JPH0750113A - Conductive protrusion transferring base material, conductive protrusion transferring method and manufacture of probe card structure - Google Patents

Abstract

PURPOSE:To provide a base material to retain a conductive protrusion which can be easily formed on an electric circuit or electric circuit parts and a method in which the conductive protrusion can be easily formed on an electric circuit or electric circuit parts. CONSTITUTION:A conductive protrusion transferring base material S is such that a conductive protrusion 2 is fixed to a soluble support 1. A conductive protrusion transferring method is such that the conductive protrusion 2 on the conductive protrusion transferring base material S is bonded to a transferred material and then the support 1 for the base material S is dissolved and removed. The manufacture of a probe card structure is such that the conductive protrusion 2 on the conductive protrusion transferring base material S is bonded to the electrode face of a probe card and then the support 1 for the base material S is dissolved and removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base material holding a conductive protrusion which can be easily formed on an electric circuit or an electric circuit component, a method for forming the conductive protrusion, and an electric circuit or The present invention relates to a method of manufacturing a probe card structure used when inspecting electric circuit components and the like.

[0002]

2. Description of the Related Art With the progress of technology in recent years, electronic devices have been made lighter and thinner and smaller and smaller. There is a strong demand for dense packaging. 2. Description of the Related Art Conventionally, in this field, a semiconductor element is provided with a protrusion (bump) made of metal to form a connection terminal, and mounting is performed by using this. Such a mounting method using bumps is useful as a method for improving the mounting density of various electric / electronic components other than semiconductor elements.

However, it is technically difficult to directly form the above bumps on a semiconductor element or other electric / electronic parts. For example, when a bump is to be formed by electroplating, it is often difficult to independently provide a current-carrying lead for this electroplating. Therefore, the bump may be formed by electroless plating.
According to this, the plating process requires a long time. Further, even if electrolytic plating is possible, it is difficult to form bumps having a sufficient height. These are the causes of yield in electronic device manufacturing.

Therefore, it has been proposed to form bumps on electric / electronic components by a transfer method. However, the method currently used as this transfer method is still unsatisfactory in terms of manufacturing cost, ease of bump transfer, and the like.

An object of the present invention is to solve the above problems and to provide a base material which holds a conductive protrusion which can be easily formed on an electric circuit or an electric circuit component. Another object of the present invention is to provide a method capable of easily forming a conductive protrusion on an electric circuit or an electric circuit component.

[0006]

The inventors of the present invention fixed the conductive protrusions to a soluble support and bonded the above-mentioned conductive protrusions to the transfer target using an electric circuit or an electric circuit component. After that, it was found that the conductive protrusions can be easily formed on an electric circuit or an electric circuit component by dissolving and removing the support, and the present invention has been completed. That is, the substrate for transferring conductive projections of the present invention is one in which the conductive projections are fixed to a soluble support. In addition, the method of transferring the conductive protrusions of the present invention,
The method is characterized in that after the conductive projection of the substrate for transferring the conductive projection is bonded to the transfer target, the support of the base is dissolved and removed. Furthermore, the method for manufacturing a probe card structure of the present invention, after bonding the conductive protrusions of the conductive protrusion transfer substrate to the electrode surface of the probe card,
It is characterized in that the support of the base material is dissolved and removed.

[0007]

In the above structure, the support holding the conductive protrusions is soluble, so that the support can be dissolved and removed after the conductive protrusions are bonded to the transfer target. As a result, it becomes easy to transfer and form the conductive protrusion on the transfer target. Moreover, since a wide variety of shapes of the conductive protrusions are possible, it is possible to adopt a mode in which the conductive protrusions do not fall off from the support before transfer, and further, the conductive protrusions are removed when the support is removed during transfer. It is also prevented that the sexual protrusions are detached from the transfer target together with the support.

The present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing one example of the conductive projection transfer base material of the present invention. In the figure, S denotes a conductive projection transfer base material, and the conductive projection 2 is fixed to the support 1. In this embodiment, the conductive protrusion 2 is fixed by the through hole H provided in the support 1.

The substrate S for transferring conductive projections of the present invention is characterized in that the conductive projections 2 are fixed to a soluble support 1, and thus the support 1 is made soluble. This makes it possible to dissolve and remove the support 1 when transferring the conductive protrusions. Thus,
It becomes easy to transfer and form the conductive protrusions on the transfer target.

The term "soluble" as used in the present invention refers to the property of being soluble in a medium that does not impair the object of the present invention.
Preferably, it means a property that can be dissolved by immersing in the above medium for 1 to 60 minutes. Examples of the medium include organic solvents such as N-methyl-2-pyrrolidone, m-cresol, and dimethylacetamide that are usually used as a solvent when dissolving polyimide, and alkaline solutions such as sodium hydroxide solution and potassium hydroxide. A solution, hydrazine or the like is used.

The support 1 is not particularly limited as long as it has the above-mentioned solubility. Examples of such a support include polyester-based resins, phenoxy-based resins, polyimide-based resins, polyamide-based resins, etc. Among them, polyimide-based resins excellent in heat resistance and mechanical strength are preferably used.

The support 1 is, for example, as shown in FIG. 2, an adhesive layer 1 on at least the surface of the conductive projection transfer side.
When 1 is formed, the adhesion reliability between the conductive protrusion 2 and the transfer target is improved, which is preferable. As the adhesive layer 11, thermosetting of epoxy resin, phenoxy resin, urethane resin, polystyrene resin, polyethylene resin, polyester resin, polyamide resin, polyimide resin, polycarbonate resin, silicon resin, etc. Of the organic resins and the thermoplastic resins, those having a melting temperature lower than that of the soluble support 1 are used. Above all, it is preferable to use a thermoplastic polyimide resin having excellent heat resistance. As this thermoplastic polyimide resin, the melt viscosity at 400 ° C. is 1 × 10 ⁸ poise or less, preferably 1 × 10 ³ to 1 × 10 ^7. The structure is not particularly limited as long as it is a poise and has a polyimide skeleton. As such a thermoplastic polyimide resin, Ultem 1000 (trade name, manufactured by General Electric Co., polyetherimide), LARC-TPI
(Trade name, polyimide manufactured by Mitsui Toatsu Co., Ltd.), one or a mixture of two or more selected from polyimides obtained from 4,4′-oxydiphthalic acid dianhydride and 3,3′-diaminodiphenyl sulfone. It is preferably used.

The transfer conductive protrusion 2 is made of a conductive substance, and examples of the conductive substance include gold, silver, copper,
Examples are various metals such as lead, tin, nickel, cobalt, and indium, and alloys made of these. Among them, low melting point metals such as solder, indium, tin, and lead, and alloys made of these are preferable.

The shape of the transfer conductive projection 2 on the transfer side is not particularly limited, but as shown in FIG. 1, it is formed in a mushroom shape which is easy to bond to the electrode surface or the like to be bonded. preferable.

On the other hand, in the present invention, a wide variety of shapes can be used as the shape of the transfer conductive projection 2 on the side opposite to the transfer side. That is, in the conventional conductive protrusion for transfer, the shape is limited to the shape that can be physically detached from the support, but in the present invention, the support 1 is dissolved and removed at the time of transfer. Shapes are possible.
For example, as shown in FIG. 3, the opposite side of the transfer conductive projection 2 from the transfer side is formed in a mushroom shape by protruding from the end of the through hole H, and the protruding portion is formed at the peripheral edge of the opening of the through hole H. The locked mode is preferable. This prevents the conductive protrusions 2 from falling off the support 1 before being transferred.

The transfer conductive projections 2 are preferably formed so as to protrude from the surface of the support 1 by 1 to 30 μm, preferably 5 to 15 μm. If the protrusion of the conductive protrusions 2 is less than 1 μm, the connection reliability of the conductive protrusions 2 is insufficient, while if it exceeds 30 μm, it takes a long time to form the conductive protrusions 2 and the manufacturing efficiency is reduced, which is preferable. Absent.

As a method of forming the conductive protrusions 2 for transfer, for example, a through hole H is formed in the support 1 and the conductive substance is projected into the through hole H to a height above the surface of the support 1. A method such as filling until. In the case of such a method, the filling of the conductive material may be performed by a method such as electrolytic plating or electroless plating,
From the viewpoint of working time, electrolytic plating is preferable.

As shown in FIG. 4, the surface of the transfer side portion of the conductive protrusion 2 is made of the low melting point metal 21 as described above, and the other portions are made of the metal 22 other than the low melting point metal 22.
It is preferable that the two-layer structure is constituted by the above because the low melting point metal 21 on the surface of the transfer side portion can be bonded to and transferred to the transferred body, and can be pressed by the metal 22 other than the low melting point metal. As the metal 22 other than the low melting point metal, a metal having good wettability with respect to the low melting point metal 21 is preferably used, and examples of such a metal include nickel and gold. At that time, the conductive protrusion 2
As shown in FIG. 4, it is preferable that both sides have the above-described aspect on both sides of the support 1.

Conductive protrusions 2 fixed to the support 1
After being bonded to the transfer target, the support 1 is dissolved and removed, so that it is transferred and formed on the transfer target.

FIG. 5 is a schematic view showing a method of transferring the conductive protrusion. Hereinafter, the transfer forming method of the conductive protrusion will be described more specifically with reference to FIG. First, as shown in FIG. 5A, the conductive protrusion transfer base material S is used.
The transfer side portion of the conductive protrusion 2 is brought into contact with the electrode portion 4 of the transfer target T. Here, as described above, when the transfer side portion of the conductive protrusion 2 has a mushroom shape as shown in FIG. 1, the contact with the electrode portion 4 and the bonding described below can be easily performed. Then, as shown in FIG. 5B, the conductive protrusion 2 is bonded to the electrode portion 4. This joining is performed, for example, by using thermoplastic polyimide or the like as an adhesive to bond the conductive projection 2 to the electrode portion 4, or at least the surface of the conductive projection 2 on the transfer side portion side is as described above. When it is composed of a low melting point metal, it is formed by a method of joining by thermocompression bonding. After that, as shown in FIG. 5C, the support 1 of the substrate S for transferring conductive protrusions is dissolved and removed. This dissolution and removal is performed by immersing the support 1 in a solvent such as an organic solvent or an alkaline solution.

By the method as described above, the conductive protrusions can be easily transferred and formed on the transferred material.

The conductive projection formed by the above method is connected to a body to be connected such as a semiconductor element by a method such as thermocompression bonding.

In the present invention, a probe card structure used for inspection of semiconductor devices and the like can be manufactured by using the same method as described above. That is, by using the electrode lead of the insulating film on which the inspection circuit pattern and the electrode lead are formed as the transfer target, and transferring and forming the conductive protrusion on the electrode lead in the same manner as described above,
A probe card structure as shown in FIG. 6 can be obtained.

[0024]

EXAMPLES The present invention will be described more specifically below with reference to examples. Needless to say, the present invention is not limited to these. Example 1 A soluble polyimide precursor solution was applied onto a copper foil so that the thickness after drying was about 15 μm and then cured to form a two-layer film consisting of a copper foil layer and a soluble polyimide layer. It was made. Then, the surface of the soluble polyimide layer of the two-layer film was irradiated with KrF excimer laser light having an oscillation wavelength of 248 nm through a mask to perform dry etching to form through holes having a diameter of 60 μm and a pitch of 200 μm. Then, a resist was applied to the surface of the copper foil layer of the above-mentioned two-layer film and then cured to insulate it, and immersed in a chemical polishing solution at 50 ° C. for 2 minutes. After washing this with water, the copper foil layer was connected to the electrode and immersed in a gold cyanide plating bath at 60 ° C., and the copper foil layer was used as a negative electrode to grow gold plating in the through-holes of the two-layer film. The plating treatment was performed for about 20 minutes until the surface of the layer was reached. After that, the resist layer was peeled off, and the copper foil layer was dissolved and removed with cupric chloride to obtain a substrate for transferring the conductive protrusions.

Separately, a circuit pattern and an electrode lead were formed using copper on a polyimide film having a thickness of 25 μm to prepare a circuit board. A thermoplastic polyimide film having a thickness of 5 μm is sandwiched as an adhesive layer between the circuit board and the conductive projection transfer base material, and the electrode lead of the circuit board and the conductive projection transfer base material are provided. After alignment with the objects, these were heated and bonded by heat pressing at 350 ° C. under the condition of 10 kg / cm ² for about 10 minutes. After that, the adhesive between the circuit board and the conductive projection transfer base material is immersed in a 30% NaOH solution at 50 ° C. for 10 minutes to dissolve and remove the soluble polyimide layer, and then the conductive material is transferred onto the circuit board. The protrusion was transferred and formed.

Comparative Example 1 A polyimide precursor solution having a thickness of about 2 after being dried was prepared on a copper foil.
After being coated so as to have a thickness of 5 μm, this was cured to prepare a two-layer film composed of a copper foil layer and a polyimide layer.
Then, on the surface of the polyimide layer of the two-layer film, in the same manner as in Example 1, a diameter of 60 μm and a pitch of 200 μm.
Through holes were formed. Then, a resist was applied to the surface of the copper foil layer of the above-mentioned two-layer film and then cured to insulate it, and immersed in a chemical polishing solution at 50 ° C. for 2 minutes. After this was washed with water, gold plating was grown in the through holes of the two-layer film by electroless plating. It took about 5 hours for the gold plating to project to a height of about 5 μm from the surface of the polyimide layer.

Example 2 A soluble polyimide precursor solution was coated on a copper foil so that the thickness after drying was about 15 μm, and then dried.
Further, a thermoplastic polyimide precursor solution is applied thereon so that the thickness after drying is about 10 μm, and both the polyimide layers are cured to form a copper foil layer, a soluble polyimide layer, and a thermoplastic polyimide layer. A three-layer film consisting of Next, through holes having a diameter of 60 μm and a pitch of 200 μm were formed in the soluble polyimide layer and the thermoplastic polyimide layer of the three-layer film in the same manner as in Example 1 above.
After filling the through-holes with gold by electrolytic plating, the copper foil layer was removed to obtain a substrate for transferring conductive projections.

After aligning the electrode leads of the circuit board and the conductive protrusions of the conductive protrusion transfer base material in the same manner as in the first embodiment, the electrode leads and the electrode leads are aligned in the same manner as in the first embodiment. The conductive protrusions were heated and adhered, the soluble polyimide layer was dissolved and removed, and the conductive protrusions were transferred and formed on the circuit board.

Comparative Example 2 A thermoplastic polyimide precursor solution was applied on a copper foil so that the thickness after drying was about 25 μm, and then cured to obtain a copper foil layer and a thermoplastic polyimide layer. The following two-layer film was prepared.

In Example 2, except that the two-layer film was used instead of the three-layer film,
A substrate for transferring conductive projections is prepared, and the electrode leads of the circuit board and the conductive projections for transferring the conductive projections are heated and pressed by a hot press. Since the plastic polyimide layer was fluidized and deformed, and the conductive protrusions moved with it, transfer formation of the conductive protrusions could not be reliably performed.

Example 3 A solder layer having a thickness of 3 μm was formed by electroless solder plating on the conductive protrusion of the substrate for transferring the conductive protrusion obtained in Example 1 above. Further, in the same manner, a solder layer was formed on the circuit of the circuit board obtained in Example 1 above.

After that, the electrode leads of the circuit board and the conductive projections of the conductive projection transfer base material are aligned with each other, and then these are heated on a hot plate at 250 ° C. for 1 minute. The electrode lead and the conductive protrusion were bonded together. Then, the adhesive between the circuit board and the conductive projection transfer substrate is immersed in a 30% NaOH solution at 50 ° C. for 10 minutes to dissolve and remove the soluble polyimide layer, and the conductive projection on the circuit board. The material was transfer-formed.

[0033]

As described above in detail, in the substrate for transferring conductive projections of the present invention, the support for holding the conductive projections is soluble, so that the conductive projections are covered with the conductive projections. After being joined to the transfer body, the support can be dissolved and removed. As a result, the conductive protrusion can be easily transferred and formed on an electric circuit, an electric circuit component, or the like, and a wide variety of shapes of the conductive protrusion are possible, so that the conductive protrusion is transferred. It is possible to adopt a mode in which it does not fall off from the support before, and it is also prevented that the conductive protrusions are detached from the transfer target together with the support when the support is removed during transfer. Therefore,
INDUSTRIAL APPLICABILITY By the present invention, a base material holding a conductive protrusion that can be easily and reliably formed on an electric circuit or an electric circuit component is obtained, and the conductive protrusion is transferred onto the electric circuit or the electric circuit component. It becomes easier to manufacture the probe card structure and the probe card structure, and it is possible to reduce the occurrence of defective products.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a conductive protrusion transfer base material of the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the conductive projection transfer base material of the present invention.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the conductive protrusion transfer base material of the present invention.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the substrate for transferring conductive protrusions of the present invention.

FIG. 5 is a schematic cross-sectional view showing an example of a method for transferring a conductive protrusion of the present invention.

FIG. 6 is a schematic cross-sectional view showing an example of a probe card structure obtained by the method of the present invention.

[Explanation of symbols]

 1 Support 2 Conductive Protrusion H Through Hole S Conductive Protrusion Transfer Substrate

Claims (7)

[Claims] 1. A substrate for transferring conductive projections, comprising conductive projections fixed to a soluble support. 2. The conductive projection is fixed to the support through a through-hole provided in the soluble support.
The substrate for transferring the conductive projections described. 3. A conductive protrusion is formed so as to protrude from both ends of a through hole provided in a soluble support, and both protrusions are locked at all or part of the peripheral edge of the opening of the through hole. The substrate for transferring a conductive protrusion according to claim 2. 4. The substrate for transferring conductive projections according to claim 1, wherein the support is soluble in an organic solvent or an alkaline solution. 5. The substrate for transferring conductive projections according to claim 1, wherein the support has an adhesive layer on the surface of the conductive projection transfer side. 6. The method for bonding a conductive protrusion of the substrate for transferring a conductive protrusion according to claim 1, 2, 3 or 5 to a transfer target, and then removing the support of the substrate by dissolution. And a method for transferring a conductive protrusion. 7. After the conductive projection of the conductive projection transfer substrate according to claim 1, 2, 3 or 5 is bonded to the electrode surface of the probe card, the support of the base is dissolved and removed. A method of manufacturing a probe card structure, comprising: