SMT process introduction

10 Oct SMT process introduction

SMT production process:

1. Programmable placement machine

According to the sample BOM patch position map provided by the customer, program the coordinates of the location of the patch components. Then carry out the first piece with the SMT chip processing data provided by the customer.

2. Printing solder paste

The solder paste is stenciled to the PCB board where the electronic component SMD needs to be soldered to prepare for the soldering of the components. The equipment used is a screen printing machine (printing machine), which is located at the forefront of the SMT chip processing production line.

3. SPI

Solder paste detector, detects whether the solder paste printing is a good product, whether there is less tin, leaking tin, more tin and other undesirable phenomena.

4. Patch

Accurately install the electronic components SMD on the fixed position of the PCB. The equipment used is a placement machine, which is located behind the screen printing machine in the SMT production line.

5. High temperature solder paste melts

Mainly, the solder paste is melted at high temperature, and after cooling, the electronic components SMD and the PCB board are firmly welded together. The equipment used is a reflow soldering furnace, which is located behind the placement machine in the SMT production line.

6. AOI

Automatic optical detector to detect whether the welded components have poor welding, such as tombstone, displacement, empty welding, etc.

7. Visual inspection

The key items of manual inspection and inspection: whether the PCBA version is the changed version; whether the customer requires components to use substitute materials or components of designated brands and brands; IC, diodes, transistors, tantalum capacitors, aluminum capacitors, switches, etc. Whether the direction of the directional components is correct; defects after welding: short circuit, open circuit, fake parts, fake welding.

8. Packaging

Products that have passed the test will be packaged separately. The commonly used packaging materials are anti-static bubble bags, electrostatic cotton, and blister trays. There are two main packaging methods, one is to use anti-static bubble bags or electrostatic cotton into rolls, which are the most commonly used packaging methods at present; the other is to customize blister trays according to the size of PCBA. Put it in a blister tray and unpack it, mainly for PCBA boards that are sensitive and have vulnerable patch components.