PCB Board production Process And Information Introduction

PCB Board production Process And Information Introduction

I. Overview

Printed circuit board (board referred to as PCB) is to concentrate the connection of ordinary electronic circuit components on a substrate, thereby improving reliability and wiring density, and also serving as the physical carrier of electronic components.

The PCB board is generally composed of a conductor layer () and an insulating layer (), and each conductor layer is electrically connected through the usual metal hole (Via hole). According to the number of conductor layers, PCB can be divided into single-sided (-side), double-sided (-side) and multi-layer () boards.

PCB circuit board production process

2. Basic process

Single panel: cutting ()→drilling () or beer hole ()→D/F→etching ()→green oil (S/M)→white (C/M)→surface treatment→forming ()→ET → FQC → Packing () → Shipment

Double-sided panel: cutting → drilling → PTH → panel (Panel) → D/F → graphic ( ) → etching → post-single-sided process

Multi-layer board: cutting → inner circuit (Inner D/F) → Brown oxide → pressing () → molding (Inner) → the same double-panel process

Water gold board process: material cutting→drilling→PTH→board electricity→water gold copper plating+nickel gold plating→etching board→after the same double-sided board process

3. Process introduction

1. Inner line

Process purpose: to form circuit graphics for each inner layer before lamination.

The basic process is: internal D/F → etching → film removal

2. Browning

Purpose of the process: to form a microscopically rough surface on the copper surface of the circuit diagram.

The basic process is: pretreatment→browning→dry board

3. Lamination

Purpose of the process: Laminate conductive layers and insulators into semi-finished products that meet MI requirements

Basic process: pre-processing→stacking→pressing→folding→forming

4. Drilling

Process purpose: to form a certain size and number of through holes or blind holes on the board

Basic process: Drill belt inspection → upper board → trial drilling → first inspection → drilling → inspection

Drilling method: a. Mechanical drilling

b. Laser drilling

5. Immersion Copper

The purpose of the process: to deposit a layer of 0.3-0.5um copper on the hole wall through a chemical reaction, so that the hole wall has conductivity. It is also called electroless copper plating and hole metallization.

Basic process: Coarse grinding → (remove slag) → degreasing → micro-etching → pre-soaking → activation → acceleration → copper cylinder → plate electric → fine grinding → copper inspection

6.D/F

Purpose of the process: transfer the circuit diagram line to the copper surface

Basic process: Grinding → Film → Exposure → Development → Leakage

7. Graphic plating

Process purpose:

a. Thicken the copper plating layer in the hole to ensure good conduction and high reliability;

b. Plating resist layer to prepare for subsequent etching process.

Basic process: pre-treatment → copper plating → tin plating → lower plate → fried sticks

8. Etching

The purpose of the process: to etch away the excess copper layer, and then form the circuit pattern required by the customer

Basic process: D/F stripping→etching→tin stripping→etching inspection Immersion Ni-gold plate needs via hole treatment and immersion before etching

9. Green Oil

The purpose of the process: a. Make the circuit board form a solder mask layer

b. Prevent the copper oxidation of the line

Basic process: pre-processing → screen printing → pre-baking → exposure → development → curing → green inspection

Waterfall method: a. Screen printing

b. Cord coating

c. Electrostatic spraying

10. White characters

Purpose of the process: use heat-curable white ink to print symbols representing each component at the corresponding position on the surface of the W/F PCB board, so that the insertion and placement of components can be clearly marked, and it is convenient to insert and mount components to avoid wrong installation and leakage. Pack.

Basic process: board entry→oiling→silk printing→curing→inspection

C/M process type: a, white silk screen printing

b. Blue glue screen printing

c, carbon oil screen printing

11. Surface treatment

The purpose of the process: to cover the surface of the holes and pads of the plug-in and patch with a layer of solderable plating or coating to prevent the oxidation of the copper surface and protect the solderability.

Surface treatment type (factory):

a, HASL, also known as hot air leveling (HAL)

b. Immersion nickel gold, also known as nickel gold (ENIG)

c. Immersion Silver (Ag)

e, anti-oxidation, also known as OSP

Introduction of various surface treatments

Thick gold plating (including G/F plating)

The process of thick gold plating is different from other surface treatments. The position of thick gold plating is generally not used as a welding basis, but as a plug connection interface, which requires high wear resistance and corrosion resistance, and has a certain hardness. .

Basic process: pre-treatment → nickel-plated gold → gold-plated

The G/F plating process also includes blue glue and flying wing grinding wheel grinding steps, and some thick gold plating also includes the second D/F process.

Hallet tin

Basic process: pre-treatment→preheating→passing rosin→spraying tin→spraying tin→washing plate→inspection (for spray tin plate with G/F, red glue is required before HAL→cold reel→baked plate→hot reel step)

Immersion Nickel Gold

Basic process: grinding plate→pretreatment→pre-soaking→activation→immersion nickel→immersion gold→anti-oxidation→dry plate→inspection

Immersion tin

Basic process: Grinding board→Pretreatment→Low temperature tin→High temperature tin→Alkaline washing→Water washing→Dry board→Inspection

The general process of immersion tin plate is to immerse tin after forming

Antioxidant

Basic process: pre-treatment → anti-oxidation immersion → dry plate → inspection

The anti-oxidation process is anti-oxidation after molding

Gold-plated surface

Basic process: pretreatment→copper plating→nickel plating→gold plating→etching plate→inspection

12. Molding

Purpose of the process: use mechanical action to process the board into the dimensions required by the customer.

Type: a, beer board

b. Gong board

A. Beer board process: beer mold inspection → mold installation → beer test → first inspection → beer board → edge grinding → board washing

B. Gong plate process: gong belt inspection → plate loading → gong test → first inspection → gong plate → washing plate

13.ET

Purpose of the process: Check whether the electrical performance of the PCB board meets the customer's requirements.

Type: a, OPEN/Short test

b. Impedance test

14. FQC

Purpose of the process: final inspection of the appearance of the product , circuit board production , to prevent leakage of defective products to the customer

15. Packaging

Process purpose: According to the storage and transportation of different types of boards for different customers, it is required to use different materials and different methods for packaging circuit board production , so as to protect and maintain the original properties of PCB to the greatest extent.

Basic process: sub-board → packing → boxing → packing