum nitride TaN, or tungsten carbide WC. One of these binders can be used alone, or two or more can be used in combination.

In the present invention, a polycrystalline diamond film is formed on a CBN sintered body substrate by a CVD method.
The CVD method for forming a polycrystalline diamond film 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. it can. In the present invention, the thickness of the polycrystalline diamond film is preferably 50 to 100 μm.
More preferably, it is 90 μm. If the thickness of the polycrystalline diamond film is less than 50 μm, the strength of the film is low, the durability of the tool working surface such as cracks and peeling is insufficient, and a sufficient number of shots may not be obtained. If the thickness of the film is 50 μm or more, it should make more effective use of the good thermal conductivity of diamond and the feature that the polycrystalline diamond film formed by the CVD method has higher purity than the diamond film formed by the sintering method. Can be. The thickness of the polycrystalline diamond film is generally 100 μm or less and has sufficient performance. Even if the thickness exceeds 100 μm, the bonding tool does not have a long life corresponding to the increase in the thickness of the polycrystalline diamond film. On top, a polycrystalline diamond film and C
Due to the difference in the coefficient of thermal expansion of the BN sintered body substrate, there is a possibility that the adhesion is reduced.

In the present invention, after depositing and coating a polycrystalline diamond film on a CBN sintered body substrate,
Polish the surface of the polycrystalline diamond film. 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. It is preferable that the surface roughness Rmax of the film surface is reduced to 0.1 μm or less by polishing the surface of the polycrystalline diamond film. By setting the surface roughness Rmax of the film surface to 0.1 μm or less, bonding of the inner leads can be performed 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 a shank. The above polishing can also be 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 them, an active silver braze in which Ti, Ta, or the like is added to a silver-based brazing material can be particularly preferably used.
After brazing, the temperature range to be used (for example, 400 to 60)
0 ° C.) so that the flatness of the working surface is 1 μm or less,
Preferably, lapping is performed.

FIG. 2 is a perspective view of one embodiment of the bonding tool of the present invention. The bonding tool in this figure is C
A tool tip having a polycrystalline diamond film 12 deposited by a CVD method on a BN sintered body substrate 11 is
It is brazed to the shank 14 by the brazing material 13.
The substrate at the tool tip of the bonding tool of the present invention is C
It is a BN sintered body, and the hardness Hv of the CBN sintered body is 3,000
Since it is as soft as 0 to 4,500, it has good workability as compared with a diamond sintered body and can be easily mass-produced. Also, since the CBN sintered body has good thermal conductivity,
The efficiency of the bonding operation is improved. When the binder of the CBN sintered body is aluminum boride, aluminum nitride, aluminum oxide, titanium carbide, titanium nitride, titanium carbonitride, hafnium carbide, tantalum nitride, or tungsten carbide, these binders are combined with the substrate and polycrystalline. Since the adhesion of diamond is not hindered, the adhesion between the polycrystalline diamond film and the substrate is improved. In addition, since the fine particles of CBN strongly adhere to polycrystalline diamond, the adhesion between the diamond film and the substrate is further improved. Further, since the CBN sintered body is excellent in wear resistance, even if tool cleaning is performed with a tungsten wire brush or the like, the tool tip, particularly the side face thereof, is not worn, and the life of the bonding tool is extended.

[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 90% by volume of CBN and 10% by volume of AlN as a binder
A CBN sintered body substrate having a thickness of 4 mm and a size of 2 mm × 18 mm was heated to 900 ° C., and methane was removed under reduced pressure of 50 Torr.
A gaseous mixture of 8% by volume and 99.2% by volume of hydrogen was introduced, diamond gas phase synthesis was performed for 40 hours by a hot filament method, a polycrystalline diamond film having a thickness of 80 μm was formed on a substrate, and further skiff polishing was performed. Going to get the tool tip. The tool tip was brazed to a shank made of austenitic low-thermal-expansion cast iron [Enomoto Casting Co., Ltd., CN-5] using activated silver brazing, and the tool working surface dimension was set to 0.8 mm × 17. It was polished to 0.5 mm to obtain a bonding tool. This bonding tool was attached to a bonder, the temperature of the tool was maintained at 520 ° C., and the heating stage was loaded with a tool load of 5 kg and a pressure cycle of 30 times / min.
One million shot tests were performed while performing cleaning using a tungsten wire brush once every 0 shots. When the working surface of the tool after completion of the test was observed using a differential interference microscope, no abnormality was found in the surface state. Example 2 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 80% by volume of CBN and 20% by volume of TiCN as a binder was used as a sintered body substrate. The working surface of the tool after 1 million shot tests was observed using a differential interference microscope, and no abnormality was found in the surface state. Example 3 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 90% by volume of CBN and 10% by volume of (AlB ₂ + AlN) as a binder was used as a sintered body substrate.
After 1 million shot tests,
Observation using a differential interference microscope revealed no abnormality in the surface state. Example 4 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 60% by volume of CBN and 40% by volume of (Al ₂ O ₃ + TiC) as a binder was used as a sintered body substrate.
After 1 million shot tests,
Observation using a differential interference microscope revealed no abnormality in the surface state. Example 5 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 60% by volume of CBN and 40% by volume of TiC as a binder was used as a sintered body substrate. The working surface of the tool after 1 million shot tests was observed using a differential interference microscope, and no abnormality was found in the surface state. Example 6 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 60% by volume of CBN and 40% by volume of TiN as a binder was used as a sintered body substrate. The working surface of the tool after 1 million shot tests was observed using a differential interference microscope, and no abnormality was found in the surface state. Example 7 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 70% by volume of CBN and 30% by volume of HfC as a binder was used as a sintered body substrate. The working surface of the tool after 1 million shot tests was observed using a differential interference microscope, and no abnormality was found in the surface state. Example 8 The same operation as in Example 1 was repeated, except that a CBN sintered body composed of 80% by volume of CBN and 20% by volume of TaN as a binder was used as a sintered body substrate. The working surface of the tool after 1 million shot tests was observed using a differential interference microscope, and no abnormality was found in the surface state. Example 9 The same operation as in Example 1 was repeated except that a CBN sintered body composed of 90% by volume of CBN and 10% by volume of (WC + Co) as a binder was used as a sintered body substrate. 100
When the working surface of the tool after 10,000 shot tests was observed using a differential interference microscope, no abnormality was found in the surface condition. Example 10 The same operation as in Example 1 was repeated, except that a CBN sintered body consisting of only CBN containing no binder was used as the sintered body substrate. After observing the tool working surface after 1 million shot tests using a differential interference microscope,
No abnormality was found in the surface condition. Comparative Example 1 The same operation as in Example 1 was repeated except that a SiC sintered body was used as a sintered body substrate. The working surface of the tool after 1 million shot tests was observed using a differential interference microscope. As a result, the substrate was worn, and the polycrystalline diamond film was broken and dropped. Comparative Example 2 A diamond sintered body substrate having a thickness of 4 mm, a size of 2 mm × 10 mm and a volume of 80% by volume of diamond and 20% by volume of Co as a binder was heated to 900 ° C., and 0.8% by volume of methane was obtained under reduced pressure of 50 Torr. A gaseous mixture of 99.2% by volume of hydrogen was introduced, diamond gas phase synthesis was performed for 40 hours by a hot filament method, a polycrystalline diamond film having a thickness of 80 μm was formed on the substrate, and further skiff polishing was performed. The polycrystalline diamond film was cracked and the tool tip could not be made. Comparative Example 3 The same operation as in Example 1 was repeated, except that a diamond sintered body composed of 80% by volume of diamond and 20% by volume of SiC as a binder was used as a sintered body substrate. After brazing, the tool working surface dimension should be 0.8mm x 17.5mm
The polishing operation was extremely long due to the high hardness, and required five times as much as in Example 1. When the working surface of the tool after 1 million shot tests was completed was observed using a differential interference microscope, it was found that minute cracks had occurred. Table 1 shows the results of Examples 1 to 10 and Comparative Examples 1 to 3.

[0010]

[Table 1]

From the results in Table 1, it can be seen that the bonding tools of Examples 1 to 10 having a tool tip having a polycrystalline diamond film deposited by a CVD method on a CBN sintered body substrate had 1,000,000 cycles. No abnormalities were found in the surface condition of the tool working surface even after the shot test, and the bonding tool of the present invention has excellent adhesion between the substrate and the polycrystalline diamond film and excellent wear resistance on the side surface of the tool head material.
It can be seen that the life is long. On the other hand, in Comparative Example 1 using the SiC sintered substrate, after 1 million shot tests, the substrate was worn, the polycrystalline diamond film was cracked and dropped, and this bonding tool had a short life. there were. Further, in Comparative Example 2 using a diamond sintered body substrate using Co as a binder, the polycrystalline diamond film was broken and a finished product could not be obtained. Comparative Example 3 using a diamond sintered body substrate using SiC as a binder
In Example 1, after the 1 million shot tests, minute cracks occurred in the polycrystalline diamond film, and the life of this bonding tool was also short.

[0012]

The bonding tool according to the present invention has a CBN
Since the sintered body is used as the substrate, the workability of the substrate is good,
Suitable for mass production. Further, since the CBN sintered body has a high thermal conductivity, the efficiency of the bonding operation is improved. ADVANTAGE OF THE INVENTION The bonding tool of this invention is excellent in the adhesiveness of a polycrystalline diamond film and a board | substrate, the wear of the surface and the side surface is small even by cleaning of the front-end | tip part of a tool, and has a long life.

[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 CBN sintered substrate 12 Polycrystalline diamond film 13 Brazing material 14 Shank

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60

Claims (1)

(57) [Claims] 1. CBN of 60% by volume or more and 40% by volume or less
Consisting of aluminum boride,
Aluminum nitride, aluminum oxide, titanium carbide, nitride
Titanium nitride, titanium carbonitride, hafnium carbide, tantalum nitride
Or one selected from the group consisting of
Is a CVD method on a CBN sintered body substrate
The thickness deposited by the method exceeds 50 μm,
Tool tip with the following polycrystalline diamond film formed
A bonding tool having an end.