JPS60133788A - Method of plating printed board - 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 (1) Technical Field of the Invention The present invention relates to improving the adhesion between layers by roughening the copper foil of laminated printed circuit boards.

(2) Background of the technology When the copper foil surface of the conductor pattern formed on the surface of the intermediate layer of a multilayer printed circuit board is pretreated and laminated, an overcurrent of copper is applied to the conductor pattern as a treatment to increase the adhesive strength between the eyebrows. Electrolytic plating is used to obtain granular copper electrodeposition on the surface of the copper foil of the conductor pattern, and due to the anchoring effect of the joint with the resin to be bonded, the adhesive strength is increased from 200 g/α in the case of no treatment. ,
It improves the physical strength of the lamination of a multilayer printed circuit board, which can have a weight of 1500 g, m or more.

(3) Prior Art and Problems FIG. 1 shows the electrolytic plating of the intermediate layer to be pretreated, and FIG. 2 shows the generation of copper particles electrodeposited on the copper foil of the conductor pattern.

In the figure, l is a plating bath, 2 is an air pipe, 3 is an air bubble, 4 is an electrolyte, 5 is an anode, 6 is a printed circuit board, 7 is a cord, 8 is a power supply, 9 is a conductive pattern, and 10 is an electrodeposition Copper is shown respectively.

As shown in FIG. 1, in the printed circuit boards 6 to be laminated, the plating layer 1 is filled with electrolyte g4, and an air bubble 3 is generated through the air pipe 21 from the bottom of the plating layer 1 to stir the "WL decomposition liquid 4". In this case, the anode 5 and the anode 5 are immersed vertically in the electrolytic solution 4 in an S-framed manner, and connected to a power source 8 using a connecting cord 7.

To perform overcurrent electrolytic plating of copper on the printed circuit board 6 and electrodeposit granular copper with a diameter of several μm, electrolytic solution 4 must be plated at a current density of about 2 A/d- without stirring with air bubbles 3.
After electrolytic plating for about 2 minutes, electrolytic plating is continued for about 2 minutes at a current density of 4 Vdff/ while stirring the electrolytic solution 4 with an air bubble 3, and as shown in FIG. The occurrence of copper 10 is the conductor pattern 9
Since granular electrolytic copper 10 is generated locally on the surface of the conductor pattern 9, granular electrolytic copper 10 is not generated on the entire surface of the conductor pattern 9. The surface adhesive strength does not increase.

(4) Purpose of the Invention In view of the above-mentioned drawbacks of the conventional art, the present invention provides a method of printing in which granular electrodeposited copper is uniformly generated over the entire surface of the copper foil on the optical surface of the intermediate layer constituting the multilayer printed circuit board. The purpose of this invention is to provide a method for plating a substrate.

(5) Structure and object of the invention According to the present invention, a printed circuit board immersed in an electrolytic solution in a plating bath is held horizontally and electrolytically plated in opposition to an anode. This is achieved by providing a plating method.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to Drawing E.

FIG. 3 shows a method for electrolytic plating of a printed circuit board according to the present invention, and in the figure, reference numeral 11 indicates a holder for the printed circuit board 6 to be plated.

The conductive pattern 9 of the printed circuit board 6 as an intermediate layer constituting the multilayer printed circuit board has an arbitrary shape on the surface of the printed circuit board 60, and when suspended vertically in the electrolytic solution 4, the conductive pattern 9 prevents the generation of electrodeposited copper 100. It is difficult to selectively generate copper 10 in a direction selectively, and the electrolytic plating method according to the present invention for producing electrodeposited copper 10 on conductor pattern 9 of printed circuit board 6 is as shown in FIG. 4, and an air pipe 2 is installed so that an air bubble 3 can be generated to stir the electrolyte 4. An anode 5 is installed horizontally at the bottom of the electrolyte 4, and an air pipe 2 is installed to generate an air bubble 3 to stir the electrolyte 4. The printed circuit board 6 to be plated is held horizontally in the electrolytic solution 4 opposing the electrolytic solution 4 using the holder 11 so that the printed circuit board 6 does not move in the electrolytic solution 4 stirred by the air bubbles 3, and the electrolytic solution 4 is held still. In this state, a current density of 4A/2 is applied between the anode 5 connected to the power supply 8 at the needle 7 and the printed circuit board 6.
After energizing the d door for about 2 minutes, the electrolyte 4 and air bubbles 3
Apply current continuously at a current density of 4/dd for about 2 minutes while stirring: When electrolytic plating is performed with IM current, the vertical lower surface of the printed circuit board 6 opposite to the anode 5 of the conductor pattern 9 of the printed circuit board 6 is formed. Observe the occurrence of electrodeposited copper 100.

The electrodeposited copper 10 grows evenly and densely on the surface area of the conductor pattern 9 while forming granules in the direction of gravity.

Conductor pattern 9 to be plated on both surfaces of printed circuit board 60
If so, continue plating on one side alternately.

The surface of the conductive butter that is in contact with the printed circuit board as an interlayer is used to cover the entire area of the conductor pattern, and the noise generated by the electrodeposited copper in the form of particles is extremely high. A contact N strength of 1500 g/m or more can be ensured.

Furthermore, substantially the same effect can be obtained even if the relative positions of the anode in the electrolyte of the plating layer according to the present invention and the printed circuit board to be plated are reversed.

[Brief explanation of the drawing]

Figure 1 shows the electrolytic plating of the intermediate layer to be pretreated;
The figure shows the generation of copper particles electrodeposited on the copper foil of the conductive pattern, and Figure 3 shows the electrolytic plating method for printed circuit boards according to the present invention. Figure 1, Figure 2, Figure 3

Claims (1)

[Claims] On the surface of the conductor of the printed circuit board, which ensures the adhesion between the layers of the intermediate printed circuit board that constitutes the multilayer printed circuit board,
Overcurrent electrolytic plating A method for plating printed circuit boards characterized by holding the printed circuit board to be plated horizontally in an electrolytic solution and positioning it opposite the anode when obtaining granular electrodeposited copper.