JPH11121533A - Bonding tool and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding tool, which is capable of reducing the degree of flatness on a bonding acting face at a use temperature and execute uniform bonding works, and a useful method for manufacturing such a bonding tool. SOLUTION: A stress relaxation layer 2, composed of a soft metal and a top end material 1 composed of a hard metal, is laminated on a shank material 4 composed of a metal material, and insertion materials 3a, 3b reside between the top end material 1 and the soft metal and between the soft metal and a shank material 4, respectively, and they are heated and molten to thereby joint each other. At manufacturing of a bonding tool as described, after being bonded so that a margin of the stress mitigation layer 2 is wider by 0.5 mm or more than a margin of the top end material 1, processings are performed so that the degree of flatness at a room temperature on a bonding acting face of the top end material 1 is set within to 1 μm, whereby changes in the degree of flatness between 500 deg.C and 600 deg.C on the bonding acting face of the top end material 1 is 1 μm or less, and also a change in the degree of flatness between a room temperature and 600 deg.C is 3 μm or less, and the degree of flatness on the bonding acting face at an arbitrary temperature between 500 deg.C and 600 deg.C is 1 μm or less. A bonding tool with such properties can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding tool in which a stress relaxing layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material. In addition, the bonding tool of the present invention is, for example, TAB (Tape Automated) used in a high temperature environment.
ated Bonding).

[0002]

2. Description of the Related Art One of the methods for electrically connecting electrodes on a semiconductor chip and leads of a film package is as follows.
The above TAB method is known. The TAB method is a method in which a lead pattern is formed on the surface of a heat-resistant resin tape, and the electrode pads of the semiconductor chip and the leads of the film carrier tape on which the lead pattern is formed are aligned and joined. It is said to be superior to the wire bonding method in terms of increasing the number of pins and reducing the thickness.

[0003] The bonding procedure in the TAB method is as follows.
It is performed as follows. First, the semiconductor chip is placed on the heating stage, and the bumps of the semiconductor chip are aligned with the inner leads of the film carrier tape. Then, in this state, the bonding tool heated to 500 to 600 ° C. presses the inner leads against the bumps of the semiconductor chip to join the two.

[0004] In recent years, semiconductor chips are as large as 16 m.
In some cases, the bonding tool must have a flat surface (bonding surface) in order to uniformly bond all the inner leads to the bumps formed over almost the entire periphery of the bonding tool. Required. For example,
When the use temperature of the bonding tool is 500 to 600 ° C., the flatness of the bonding working surface is ideally 1
It is required that the thickness be less than μm.

[0005] The bonding tool comprises a shank material to be attached to a predetermined position of the apparatus, forming a base of the tool;
And a tip material having a tip surface (the bonding action surface) for performing a bonding operation. Normal,
A hard material such as ceramics is used as the tip material of the bonding tool, and a metal material is used as the shank material.

However, when a joined body in which a hard material such as a ceramic material as a tip material is directly joined to a metal material as a shank material is used as a material for a bonding tool, a difference in thermal expansion coefficient between the two causes a difference. Even when deformation occurs and the flatness of the bonding surface satisfies the required characteristics at room temperature, the required characteristics may not be satisfied at a high use temperature. As a result, inner leads that are not sufficiently pressurized and heated with respect to the bumps of the semiconductor chip are generated, and a bonding failure occurs.

[0007] As a means for reducing the flatness of the bonding surface at the operating temperature to 1 µm or less, a method of performing flat polishing in an atmosphere at the operating temperature is known. However, the operating temperature of the bonding tool is 500 at present.
Although it is in a temperature range of -600 ° C, it is not fixed to one temperature, but is appropriately selected from a temperature of 500-600 ° C depending on the state of the bump to be bonded. Under these circumstances, the flat polishing temperature of the bonding tool cannot be limited. As a result, a bonding tool that has been polished flat at a certain temperature,
When used at a temperature other than the polishing temperature, the flatness of the bonding operation surface is deteriorated, and bonding failure may occur. Moreover, the method of polishing at the operating temperature is
Considering that the use temperature is 500 to 600 ° C., it is inevitable that workability is necessarily reduced.

From the above, it can be said that flat polishing is most preferably performed at room temperature. However, the metal material used as a shank material has a larger linear expansion coefficient than a hard material such as ceramics used as a tip material. The bonding surface greatly changes between the room temperature and the use temperature. Normally, as shown in FIG. 1 (a) (arrows in the figure indicate the magnitude of the linear expansion coefficient), the tip material 1 is pulled from the shank material 4 at the lower part, and the bonding surface becomes concave. It is general. For this reason, in anticipation of the above-mentioned deformation, flat polishing at normal temperature is made convex as shown in FIG. 1B, and the bonding surface is made as flat as possible in the deformed state. Is the actual situation.

However, the most ideal is that the flatness does not change with temperature. If such a bonding tool can be realized, it can be expected that the usable temperature range of the bonding tool will be widened. As a result, it is expected that bonding can be performed to various types of bumps / leads, and that the bonding tool can be applied to a wider range.

[0010] The flatness means the unevenness of the bonding surface.
Is the maximum value, for example, in FIGS.
(In the figure, the reference of the virtual flat surface is indicated by a broken line.)₁ 
~ X _Four Pointing to. The change in flatness refers to the flatness
Flatness at two temperatures regardless of measured position
Shows how much has changed, for example,
2 (a) is changed to FIG. 2 (b).
The degree change is X₁ And X_Two Difference (X₁ -X_Two : However, X₁ > X
_Two ), And changes from FIG. 2 (b) to FIG. 2 (d) (ie,
Change from convex to concave), the flatness change is X
_Two And X_Four The sum of (X_Two + X_Four ).

[0011]

In order to ensure the flatness of the bonding surface at the operating temperature, the flatness at normal temperature is improved, and the flatness change when the temperature is changed from normal temperature to the operating temperature. Need to be smaller. The flatness at room temperature is 2 μm or less, and the change amount is 3 μm in consideration of the above-mentioned change from the convex type to the concave type.
It is required that: As a technique for reducing such thermal strain, a technique of interposing a material having a coefficient of linear expansion intermediate between the ceramic and the metal material or a soft metal between the two has been proposed. .

For example, Japanese Patent Application Laid-Open No. Hei 5-67651 proposes a bonding tool in which a soft metal such as Au is formed as two stress relaxation layers between a ceramic and a metal material. In this technology, it is shown that the flatness change is small when two stress relaxation layers are formed, but the flatness change is large when only one stress relaxation layer is formed. In this technical example, the flatness at room temperature (flatness after polishing): 0.9 μm and the flatness at high temperature (flatness at operating temperature): 2.7 μm are shown. In consideration of the fact that the flatness may be concave at the operating temperature, the flatness change is 1.9 μm at the minimum and 3.6 μm at the maximum, and there are cases where the required flatness change of 3 μm or less cannot be satisfied. It is expected that there is. In this technique, when the stress relaxation layer is one layer,
Both have a flatness of 1 μm at the operating temperature (600 ° C)
Not satisfied with:

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to perform a uniform bonding operation by minimizing the flatness of a bonding working surface at a use temperature as much as possible. It is to provide a bonding tool and a useful method for manufacturing such a bonding tool.

[0014]

A bonding tool according to the present invention which can solve the above-mentioned problems is characterized in that a stress relaxation layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material. In a bonding tool joined between an end material and a soft metal and between a soft metal and a shank material with an insert material interposed therebetween, the bonding tool has a temperature of 500 ° C.
The change in flatness during 600 ° C. is 1 μm or less,
The flatness change between normal temperature and 600 ° C. is 3 μm or less,
The point is that the flatness of the bonding surface at an arbitrary temperature between 500 and 600 ° C. is 1 μm or less. The change in flatness between normal temperature and 600 ° C. is preferably 2 μm or less. Further, since the bonding tool is not always kept at a uniform temperature, different temperatures may be obtained depending on the temperature measurement position. Therefore, the temperature used in the present invention is 3 to 15 mm from the joint surface of the shank material. Is measured at this position, and is also measured at this position in a normal bonding tool.

In the bonding tool according to the present invention, the peripheral edge of the stress relaxation layer is 0.5 mm more than the peripheral edge of the tip member.
What is configured to be wider as described above is a basic configuration.

Further, as a more specific configuration of the bonding tool of the present invention, (A) Au is used as a stress relaxation layer, and the stress relaxation layer and the tip are provided with a mass ratio of Au to Ni (A
(B) Ag or Cu is used as a stress relaxation layer, and the stress relaxation layer and the tip material are made of Ag and Cu. Has a mass ratio (Au / Cu) of 0.4 to 9
A bonding tool bonded by a bonding layer of 9.0, and the like.

On the other hand, the manufacturing method of the present invention which can solve the above-mentioned problem is that a stress relaxation layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material. And a stress relief layer, and between the stress relief layer and the shank material, the bonding tool is joined by heating and melting with an insert material interposed therebetween, wherein the peripheral edge of the stress relief layer is the tip material. The point is that the bonding is performed so that the flatness of the bonding surface of the tip material at room temperature becomes 2 μm or less after joining by making the width 0.5 mm or more wider than the peripheral edge. The flatness at room temperature is preferably 1 μm or less.

Further, the specific structure of the method of the present invention is as follows: (a) Au or N
In a state where an insert material containing i as a main component is interposed between the tip material and the stress relaxation layer, the insert material is heated and melted to a temperature of 1032 ° C. or less at a temperature not lower than its liquidus line. (B) Ag or Cu is used as the stress relaxation layer,
Alternatively, while an insert material containing Cu as a main component is interposed between the tip material and the stress relaxation layer, the insert material is heated and melted to a temperature not lower than its liquidus temperature and not more than 950 ° C. And a method of joining the stress relaxation layer to the substrate.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is constructed as described above. In short, a stress relaxation layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material. In a method of manufacturing a bonding tool in which an insert material is interposed between a stress relaxation layer and between a stress relaxation layer and a shank material to be joined by heating and melting, the periphery of the stress relaxation layer is larger than the periphery of the tip material. Also, if the flatness at normal temperature on the bonding surface of the tip material at room temperature is 1 μm or less, the thermal deformation difference between the tip material and the shank material is reduced. It was found that the relaxation effect of the stress relaxation layer was effectively exhibited, and a bonding tool satisfying the following characteristics (1) to (3) was obtained.
The present invention has been completed. (1) 500 ℃ ⇔6 on the bonding surface of the tip material
The change in flatness during 00 ° C. is 1 μm or less. (2) The change in flatness between normal temperature and 600 ° C. is 3 μm or less. (3) The flatness of the bonding surface at any temperature between 500 and 600 ° C. is 1 μm or less.

The operation of the present invention will be described while explaining how the present invention was completed. As a method of manufacturing a bonding tool, a stress relaxation layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material, and the stress relaxation layer and the shank are formed between the tip material and the stress relaxation layer. From the viewpoint of bonding strength, it can be said that a method of bonding by interposing an insert material between the materials and melting them by heating is preferable. As described above, the role of the stress relaxation layer in such a bonding tool is to reduce the thermal deformation difference between the tip material made of a hard material such as ceramics and the shank material made of a metal material. That is, since the soft metal is easily plastically deformed, the deformation makes it possible to absorb the difference in thermal deformation between the tip material and the shank material. Therefore, if a hard material that inhibits deformation of the soft metal exists between the tip material and the shank material,
The soft metal cannot be sufficiently deformed, and the difference in thermal deformation between the tip material and the shank material cannot be sufficiently reduced.

The present inventors have studied the cause of the insufficient relaxation effect when one stress relaxation layer is formed from such a viewpoint, and obtained the following findings. When joining between the tip material and the stress relieving layer or between the stress relieving layer and the shank material with the insert material, as shown in FIG. 3, the molten insert material overflows from both ends and is joined. Fillet 5 around the stress relaxation layer with
Is formed. The insert material is generally an alloy composed of two or more elements to lower the melting point, and has a higher hardness than the stress relaxation layer. As a result, the fillet 5 restrains the periphery of the stress relieving layer and hinders deformation of the soft metal. In particular, when minute deformation such as a bonding tool poses a problem, the soft metal may not be able to absorb the thermal deformation difference between the tip material and the shank material.

Based on these findings, the present inventors have studied from the viewpoint of avoiding the above-mentioned inconvenience, and found that the periphery of the stress relaxation layer is 0.5 m longer than the periphery of the tip material.
m or more, the insert material overflowing between the tip material and the stress relieving layer and between the stress relieving layer and the shank material can be separated. It was found that the fillet 5 as described above was not formed, the deformation of the soft metal as the stress relaxation layer was not hindered, and the flatness characteristics as shown in the above (1) to (3) were obtained. completed.

The configuration of the present invention will be described in more detail with reference to the drawings. FIG. 4 is a schematic explanatory view showing one configuration example near the tip of the bonding tool of the present invention. In the drawing, 1 is a tip material (hard material), 2 is a stress relaxation layer (soft metal), 3
Reference numerals a and 3b denote joining layers (insert materials), and reference numeral 4 denotes a shank material. FIG. 5 is a plan view of a main part of the bonding tool (in the vicinity of the tip member 1 and the stress relaxation layer 2). Since the bonding surface is often rectangular in view of the shape of the semiconductor chip, the bonding surface is rectangular in FIGS. 4 and 5, but the bonding surface of the bonding tool of the present invention is limited to a rectangular shape. It is not something to be done.

The greatest feature of the bonding tool of the present invention is that it is manufactured such that the peripheral edge of the stress relaxation layer 2 is at least 0.5 mm wider than the peripheral edge of the tip 1. That is, the distance indicated by d1 and d2 in FIG.
The thickness is set to 5 mm or more. If both d1 and d2 are less than 0.5 mm, it is impossible to suppress the change in flatness of the bonding surface. However,
As shown in FIG. 5, when the joining surface is rectangular, the change in flatness is large on the long side (L1 indicates the length of the long side), so the short side (L2 is the short side) The distance d2 on the long side, even if the distance d2 is less than 0.5 mm.
If 1 is 0.5 mm or more, the object of the present invention can be achieved.

FIG. 6 is a schematic explanatory view showing another example of the structure near the tip of the bonding tool of the present invention. In this bonding tool, a plurality of (6 in this figure) positioning is performed on the surface of the shank material 4. Protrusions 7 are provided to prevent displacement of the tip 1 and the stress relieving layer 2 during joining. That is, FIG. 7 shows a state in which the stress relaxation layer 2 and the tip material 1 are laminated on the shank material 4. The notch 8 is formed in the stress relaxation layer 2 at a position corresponding to the positioning projection 7. The stress relief layer 2 is laminated on the shank material 4 so that the positioning projection 7 fits into the notch 8, and the tip material 1 is placed on the stress relief layer 2 so as to fit between the positioning projections 7. Laminated. Other basic configurations of the bonding tool shown in FIGS. 6 and 7 are similar to those of the bonding tool shown in FIGS. 4 and 5, and corresponding portions are denoted by the same reference numerals. .

FIG. 8 is a plan view of a main part (in the vicinity of the tip 1 and the stress relaxation layer 2) of the bonding tool shown in FIGS.
Shown in In this bonding tool, the distances d1 and d2 cannot be set to 0.5 mm or more in the notch 8 of the stress relaxation layer 2. From the point of the invention,
It is preferable that the notch 8 is as small as possible. However, if the distances d1 and d2 in the portion excluding the notch 8 are 0.5 mm or more, the change in flatness of the bonding surface is not significantly affected. Absent.

The distances d1 and d2 shown in FIGS.
The upper limit is not particularly limited, but is preferably equal to or smaller than the size of the joining surface of the shank material in consideration of cost, workability after joining, and the like.

As described above, by forming the periphery of the stress relaxation layer to be 0.5 mm or more wider than the periphery of the tip material, a fillet is prevented from being formed around the stress relaxation layer, and the stress is reduced. Since the factor that hinders the deformation of the soft metal constituting the relaxation layer is eliminated, the difference in thermal deformation between the tip material and the shank material due to the stress relaxation layer can be sufficiently reduced. Considering such an effect of the stress relaxation layer, the fillet 5 as shown in FIG. 3 is formed around the stress relaxation layer at the time of joining without the peripheral edge of the stress relief layer being wider than the peripheral edge of the tip material by 0.5 mm or more. It is conceivable that the fillet 5 is formed and removed after processing after the joining. However, if a part (peripheral portion) of the stress relaxation layer is dissolved when the insert material is melted, as shown in FIG. Since the hard layer is formed inside the peripheral edge of the tip material, the hard layer cannot be effectively processed and removed. However, as shown in FIG. 9, after joining by forming the periphery of the stress relieving layer to be 0.5 mm or more wider than the peripheral edge of the tip material, the stress relieving layer may be cut by means such as cutting or wire cutting. The fillet portion can be easily removed by removing the fillet portion around the portion along with the portion, and such a configuration is also included in the technical scope of the present invention.

Next, the soft metal used as the stress relaxation layer in the present invention will be described. As described above, the stress relaxation layer is interposed between the tip material and the shank material to reduce the difference in thermal deformation due to the difference in the coefficient of linear expansion between the tip material and the shank material. For this reason, any soft metal that is used as the stress relaxation layer can be used as long as it is soft and easily causes plastic deformation.Specific required characteristics are soft metals having a Vickers hardness of 120 or less. And more preferably 10 in Vickers hardness.
It is a soft metal of 0 or less. Considering these properties, the soft metal is preferably a pure metal except for inevitable impurities, and examples thereof include, but are not limited to, Au, Ag, Cu, Ni, and Pd. However, the soft metal used in the present invention does not necessarily need to be a pure metal, and can be applied to alloys to which various alloying elements are added. Examples of such alloys include, but are not limited to, Au alloy, Ag alloy, Cu alloy, P
d alloy and the like.

The thickness of the stress relaxation layer is preferably about 0.15 to 5.0 mm after joining. If the thickness is less than 0.15 mm, the thermal deformation difference between the tip material and the shank material cannot be sufficiently reduced, and
The change in flatness of the bonding surface increases. Conversely, when the thickness exceeds 5.0 mm, the influence of the linear expansion coefficient of the soft metal on the flatness change of the bonding surface increases, and the flatness change of the bonding surface increases.

The hard material used as the tip material in the present invention is:
All commonly used ones can be used. Examples of such hard materials include, but are not limited to, a sintered body mainly composed of SiC, a sintered body mainly composed of Si ₃ N ₄ , metal Si, a cemented carbide and the like. When joining a hard material such as ceramics by fusion and solidification of the insert material, metallizing the joint surface of the hard material to improve the wettability with the insert material or to prevent the reaction between the hard material and the insert material. Although a coating may be applied, it is a matter of course that the hard tool may be provided with such a coating even in the bonding tool of the present invention. Typical examples of such a coating layer include, but are not limited to, Cr, Ti, Pt, and A.
u, TiC, TiN, diamond and the like.
This coating is not limited to a single layer, and may be formed in multiple layers.

Incidentally, Sn is generally used as a bonding material for bonding the bump and the inner lead.
During the bonding operation using a bonding tool, Sn as a bonding material may adhere to the bonding surface. Therefore, it is required that Sn does not adhere to the bonding surface. Also, on the bonding action surface,
It is also important to have excellent wear resistance. For this reason, various types of coating may be applied to the bonding surface of the tip material. Such a coating may also be applied to the bonding tool of the present invention, and examples of such a coating layer include vapor-phase synthetic diamond, cBN, and AlTiN.

The metal material used as the shank material in the present invention is usually a Kovar alloy (Fe-2) because the linear expansion coefficient of the ceramic used as the tip material is close.
9 mass% Ni-17 mass% Co alloy) as a typical example. However, the metal material used as the shank material in the present invention is not limited to the above-mentioned Kovar alloy. W-Ni alloy, cemented carbide, etc. can also be used.

In the present invention, the insert material used for joining between the tip material and the stress relieving layer and between the stress relieving layer and the shank material is not particularly limited. used. Non-limiting examples of typical insert materials include A
g-28% Cu alloy, Ag-30% Cu-10% Sn alloy, Au-18% Ni alloy, Au-20% Cu alloy, A
g-28% Cu-2% Ti alloy, Au-22% Ni-6
% Cr alloy, Au-15.5% Ni-0.75Mo-
1.75% V alloy, Au-3.0% Ni-0.6% Ti
Alloy (all of which means "% by mass"). In addition, as for the insert material, in order to avoid mixing different materials, it is general that both insert materials used between the tip material and the stress relaxation layer and between the stress relaxation layer and the shank material have the same composition. In the present invention, those having the same composition or different compositions can be used.

In the present invention, the insert material as described above is used
The insert material is joined by heating and melting the insert material in a state interposed between the tip material and the stress relieving layer and between the stress relieving layer and the shank material. Temperature) must be equal to or higher than the liquidus temperature of the insert material. On the other hand, considering only the joining strength, the joining temperature is preferably as high as possible. However, if the joining temperature is too high, the amount of the stress relaxation layer dissolved when the insert material is melted is not preferable. From this point of view, the upper limit of the joining temperature is set as A for the stress relaxation layer.
When u is used and an alloy containing Au or Ni as a main component is used as an insert material, the temperature is 1032 ° C., Ag or Cu is used as a stress relaxation layer, and Ag or Cu is mainly used as an insert material. When an alloy is used, the temperature is 950 ° C.

When bonding is performed at the above-described bonding temperature, the bonding layer between the tip member and the stress relaxation layer after bonding has a composition defined by the bonding temperature. For example, when an alloy containing Au is used as the stress relaxation layer and Au and Ni are used as the insert material, Au melts in the insert material when heated, and the liquidus temperature of the insert material in a molten state is increased. When the temperature reaches the joining temperature, the insert material solidifies. Since the bonding temperature at this time is 1032 ° C. or lower as described above, the liquidus temperature of the bonding layer is 1032 ° C. or lower. And Au-
In the Ni binary system, the composition at which the liquidus temperature is lower than 1032 ° C. is determined by the phase diagram according to the weight ratio of Au to Ni (A
u / Ni) of 2.2 to 32.3, the composition between the tip material and the stress relaxation layer is determined by the mass ratio (A) excluding other components.
u / Ni) is in the range of 2.2 to 32.3. On the other hand, when an alloy containing at least Au and Ni is used as the stress relieving layer and at least Au and Ni are used as the insert material, the composition between the tip material and the stress relieving layer depends on the mass ratio (Ag) excluding other components. / Cu) is in the range of 0.4 to 99.0.

[0037]

EXAMPLES Next, the structure and operation and effect of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and can be adapted to the spirit of the preceding and following examples. Of course, the present invention can be implemented with modifications within the scope, and all of them are included in the technical scope of the present invention.

Embodiment 1 FIG. 10 is a schematic view showing an example of a bonding tool according to the present invention. In this bonding tool, SiC is used as the tip material 1, oxygen-free copper (thickness: 0.5 mm) is used as the stress relaxation layer 2, and Ag is used as the insert materials 3a and 3b.
A −28.0 mass% Cu-2.0 mass% Ti alloy (liquidus temperature: 780 ° C.) and a Kovar alloy were used as the shank material 4. An air layer synthetic diamond film (thickness: 60 μm) was synthesized on the bonding surface of the tip material 1 as a coating film 1a.

The above bonding tool was prepared in the following procedure. First, prior to joining, a coating film 1a was formed on the bonding material side of the tip material 1. Next, the insert material 3b, the stress relaxation layer 2, the insert material 3a, and the tip material were sequentially laminated on the shank material 4. And A
In an r gas atmosphere, the insert materials 3a and 3b were heated to 820 ° C. to fuse and perform the joining. At the time of this joining, the short side dimension (short side length:
L1, distance: d1) and long side dimension (long side length: L)
2. The distance: d2) was variously changed.

The obtained bonding tool was polished flat at room temperature, and then the change in flatness of the bonding surface was measured at room temperature and 600 ° C. The results are shown in Table 1 below.

[0041]

[Table 1]

The following can be considered from the results in Table 1. First, when d1 and d2 are larger than 0.5 mm,
A bonding tool satisfying any of the characteristics (1) to (3) was obtained and could be suitably used. (1) 500 ° C on the bonding surface of the hot tip material
The change in flatness during 600 ° C. is 1 μm or less. (2) The change in flatness between normal temperature and 600 ° C. is 3 μm or less. (3) The flatness of the bonding surface at an arbitrary temperature between 500 ° C. and 600 ° C. is 1 μm or less.

On the other hand, when d1 is less than 0.5 mm, L1 is not less than 5.0 mm and d2 is 0.5 m
If it is less than m, the change in flatness of the bonding surface at room temperature @ 600 ° C is larger than 3 µm, or the change in flatness at 500 ° C @ 600 ° C is larger than 1 µm, and it can be used as a bonding tool. The temperature range is limited. When L1 is 3.5 mm, the change in flatness is as small as 2 μm or less even when d2 is less than 0.5 mm,
It could be suitably used as a bonding tool.

Embodiment 2 FIG. 11 is a schematic view showing another example of the bonding tool of the present invention. In this bonding tool, SiC is used as the tip material 1 and Au (purity:
99.9%, thickness: 0.5 mm), insert material 3a,
Au-15.5% by mass Ni-0.75% by mass as 3b
Mo-1.75 mass% V alloy (liquidus temperature: 960
° C), and a Kovar alloy was used as the shank material 4.
The tip material 1 has an air-synthetic diamond film (thickness: 60) as a coating film 1a on the bonding surface.
μm), and a gas-phase synthetic diamond film (film thickness: 20 μm) is synthesized on the bonding surface side as a coating film 1b.

The above bonding tool was prepared in the following procedure. Prior to joining, a coating coating film 1a was formed on the bonding surface of the tip material 1, and a coating coating film 1b was formed on the bonding surface side. Next, the insert material 3b, the stress relaxation layer 2, the insert material 3a, and the tip material were sequentially laminated on the shank material 4. And in a vacuum, 98
Heating was performed to 0 ° C., and the insert materials 3a and 3b were melted and joined. In this joining, the short side dimension (short side length: L1, distance: d1) and long side dimension (long side length: L2, distance: d2) shown in FIG. 11 were variously changed.

The obtained bonding tool was polished flat at room temperature, and then the change in flatness of the bonding surface was measured at room temperature and 600 ° C. The results are shown in Table 2 below.

[0047]

[Table 2]

The following can be considered from the results in Table 2. First, when d1 and d2 are larger than 0.5 mm,
A bonding tool satisfying any of the characteristics (1) to (3) was obtained and could be suitably used.

On the other hand, when d1 is less than 0.5 mm, L1 is 5.0 mm or more and d2 is 0.5 m
If it is less than m, the change in flatness of the bonding surface at room temperature of about 600 ° C. becomes larger than 3 μm, or
Or the change in flatness at 500 ° C.⇔600 ° C. is 1 μm
And the temperature range that can be used as a bonding tool is limited. When L1 was 3.0 mm, even when d2 was less than 0.5 mm, the change in flatness was as small as 2 μm or less, so that it could be suitably used as a bonding tool.

Embodiment 3 In the bonding tool having the basic structure shown in FIG. 11, SiC is used as the tip material 1 and A is used as the stress relaxation layer 2.
u (purity: 99.9%), Au-22.0% by mass Ni-6.0% by mass Cr alloy (liquid layer temperature: 1000 ° C.) as the insert materials 3a and 3b, and Kovar alloy as the shank material 4. Using. The tip material 1 has a gas-phase synthetic diamond film (film thickness: 60 μm) as the coating film 1a on the bonding surface side, and a gas-phase synthetic diamond film (film thickness: 60 μm) as the coating film 1b on the bonding surface side.
20 μm).

The above bonding tool was prepared in the following procedure. First, prior to joining, a coating film 1a was formed on the bonding surface of the tip 1 and a coating film 1b was formed on the bonding surface. Next, on the shank material 4, the insert material 3b, the stress relaxation layer 2, the insert material 3
a and the tip material 1 were sequentially laminated. Then, the material is heated to 1020 ° C. in a vacuum, and the insert materials 3a and 3b are heated.
Was melted to perform joining. In this joining, L
1: 3.0 mm, L2: 15 mm, d1: 1.0 mm,
Assuming that d2 was 1.0 mm, the thickness of the stress relaxation layer 2 before joining was variously changed.

The obtained bonding tool was polished flat at room temperature, and the change in flatness of the bonding surface was measured at room temperature and 600 ° C. The results are shown in Table 3 below. After measuring the change in flatness, the bonding tool was cut, and the thickness of the stress relaxation layer 2 was measured by cross-section observation. The reason why the cross section was observed after the joining was that the metal used for the stress relieving layer 2 was dissolved in the insert material when the insert material was melted, so that the thickness of the stress relieving layer 2 of the bonding tool was reduced after the joining. Table 3 also shows the measured thickness of the stress relaxation layer 2.

[0053]

[Table 3]

The following can be considered from the results in Table 3. When the thickness of the stress relaxation layer 2 is 0.15 mm or more and less than 5.0 mm, the flatness change from room temperature to 600 ° C. is 2 μm.
The following bonding tool was obtained and could be suitably used.

On the other hand, when the thickness of the stress relaxation layer is 0.1
When the thickness is less than 5 mm and when the thickness is more than 5.0 mm, the change in flatness of the bonding surface at ordinary temperature of 600 ° C. becomes larger than 3 μm or 500 ° C./6
The change in flatness at 00 ° C. was large exceeding 1 μm, and the temperature range usable as a bonding tool was limited.

[0056]

The present invention is configured as described above, and a bonding tool capable of performing a uniform bonding operation by reducing the flatness of the bonding working surface at a use temperature can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining how a bonding surface of a bonding tool changes with temperature.

FIG. 2 is a schematic diagram for explaining flatness of a bonding surface.

FIG. 3 is a diagram for explaining a cause of insufficient relaxation effect when one stress relaxation layer is formed.

FIG. 4 is a schematic explanatory view showing an example of a configuration near a tip portion of a bonding tool according to the present invention.

5 is a plan view showing a main part (near the tip member 1 and the stress relaxation layer 2) of the bonding tool shown in FIG.

FIG. 6 is a schematic explanatory view showing another configuration example near the tip end of the bonding tool of the present invention.

FIG. 7 shows a stress relaxation layer 2 and a tip material 1 on a shank material 4.
It is a figure explaining the state which laminates.

FIG. 8 is a plan view showing a main part (in the vicinity of the end member 1 and the stress relaxation layer 2) of the bonding tool shown in FIGS.

FIG. 9 is a diagram for explaining an embodiment of the present invention.

FIG. 10 is a schematic view showing an example of a bonding tool according to the present invention.

FIG. 11 is a schematic view showing another example of the bonding tool of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tip material (hard material) 2 Stress relaxation layer (soft metal) 3a, 3b Joining layer (insert material) 4 Shank material

Continued on the front page (72) Inventor Masatoshi Nishikawa 179-1 Kanegasaki Nishi-Oike, Uozumi-cho, Akashi-shi, Hyogo Prefecture Shinko Kobelco Tool Co., Ltd.

Claims (7)

[Claims] 1. A stress relaxation layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material, and between the tip material and the stress relaxation layer, and between the stress relaxation layer and the shank material. In a bonding tool joined with an insert material interposed therebetween, the flatness change between 500 ° C. and 600 ° C. on the bonding working surface of the tip material is 1 μm or less and the flatness between normal temperature and 600 ° C. The change is 3 μm or less, and 500 to 600 ° C.
A bonding tool characterized in that the flatness of the bonding action surface at an arbitrary temperature therebetween is 1 μm or less. 2. The bonding tool according to claim 1, wherein a peripheral edge of the stress relaxation layer is wider than a peripheral edge of the tip member by 0.5 mm or more. 3. A stress relaxation layer made of Au, wherein the stress relaxation layer and the tip material have a mass ratio of Au to Ni (Au / N).
The bonding tool according to claim 1, wherein the bonding tool is bonded by a bonding layer in which i) is 2.2 to 32.3. 4. Ag or Cu is used as a stress relieving layer, and the stress relieving layer is joined with a tip material by a joining layer having a mass ratio of Ag to Cu (Au / Cu) of 0.4 to 99.0. The bonding tool according to claim 1, wherein the bonding tool is used. 5. A stress relaxation layer made of a soft metal and a tip material made of a hard material are laminated on a shank material made of a metal material, and between the tip material and the stress relaxation layer and between the stress relaxation layer and the shank material. In a method of manufacturing a bonding tool, which is joined by heating and melting with an insert material interposed therebetween, the joining is performed such that the periphery of the stress relaxation layer is at least 0.5 mm wider than the periphery of the tip material. A method of manufacturing the bonding tool, wherein the flatness of the tip material at the bonding operation surface at room temperature is 2 μm or less. 6. A method according to claim 1, wherein the stress relaxation layer is made of Au, and an insert material containing Au or Ni as a main component is interposed between the tip material and the stress relaxation layer. The method for manufacturing a bonding tool according to claim 5, wherein the tip material and the stress relaxation layer are joined by heating and melting to a temperature of 1032 ° C or less. 7. An insert material containing Ag or Cu as a main component using Ag or Cu as a stress relaxation layer,
6. The tip material and the stress relaxation layer are joined by heating and melting the insert material to a temperature not lower than its liquidus temperature and not more than 950 ° C. while being interposed between the tip material and the stress relaxation layer. Method of manufacturing a bonding tool.