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PCB circuit board production process
Cutting - inner layer graphics - lamination - drilling - electroplating - outer layer - solder mask - surface treatment - forming - electrical testing - FQC - FQA - packaging - finished product
Solder mask
principle:
The pre-treated PCB board is printed on the board surface through the screen, and under a certain temperature, time and air volume, the solvent in the ink is initially volatilized, and then the film is used to meet the needs of the customer. The pads and holes are protected from exposure, and the ink that has not reacted with the UV light is dissolved during development, and finally the pads and holes that the customer needs to solder are obtained.
The role of solder mask:
1, beautiful; 2, protection; 3, insulation; 4, anti-welding; 5, acid and alkali resistance
Production Process:
Grinding plate - silk screen soldering - pre-bake - exposure - development - PQC inspection - post-cure - the next process
Text
principle:
Under a certain force, the character ink required by the customer is screened on the surface of the PCB through a mesh of a certain number of meshes to form a character pattern, and information is provided for component mounting and future maintenance of the PCB.
Production Process:
Check the LOT card to determine whether silk screen characters and character production requirements are required - select the character ink to open the oil according to the LOT card requirements - check whether the character network is qualified and repair with the mesh - change the cycle according to MI requirements - lock the screen in Manual screen printing machine on the stage - alignment - printing the first board - first board OK after batch printing - oil collection - cleaning the screen version from the machine to remove the screen version temporarily placed in the relevant area
Character ink type:
The character ink is a thermosetting ink. When it is thermosetting, it is difficult to clean it with strong acid and alkali.
Common defects:
Character on the PAD; character film paste; characters do not oil; board sticky characters.
Surface treatment
Common surface treatment:
Lead-spray tin; lead-free spray tin; sinking gold; sink tin; sinking silver; anti-oxidation (OSP); electric gold; plug gold-plated fingers
A, production process:
Micro-etching - washing - coating flux - spray tin - air bed cooling - hot water washing - washing - drying PQC inspection - the next process
B, alloy solder melting point comparison:
Lead solder has a melting point of 183 ° C (Sn63/Pb37)
Lead-free solder has a melting point of 217 ° C (Sn / Cu / Ni)
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