Tinning method for SMD stamp-mounting-paper diode

A diode and chip technology, applied in the field of tin plating of SMD chip diodes, can solve the problems of environmental pollution, inability to adapt to the performance of the plating solution, etc., and achieve the effect of shortening the plating time, maintaining long-term stability and good bonding force.

Inactive Publication Date: 2011-02-16
CHANGZHOUSR SEA ELECTRONICS
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

[0006] Therefore, due to the defects of the performance of the plating solution itself and the problems of environmental pollution, it has been unable to meet the current product quality requirements and environmental protection requirements.

Method used

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  • Tinning method for SMD stamp-mounting-paper diode
  • Tinning method for SMD stamp-mounting-paper diode

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Embodiment Construction

[0026] refer to figure 1 , the tinning method of SMD chip diode of the present invention, realizes by following steps:

[0027] 1. Remove the oxide film:

[0028] An oxide film whose main component is copper oxide is formed on the surface of the SMD chip diode. During electroplating, the pin and the plating solution will be separated by the oxide film. If it is not treated, it cannot be used for direct electroplating. Even if it is plated with tin, the tin layer will not be firmly bonded to the surface of the substrate, otherwise it will cause blistering of the coating, Peeling, even can not be plated with tin, etc. Therefore, deoxidation film is an indispensable and important link in the electroplating process. In this embodiment, the sulfuric acid solution with a concentration of 10% is used to remove the oxide film on the surface of the pins of the SMD chip diode.

[0029] Two, cleaning

[0030] The surface of the SMD chip diode is stained with sulfuric acid residue and...

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Abstract

The invention relates to a plating method, in particular to a tin plating method of an SMD surface mounting diode, which comprises removing oxide films on the surface of the pins of the SMD surface mounting diode with sulfuric acid solution, cleaning the pins of the SMD surface mounting diode through adopting a multi-stage back rinsing device, placing the cleaned SMD surface mounting diode into methanesulfonic acid solution with 3-5% concentration, removing the oxide films generated on the surface of the pins to expose metal crystalline structures on the surface of the pins, placing the SMD surface mounting diode into an electroplating bath which holds electroplating solution to electroplate for 1.5-2 hours, and adopting 25-35 DEG C temperature when in the electroplating, wherein the electroplating solution is mixing solution which comprises methanesulfonic acid, tin methanesulfonic acid and methanesulfonic acid additive. The invention provides a tin plating method of the SMD surface mounting diode, which can increase the product quality and electroplating efficiency, and can prevent the tin plate layer from growing tin beards.

Description

technical field [0001] The invention relates to an electroplating method, in particular to a tinning method for SMD patch diodes. Background technique [0002] In the electronics industry, diodes have become the basic components of various electronic products. Traditional diodes have a pin at each end. When using it, you need to insert the pins of the diode into the holes on the circuit board so that the diode can be fixed in the circuit. board. However, at present, electronic products such as telephones, televisions, fax machines, computers and computer peripheral products all over the world are researched and developed with thinness, lightness and smallness as their research and development goals. Multi-layer circuit board technology cannot punch holes like traditional single-layer circuit boards, so the diode volume is required to be as small as possible. In order to adapt to the trend, some people invented SMD diodes (such as SMD series SMD diodes). Chip diodes are fi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L21/60
Inventor 顾坚
Owner CHANGZHOUSR SEA ELECTRONICS
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