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A kind of non-toxic gold stripping liquid and its application method for printed circuit board detection

A printed circuit board and gold stripping technology, which is applied in the field of non-toxic gold stripping solution, can solve the problems of risky operation, limited scope of use, high cost of management and wastewater treatment, and achieve fast gold stripping speed, simple configuration, and easy operation simple effect

Active Publication Date: 2016-09-21
SHANTOU ULTRASONIC PRINTED BOARD NO 2 FACTORY +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

To peel off the gold layer, the well-known method is to use a solution of cyanide. Cyanide is a highly toxic substance, the operation is risky, and the cost of management and waste water treatment is high. National laws have strict regulations to limit its scope of use.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] In the embodiment of the present invention, a non-toxic gold stripping solution and its application to printed circuit board detection method,

[0017] 1) Prepare 1L of A solution: pipette 10ml of 98% sulfuric acid, add it to deionized water to make a 1L solution, then weigh 80g of ferric sulfate, add it to the above solution to dissolve, that is, prepare 1L of A solution, brown container Keep airtight.

[0018] 2) Prepare 1L of B solution: weigh 60g of thiourea, add it to 1L of deionized water, that is, prepare 1L of B solution, and keep it sealed.

[0019] 3) Pipette 50ml of solution A and 50ml of solution B and mix to obtain 100ml of non-toxic gold stripping solution. The best effect is to use it within 2 hours, and it can be stored in a sealed and dark place to prolong its use time.

[0020] 4) Soak the test sample in the above non-toxic gold stripping solution. The stripping process can be taken out for observation. Depending on the thickness of the gold layer, th...

Embodiment 2

[0022] In the embodiment of the present invention, a non-toxic gold stripping solution and its application to printed circuit board detection method,

[0023] 1) Prepare 1L of A solution: pipette 8ml of 98% sulfuric acid, add it to deionized water to make a 1L solution, then weigh 40g of ferric sulfate, add it to the above solution to dissolve, that is, prepare 1L of A solution, brown container Keep airtight.

[0024] 2) Prepare 1L of B solution: Weigh 30g of thiourea, add it to 1L of deionized water, that is, prepare 1L of B solution, and keep it sealed.

[0025] 3) Pipette 50ml of solution A and 60ml of solution B and mix to obtain 100ml of non-toxic gold stripping solution. The best effect is to use it within 2 hours, and it can be stored in a sealed and dark place to prolong its use time.

[0026] 4) Soak the test sample in the non-toxic gold stripping solution, shake it for 30-60s, take out the sample, and then add the non-toxic gold stripping solution to the gold surfac...

Embodiment 3

[0028] In the embodiment of the present invention, a non-toxic gold stripping solution and its application to printed circuit board detection method,

[0029] 1) Prepare 1L of A solution: pipette 6ml of 98% sulfuric acid, add it to deionized water to make a 1L solution, then weigh 20g of ferric sulfate, add it to the above solution to dissolve, that is, prepare 1L of A solution, brown container Keep airtight.

[0030] 2) Prepare 1L of B solution: Weigh 17g of thiourea, add it to 1L of deionized water, that is, prepare 1L of B solution, and keep it sealed.

[0031] 3) Pipette 50ml of solution A and 75ml of solution B and mix to obtain 100ml of non-toxic gold stripping solution. The best effect is to use it within 2 hours, and it can be stored in a sealed and dark place to prolong its use time.

[0032] 4) In order to judge the corrosion degree of the nickel-phosphorus alloy layer, the reference sample and the test sample were stripped of the gold layer together. After the gold...

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PUM

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Abstract

The invention discloses non-toxic gold stripping liquid and a method for detecting a printed circuit board through the non-toxic gold stripping liquid. The liquid consists of a solution A and a solution B, wherein the solution A and the solution B are mixed according to the volume ratio of 1: (1-1.5); the solution A is an acid solution containing iron ions; the solution B contains a thiourea or thiourea derivative. A test sample is immersed in the non-toxic gold stripping liquid; and after a certain time, a chemical gold-plated layer is stripped. In order to judge the corrosion degree of a nickel-phosphorus alloy layer, the stripping of gold layers is performed on a reference sample and the test sample at the same time; after the gold layers are stripped, the corrosion degree of the test sample is determined by comparing the appearance brightness of the reference sample and the test sample. According to the invention, a conventional drug is used for inventing the non-toxic gold stripping liquid with simple configuration; the gold stripping speed is high; the non-toxic gold stripping liquid is applied to the detection of the corrosion degree of the nickel-phosphorus alloy layer, is simple to operate and is especially suitable for the quality detection of products at production sites.

Description

technical field [0001] The invention relates to a gold stripping solution, in particular to a non-toxic cyanide-free gold stripping solution and its application in the field of printed circuit boards. A method for detecting the corrosion degree of an alloy layer. Background technique [0002] In the field of printed circuit board manufacturing, electroless nickel-gold plating (ENIG) is a mainstream surface treatment process. In its process, a certain thickness of nickel-phosphorus alloy layer is deposited on the copper surface through oxidation-reduction reaction, and then through replacement reaction, A gold layer with a certain thickness is deposited on the surface of the nickel-phosphorus alloy. During the production process of electroless nickel-gold plating, the nickel-phosphorus alloy layer will be attacked to varying degrees and cause corrosion. The more severe the corrosion of the nickel-phosphorus alloy layer, the darker the appearance and cracks will occur, that i...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23F1/30H05K3/06
Inventor 李国有邱彦佳洪泳坚张学东
Owner SHANTOU ULTRASONIC PRINTED BOARD NO 2 FACTORY
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