JPH03182082A - Manufacture of member for electric connection - Google Patents

Abstract

PURPOSE:To make a connecting member by casting a high energy beam from the double insulation layer side in different types, removing partially the insulation layer and the base, further widening hole in the upper insulation layer, filling with an electro-conducting material, and then removing the base. CONSTITUTION:Polyimide resin 2 and resist 3 are put on one side of a base 1 of Cu and irradiated with eximer laser beam 6, and the insulation layers thus formed 3, 2 are provided with hole 7 while the base 1 with hole 8. The depth of the hole 8 is adjusted by controlling the number of pulses according to the irradiation energy of laser beam 6 and the eroding speed into the base. The resist 3 is eroded chemically, and holes are provided having a dia. as d2>d1. Then the holes 7, 8 are filled with Au 9 by means of Au plating using the base 1 as a common electrode so as to form an Au bump 10. The residual resist 3 is eroded away while the Cu base 1 is selectively eroded away so as to complete a connecting member 31. If the hole 8 in the base 1 is made greater than the hole 7 using eroding solution, it is ensured that the Au 9 is free from separation after removal of the base 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing an electrical connection member that electrically connects electrical circuit components to each other.

[Conventional technology]

Recently, as a method for manufacturing electrical connection members, for example, there is a method as shown in Japanese Patent Application No. 133401/1983.

FIG. 3 is a cross-sectional view showing the steps of the manufacturing method shown here. First, a metal sheet 501 as shown in FIG. 3 (al) is prepared. As shown in Figure 3 (bl), photosensitive resin 505 (polyimide resin (PI)
)) is applied onto a metal sheet 501 and prebaked at a temperature of around 100°C. Next, as shown in Figure 3 (C1), light (ultraviolet light) is irradiated through a photomask (not shown), and development is performed after exposure. Resin 505 remains, and the polyimide resin 505 is removed by development in areas not exposed to light to form holes 142. After that, 200 to 40
The polyimide resin 505 is immediately converted into hydrogen by heating to 0''C.

Next, as shown in FIG. 3(d), the metal sheet 501 and the imidized polyimide resin 505 on the metal sheet 501 are placed in a metal etching solution, and the bottom of the hole 142 and the metal sheet 50I in the vicinity are etched. Then, a recess 502 is formed. As shown in FIG. 3(e), gold plating is performed using the metal sheet 501 as a common electrode, and holes 1000 are formed.
The fourth part 502 is filled with gold 150, and gold plating is continued until a bump is formed. Finally, as shown in FIG. 3(f), the metal sheet 501 is removed by metal etching to produce the electrical connection member 125.

In the electrical connection member 125 manufactured in this way, the gold 150 constitutes the electrically conductive member 107, and the polyimide resin 505 constitutes the holder (electrical insulator) 115.

The dimensions of the electrical connection member 125 are as follows: the thickness of the polyimide resin 505 is about 10 μm, the diameter of the columnar part of the gold 150 is about 20 μm, the pinch between the conductive members 107 is about 40 μm,
The amount of protrusion of gold 150 (conductive member 107) is several μ on both the front and back surfaces.
It was set as m.

The thickness of the electrical connection member 125 is different between FIG. 3('b) and FIG. 3(f). This is polyimide resin 50
This is mainly caused by the curing shrinkage reaction of No.5. Further, the opening diameter and opening pinch of the polyimide resin 505 of the electrical connection member 125 are different between FIG. 3(C) and FIG. 3(f).

Possible causes of this include the curing shrinkage reaction of the polyimide resin 505 and the difference in coefficient of thermal expansion between the polyimide resin 505 and the metal sheet 501 during heating processing after the development process.

[Problem to be solved by the invention]

However, in recent methods of manufacturing electrical connection members, there is room for further improvement in that the following problems may occur.

(2) Since electrically insulating material (polyimide resin) is applied to a metal sheet using a spin cord to form a holder for electrically connecting members, it is not possible to form a thick film. Furthermore, it is difficult to control the film thickness and pattern dimensions because it shrinks during heat processing and has residual stress because its coefficient of thermal expansion is different from that of the metal sheet.

■Photosensitive polyimide resin is PL-1100, 1200
(Hitachi Chemical #a), Photonice (Higashishin), Propimide (Chiba Geigy), Selectirasox (E.

Mark), Lisocoat (Ube Industries ■), etc., but compared to the types of polyimide resins that are already imidized and commercially available, the number of them is still small and the range of material selection is small. Moreover, its price is also very high.

■The bumps formed on the side of the photosensitive polyimide resin opposite to the metal sheet are formed by continuing to grow gold plating onto the polyimide resin through holes drilled in the polyimide resin, but the height of the protruding bumps is When trying to make it higher, it spreads laterally and short-circuits with adjacent bumps. If the spacing between the bumps is widened to prevent short circuits, it becomes impossible to connect high-density electrical circuit components (for example, semiconductor RC chips). In other words, unless the growth of the protruding bumps is restricted in the lateral direction, the range in which the protruding shape can be controlled is narrow. This is a relatively big problem as a method of manufacturing an electrical connection member for connecting electrical circuit components.

■The metal sheet is etched using wet etching to form a recess, and this recess becomes a bump shape that protrudes toward the metal sheet side.Wet etching is isotropic etching, so the height of the bump that protrudes toward the metal sheet side is When trying to increase the height, if the recess is made deeper, it will also expand laterally (
side etching), resulting in a short circuit with the adjacent hump.

If the spacing between the bumps is widened to prevent short circuits, it becomes impossible to connect high-density electric circuit components (for example, semiconductor IC chips). In other words, if an attempt is made to control the protruding shape of the bumps by forming recesses in the metal sheet only by wet etching, the controllable range is narrow. This is a relatively big problem as a method of manufacturing an electrical connection member for connecting electrical circuit components.

The present invention has been made in view of the above circumstances, and involves making a hole in the second insulating layer and the first insulating layer serving as a holder by irradiating a high-energy beam, and forming a hole in the wall surface of the hole in the second insulating layer. After chemically etching the hole, by filling the hole with a conductive material that will become a conductive member, it is possible to maintain insulation between adjacent conductive members and fill the conductive members at a narrow pitch, thereby preventing the conductive member from falling off from the holder. In addition to making it possible to manufacture electrical connection members that can realize high-density connections between electrical circuit components, the exposed surface of the base is etched by high-energy beam irradiation to widen the diameter of the hole at the bottom. An object of the present invention is to provide a method for manufacturing an electrical connection member that can more completely prevent the filled conductive member from missing by preparing the electrical connection member.

[Means for Solving the Problems] The method for manufacturing an electrical connection member of the first invention according to the present application includes a holder made of an electrically insulating material, and a plurality of holders provided in the holder insulated from each other. and a conductive member, one end of each of the conductive members being exposed on one surface of the holder, and the other end of each of the conductive members being exposed on the other surface of the holder. In a method for manufacturing a member, a base material comprising a base, a first insulating layer serving as the holder, and a second insulating layer made of a material different from the first insulating layer are laminated in this order. On the other hand, a high-energy beam is irradiated from the second insulating layer side, and a plurality of regions are irradiated with a high-energy beam from the first insulating layer side. a first step of removing all of the second insulating layer and a part of the base material to form a plurality of holes in the base material; A second step of etching is carried out in a range that is larger than the diameter of the hole formed and smaller than half of the distance to the outer periphery of the adjacent hole, and the plurality of holes formed are etched. a third step of filling a conductive material to become the conductive member to a position higher than the interface of the second insulating layer; a fourth step of removing the second insulating layer; and a fifth step of removing the base. It is characterized by having the steps of.

In the method for manufacturing an electrical connection member according to a second aspect of the present application, in the first aspect, after the first step or the second step, the first method is applied to the base exposed in the first step. The method is characterized in that it includes a step of etching in a range that is larger than the diameter of the hole formed by the step and smaller than half the distance to the outer periphery of an adjacent hole.

[Effect]

In the first invention of the present application, the base, the first insulating layer and the second
A high-energy beam is irradiated onto the base material in which the first and second insulating layers are laminated, and all of the first and second insulating layers and part of the base are removed in a plurality of regions, thereby forming a plurality of holes that do not communicate with each other. form. Next, a portion of the second insulating layer is removed by etching within a range larger than the diameter of the formed hole and less than half the distance between adjacent holes. Next, the first holes are inserted into the plurality of holes formed in the base material. A conductive material is filled so as to protrude beyond the interface position of the second insulating layer, and the remaining second insulating layer and the base body are removed. Then, the conductive material filled in the hole is in the t-state and insulated from each other, and the holder (
The first insulating layer) is filled with multiple electrically conductive members, and both ends of each electrically conductive member are bent to form an electrical connection member.

At this time, since the holes are formed by irradiation with a high-energy beam, it is possible to make the pitch of the conductive members fine. In addition, by etching, the diameter of the hole in the second insulating layer 2 is changed to the first
Since the hole diameter is made larger than the diameter of the hole in the first insulating layer (holding body), the diameter 8 of the conductive member is larger in the exposed part than in the part buried in the first insulating layer (holding body), and the conductive member is missing from the holding body, causing stress. .

In the second invention of the present application, after the hole is formed by irradiation with the high energy beam 1, the exposed surface of the substrate is made larger than the diameter of the formed hole and less than half the distance to the outer periphery of the adjacent hole C. Etch a small area and remove part of it. By doing so, when this hole is filled with a conductive material, the diameter of the conductive member becomes larger in the exposed part than in the part buried in the first fringe layer, thereby preventing the conductive member from being missing.

[Examples] Hereinafter, the present invention will be specifically described based on drawings showing examples thereof.

FIG. 1 is a schematic cross-sectional view showing the manufacturing process of the first invention according to the present application. First, a base material 4 is prepared, in which an insulating layer 2 made of polyimide resin is laminated on one side of a substrate 1 made of copper, and a resist 3 is further laminated on one side of the insulating layer 2 (FIG. 1(a)). The resist 3 is made of a material different from that of the insulating layer 2 (polyimide resin), and is made of a material that has a faster chemical etching rate than polyimide resin. A metal material may be vapor-deposited, plating may be used, or a painting method may be used in combination.Also, a polyimide resin for forming the insulating layer 2 may be applied to one side of the substrate i. As a method for laminating the resist 3 on the insulating layer 2, any coating method such as a spinner, a roll coater, etc. that can provide a uniform film thickness may be used.

Next, a positive mask 5 is placed above the resist 3, and a high-energy beam of KrF excimer laser light 6 is irradiated onto the base material 4 from the resist 3 side (FIG. 1(b)). The light energy of the excimer laser beam 6 separates molecules of the resist 3 and the insulating layer 2 (polyimide resin) in the irradiated portions, and holes 7 reaching the surface of the base 1 are formed in the resist 3 and the insulating layer 2. . Even if the surface of the base 1 is exposed, irradiation with the excimer laser beam 6 is continued, a part of the base 1 is removed, and a hole 8 communicating with the hole 7 is formed in the base 1 at a predetermined depth. At this time, the depth of the laser beam 68 is adjusted by controlling the number of pulses according to the irradiation energy per pulse of the excimer laser beam 6 and the etching rate for the substrate (2).

Next, resist 3 is coated with a low-temperature resist stripping solution.
Chemical etching is applied to a region larger than the diameter of the hole 7 and smaller than half the distance to the adjacent hole 7, and the entire exposed portion of the resist 3 is regressed (Fig. 1(C)).
). By such chemical etching, dI (insulation N2
The relationship between the diameter of the hole 7 in the resist 3) and dz (the diameter of the hole 7 in the resist 3) is dI × d2. The shape of the hole 7 in the resist 3 at this time becomes the horizontal pattern of the protruding shape of the gold bump later. Therefore, by controlling the thickness of the resist 3 and the amount of chemical etching,
The protruding shape of the conductive member in the manufactured electrical connection member can be determined.

Next, by gold plating using the base 1 as a common electrode,
A conductive material 9 made of gold is inserted into the hole 7. Fill the hole 8 (FIG. 1(d)). At this time, the conductive material 9 is filled at least until it protrudes from the interface between the insulating layer 2 and the resist 3, and the protruding portion becomes the gold bump 10. The remaining resist 3 is completely removed using a resist stripping solution as shown in Figure 1 (
e) Using an etching solution that does not etch the L insulating layer 2 and the conductive material 9, the base 1 is etched away to produce the electrical connection member 31 (FIG. 1(f)).

In this embodiment, in the manufactured electrical connection member 31, the conductive member 34 is made of gold, and the holder 35 is made of polyimide resin.

FIG. 2 is a schematic cross-sectional view showing the manufacturing process of the second invention of the present application. The steps shown in FIG. 2(al) to FIG. 2(C) are as follows:
In the first invention described above, FIGS. 1(a) to 1(C1
Since the process is the same as that shown in , the explanation thereof will be omitted.

Holes 7 that communicate with each other by irradiation with excimer laser light 6
．． 68 is formed on the base material 4 (FIG. 2(C)), an insulating layer 2.6 is formed on the exposed surface of the base body 1. Using an etching solution that does not etch the resist 3, chemical etching is performed to widen the 68 vertically and laterally to form the hole 11.
(Figure 2(d)). At this time, the size of the horizontal expansion is set to be smaller than half the distance to the outer periphery of the adjacent holes 7. By controlling the width in the lateral direction in this manner, adjacent holes 11 do not communicate with each other.

The diameter of the hole 11 formed in the base body 1 is larger than the diameter of the hole 7 formed in the insulating layer 2. Since the holes 8 are formed downward by irradiation with excimer laser light 6 before chemical etching, the holes 11 formed after chemical etching have a shape that is larger in the downward direction than in the lateral direction.

Next, conductive material 9 made of gold is formed in hole 7. by gold plating using substrate 1 as a common electrode. Fill the hole 11 (FIG. 2(e)). At this time, the conductive material 9 is filled at least until it protrudes from the interface between the insulating layer 2 and the resist 3, and the protruding portion becomes the gold bump 10. The presence of the resist 3 in the lateral direction restricts the growth of gold plating, and a tall gold bump 10 is formed in the upward direction. Further, the lower part of the conductive material 9 to be filled becomes a gold bump 12 that matches the shape of the hole 11. The remaining resist 3 is completely removed using a resist stripping solution (FIG. 2(f)), and the substrate 1 is etched away using an etching solution that does not etch the insulating layer 2 and the conductive material 9. A connecting member 31 is manufactured (FIG. 2 (river)).

The electrical connection member manufactured in this way is
The conductive member 34 (gold pan 1) exposed beyond the diameter of the conductive member 34 (conductive material 9) embedded in
10.12) Since the diameter of the conductive member 34 is large, the conductive member 34 does not come off from the holder 35, and when connecting with an electric circuit component, connection failure due to the conductive member missing does not occur. Further, in the second invention, even if the conductive member pitch is extremely small (about 30 μm), a sufficient amount of protrusion of the gold bumps can be provided.

In addition to the copper (Cu) used in the examples, the metal materials used for the base 1 include Au, Ag, Be, Ca,
Mg.

Mo, Ni, W, Fe, Ti, In, Ta
, Zn, AI, Sn, Pb-5n, and other metals or alloys can be used. Further, even if the material is other than metal 1 alloy, if it exhibits conductivity, a material in which the metal material contains one or both of an organic material and an inorganic material may be used. Furthermore, a ceramic exhibiting superconductivity may also be used.

Although gold is used as the conductive material 9 in the embodiment, any metal or alloy other than the gold plate can be used. The conductive material 9 may be formed from one type of metal or alloy, or may be formed by mixing several types of metals and alloys. Alternatively, a metal material containing one or both of an organic material and an inorganic material may be used. Note that the cross-sectional shape of the conductive material 9 can be circular, square, or other shapes, but a shape without corners is desirable in order to avoid excessive concentration of stress.

In the example, polyimide resin was used as the insulating layer 2, but
Other organic resin materials such as epoxy resins, silicone resins, etc. may also be used. Using an organic material containing dispersed one or more types of inorganic materials, metal materials, 9 alloy materials, etc., in a desired shape such as powder, fiber, plate-shaped body, rod-shaped body, 3 spherical body, etc. Good too. Inorganic materials may also be used, and one or more of organic materials, metal materials, alloy materials, etc., may be dispersed in a desired shape such as powder, fibers, plates, rods, and spheres. You may also use inorganic materials contained in Specifically, as the metal material 3 alloy material contained, A
u, ^g+ Cur Alt Be+ Ca, Mg+
Mo+ Fe, Ni+ Co, Mn+ W, Cr,
Nb+ Zr, Ti+ TaZn, Sn, Pb
-5n etc., and the contained inorganic materials include 5i
n2. B2O33Al2O3, NazO+ K2O,
CaO+ZnO, Bad, pbo, 5bZo,,
AS20:l+ La2O3, ZrO2+ PzOs+
Ti0z, MgO, SiC+ Bed, BP, B
N, AIN, B4C, TaC+TiB2+ CrB
Examples include ceramic diamonds such as z, TtN, Sl:lN41 Taz05, glass, carbon boron, and the like.

Although KrF excimer laser light was used as the high-energy beam in the embodiment, the present invention is not limited to this.
Any material having enough energy to remove the resist 3 to a desired size may be used.

For example, ArF excimer laser, CO laser,
Laser beams such as YAG laser + N2 laser, Herr laser + Kr laser, and ion beam etching (1, B
P, ), 7 orcust ion beam etching (
FIBE), ion beams such as Suba-Inta etching, and electric beams using discharge, but methods using ion beams require the sample to be in a vacuum atmosphere.
Further, since minute machining is relatively difficult in electrical discharge machining, laser light is most suitable for the present invention.

In addition, although we decided to use the plating method as a method for filling the conductive material, other methods include CVD (Chemistry).
Alternatively, selective growth may be performed using cal vapor deposition. When filling with a conductive material by the CVD method, the base material constituting the base material does not need to be made of the conductive material.

〔Effect of the invention〕

As detailed above, in the first invention, a hole is made in the base material including the first insulating layer which becomes the holder by irradiating the high energy beam, and the hole is filled with a conductive material which becomes the conductive member. It is possible to manufacture an electrical connection member in which conductive members are provided at narrow pitches while maintaining insulation between them. Furthermore, even when the size of the bumps is reduced, the amount of protrusion can be stabilized, so there will be no missing bumps and no short circuit between adjacent pans 1. Therefore, by using the electrical connection member manufactured according to the present invention, high density connection between electrical circuit components can be achieved.

Fine connections can be made.

In addition, in the second invention, the diameter of the hole at the bottom is enlarged by chemically etching the surface of the substrate exposed by irradiation with the high-energy beam, so that the diameter of the part exposed from the holder is An electrical connection member having a conductive member having a diameter larger than the diameter of the portion inside can be manufactured;
Missing of the conductive member can be more completely prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the manufacturing process of the first invention;
The figure is a schematic sectional view showing the manufacturing process of the first invention, and FIG. 3 is a schematic diagram showing the conventional manufacturing method of an electrical connection member.

Claims (1)

[Claims] 1. A holder made of an electrically insulating material, and a plurality of conductive members provided in the holder insulated from each other, one end of each of the conductive members being connected to the holder. A method for manufacturing an electrical connection member, wherein the electrical connection member is exposed on one surface of the holder, and the other end of each of the conductive members is exposed on the other surface of the holder, comprising: a base body; A high-energy beam is irradiated from the second insulating layer side to a base material having an insulating layer and a second insulating layer made of a material different from the first insulating layer stacked in this order. in the area of the first
, removing all of the second insulating layer and a portion of the substrate;
a first step of forming a plurality of holes in the base material; and a first step of forming a plurality of holes in the second insulating layer, which is larger than the diameter of the hole formed in the base material and smaller than half the distance to the outer periphery of an adjacent hole. a second step of etching within the range; and a third step of filling the plurality of holes formed with a conductive material to become the conductive member up to a position higher than the interface between the first and second insulating layers. A method for manufacturing an electrical connection member, comprising: a fourth step of removing the second insulating layer; and a fifth step of removing the base. 2. After the first step or the second step, the first
A claim characterized by comprising the step of etching the substrate exposed in the step in an area that is larger than the diameter of the hole formed in the first step and smaller than half the distance to the outer periphery of an adjacent hole. Item 1. A method for manufacturing an electrical connection member according to item 1. 3. The electrical connection according to claim 1, characterized in that the base body is formed using a conductive material different from the conductive material that becomes the conductive member, and a laser beam is used as the high-energy beam. Method of manufacturing parts. 4. The electrical connection member according to claim 2, wherein the base is formed using a conductive material different from the conductive material that becomes the conductive member, and the etching is wet etching. Production method.