PCB Technical - Multi-layer PCB circuit board proofing process?

The purpose of multi-layer PCB proofing is to determine the strength of the manufacturer, to effectively reduce the defective rate of multi-layer PCB circuit boards, and to lay a solid foundation for future mass production. The following is a multi-layer PCB made by Shenzhen Lei Chuangda The circuit board proofing process will be explained for everyone.

Multi-layer PCB circuit board proofing process:

1. Contact the manufacturer

First, you need to inform the manufacturer of the documents, process requirements, and quantity, about "What parameters need to be provided to the manufacturer for multi-layer PCB circuit board proofing?", And follow up the production schedule.

2. Cutting

Purpose: According to the requirements of the engineering data MI, on the large sheets that meet the requirements, cut into small pieces of production board, and small pieces that meet the customer's requirements.

Process: large sheet - cutting board according to MI requirements - curium board - beer fillet\grinding - board out

Three, drilling

Purpose: According to the engineering data, drill the required aperture at the corresponding position on the sheet material that meets the required size.

Process: stacked board pin - upper board - drilling - lower board - inspection\repair

Fourth, sink copper

Purpose: Immersion copper is to deposit a thin layer of copper on the wall of the insulating hole by chemical method.

Process: rough grinding - hanging board - automatic copper sinking line - lower board - dip 1% dilute H2SO4 - thickened copper

Five, graphics transfer

Purpose: Graphic transfer is to transfer the image on the production film to the board.

Process: (blue oil process): grinding plate - printing the first side - drying - printing the second side - drying - exploding - shadowing - inspection; (dry film process): hemp board - pressing film - standing - right Position-Exposure-Standing-Development-Check

Six, graphic plating

Purpose: Pattern electroplating is to electroplate a copper layer with the required thickness and a gold-nickel or tin layer with the required thickness on the exposed copper skin of the circuit pattern or the hole wall.

Process: upper board - degreasing - second washing with water - micro-etching - washing - pickling - copper plating - washing - pickling - tin plating - washing - lower board

Seven, remove the film

Purpose: Use NaOH solution to remove the anti-plating coating film to expose the non-circuit copper layer.

Process: water film: insert rack - soak alkali - rinse - scrub - pass machine; dry film: release board - pass machine

Multi-layer PCB circuit board proofing process

Eight, etching

Purpose: Etching is to use chemical reaction to corrode the copper layer of non-circuit parts.

Nine, green oil

Purpose: Green oil is to transfer the graphics of the green oil film to the board to protect the circuit and prevent the tin on the circuit when welding parts.

Process: grinding plate - printing photosensitive green oil - curium plate - exposure - developing shadow; grinding plate - printing the first side - drying plate - printing the second side - drying plate

Ten, characters

Purpose: Characters are provided as a mark for easy identification.

Process: After the green oil finishes - cool and stand - adjust the screen - print characters - rear curium

Eleven, gold-plated fingers

1. Purpose: Plating a nickel/gold layer with the required thickness on the plug finger to make it more hard and wear-resistant.

Process: upper plate - degreasing - washing twice - micro-etching - washing twice - pickling - copper plating - washing - nickel plating - washing - gold plating

2. Tin plate (a process in parallel)

Purpose: Tin spraying is to spray a layer of lead tin on the exposed copper surface that is not covered with solder mask to protect the copper surface from corrosion and oxidation and to ensure good soldering performance.

Process: micro-erosion - air drying - preheating - rosin coating - solder coating - hot air leveling - air cooling - washing and air drying

12. Forming

Purpose: Organic gongs, beer boards, hand gongs, and hand-cutting methods are used to form the shapes required by customers through die stamping or CNC gongs.

Note: The accuracy of the data gong machine board and the beer board is high. The hand gong is second, and the minimum hand-cutting board can only make some simple shapes.

13. Test

Purpose: To pass electronic 100% testing to detect defects that affect functionality such as open circuits and short circuits that are not easy to find visually.

Process: upper mold - release board - test - pass - FQC visual inspection - unqualified - repair - return test - OK - REJ - scrap

14. Final inspection

Purpose: To pass 100% visual inspection of the board's appearance defects and repair minor defects to avoid problems and defective boards from flowing out.

Specific work flow: incoming materials - view information - visual inspection - qualified - FQA spot check - qualified - packaging - unqualified - processing - inspection OK!

Due to the high technical content of the design, processing and manufacturing of multi-layer PCB circuit boards. Therefore, only by accurately and rigorously doing a good job in every detail of PCB proofing and production, can we have high-quality PCB products. Win the favor of more customers and win a bigger market.