JPH03185897A - Multilayer wiring board manufacturing method - 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 plating connection electrodes formed on a wiring board in a multilayer wiring board used in electrical equipment and the like.

BACKGROUND OF THE INVENTION In recent years, with the miniaturization of electronic devices, high-density circuit boards have been required. Conventional circuit board electrodes are Cu for printed circuit boards and Cu and Ag for ceramic boards.
7Pd, Ag-Pt, etc. are often used, but when trying to mount a pair of IC chips in order to obtain a high-density circuit board, it is necessary to apply treatments such as gold plating to the electrodes connected to the IC on the circuit board. Therefore, in this first method, gold plating was performed by dipping the circuit board in an electroless gold plating solution.

Problems to be Solved by the Invention However, the above-mentioned plating method has the disadvantage that gold is deposited on the entire electrode portion exposed on the surface, resulting in high costs. It was a cabinet.

If masking is performed in advance on areas where plating is not needed using a resist, etc., the resist will be eroded because the electroless plating solution is generally a strong alkali, resulting in gold being deposited on unnecessary areas. was there. Furthermore, in terms of the chemical resistance of the resist, the pH of the electroplating solution is close to neutral, and the resist can withstand use sufficiently if electroplating is performed. It is necessary to apply a predetermined voltage to each of the plurality of electrode parts, which is almost impossible in practice.

In response to these points, it is an object of the present invention to provide a manufacturing method for electroplating predetermined electrodes formed on the surface of a multilayer wiring board.

Means for Solving the Problems The method for manufacturing a multilayer wiring board of the present invention includes a common electrode formed on a second multilayer wiring board part that is integrally continuous with a first multilayer wiring board part that is a product. , a plurality of connection electrodes to be plated on the surface of the first multilayer wiring board are connected via an inner layer conductor in the first multilayer wiring board section, and a predetermined voltage is applied to the common electrode during wet plating to connect the plurality of connection electrodes to be plated. An electroplating layer is formed on each of the connection electrodes, and after the plating is formed, the first and second multilayer wiring board parts are separated, and the connection IFIL is separated from the first and second multilayer wiring board parts.
The method is characterized in that the connection electrodes that are electrically connected to the poles via the inner layer conductors are electrically separated from each other.

According to the method described above, multiple connections to be electroplated! The poles are connected to a common electrode via an inner layer conductor formed inside the multilayer wiring board in advance, so if a predetermined voltage is applied to this common electrode during plating, a predetermined voltage is applied to each of the multiple connection electrodes. It can be applied. Also,
Since the inner layer conductor inside the multilayer wiring board is used, the degree of freedom in designing the conductive pattern for connecting the connection electrode and the common electrode is increased.

EXAMPLE Hereinafter, a method for manufacturing a multilayer wiring board according to an example of the present invention will be described with reference to one drawing. As shown in FIG. 2, a green sheet 7a is a green sheet 7a in which a glass ceramic is uniformly dispersed in an organic binder.

After making a pier hole in 7b and 7c by NC punching, the pier hole was filled with copper oxide paste 5, and green sea was filled with oxidized steel paste 5).
A plurality of printed and dried wiring patterns 6 are laminated on the surfaces of 7b and 7c, and fired in air at about 500°C to dissipate the organic binder.
Copper oxide was reduced to copper in a mixed gas of nitrogen and hydrogen at 900°C, and the copper and glass ceramic were sintered in nitrogen at 900°C.

Form a multilayer wiring board. At this time, Green Sea)
A slit 3 is provided in advance in 7a to facilitate separation into the first multilayer wiring board part 1a, which will become a product, and the second multilayer wiring board part 1b, which will be removed after plating. Further, the design of the wiring pattern 6 is such that, as shown in FIG. 1, a plurality of plated electrodes fM2b and an unplated electrode 2a are formed on the surface layer of the first multilayer wiring board portion 1a.

A common electrode 2C is formed on the surface layer of the second multilayer wiring board part 1b, and as shown in FIG. Connected by 4. Next, this multilayer wiring board is immersed in a gold plating solution, the common electrode 2C is connected to the negative electrode of the power source, and the platinum is connected to the positive electrode of the power source.
Electroplating was performed for F110 minutes at a current density of mA/d,
Gold plating is selectively deposited to a thickness of about 3 μm only on the surface of the electrode 2b to be plated. Finally, at the slit 3 part,
The multilayer wiring board section 1a and the second multilayer wiring board section 1b are divided, and the plurality of electrodes 2b that are electrically connected via the common electrode 2c are electrically separated. Obtain a wiring board. Note that the materials and numerical values in the above manufacturing process are merely examples, and may be changed within the range that achieves the purpose.

Effects of the Invention As described above, according to the present invention, a plurality of connection electrodes formed on the surface of a first multilayer wiring board part, which is a product, are each integrally continuous with the first multilayer wiring board part. After forming an electroplating layer on the connection electrode, the common electrode is connected to the common electrode on the second multilayer wiring board formed by using the inner layer conductor in the first multilayer wiring board section. By separating the multilayer wiring board part 2, selective electroplating becomes possible, and there is no need for a masking process.
Although it is possible to simplify the process, it is also possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a multilayer wiring board before electroplating in one embodiment of the method for manufacturing a multilayer wiring board of the present invention, and FIG. 2 is a side view of the multilayer wiring board in a state before firing in the same embodiment. FIG. 1a...first multilayer wiring board, 1b...
・Second multilayer wiring board, 2a...electrode not plated, 2b...electrode to be plated, 2C...
...Common electrode, 3...Slit, 4...
...Inner conductor.

Claims (1)

[Claims] A plurality of connection electrodes formed on the surface of the first multilayer wiring board section are connected to a second multilayer interconnection board integrally connected to the first multilayer wiring board section via inner layer conductors in the first multilayer wiring board section. connecting to a common electrode of a wiring board part, forming an electroplating layer on the plurality of connection electrodes using the common electrode, separating the first and second multilayer wiring board parts after forming the electroplating layer, and A method for manufacturing a multilayer wiring board, in which the plurality of connection electrodes that are electrically connected via a common electrode inner layer conductor are electrically separated from each other.