JPH0495371A - Manufacture of electric connecting member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

[Prior art]

Wire bonding methods and TAB (Tape Out) are methods for electrically connecting electrical circuit components to each other.

(mated bonding) method etc. are well known. However, with these methods, the minimum pitch required to prevent adjacent connection parts from coming into contact with each other is relatively large, so there is a problem that they cannot be used when a small pitch between connection parts is required. There was a point.

In order to solve these problems, electrical circuit components can be electrically connected to each other using an electrical connection member that has a structure in which a plurality of conductive members are mutually insulated and held in an insulating holder. It has been proposed (Japanese Unexamined Patent Publication No. 63-222437, Unexamined Japanese Patent Application No. 63-224235, etc.).

FIG. 3 is a schematic diagram showing electrical connections between electrical circuit components using such electrical connection members, in which reference numeral 31 indicates electrical connection members, and 32 and 33 indicate electrical circuit components to be connected. show. The electrical connection member 31 holds a plurality of rod-shaped conductive members 34 made of metal or alloy in a thin plate-like holder 35 made of an electrically insulating material, with the conductive members 34 electrically insulated from each other. The electric circuit component 32 has a configuration in which both ends of the conductive member 34 are used as humps 38 and 39, respectively.
and a protrusion on the 33 side (Fig. 3(a)). and,
The connecting portion 36 of one electric circuit component 32 and the bump 38 of the conductive member 34, and the connecting portion 37 of the other electric circuit component 33 and the bump 39 of the conductive member 34 are alloyed by, for example, ultrasonic heating. The electrical circuit components 32 and 33 are electrically connected to each other (see Fig. 3).
b)).

By the way, as a method for manufacturing the electrical connection member 31, one of the present applicants has proposed a method shown in FIG. 4 (Japanese Patent Application No. 133401/1982).

First, a photosensitive resin 35a that will become the holder 35 is applied onto the base 40 made of a conductive material (FIG. 4(a)). Next, in a post-process, a predetermined position to be filled with the conductive member 34 is exposed and developed to form a hole 35b in the photosensitive resin 35a and expose the base 40, and then the temperature is raised to form the photosensitive resin 35a. Harden (Fig. 4(b)).

Then, the substrate 40 near the hole 35b is etched to form a recess 41 in the lower part of the hole 35b (FIG. 4(C)).
.

Thereafter, by plating the base body 40 with gold or the like, the conductive member 34 is filled in the recess 41 and the hole 35b, the hump 39 is formed in the recess 41, and the bump is formed on the upper surface of the photosensitive resin 35a. 38 (Fig. 4 (
d)).

Thereafter, the electrical connection member 31 is completed by removing the base 40 by metal etching (FIG. 4(e)).

[Problem to be solved by the invention]

By the way, in the above manufacturing process, the recess 4 is formed in the base body 40.
Etching is performed to form 1.

This etching is a chemical etching using a common etching solution such as cupric chloride, ammonium persulfate, or ferric chloride. When attempting to etch a metal substrate 40 having grain boundaries such as copper by such chemical etching, etching is performed from the grain boundaries and/or crystal planes that are easily etched, and after etching, the surface of the recess 41 is etched. Unevenness due to crystal grains remains. For this reason, Part 4
As a result of unevenness being formed on the surface of the bumps 39 formed by plating in the inside of the bump 39, the shape and height of each hump 39 become uneven, and the problem that uniform connection with electric circuit components cannot be made on the side of the hump 39. There is. In particular, when the humps become finer and more dense, the influence of these grain boundaries becomes greater.

Moreover, if the surface shape and depth of the recessed portion 41 become uneven in this way, the height and shape of the opposite side bread 138, which is formed by being raised by plating, will also be affected.
Similarly, even connections with electrical circuit components cannot be made on the side.

The present invention has been made in view of the above circumstances, and it is possible to create recesses with a uniform surface shape and depth with few irregularities when manufacturing an electrical connection member using a metal substrate having grain boundaries. An object of the present invention is to provide a method for manufacturing an electrical connection member that can form a plurality of uniform bumps with no variation in shape and height by forming a plurality of bumps on a base body.

[Means to solve the problem]

A first method for manufacturing an electrical connection member according to the present invention includes forming a plurality of holes penetrating the holder in a base material formed by laminating a base body and a holder made of an electrically insulating material, and forming a plurality of holes through the holder. After etching a portion of the base body exposed inside to form a recess communicating with the hole, and filling the recess and the hole with a conductive member such that one end thereof is exposed from the surface of the holder, In the method of manufacturing an electrical connection member in which the other end of the conductive member is exposed from the rear surface of the holder by removing the base, the etching is performed by sequentially performing chemical etching and electrolytic etching.

Further, the second method for manufacturing an electrical connection member according to the present invention includes:
The first method for manufacturing an electrical connection member is characterized in that the etching process including the chemical etching and the electrolytic etching is repeated multiple times.

[Effect]

The portion of the substrate exposed through the through-hole of the holder is first subjected to chemical etching, which requires a short processing time, and then electrolytic etching. Then, the unevenness caused by crystal grains remaining on the surface of the four parts that have been etched in a short time by chemical etching is polished and smoothed by the electrolytic etching solution. As a result, when the recess and the through-hole are filled with the conductive member, the exposed portions of the conductive member from the holder are each formed to have a uniform shape and protrusion height.

[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 an electrical connection member according to the present invention. 1(a) to (b) are the same as the conventional method described above, in which copper foil, for example, is used as the base 1, and a negative type polyimide resin, for example, is coated on the base 1 as the insulating layer 2 serving as the holder. Then, the material is prepared as a base material (Fig. 1(a)). Next, the insulating layer 2 is irradiated with light (exposure) through a photomask on which a conductive member arrangement pattern is formed, and development is performed. In this example, by using a photomask, the polyimide resin remains after development in the areas irradiated with light, and the polyimide resin is removed by development in the areas not irradiated with light, forming a plurality of holes 3. (Fig. 1(b)). Thereafter, the temperature is raised to cure the polyimide resin, thereby curing the insulating layer 2. As a result, a part of the base body is exposed by the cover 3 of the insulating layer 2.

Next, the exposed substrate 1 is chemically etched using the general etching solution mentioned above to form the recess 4a communicating with the hole 3.
is formed on the substrate 1 (FIG. 1(C)).

For example, when forming the recess 4a to a depth of 4 to 5 μm, the etching time is about 5 to 20 seconds, and in this chemical etching, the crystal grain boundaries and/or activation energy of the copper used in the substrate 1 is small. Etching progresses from crystal planes such as (111) crystal planes, and crystal grains (
In the case of copper, unevenness of 1 to 30 μm remains. Due to this unevenness, each recess 4a has an uneven shape and depth.

Next, the substrate 1 after this chemical etching is used as an anode,
Electrolytic etching is performed with a Cu plate facing the negative electrode. Here, the electrolyte is 2N-H2SO4 or) 1cI,
Na0)1+N)I, Cff, etc. can be used,
For example, when electrolytic etching is performed for 1 to 10 minutes with Q: 0.33 V applied between both electrodes using electrolytic 'i4co2N-)12SO, etching progresses from the white part of the unevenness on the surface of the recess 4a. After the etching is finished, the recesses 4b with a smooth surface shape are formed (the first
Figure (d)). Note that during the chemical etching in the previous step, organic impurities contained in the etching solution adhere to the recesses 4a, which further worsens the unevenness of the recess surfaces, but these impurities can be removed by electrolysis.

Next, by plating the base 1 with gold or the like, the recess 4b and the hole 3 are filled with metal that will become the conductive member 5, and the bump 51 is placed inside the recess 4b on the surface side of the insulation N2. Bumps 52 are respectively formed.

Finally, the base 1 is etched away using an etching solution that does not etch the insulating layer 2 and the conductive member 5, thereby producing an electrical connection member 6 in which the insulating layer 2 serves as a holder for the conductive member 5. (Figure 1(f)).

Note that when the target value of the protrusion height of the humps 51 and 52 from the holder 2 is 5 μm, the conventional method, that is, the base l
When the concave portions were formed only by chemical etching, there was considerable variation in the error of ±3 μm in the hump 52, and the shape of the hump 51 was also non-uniform. However, when electrolytic etching was used in conjunction with the method of the present invention, The error was reduced to ±1 μm, and the shapes of both humps were made uniform.

FIG. 2 shows the surface condition of the recesses formed in the base body 1 in the above manufacturing process. FIG. 2(a) shows the surface of the recess after chemical etching, and FIG. 2(b) shows the surface of the recess after electrolytic etching. As is clear from this figure, the unevenness on the surface of the recesses caused by chemical etching has been smoothed by the polishing action of electrolytic etching.

〔effect〕

As described above, in the method for manufacturing an electrical connection member according to the present invention, by using a combination of chemical etching and electrolytic etching to form recesses in a substrate having grain boundaries, recesses that occur when chemically etching are removed. Surface irregularities are polished by electrolytic etching.

The surface is smoothed, and at this time, impurities of the etching solution adhering to the recesses are also removed by chemical etching.

As a result, the shape and depth of the multiple recesses become uniform, so
The shape and protrusion height of the bumps of the conductive member formed in the recess are made uniform, and the bumps formed on the opposite side of the holder are also made uniform in shape and protrusion height. This ensures uniform and good connectivity with electrical circuit components on both sides.

In addition, most of the recesses are formed by chemical etching, which takes a short processing time, and electrolytic etching, which takes a relatively long time, is performed for the purpose of polishing the unevenness on the surface of the recesses, so the overall etching processing time can be shortened. The present invention has excellent effects such as high productivity.

[Brief explanation of drawings]

Fig. 1 is a schematic cross-sectional view showing the manufacturing process of the electrical connection member according to the present invention, Fig. 2 shows the surface condition of the recess formed in the base, and Fig. 3 shows the structure of the electrical connection member. The schematic diagram shown in FIG. 4 is a schematic sectional view showing a conventional manufacturing process of an electrical connection member. DESCRIPTION OF SYMBOLS 1... Base body 2... Insulation N (holding body) 3... Hole 4a, 4b... Recessed part 5... Conductive member 6...
Electrical connection member 51.52...Bump patent Applicant Canon Co., Ltd. (1 other person) Agent
Patent Attorney Noboru Kono] Figure (a) Figure (b) Figure (b) Procedure amendment method) November 20, 1990 Relationship with 1990 Patent Application No. 206387 Location of patent applicant Tokyo 3-30-2 Shimomaruko, Ota-ku, Tokyo Name
Canon Co., Ltd. Representative Keizo Yamaji Address 4-5-33 Kitahama, Chuo-ku, Osaka Name (
211) Yasuo Shingu, Representative of Sumitomo Metal Industries, Ltd.

Claims (2)

[Claims] 1. A plurality of holes passing through the holder are formed in a base material formed by laminating a base body and a holder made of an electrically insulating material, and a part of the base body exposed in the holes is etched to form the holes. After forming a communicating recess and filling the recess and the hole with a conductive member such that one end thereof is exposed from the surface of the holder, the base is removed and the other conductive member is inserted from the back surface of the holder. A method of manufacturing an electrical connection member in which an end is exposed, wherein the etching includes chemical etching and electrolytic etching performed in sequence. 2. 2. The method of manufacturing an electrical connection member according to claim 1, wherein the etching process including the chemical etching and the electrolytic etching is repeated multiple times.