JP2003017532A - Bonding tool and bonding stage, and head for bonding tool and stage part for bonding stage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding toll and a boding stage that have an exchangeable head. SOLUTION: The boding toll or bonding stage for mounting semiconductor is composed of the head and a shank part or a pedestal part. The bonding tool is characterized in that a rectangle or circular substrate part to configure the head and a protrusion that protrudes from the substrate part are constructed from one material, the top of the protrusion is coated with vapor-phase synthetic diamond, and the substrate part is mechanically fixed or fixed by vacuum suction to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a bonding tool and / or a bonding stage used when mounting semiconductor elements such as ICs and LSIs.

[0002]

2. Description of the Related Art In order to bring out the electrical characteristics of a semiconductor element, it is necessary to electrically connect an electrode formed on the semiconductor element and a lead of a package, and this lead and an external terminal such as a wiring board. There is. Conventionally, the electrode on the semiconductor element side and the lead wire are joined by a method called wire bonding, in which a thin metal wire made of gold or copper is used as a conducting wire and they are joined one by one using a tool called a capillary, and a patterned copper foil. A TAB method (Tape Automated Bonding) in which lead wires called tin film-plated film carriers are collectively connected to all electrodes on a semiconductor element by using a bonding tool and a bonding stage heated to a predetermined temperature. ) Is done by a method called. The bonding tool and the bonding stage mentioned here are attached to the bonding apparatus and function as a pair. Generally, the semiconductor element, the lead parts of the package, the wiring board, etc. are positioned with a predetermined accuracy and temporarily placed on the tool surface of the bonding stage that is fixed downward with the tool surface facing upward, and the tool surface is placed above. Is bonded by pressing with a bonding tool movably installed downward. Depending on the bonding method, the vacuum suction mechanism may be necessary for the bonding tool or the bonding stage.
Further, the heating mechanism may be required for either one or both depending on the joining method.

Recently, a bonding tool and a bonding stage heated to a predetermined temperature are used to directly bond a semiconductor element to a wiring formed on a film or glass.

On the other hand, the lead wire is connected to an external terminal such as a wiring board or a lead frame by means of a tin-plated lead wire, or an unplated lead wire and a solder electrode formed on the wiring board by screen printing or the like. Or a gold-plated lead wire is bonded to a gold-plated or silver-plated lead frame using a bonding tool and a bonding stage heated to a predetermined temperature.

Further, recently, depending on the IC chip, a lead frame is directly attached to a semiconductor element via an adhesive tape such as polyimide, and thereafter, the electrode formed on the semiconductor element and the lead frame are bonded by the above-mentioned wire bonding. There is a bonding method, but in this case as well, a bonding tool and a bonding stage heated to a predetermined temperature are used when the lead frame is bonded to the semiconductor element.

The bonding tool and the bonding stage used here consist of a shank portion, a tip portion, a pedestal portion and a stage portion. The shank part and the pedestal part are made of metal conventionally made of molybdenum, cemented carbide, nickel base alloy, tungsten or tungsten alloy, iron-nickel-cobalt alloy, stainless steel, iron-nickel alloy, titanium or titanium alloy, etc. Things are used. In addition, the tip part and the stage part have flatness of the tool surface,
In order to improve wear resistance and temperature distribution, vapor phase synthetic diamond, diamond single crystal, diamond sintered body,
A hard material such as a cubic boron nitride sintered body adhered to the metal tip is used. Heating the bonding tool and / or the bonding stage
The heat block in which the cartridge heater is inserted is attached to the shank portion and / or the pedestal portion. Alternatively, a cartridge heater in which an electric heating mechanism is incorporated into a base material such as AlN or SiC is inserted between the tip portion and the shank portion and / or the stage portion and the pedestal portion, and mechanically or by means such as vacuum adsorption. It is done by fixing.

[0007]

The background of the development of the conventional bonding tool and bonding stage is as follows. There are a great variety of products of semiconductors such as ICs and LSIs, and the number of leads and wirings connected to each product and the shape of the semiconductor are different for each product. Therefore, IC, LS
It is necessary to prepare a dedicated bonding tool and bonding stage for each I product, which is high in cost, requires time to replace the bonding tool and bonding stage installed in the equipment, and manages the bonding tool and bonding stage. There was a problem that it became complicated.

In order to solve such a problem, Japanese Patent Laid-Open No. 3-191538 proposes a method in which the tip portion of the bonding tool is mechanically attached with a screw or the like to facilitate the attachment and detachment of the tip portion. ing. However,
Since the screw method is used, the screw part is seized after long-term use, and there remains a problem that the tip part cannot be attached or detached.

Further, Japanese Unexamined Patent Publication (Kokai) No. 8-107129 proposes a bonding tool of a system using an eccentric shaft as a mechanical attachment method, which is a further improvement of the above-mentioned Japanese Unexamined Patent Publication No. 3-191538. According to this method, it is easier to attach / detach, and even if it is used for a long time, the fixing portion between the tip portion and the shank portion is not seized. However, recently, the usage conditions have become severe, and the ceramic coating for the purpose of preventing seizure may be partly peeled off by repeating the cooling / heating cycle for attachment / detachment. As a result, at a high temperature of 500 ° C., after the bonding for about 300,000 times, the tip portion and the shank portion may be seized. The burned one could not be replaced with another tip. This also applies to the bonding stage.

At the tip of the conventional bonding tool shown in FIG. 8, the diamond-coated ceramic projection and the metal base are first brazed. After that, since the diamond surface is polished so as to obtain parallelism between the upper and lower surfaces of the tip, polishing takes time. When the parallelism between the bottom surface of the tip and the tool surface is equal to or larger than the thickness of the diamond film coated on the tool surface, the adjustment cannot be performed, and brazing must be redone. When using a bonding tool that has a tip with insufficient parallelism between the bottom surface and the tool surface,
There remains a problem that it takes a very long time to adjust the parallelism at the time of starting the bonding apparatus.

In the bonding tool having the structure shown in FIG. 8, the ceramic projection has a smaller coefficient of thermal expansion than the metal base. Therefore, when these two parts are joined by brazing, the thermal stress generated at the joint interface increases as the size of the protrusion increases. This has been a problem in that the protruding portion is separated from the metal of the base portion during use. Even when peeling does not occur, the flatness of the bottom surface of the tip and the tool surface changes due to the influence of internal stress, and thermal stress accumulates at the joint interface due to repeated mounting loads, and the protrusions crack. The problem remained.

The actual operating temperature of the bonding tool and the bonding stage may differ from the design temperature. The tool surface of the bonding tool having the structure shown in FIG.
Finished by polishing so that it becomes flat at the design temperature. However, when used at a temperature different from the initially designed temperature, the flatness of the tip portion deviates from the design value because the thermal expansion coefficient of the metal base portion of the tip portion and the ceramic projection portion are different. Therefore, it is difficult to perform uniform welding over the entire tool surface, or in some cases, a portion that cannot be welded occurs. This tendency becomes more remarkable as the tip portion, especially the protruding portion, becomes larger. As for the recent situation, the sizes of ICs and LSIs are becoming larger and larger.
Alternatively, it has become very difficult to maintain the precision such as the flatness of the tool surface of the bonding stage and the temperature distribution during use at the conventional level.

Further, it is desired to shorten the tool replacement time and prolong the service life. To reduce the replacement time,
First, to eliminate seizure, and secondly, to reduce the parallelism adjustment time between the tool surfaces of the bonding tool and the bonding stage, the accuracy of the parallelism between the tip surface and / or the bottom surface of the stage and the tool surface must be improved. It is important to raise. In order to extend the life, it is important to minimize the change in flatness of the tool surface during use and to prevent the tip portion and / or the stage portion from being damaged.

Recently, there has been a particularly strong demand for sharing a so-called shank, which can deal with a wide variety of products by replacing only the tip. Conventional products are no longer able to cope with these various recent situations. The present invention is to provide a bonding tool and a bonding stage that further improve on these conventional problems.

[0015]

SUMMARY OF THE INVENTION The present invention is a bonding tool for mounting a semiconductor comprising a tip portion and a shank portion, wherein a base portion forming the tip portion and a protruding portion protruding from the base portion are integrated. A bonding tool comprising a material, a tool surface of a protruding portion of which is coated with vapor-phase synthetic diamond, and the base portion and the shank portion are mechanically fixed or fixed by vacuum suction. . The shank part has an attachment mechanism to the device for fixing the tip part to the bonding device within a range of a certain positional accuracy and angular accuracy, and at the same time, in order to heat the tip part to the temperature necessary for the bonding process. It has the mechanism of.

Another aspect of the present invention is a bonding stage for semiconductor mounting, comprising a stage part and a pedestal part, wherein the base part forming the stage part and the protruding part protruding from the base part are made of an integral material. The bonding stage is characterized in that the tool surface of the protruding portion is covered with vapor phase synthetic diamond, and the stage portion and the pedestal portion are mechanically fixed or fixed by vacuum suction. The pedestal part has a mounting mechanism to the device for fixing the stage part to the bonding device within a range of a certain positional accuracy and angular accuracy, and at the same time, for heating the stage part to a temperature necessary for the bonding process. It has the mechanism of.

In the bonding apparatus, the bonding tool and the bonding stage are generally used as a pair. The bonding tool of the present invention can also be used in combination with a conventional bonding stage, and
It is also possible to use it in combination with the bonding stage of the present invention. Further, the bonding stage of the present invention can be used in combination with conventional bonding tools.

In the bonding tool and the bonding stage of the present invention, the tip portion and / or the stage portion is formed on a sintered body containing any one of SiC, Si ₃ N ₄ and AlN as a main component by a vapor phase synthesis method. It is preferably coated with polycrystalline diamond.

The shank portion and the pedestal portion are selected from molybdenum, cemented carbide, nickel base alloy, tungsten or tungsten alloy, iron-nickel-cobalt alloy, stainless steel, iron-nickel alloy, titanium or titanium alloy. It may be composed of one or more metals. Among these, the iron-nickel-cobalt alloy and the tungsten-Cu alloy which are tungsten alloys are excellent in heat resistance and workability.

In the tip portion and / or the stage portion in the present invention, the base portion forming the tip portion and / or the stage portion and the protrusion protruding from the base portion are made of an integral material, and the tool surface of the protrusion is a And a tip of at least SiC, S
It is preferable that the sintered body contains as a main component any one of i ₃ N ₄ and AlN.

Furthermore, the parallelism between the tip of the bonding tool and / or the bonding stage and / or the bottom surface of the stage and the tool surface is 2 μm at room temperature.
The following is preferable.

A trapezoidal shape in which the side length or the diameter decreases toward the tool surface when the mounting portion of the tip portion and / or the stage portion to the shank portion and / or the pedestal portion is viewed from the side surface side. It is preferable to have a mounting side surface having a sectional shape of. With this configuration, the bonding strength can be enhanced by the wedge effect of the side surface of the mounting portion and the pressing portion. In addition, the directionality of the tip can be confirmed by changing the inclination of the slope.

The feature of the tip portion for the bonding tool and / or the stage portion for the bonding stage obtained in the present invention is that the flatness change of the tip portion from 100 ° C. to 550 ° C. is preferably 1 μm or less. Optionally, the tip may have one or more vacuum suction holes for sucking the semiconductor element. Further, the tip portion and / or the stage portion may have a vacuum suction groove and at least one suction hole for sucking a semiconductor.

In the tip portion and / or the stage portion of the present invention, the surface roughness of the contact surface with the shank portion and / or the pedestal portion is preferably 0.1 μm or less in terms of average surface roughness Ra. This is to ensure heat transfer between the shank and / or pedestal and the tip. Between the tip and shank or between the stage and pedestal, gold, silver, copper,
It is also possible to interpose one or two or more layers of metal selected from soft metals such as platinum, tantalum, nickel, and aluminum. In particular, when the top and bottom surfaces of the tip portion have a high degree of parallelism, it is easy to adjust the degree of parallelism, and the adhesion with the shank portion can be improved and heat conduction can be enhanced.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The progress of bonding tools and bonding stages is very fast, and the tools have a short life cycle like ICs and LSIs. The usage method has been gradually improved, and even the same bonding tool has a life that is two to three times longer than the conventional one. Furthermore, although ICs and LSIs have become dramatically larger, the dimensional accuracy of tools is not relaxed. In addition, it is required that the flatness from 100 ° C. to a high temperature of several hundreds of degrees has a dimensional accuracy of 1 μm or less and does not cause seizure.

In response to such a request from the market, first,
Tip and / or stage and shank and / or
Or a group in which the materials of the pedestal are considered not to react with each other
The combination was selected from the following various materials. Ie carbide
Alloys, molybdenum, nickel-based alloys, tungsten,
Ngusten alloy, iron-nickel-cobalt alloy, stainless
Stainless steel, iron-nickel alloy, titanium or titanium alloy, etc.
Metal, SiC, Si _ThreeN_Four, AlN and other ceramics
We examined various combinations.

As a result, it becomes clear that the shank portion and the pedestal portion have a thermocouple storage portion and a cartridge heater storage portion, so that they have to have a complicated shape, and considering the shape, metal is economical. is there.

Then, the material that can be used for the base portion of the tip portion and / or the stage portion is SiC, Si ₃ N ₄ ,
Ceramics such as AlN are suitable. Other materials burn with the metal of the shank during use, and it takes a long time to remove them after long-term use.

If only seizure is to be prevented, the base portions 3 and 103 in FIGS. 1 and 3 are replaced with SiC, Si ₃
Ceramics such as N ₄ and AlN may be used, or the shank portion 14 in FIG. 2 and the pedestal portion 114 in FIG. 4 may be ceramics. When the shank portion 14 and the pedestal portion 114 are made of ceramics, it is very disadvantageous in terms of cost to process hard ceramics into a complicated shape. Therefore, the base portion is made of ceramics such as SiC, Si ₃ N ₄ or AlN. Good to do.

When the base portions 3 and 103 are made of ceramics, it is preferable that the diamond-coated protrusions are also made of the same ceramic so that the protrusions and the base portion are not brazed. According to the present invention, the protruding tip portion is directly coated with the polycrystalline diamond, so that it has no brazing with metal. Therefore, in addition to the occurrence of seizure, cracks, changes in flatness during use, changes in flatness due to temperature, etc., which occur due to the difference in coefficient of thermal expansion from metal, are reduced,
The tool surface temperature distribution is improved. Further, since the polishing process for adjusting the parallelism of the tip portion after brazing is not necessary, the accuracy and the economic efficiency can be improved at once. Therefore, in the present invention,
The tip portion and / or the stage portion has a ceramic integral molding structure in which the tool surface is coated with polycrystalline diamond, and the method of attaching to the shank portion and / or the pedestal portion is mechanical fixing or vacuum suction. In the case of mechanical fixation, the tip portion is less likely to be displaced during the bonding process, and highly accurate bonding can be performed. When fixing by vacuum suction, the tip portion can be easily replaced and the size of the product to be bonded can be easily changed. The shape of the protruding part can be arbitrarily designed according to the shape and size of the product to be bonded,
In addition to the rectangular shape shown in the first and third embodiments of the present invention, a cylindrical shape or the like may be adopted.

The mechanical fixing method will be described below with reference to the drawings. The bonding tool of this invention is shown in FIG.
It is desirable that the tip portion shown in FIG. 2 has a mounting structure as shown in FIG. In FIG. 1, 1 is a tip portion, 2 is a mounting side surface, 3 is a base portion, 4 is a protruding portion, and 5 is a diamond coating layer (tool surface). Although the base of the bonding tool has a rectangular shape as an example of the tip of the bonding tool in FIG. 1, the base may have a circular shape or a curved surface as shown in FIG. In FIG. 2, 14 is a shank portion, 16 is a member for transmitting the movement of the eccentric shaft, 12 is a pressing portion, 19 is a thermocouple housing portion, and 10 is a cartridge heater housing portion.
Further, the bonding stage of the present invention preferably has the mounting structure as shown in FIG. 4 at the tip portion shown in FIG. In FIG. 3, 101 is a stage portion, 102 is a mounting side surface, 103 is a base portion, 104 is a protruding portion, and 105 is a diamond coating layer (tool surface). In addition, in FIG. 3, although the base portion is circular as an example of the tip of the bonding stage, even if the base portion is rectangular as shown in FIG. It doesn't matter. In FIG. 4, 114 is a pedestal part, 116 is a member for transmitting the movement of the eccentric shaft, 112 is a pressing part, 119 is a thermocouple housing part, and 110 is a cartridge heater housing part.

2 and 4, when the tip portion and / or the stage portion is pushed in the direction of the arrow, the pushing portion firmly contacts the tip portion and / or the stage portion with the bottom surface of the shank portion and / or the pedestal portion. However, the heat conduction between the shank portion and / or the pedestal portion and the tip portion and / or the stage portion is ensured. The bonding tool and the bonding stage are attached to the bonding apparatus by the mounting portions 11 and 111 of the shank portion 14 and the pedestal portion 114.

FIG. 5 is a partial cross-sectional view showing the structure of the mounting portion when the tip portion is fixed to the shank portion and / or the pedestal portion, using a bonding tool as an example. In the case of the bonding stage, the same mechanism can be provided by changing the following tip part to the stage part and the shank part to the pedestal part. The structure for fixing the tip portion to the shank portion is mechanically fixed to the shank portion 14 by a member 16 that transmits the movement of the eccentric shaft 15 attached to the shank portion 14. At this time, the member 16 transmitting the movement of the eccentric shaft rotates around the support shaft 18 of the member.

As shown in FIG. 5, the tip portion 1 is pressed against the shank portion by the eccentric shaft 15 via the member 16 for transmitting the movement of the eccentric shaft. And shank part 1
A thermocouple and a cartridge heater are attached to the thermocouple housing section 19 and the cartridge heater housing section 10 of FIG. At this time, the tip portion is attached to the shank portion by the pressing portion 12 and the member 16 that transmits the movement of the eccentric shaft. It is desirable that the mounting side surface of the tip portion has a wedge shape. This is because it makes good contact with the shank. Needless to say, it is desirable that the contact portion of the member 16 that transmits the movement of the eccentric shaft and the tip portion have the same structure as the pressing portion.

FIG. 6 shows details of the fixing structure of the bonding tool and the bonding stage shown in FIGS. 2 to 4. As shown in FIG. 6 (A), the eccentric shaft 15
Rotates about the support shaft 17, and the member 16 that transmits the movement of the eccentric shaft is pushed by the eccentric shaft 15 and rotates about the instruction shaft 18. Then, the tool tip 1 is inserted through the member 16.
Is pressed against the shank portion 14 and fixed. Therefore, in the side view of the base portion, it is desirable that at least the mounting side surface be a slope and have a trapezoidal shape. It goes without saying that it is desirable that both mounting side surfaces are sloped. Further, as shown in FIG. 6B, if the eccentric shaft 15 is rotated in the opposite direction, the member 16 is separated from the tip portion, and the tip portion 1 can be removed.

The present invention exerts a particularly great effect when the maximum length of the bonding tool and the protruding portion of the bonding stage exceeds 15 mm, particularly when it exceeds 20 mm. This is because if the maximum length is increased, there is no other means for eliminating the difference in thermal expansion between the protruding portion of the tip portion and / or the stage portion and the base portion. Further, in the present invention, it is preferable that the bottom surface of the tip portion and / or the stage portion, that is, the portion that comes into contact with the shank portion and / or the pedestal portion has a small surface roughness. The surface roughness of the bottom surface is the average surface roughness Ra,
When the thickness is 0.1 μm or less, the degree of heat conduction between the shank portion and / or the pedestal portion and the tip portion and / or the stage portion does not cause any problem in actual use.

In the present invention, the parallelism between the bottom surface of the base portion of the tip portion and / or the stage portion and the tool surface is preferably 2 μm or less. This means that the parallelism between the tool surface and the bottom surface of the tip and / or stage before diamond coating is 5
It can be easily achieved by setting the thickness to less than μm. If the thickness exceeds 5 μm, the processing cost for processing the diamond, which is much more difficult to process than the ceramic after the diamond coating, to obtain the parallelism of 2 μm or less becomes too high. The effect of increasing the accuracy of the tip and / or stage before coating with diamond is that the coated diamond layer can be thinned in addition to the above. The diamond coating time can be shortened, and generally, when the diamond coating time is short, the diamond particle size after synthesis is small and smooth, so that the polishing time can be further shortened. This is because particles grow as the synthesis time increases. On the other hand, the conventional brazing type is
The limit was that the parallelism after brazing was about 11 μm.

Another feature of the present invention is that the coating diamond layer is thin and that the thickness of the diamond is uniform over the entire working area. The thickness range is at most 7 μm
Is. The parallelism between the bottom surface of the base and the tool surface is measured by placing the tip and / or the stage on a surface plate and running a stylus on the diamond layer.

[0039]

EXAMPLES The present invention will be described in detail below with reference to examples.

[0040]

Example 1 First, 36 mm × 36 mm × 11 mm S
From the iC block, the bottom surface of the base portion is 35 mm × 35 mm and the protrusion is 5.4 mm × 3 in width as shown in FIG.
The tip portion having a height of 0.4 mm and a height of 6 mm and an overall height of 10 mm was processed. Hole diameter 0.5 mm and depth 0.5 mm from the tool surface side of the protrusion, hole diameter 1.8 mm and depth 7 m from the bottom surface side
Three vacuum suction holes of m were formed in the hole having a diameter of 6 mm and a depth of 2.5 mm to form through holes. Vacuum adsorption of semiconductors,
Relocate or bond. Also, the tool face edge is
Each ridge line was chamfered with a width of 0.2 mm and an angle of 45 degrees, and the effective dimension of the protrusion was processed to 5 mm × 30 mm.

As a filament, a known filament CVD method using a tungsten wire having a diameter of 0.5 mm and a length of 100 mm was used, and a thickness of 50 μm was formed on the tool surface of the tip portion.
m polycrystalline diamond was coated. The coating conditions are as follows.

[0042] Raw material gas (flow rate): CH4 / H2 = 1%, Total flow rate: 500 CC / min Gas pressure: 10000Pa Filament temperature: 2200 ° C Distance between filament and protruding surface: 5 mm SiC temperature: 920 ° C

The diamond coating layer 5 thus obtained was polished with a diamond grindstone, and the effective dimension of the protrusion was 5 mm.
A tip portion of × 30 mm was manufactured. The tip portion 1 of the bonding tool thus obtained was fixed to the shank portion made of an iron-nickel-cobalt alloy shown in FIG. 2 via a clamp lever with an eccentric shaft made of the same material.
The shank shown in FIG. 2 has a hole communicating with the vacuum suction hole 6 (not shown in the drawing). It should be noted that the vacuum suction holes provided in the protruding portion before coating are not covered with diamond, and are therefore through holes even after the diamond coating layer is provided.

Similarly, a bonding tool having a conventional structure shown in FIG. 8 was prepared as a comparative example. The protrusion is
S of (length) 60 mm x (width) 60 mm x (height) 3 mm
The iC substrate was coated with 50 μm polycrystalline diamond and then cut into a size of 5.4 mm × 30.4 mm. The base portion was produced by machining an iron-nickel-cobalt alloy into a predetermined shape. After that, the protruding portion and the base portion were joined by silver brazing to form a tip portion. In this figure, reference numeral 20 denotes a projection portion made of SiC coated with polycrystalline diamond and a base portion made of Kovar, which are joined by brazing. In all other respects, a sample of a comparative example was prepared in the same manner as this example.

In the bonding tool thus obtained, the parallelism of the upper and lower surfaces of the tip portion, the tool surface temperature distribution at the thermocouple portion at a temperature of 500 ° C., the tip portion and the shank when heated to 500 ° C. Seizure test with parts, durability of the joint interface between the base part and the protrusion when heating and cooling are repeated from room temperature to 600 ° C., and at a temperature of 600 ° C.
A load of kg was applied and the durability of 2 million times was compared. The results are shown in Table 1.

[0046]

[Table 1]

Details of the test conditions are as follows.

Tool surface temperature distribution: Temperature of thermocouple part is 5
Maximum and minimum temperature difference of the tool surface at 00 ℃.

Tip seizure test: 500 ° C., load 20
After the bonding test of 1,000,000 times for kg, it is confirmed every 100,000 times whether the tip can be removed.

Heat cycle test: A cycle of heating from room temperature to 600 ° C., holding for 2 hours, and returning to room temperature is repeated 100 times.

600 ° C. bonding test: 600 ° C., weight 20 kg, 2 million times bonding test.

In the conventional product, the parallelism between the upper and lower surfaces of the tip portion after brazing the base portion and the protruding portion is poor. This was tilted and polished with a # 170 diamond grindstone, and adjusted to a parallelism of 11 μm. This is because the polishing was performed with an inclination to adjust the parallelism, so that the polishing could not be performed until a part of the diamond film was lost, and further adjustment could not be performed.
On the other hand, in the present invention, since the projection is directly brazed by coating the polycrystalline diamond, since the parallelism does not deteriorate due to brazing,
The accuracy of parallelism of 1 μm was achieved. By setting the flatness of the upper and lower surfaces of the tip portion to 5 μm or less before diamond coating, the above-described accuracy after coating can be more easily achieved. In the present invention, since there is no brazing part at the tip,
In the above test, all items were superior to the comparative examples.

[0053]

Example 2 From a φ32 mm × 12 mm SiC block, the bottom surface of the base portion was φ31 mm in a shape as shown in FIG.
With a protrusion of width 5.4 mm x 30.4 mm and height 6 mm,
The stage part having an overall height of 11 mm was processed. A vacuum suction hole with a hole diameter of 0.5 mm and a depth of 0.5 mm from the tool surface side of the protrusion, and a hole diameter of 1.8 mm and a depth of 7 mm from the bottom surface side has a diameter of 6 mm and a depth of 2.5 mm. It was a through hole. It vacuum-sucks semiconductors, etc. and transfers, bonds, or fixes them. The edge of the tool surface was chamfered on each ridgeline with a width of 0.2 mm and an angle of 45 degrees, and the effective dimension of the protruding portion was processed to 5 mm × 30 mm.

As a filament, a known filament CVD method using a tungsten wire having a diameter of 0.5 mm and a length of 100 mm was used to form a SiC projection having a thickness of 50 μm.
Of polycrystalline diamond. The coating conditions are as follows.

[0055] Raw material gas (flow rate): CH4 / H2 = 1%, Total flow rate: 500 CC / min Gas pressure: 10000Pa Filament temperature: 2200 ° C Distance between filament and protruding surface: 5 mm SiC temperature: 920 ° C

The diamond coating layer 5 thus obtained was polished with a diamond grindstone, and the effective dimension of the protrusion was 5 mm.
A stage unit of × 30 mm was manufactured. The stage portion 1 of the bonding stage thus obtained was fixed to the pedestal portion formed of the iron-nickel-cobalt alloy shown in FIG. 4 by the eccentric shaft formed of the same material via the clamp lever. The pedestal portion shown in FIG. 4 has a hole communicating with the vacuum suction hole 6 (not shown in the drawing). It should be noted that the vacuum suction holes provided in the protruding portion before coating are not covered with diamond, and are therefore through holes even after the diamond coating layer is provided.

Similarly, as a comparative example, a bonding stage having a conventional structure having the same structure as shown in FIG. 8 was prepared. The protruding part is (vertical) 60 mm x (horizontal) 60 mm
It was produced by coating a 50 μm polycrystalline diamond on a SiC substrate of × (height) 3 mm and then cutting it into a size of 5.4 mm × 30.4 mm. The base portion was produced by machining an iron-nickel-cobalt alloy into a predetermined shape. After that, the protruding portion and the base portion were joined by silver brazing.

In the bonding stage thus obtained, the parallelism between the bottom of the stage and the tool surface, the temperature distribution of the tool surface at the temperature of 500 ° C. in the thermocouple section,
A seizure test of the stage part and the pedestal part when heated to 500 ° C., durability of the bonding interface between the base part and the protruding part when heating and cooling are repeated from room temperature to 600 ° C., and 600
A load of 20 kg was applied at a temperature of ° C, and durability was compared 2 million times. The results are shown in Table 1.

[0059]

[Table 2]

Details of the test conditions are as follows.

Tool surface temperature distribution: The temperature of the thermocouple part is 5
Maximum and minimum temperature difference of the tool surface at 00 ℃.

Burning test of the stage part: After the bonding test at 500 ° C., a load of 20 kg and one million times, it is checked every 100,000 times whether the stage part can be removed.

Heat cycle test: A cycle of heating from room temperature to 600 ° C., holding for 2 hours, and returning to room temperature is repeated 100 times.

600 ° C. bonding test: 600 ° C., weighted 20 kg, 2 million times bonding test.

In the conventional product, the parallelism between the upper and lower surfaces of the stage after brazing the base and the protrusion is poor. This is # 17
Angled and polished with a 0 diamond grindstone, parallelism of 15 μm
It was adjusted and processed. This is because the polishing was performed with an inclination to adjust the parallelism, so that the polishing could not be performed until a part of the diamond film was lost, and further adjustment could not be performed. On the other hand, in the present invention, since the projection is directly coated with the polycrystalline diamond without brazing, the parallelism does not deteriorate due to the brazing. It has been achieved. By setting the flatness of the upper and lower surfaces of the stage portion to 5 μm or less before diamond coating, the above-described accuracy after coating can be more easily achieved.

In the present invention, since there is no brazing part in the stage part, all the items in the above test were superior to the comparative example.

[0067]

Example 3 Using the bonding tool of the present invention manufactured in Example 1 and the bonding tool of the comparative example, the relationship between temperature and flatness was investigated. Each was mounted on the shank shown in FIG. 2 and heated by a cartridge heater to measure the surface temperature of the tool surface and the flatness of the tool surface at that temperature. The result is shown in FIG. 7. The measurement of flatness is described in JP-A-5-326642. A gold wire or the like is pressed by the tool surface of the bonding tool, and the flatness of the transferred gold wire is measured and used as the flatness of the tool surface.

The conventional brazing type measurement results are indicated by Δ, and the measurement results of the present invention product are indicated by black circles. As shown in FIG. 7, in the case of the present invention, there is almost no change in the range of 100 ° C to 550 ° C. On the other hand, in the conventional product, the flatness changes in the concave direction as the temperature rises. This is because the ceramics of the protrusions brazed to the base portion have a smaller coefficient of thermal expansion than the metal of the base portion. On the other hand, the integrated product has no difference in the coefficient of thermal expansion and no brazing, so that there is no difference in the thermal expansion of the brazed portion.

The same measurement was carried out also in the bonding stage of the present invention, and the same result as this example was obtained.

[0070]

As described above, the bonding tool and / or the bonding stage obtained by the present invention has a great feature that various tool shapes can be dealt with by simply exchanging the tip portion, and it has a long length. The sticking part does not burn even during use for a period of time. In addition, unlike the conventional bonding tool, since there is no joint by brazing, the processing cost and the adjustment cost for maintaining the parallelism of the entire bonding apparatus are low.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a tip portion of a bonding tool of the present invention.

FIG. 2 is a perspective view of a bonding tool of the present invention, in which a tip portion is fixed to a shank portion.

FIG. 3 is a perspective view showing an example of a tip portion of a bonding stage of the present invention.

FIG. 4 is a perspective view of a bonding stage of the present invention, in which a stage unit is fixed to a pedestal unit.

FIG. 5 is a partial cross-sectional view showing the structure of attaching the tip portion to the shank portion according to the present invention.

FIG. 6 is a diagram for explaining the movement of a member for transmitting the movement of the eccentric shaft according to the present invention.

FIG. 7 is a diagram comparing the flatness of the bonding tool obtained in the present invention with that of a conventional bonding tool.

FIG. 8 shows a conventional bonding tool in which the tip and the shank are fixed.

[Explanation of symbols]

1. Tip 2. Mounting side 3. Base part 4. Protrusion 5. Diamond coating layer (tool surface) 6. Vacuum suction hole 10. Cartridge heater compartment 11. Mounting part 12. Pressing part 14. Shank part 15. Eccentric shaft 16. A member that transmits the movement of the eccentric shaft 17. Eccentric shaft support shaft 18. Support shaft of member 16 19. Thermocouple storage 20. Brazing surface 101. Tip 102. Mounting side 103. Base part 104. Protrusion 105. Diamond coating layer (tool surface) 106. Vacuum suction hole 110. Cartridge heater compartment 111. Mounting part 112. Pressing part 114. Pedestal 116. A member that transmits the movement of the eccentric shaft 119. Thermocouple storage

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Kawauchi             Sumitomo, 1-1 1-1 Koyokita, Itami City, Hyogo Prefecture             Electric Industry Co., Ltd. Itami Works (72) Inventor Tetsuo Yashiki             Sumitomo, 1-1 1-1 Koyokita, Itami City, Hyogo Prefecture             Electric Industry Co., Ltd. Itami Works (72) Inventor Toshiya Takahashi             Sumitomo, 1-1 1-1 Koyokita, Itami City, Hyogo Prefecture             Electric Industry Co., Ltd. Itami Works (72) Inventor Toshiaki Ohara             Sumitomo, 1-1 1-1 Koyokita, Itami City, Hyogo Prefecture             Electric Industry Co., Ltd. Itami Works F-term (reference) 5F044 PP02

Claims (11)

[Claims] 1. A bonding tool for mounting a semiconductor, comprising a tip portion and a shank portion, wherein a base portion forming the tip portion and a protruding portion protruding from the base portion are made of an integral material, and a tool for the protruding portion. A bonding tool characterized in that the surface is coated with vapor phase synthetic diamond, and the tip and the shank are mechanically fixed or fixed by vacuum suction. 2. A bonding stage for semiconductor mounting, comprising a stage part and a pedestal part, wherein a base part forming the stage part and a protruding part protruding from the base part are made of an integral material, and a tool for the protruding part. A bonding stage characterized in that the surface is covered with vapor phase synthetic diamond, and the stage and the pedestal are mechanically fixed or fixed by vacuum suction. 3. The tip portion and / or the stage portion is made of Si.
_{3. A} sintered body containing any one of C, Si ₃ N ₄ and AlN as a main component, the tool surface of which is coated with polycrystalline diamond by a vapor phase synthesis method. The bonding tool and / or the bonding stage according to 1. 4. The shank portion and / or pedestal portion is selected from molybdenum, cemented carbide, nickel base alloy, tungsten or tungsten alloy, iron-nickel-cobalt alloy, stainless steel, iron-nickel alloy, titanium or titanium alloy. It is 1 or 2 or more, The bonding tool and / or the bonding stage of Claim 1, 2 or 3 characterized by the above-mentioned. 5. A tip portion and / or a stage portion is constituted.
The base part and the protruding part protruding from the base part are made of an integral material.
And the integral material is at least SiC, Si
_ThreeN_FourA sintered body containing at least one of Al, AlN as a main component
And the tool surface of the protruding part is a vapor phase synthetic diamond coating layer
A tip part for a bonding tool characterized by comprising
And / or a stage part for the bonding stage. 6. The tip portion for a bonding tool and / or the bonding stage according to claim 5, wherein the parallelism between the bottom surface of the tip portion and / or the stage portion and the tool surface is 2 μm or less at room temperature. Stage section. 7. A mounting side surface having a trapezoidal cross-sectional shape in which the side length or diameter decreases toward the tool surface when the mounting portion to the shank portion and / or the pedestal portion is viewed from the side surface side. The tip portion for a bonding tool and / or the stage portion for a bonding stage according to claim 5 or 6. 8. The flatness change of the tool surface from 100 ° C. to 550 ° C. is 1 μm or less.
7. The tip part for a bonding tool and / or the stage part for a bonding stage according to any one of 7. 9. The bonding tool according to claim 5, wherein the tool surface of the tip portion and / or the stage portion has one or more vacuum suction holes for suctioning semiconductor elements. Tip and / or stage part for bonding stage. 10. The tool surface of the tip portion and / or the stage portion has a vacuum suction groove for sucking a semiconductor and one or more vacuum suction holes, according to any one of claims 5 to 8. Bonding tool tip and /
Or stage part for bonding stage. 11. A metal of one or more layers selected from soft metals such as gold, silver, copper, platinum, tantalum, nickel and aluminum is interposed between the tip and the shank or between the stage and the pedestal. Claim 1 characterized by the above-mentioned.
Bonding tool according to any one of 10 to 10 and /
Or a bonding stage.