JPH05186884A - Metallic conductive foil or metallic alloy conductive foil and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide conductive foil high in the joining strength of a solder joint part and free from the generation of soldering balls. CONSTITUTION:In the objective metallic conductive foil or metallic alloy conductive foil, a solder film 50 with 1 to 50mum thickness constituted in such a manner that plural lead layers 31 and 32 and tin layers 41 and 42 are alternately laminated is formed on the surface 21 of foil body 20 constituted of metal or alloy essentially consisting of the metal. At the time of using one kind selected from gold, silver, platinum and palladium as the above-mentioned metal, the thickness of the solder film is regulated to 3 to 50mum, and at the time of using lead as the above-mentioned metal, the thickness of the solder film is regulated to l to 30mum as well as the thickness of the layer constituted of the adjacent one lead layer and tin layer is regulated to <=8mum. Moreover, the objective conductive foil is manufactured by a vacuum deposition method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal conductor foil or metal alloy conductor foil suitable for use as a conductor for devices such as transistors, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, for example, as a conductor used in a power transistor or a photoelectric conversion element through which a relatively large current flows, and used in an environment susceptible to vibration, a specific resistance is lowered and flexibility is obtained. Conductive foil made of metal or metal alloy with a structure in which a bending process is inserted in the middle of the mesh or conductor in order to have
Is abbreviated. ).

A solder film made of a lead-tin alloy is usually formed on one surface of the conductor foil. When the conductor foil is soldered to an element, the solder film is brought into contact with the element. By pressing the heat block from the other surface side of the solder film in this state, the solder film can be melted and connected.

By the way, as a method of forming a solder film on the conductor foil, an immersion method of forming a solder film by immersing a portion to be soldered in a molten solder bath, or a solder film by masking the conductor foil is used. There are a plating method in which only a portion to which is attached is exposed and then a solder is plated, and then the mask is removed, and a sputtering method in which a solder film is formed by sputtering.

However, in the dipping method, there is a large variation in the solder film thickness between products, so that soldering failure due to insufficient film thickness, short-circuit with other joints due to excessively applied solder, and foil. There is an inconvenience that the material is easily broken. Further, in particular, when the material of the conductor foil is lead or a lead alloy, there is a disadvantage that the conductor foil is melted in the molten solder.

Further, in the above-mentioned plating method, since there are large variations in the thickness and composition of the solder between products, there is a problem that soldering failure due to insufficient solder and breakage of the foil material due to excessive solder are likely to occur. Also, for example,
In the conductor foil with the mesh plated with solder, when the mask is removed after the solder plating is completed, the residue of the mask remains in the mesh formed on the conductor foil. There is the inconvenience of causing defects.

Further, the sputtering method requires a very long time to form a solder film having a thickness of 1 μm or more, which is required for practical use, because the film forming speed is slow, and is not suitable for practical use. Therefore, a method of forming a solder film on the surface of the conductor foil by using a solder alloy composed of a lead-tin alloy as an evaporation source using a vacuum vapor deposition apparatus has been proposed and put into practical use. This vacuum vapor deposition method has an advantage that the above-mentioned inconveniences and the like can be eliminated.

[0008]

However, in the conventional vacuum vapor deposition method, the vapor pressure of lead is much higher than that of tin at the same temperature (for example, at 1000 ° C., lead is less tin). 2), the solder film 1 obtained by this method has an extremely lead-rich lead-based alloy layer 3 formed on the foil main body 2 side and this layer 3 as shown in FIG. And a tin-based alloy layer 4 which is extremely rich in tin and is formed on the surface side of. Therefore, at the time of soldering, it is necessary to melt both the lead-based alloy layer 3 and the tin-based alloy layer 4 simultaneously to form a uniform alloy phase.

In the case of the solder film 1, since the melting points of lead and tin alone are higher than the melting point of the solder alloy, the soldering temperature is higher than that when the solder film is composed of only the solder alloy. Has to be increased, which damages the element to be soldered and reduces the reliability of the element. In particular, when lead or an alloy containing lead as a main component is used for the conductor foil, the conductor foil is exposed to a high temperature for a long time for soldering, which lowers the mechanical strength of the conductor foil. There is also.

Therefore, as a result of various studies conducted by the present inventors in order to solve these disadvantages, the mutual diffusion of the lead layer and the tin layer is facilitated by alternately laminating a plurality of lead layers and tin layers. It was found that the melting point of the entire layer can be brought close to the melting point of the solder alloy, and therefore the soldering temperature can be lowered.

Further, if the thickness of each of the plurality of lead layers and the tin layer is controlled to be equal to or less than a certain thickness, the melting point of the entire layer can be brought closer to the melting point of the solder alloy, and therefore,
It has also been found that the soldering temperature can be further reduced.

It has also been found that in the vacuum vapor deposition method, a solder film in which a plurality of lead layers and tin layers are alternately laminated can be formed by sequentially evaporating a plurality of evaporation sources.

The present invention has been made on the basis of the above findings, and a metal conductive foil or a metal alloy conductive foil capable of lowering the soldering temperature while maintaining the advantages of the vacuum deposition method, and a method for manufacturing the same. It is intended to provide.

[0014]

In order to solve the above-mentioned problems, the present invention employs the following metal conductor foil or metal alloy conductor foil and its manufacturing method.

That is, in the metal conductor foil or the metal alloy conductor foil according to the first aspect, a plurality of lead layers and tin layers are alternately formed on the surface of the foil body made of a metal or an alloy containing the metal as a main component. A laminated solder film is formed, and the thickness of the solder film is 1 μm or more and 50 μm or less.

Here, the thickness of the solder film is 1 μm or more and 50
The reason for limiting the thickness to μm or less is that if the thickness of the solder film is 1 μm or less, there is a risk of defective joint between the element and the conductor foil due to insufficient solder, and if the thickness of the solder film exceeds 50 μm. This is because excess solder flows into the adjacent electrodes to cause a short circuit, or the solder protruding from the joint forms a ball shape and contacts another electrode or the like, which causes a short circuit.

The metal conductor foil or metal alloy conductor foil according to claim 2 is the metal conductor foil or metal alloy conductor foil according to claim 1, wherein the metal is gold (A
u), silver (Ag), platinum (Pt) and palladium (P
The solder film is made of one kind selected from d) and has a thickness of 3 μm or more and 50 μm or less.

Here, the thickness of the solder film is 3 μm or more and 50
The reason for limiting to less than μm is that the main component of the foil body is gold (A
u), silver (Ag), platinum (Pt) and palladium (P
When the thickness of the solder film is 3 μm or less in the case of one kind selected from d), there is a risk of defective bonding between the element and the conductor foil due to insufficient solder, and the thickness of the solder film. Is more than 50 μm, excess solder may flow into the adjacent electrodes to cause a short circuit, or the solder protruding from the joint may become balls and contact other electrodes, causing a short circuit. Is.

The metal conductor foil or metal alloy conductor foil according to claim 3 is the metal conductor foil or metal alloy conductor foil according to claim 1, wherein the metal is lead (Pb).
And the thickness of the solder film is 1 μm or more and 30 μm or less, and the thickness of one adjacent lead layer and tin layer is 8 μm or less.

Here, the lead alloy is, for example, tin (S
n), indium (In), silver (Ag), and other elements as subcomponents, and having a melting point higher than that of the solder film formed by vapor deposition.

Further, the thickness of the solder film is 1 μm or more and 30 μm.
The reason for limiting to m or less is that the main component of the foil body is lead (Pb).
When the thickness of the solder film is 1 μm or less,
There is a risk of defective joint between the element and the conductor foil made of the metal due to insufficient solder, and if the thickness of the solder film exceeds 30 μm, excess solder will flow into an adjacent electrode to cause a short circuit, There is an inconvenience that the solder protruding from the joint becomes a ball shape and contacts other electrodes or the like, causing a short circuit, and further, the conductor foil is broken or the mechanical strength of the joint is lowered. This is because problems such as

The reason why the thickness of the layer composed of one lead layer and tin layer adjacent to each other is limited to 8 μm or less is that the layer thickness is 8 μm.
If the thickness is at least μm, it is necessary to further raise the heating temperature or extend the heating time in order to melt the layer to form a uniform solder film, and consequently, the conductor foil containing Pb as a main component. This is because the mechanical strength of the device is deteriorated and the function of the element to be soldered is deteriorated.

According to a fourth aspect of the present invention, there is provided a method for producing a metal conductive foil or a metal alloy conductive foil, wherein lead-tin is formed on a surface of a foil body made of a metal or an alloy containing the metal as a main component by a vacuum deposition method. A method for producing a metal conductor foil or a metal alloy conductor foil, which is configured to form a solder film of a system, wherein a plurality of lead layers and tin layers are alternately laminated by sequentially evaporating a plurality of evaporation sources. It is characterized in that a solder film is formed.

The method for producing a metal conductor foil or a metal alloy conductor foil according to claim 5 is the method for producing a metal conductor foil or a metal alloy conductor foil according to claim 4, wherein the metal is gold. It is characterized by being composed of one kind selected from (Au), silver (Ag), platinum (Pt) and palladium (Pd).

The method for producing a metal conductor foil or a metal alloy conductor foil according to claim 6 is the same as the method for producing a metal conductor foil or metal alloy conductor foil according to claim 4, wherein the metal is lead. (Pb).

[0026]

Embodiments of the conductor foil according to the present invention will be described with reference to the drawings.

[First Embodiment] FIG. 1 shows a metal conductor foil or a metal alloy conductor foil (hereinafter, referred to as a first embodiment of the present invention.
It is a partial enlarged sectional view of abbreviated as a conductor foil) 10.

In this conductor foil 10, a solder film 50 is formed on the surface 21 of a foil body 20 formed in a sheet shape. The solder film 50 is composed of two lead layers 31, 32 and a tin layer 4.
1, 42 are alternately laminated. The thickness D of the solder film 50 is 3 μm or more and 50 μm or less.

The foil body 20 is made of gold (Au), silver (Ag),
1 selected from platinum (Pt) and palladium (Pd)
It is made of a precious metal consisting of a seed or a precious metal alloy containing the precious metal as a main component. Further, the number of the lead layers and the number of the tin layers may be two or more, and in short, the lead layers and the tin layers may be alternately laminated and the total thickness may be 3 μm or more and 50 μm or less.

Next, a method of manufacturing the conductor foil 10 according to this embodiment will be described. First, a vacuum vapor deposition apparatus provided with two evaporation sources is prepared. Then one of these evaporation sources
The two evaporation sources are heated to form a lead layer 31 on the surface 21 of the foil body 20.
And the tin layer 41 is sequentially laminated. Then, the other evaporation source is heated to form the lead layer 3 on the surface of the tin layer 41 of the foil body 20.
2 and tin layer 42 are sequentially laminated. In this way
A solder film 50 in which two lead layers 31 and 32 and tin layers 41 and 42 are alternately laminated can be formed.

When three or more lead layers and tin layers are formed, three or more evaporation sources may be sequentially heated to sequentially stack the respective layers.

Table 1 compares the structures of the conductor foils of the above-mentioned examples and the conductor foils prepared as comparative examples.

[0033]

[Table 1]

Table 2 shows the evaluation results of the mechanical strength of the conductor foils of the above-mentioned examples and comparative examples.

[0035]

[Table 2]

Here, the conductor foils and evaluation samples of the above Examples and Comparative Examples were prepared as follows. (Examples 1 to 6) First, as shown in FIG. 3, the width (W) is 5 m.
A foil body 20 was prepared in which a large number of through holes 22 having an inner diameter of 0.5 mm were formed on the entire surface of a sheet having m, a length (L1) of 10 mm, and a thickness (t) of 30 μm. The material of the foil body 20 was two kinds, silver (Ag) and platinum (Pt).

Then, according to the method of the above-described embodiment, the solder film 50 was formed on the one surface side end portion of the foil main body 20 over the length (L2) of 1 mm. This solder film 50 is
The respective thicknesses of the lead layers 31 and 32 and the tin layers 41 and 42 were set so that the composition was Sn 60 wt% -Pb 40 wt%, and the lead layers 31 and 32 and the tin layers 41 and 42 were alternately laminated. In this way, the conductor foil 10 was prepared.

On the other hand, as shown in FIG. 4, one side is 20 mm,
On the surface of a square silicon (Si) plate 60 having a thickness of 0.5 mm, a titanium (Ti) layer having a thickness of 0.1 μm, a palladium (Pd) layer having a thickness of 1 μm, and
A silver (Ag) layer having a thickness of 1 μm was sequentially laminated.

Next, the solder film 50 of the conductor foil 10 is brought into contact with the surface of the silicon plate 60, and then 210-2.
A heat block heated to 50 ° C. was pressed against the conductor foil 10 in the atmosphere to melt the solder film 50 and perform soldering. In this way, an evaluation sample was prepared.

Regarding the evaluation of the breaking strength and the breaking place, a gentle pulling force is applied to the free end 11 of the conductor foil 10 in the direction perpendicular to the silicon plate 60 (upward in FIG. 4) to determine the breaking strength and the breaking place. It went by investigating. In addition, it was investigated whether or not balls were formed during soldering. The number of samples was 100 for each example.

(Comparative Examples 1 to 9) A conductor foil having a single-layer solder film formed by a conventional dipping method, plating method, or vacuum evaporation method was used as a comparative example. Further, in the vacuum vapor deposition method according to the above-described example, a solder film having a thickness of less than 3 μm and a solder film having a thickness of more than 50 μm were prepared, respectively, and used as comparative examples. In these conductor foils, the constituent elements other than those described above are the same as those in the first to sixth embodiments, so the detailed description will be omitted.

With respect to each of the conductor foils of Comparative Examples 1 to 9, the breaking strength, the breaking place, and the presence or absence of generation of solder balls were evaluated in the same manner as in Examples 1 to 6. Further, the number of samples was set to 100 for each comparative example, as in the above-mentioned examples.

From Tables 1 and 2, it can be seen that in the conductor foil of this example, there were no fractures from the soldered portion and the joint strength was high. Further, it is clear that none of the solder balls were generated and there was no fear of causing a short circuit with respect to other contacts.

In contrast to these examples, in the conductor foils according to Comparative Examples 1 and 2, there were variations in the thickness of the solder film, and therefore, some of the conductor foils broke at solder joints and some of which produced solder balls. You can see that It is also found that the conductor foils of Comparative Examples 3 and 4 have insufficient solder joint strength due to the influence of the plating residue. Further, in the conductor foils according to Comparative Examples 5 to 7, the solder layer could not be sufficiently melted, and it was found that the joint strength of the solder portion was insufficient. Furthermore, in the conductor foil according to Comparative Example 8, since the solder film is insufficient in thickness, the joint strength of the solder portion is insufficient, and in the conductor foil according to Comparative Example 9, the breaking strength is sufficient, It can be seen that solder balls are generated, which causes a short circuit or the like.

As described above in detail, according to the conductor foil 10 of the above embodiment, the foil body 20 is made of the noble metal such as silver (Ag) or platinum (Pt) or the alloy containing the noble metal as a main component. A solder film 50 formed by alternately stacking a plurality of lead layers 31 and 32 and tin layers 41 and 42 is formed on the surface 21 of the solder film 50. The solder film 50 has a thickness of 3 μm or more and 50 μm or more.
Since the following is adopted, the soldering temperature of the conductor foil can be lowered, the joint strength of the solder joint portion is high, and a conductor foil in which solder balls are not generated can be provided. .. Therefore, the element to be soldered is not damaged and the reliability of the element is not likely to be deteriorated.

Further, according to the method for manufacturing the conductor foil of this embodiment, the plurality of lead layers 31, 32 and the tin layers 41, 42 are formed on the surface 21 of the foil body 20 by sequentially evaporating the plurality of evaporation sources. Since it was decided to stack alternately, the foil main body 2
A plurality of lead layers 3 forming the solder film 50 on the surface 21 of 0.
It is possible to form the solder film 50 capable of accurately controlling the thicknesses of the tin layers 1, 32 and the tin layers 41, 42.
Therefore, it is possible to manufacture a conductor foil having high bonding strength and free of solder balls.

[Second Embodiment] FIG. 5 is a partially enlarged sectional view of a conductor foil 70 according to a second embodiment of the present invention.

In the conductor foil 70, a solder film 73 is formed on a surface 72 of a foil body 71 formed in a sheet shape. The solder film 73 has three lead layers 81 to 83 and a tin layer 91.
~ 93 are alternately stacked. The thickness D of the solder film 73 is 1 μm or more and 30 μm or less, and the adjacent lead layer 81 (82, 83) and tin layer 91 (9
2, 93) has a thickness of 7 μm or less.

The foil main body 71 contains lead (Pb) alone or is mainly composed of lead (Pb), and contains tin (Sn), indium (I).
n), an element such as silver (Ag) as a sub-component, and a melting point higher than that of the solder film 73 formed by vapor deposition. The number of lead layers and tin layers may be two or more, and in short, the lead layers and tin layers are alternately laminated, and the total thickness is 1 μm.
It is sufficient if the thickness of the lead layer and the tin layer adjacent to each other is 8 μm or less.

Next, a method for manufacturing the conductor foil 70 according to this embodiment will be described. First, a vacuum vapor deposition apparatus equipped with three evaporation sources is prepared. Then one of these evaporation sources
The two evaporation sources are heated to form a lead layer 81 on the surface 72 of the foil body 71.
And the tin layer 91 is sequentially laminated. Next, one of the remaining two evaporation sources is heated to sequentially stack the lead layer 82 and the tin layer 92 on the surface of the tin layer 91. Next, the other evaporation source is heated to sequentially stack the lead layer 83 and the tin layer 93 on the surface of the tin layer 92. In this way, the solder film 73 in which the three lead layers 81 to 83 and the tin layers 91 to 93 are alternately laminated can be formed.

When four or more lead layers and tin layers are formed, the four or more evaporation sources may be sequentially heated to sequentially stack the layers.

Table 3 compares the structures of the conductor foils of the above-mentioned examples and the conductor foils prepared as comparative examples.

[0053]

[Table 3]

Table 4 shows the evaluation results of the mechanical strength of the conductor foils of the above Examples and Comparative Examples.

[0055]

[Table 4]

Here, the respective conductor foils and evaluation samples of the above-mentioned Examples and Comparative Examples were prepared as follows. (Examples 1 to 6) First, as shown in FIG. 3, the width (W) is 5 m.
A foil main body 71 was prepared in which a large number of through holes 22 having an inner diameter of 0.5 mm were formed on the entire surface of a sheet having m, a length (L1) of 10 mm, and a thickness (t) of 30 μm. The material of the foil body 71 was Pb, Pb-1 wt% Sn, and Pb-5 wt% Sn. In addition, the same number of types of foil bodies having the same shape and having no through holes 22 were prepared.

Then, according to the method of the above-mentioned embodiment, the solder film 73 was formed at the one surface side end portion of the foil main body 71 over the length (L2) of 1 mm. This solder film 73 is
The respective thicknesses of the lead layer 81 (82, 83) and the tin layer 91 (92, 93) are set so that the composition is Sn 60 wt% -Pb 40 wt%, and these lead layers 81 (82, 8)
3) and tin layers 91 (92, 93) were alternately laminated.
In this way, the conductor foil 70 was prepared.

On the other hand, as shown in FIG. 4, one side is 20 mm,
On the surface of a square silicon (Si) plate 60 having a thickness of 0.5 mm, a titanium (Ti) layer having a thickness of 0.1 μm, a palladium (Pd) layer having a thickness of 1 μm, and
A silver (Ag) layer having a thickness of 1 μm was sequentially laminated.

Then, the solder film 73 of the conductor foil 70 is brought into contact with the surface of the silicon plate 60, and then 210-2.
A heat block heated to 50 ° C. was pressed against the conductor foil 70 in the atmosphere to melt the solder film 73 and perform soldering. In this way, an evaluation sample was prepared.

Regarding the evaluation of the breaking strength and the breaking place, a pulling force is gently applied to the free end 75 of the conductor foil 70 in the direction perpendicular to the silicon plate 60 (upward in FIG. 4) to determine the breaking strength and the breaking place. It went by investigating. In addition, it was investigated whether or not balls were formed during soldering. The number of samples was 100 for each example.

(Comparative Examples 1 to 7) A conductive foil having a single-layer solder film prepared by the conventional dipping method, plating method and vacuum deposition method was used as a comparative example. In addition, in the vacuum vapor deposition method according to the above-described example, a solder film having a thickness of less than 1 μm, a solder film having a thickness of more than 30 μm, and a layer of adjacent lead layers and tin layers having a thickness of more than 8 μm are prepared. As a comparative example. In these conductor foils, the constituent elements other than those described above are the same as those in the first to third embodiments.
Since it is the same as 6, the detailed description will be omitted.

With respect to each of the conductor foils of Comparative Examples 1 to 7, the breaking strength, the breaking place, and the presence or absence of generation of solder balls were evaluated in the same manner as in Examples 1 to 6. Further, the number of samples was set to 100 for each comparative example, as in the above-mentioned examples.

As can be seen from Tables 3 and 4, in the conductor foil of this example, there were no fractures from the interface between the solder film and the foil body and from the soldered portion, and the joint strength was higher than in the comparative example. I understand. Further, it is clear that none of the solder balls were generated and there was no fear of causing a short circuit with respect to other contacts.

As described in detail above, according to the conductor foil 70 of the above-mentioned embodiment, a plurality of leads are formed on the surface 72 of the foil body 71 made of lead (Pb) alone or an alloy containing lead as a main component. Layer 81 (82, 83) and tin layer 91 (92, 93)
The solder film 73 is formed by alternately laminating the solder film 73, the total thickness of the solder film 73 is 1 μm or more and 30 μm or less, and the thickness of the adjacent lead layer and tin layer is 8 μm or less. Therefore, the soldering temperature of the conductor foil can be lowered, the joint strength of the solder joint portion is high, and a conductor foil in which solder balls are not generated can be provided. Therefore, the element to be soldered is not damaged and the reliability of the element is not likely to be deteriorated.

Further, according to the method for manufacturing the conductor foil of this embodiment, the plurality of lead layers 81 (82, 83) and the tin layer are formed on the surface 72 of the foil body 71 by sequentially evaporating the plurality of evaporation sources. Since 91 (92, 93) are alternately laminated, a plurality of lead layers 81 (82, 83) and tin layers 91 (9) forming the solder film 73 are formed on the surface 72 of the foil body 71.
It is possible to form the solder film 73 whose thickness can be controlled accurately. Therefore, it is possible to manufacture a conductor foil having high bonding strength and free of solder balls.

[0066]

As described above in detail, according to the metal conductor foil or metal alloy conductor foil of claim 1 of the present invention, a foil body made of a metal or an alloy containing the metal as a main component is used. A solder film formed by alternately stacking a plurality of lead layers and tin layers is formed on the surface of, and the thickness of this solder film is 1 μm.
Since the thickness is set to m or more and 50 μm or less, it is possible to provide a conductor foil having a high bonding strength at the solder bonding portion and in which solder balls are not generated.

According to the metal conductor foil or metal alloy conductor foil of claim 2, in the metal conductor foil or metal alloy conductor foil according to claim 1, the metal is gold (Au), Since the solder film is made of one kind selected from silver (Ag), platinum (Pt), and palladium (Pd), and the thickness of the solder film is 3 μm or more and 50 μm or less, the soldering temperature of the conductor foil is It is possible to provide a conductor foil that can be reduced in strength, has a high bonding strength at the solder bonding portion, and does not generate solder balls. Therefore, the element to be soldered is not damaged and the reliability of the element is not likely to be deteriorated.

According to the metal conductor foil or metal alloy conductor foil of claim 3, in the metal conductor foil or metal alloy conductor foil according to claim 1, the metal is lead (Pb). And the thickness of the solder film is 1 μm or more 3
Since the thickness of the adjacent lead layer and tin layer is set to 0 μm or less and 8 μm or less, the soldering temperature of the conductor foil can be lowered, and the joining of the solder joints can be achieved. It is possible to provide a conductor foil that has high strength and does not generate solder balls. Therefore, the element to be soldered is not damaged and the reliability of the element is not likely to be deteriorated.

Further, according to the method for producing a metal conductor foil or a metal alloy conductor foil according to claim 4, lead is formed on the surface of the foil body made of a metal or an alloy containing the metal as a main component by a vacuum deposition method. A method for producing a metal conductor foil or a metal alloy conductor foil, which is configured to form a tin-based solder film, wherein a plurality of evaporation sources are sequentially evaporated to alternately form a plurality of lead layers and tin layers. Since the laminated solder film is formed, the solder film can be formed by alternately laminating a plurality of lead layers and tin layers on the surface of the foil body. Therefore, by controlling the thickness of the solder film, it is possible to manufacture a conductor foil having high bonding strength and free of solder balls.

According to the method for producing a metal conductor foil or a metal alloy conductor foil according to claim 5, in the method for producing a metal conductor foil or a metal alloy conductor foil according to claim 4, the metal is , Gold (Au), silver (Ag), platinum (P
Since it is made of one selected from t) and palladium (Pd), it is possible to accurately control the thicknesses of a plurality of lead layers and tin layers forming the solder film on the surface of the foil body. Can be formed. Therefore, it is possible to manufacture a conductor foil having high bonding strength and free of solder balls.

According to the method for producing a metal conductor foil or a metal alloy conductor foil according to claim 6, in the method for producing a metal conductor foil or a metal alloy conductor foil according to claim 4, the metal is Since it is decided to consist of lead (Pb),
It is possible to form a solder film on the surface of the foil body, which can control the thicknesses of a plurality of lead layers and tin layers forming the solder film with high accuracy. Therefore, the bonding strength is high,
In addition, it is possible to manufacture a conductor foil without generation of solder balls.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view showing a conductor foil according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view showing a conventional conductor foil.

FIG. 3 is a perspective view of a conductor foil according to first and second embodiments of the present invention.

FIG. 4 is a perspective view showing a state in which conductor foils according to the first and second embodiments of the present invention are soldered to a silicon plate.

FIG. 5 is a partially enlarged sectional view showing a conductor foil according to a second embodiment of the present invention.

[Explanation of symbols]

 10 conductor foil 20 foil body 21 foil body surface 31,32 lead layer 41,42 tin layer 50 solder film D solder film thickness 70 conductor foil 71 foil body 72 foil body surface 73 solder film 81-83 lead layer 91 to 93 Tin layer

Front Page Continuation (72) Inventor Naoki Uchiyama Inside Mita Plant, Mitsunori Material Co., Ltd.

Claims (6)

[Claims] 1. A solder film formed by alternately laminating a plurality of lead layers and tin layers is formed on the surface of a foil body made of a metal or an alloy containing the metal as a main component, and the thickness of the solder film is 1 μm. The metal conductor foil or the metal alloy conductor foil is characterized by being 50 μm or less. 2. The metal is gold (Au), silver (Ag),
1 selected from platinum (Pt) and palladium (Pd)
The metal conductive foil or the metal alloy conductive foil according to claim 1, wherein the solder film has a thickness of 3 μm or more and 50 μm or less. 3. The metal is lead (Pb), and the solder film has a thickness of 1 μm or more and 30 μm or less, and
The metal conductive foil or the metal alloy conductive foil according to claim 1, wherein the thickness of a layer composed of one lead layer and a tin layer adjacent to each other is 8 μm or less. 4. A metal-made conductor foil or a metal-alloy conductor foil in which a lead-tin solder film is formed on the surface of a foil body made of a metal or an alloy containing the metal as a main component by a vacuum deposition method. The method for manufacturing a metal foil or a metal alloy foil, wherein a plurality of lead layers and tin layers are alternately laminated to form a solder film by sequentially evaporating a plurality of evaporation sources. Manufacturing method. 5. The metal is gold (Au), silver (Ag),
1 selected from platinum (Pt) and palladium (Pd)
The method for producing a metal-made conductor foil or a metal alloy-made conductor foil according to claim 4, wherein the metal-made conductor foil is made of a seed. 6. The method for producing a metal conductive foil or a metal alloy conductive foil according to claim 4, wherein the metal is lead (Pb).