Method for removing suspension copper in blind hole of circuit board

A circuit board and blind via technology, which is applied in the directions of printed circuits, printed circuit manufacturing, and the formation of electrical connections of printed components, can solve the problems of surface copper and bottom copper etching, voids, and large production capacity, and achieves low cost and simple process. Effect

Inactive Publication Date: 2016-05-04
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If the hanging copper is not removed, poor electroplating problems such as copper nodules and voids will occur in the electroplating process
[0003] Chinese patent CN103014825A proposes to remove the suspended copper of the printed circuit board and the packaging substrate by anodic electrolysis. Although the electrolysis process takes a short time, there is still corrosion to the copper outside the h

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Prepare liquid A and liquid B as follows:

[0019] Liquid A: 10% sulfuric acid, 1% ethanol, and the rest is water.

[0020] B solution: 10% sodium nitrate, the rest is water.

[0021] The workpieces of blind hole hanging copper are handled as follows:

[0022] Step 1: Soak in liquid A at 30°C for 5 minutes;

[0023] Step 2: Without washing, the workpiece is taken out of solution A, parked for a few seconds, then put into solution B at 30°C, and soaked for 5 minutes;

[0024] Step 3: Take out from liquid B, wash with water, and dry.

Embodiment 2

[0026] Prepare liquid A and liquid B as follows:

[0027] Liquid A: 30% sulfuric acid, 5% polyethylene glycol (molecular weight 400), and the rest is water.

[0028] Liquid B: 30% hydrogen peroxide, the rest is water.

[0029] The workpieces of blind hole hanging copper are handled as follows:

[0030] Step 1: Soak in liquid A at 20°C for 2 minutes;

[0031] Step 2: Without washing, the workpiece is taken out from solution A, parked for a few seconds, then put into solution B at 20°C, and soaked for 2 minutes;

[0032] Step 3: Take out from liquid B, wash with water, and dry.

Embodiment 3

[0034] Prepare liquid A and liquid B as follows:

[0035] Liquid A: 10% acetic acid, 3% ethylene glycol, and the rest is water.

[0036] B liquid: 1% sodium persulfate aqueous solution.

[0037] The workpieces of blind hole hanging copper are handled as follows:

[0038] Step 1: Soak in liquid A at 50°C for 3 minutes;

[0039] Step 2: Without washing, the workpiece is taken out from solution A, parked for a few seconds, then put into solution B at 50°C, and soaked for 3 minutes;

[0040] Step 3: Take out from liquid B, wash with water, and dry.

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PUM

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Abstract

The invention relates to a method for removing suspension copper in a blind hole of a circuit board, belonging to the technical field of chemical industry. The method comprises the following steps of (1) respectively preparing a liquid A and a liquid B, wherein the liquid A comprises an acidic or alkaline substance and a wetting agent, and the liquid B comprise one or more of hydrogen peroxide, peroxysulphate, nitrate, hypochlorite, copper sulfate and ammonium chloride substances; (2) respectively heating the liquids obtained in the step (1) to be 20-60 DEG C; and (3) immersing a workpiece with suspension copper in the blind hole in the liquid A for 1 to 10 minutes, taking out the workpiece, dropping the liquid for several seconds, immersing the workpiece in the liquid B for 1 to 10 minutes, and finally washing and drying the workpiece. By the method, chemical etching can be carried out on the suspension copper in the blind hole, and no etching is carried out on copper outside the hole and copper at the bottom of the hole. The process is simple, economic and efficient.

Description

technical field [0001] The invention relates to a method for removing hanging copper in a blind hole of a circuit board, in particular to an AB liquid method for chemically etching the hanging copper in the blind hole without substantially etching the copper outside the hole and the copper at the bottom of the hole, and belongs to the technical field of chemical industry. Background technique [0002] With the miniaturization and high-speed development of intelligent electronic products, printed circuit boards are advancing in the direction of high density, high integration, small holes, and large capacity. Taking drilling as an example, HDI boards have made mechanical drilling reach the limit; for blind buried tiny holes, mechanical drilling methods can no longer meet the requirements. Therefore, laser drilling technology capable of processing tiny holes is becoming more and more popular. When the aperture is as small as the micron level, laser drilling also creates new pr...

Claims

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Application Information

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IPC IPC(8): H05K3/42C23F1/02
CPCC23F1/02H05K3/421H05K2203/0789H05K2203/0793
Inventor 胡光辉杜晓吟杨文健付正皋潘湛昌魏志钢罗观和
Owner GUANGDONG UNIV OF TECH
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