4mil Smt PCB Assembly Service Pcb Manufacturing And Assembly

Our PCB Sevices:

1. PCB fabrication.

2. Turnkey PCBA

3. PCB+components

4. SMT and through-hole assembly

5. Pnclosure molding&housing

6. PCBA mass production

7. PCBA copy

8. PCB design

PCB Assembly(SMT) Product Capacity

The Printed Circuit Board Assembly (PCBA) Process

Transforming your design into the completed physical structure requires three steps: 1) fabrication, 2) component procurement and 3) assembly. Printed circuit board assembly or PCBA is one of the two PCB manufacturing processes. The other stage, fabrication, is performed first. During fabrication, your board design is constructed and prepared for assembly, where the components are securely attached to the board. Although PCBA may be comprised of ten or more steps, the process can be divided into the following major tasks:

Preparation
Before placing surface mount technology (SMT) components, an initial layer of solder paste is applied to the board’s pads. This is done to promote good flow during soldering and minimize assembly defects. The application method may be manual or automated using a stencil or jet printing.

Component Placement
For SMT components, accurate placement of components on pads is crucial. Misalignment can lead to bad solder joints or tombstoning, where one side of the component is not attached to the board. Through-hole technology (THT) components are more flexible; 

Soldering
The most common method for securing SMT components is reflow. For THT components, wave soldering is the preferred method. If both types of components are used, the SMT components are usually placed and soldered first. Only then are the THT components are placed and soldered, which extends the soldering task. Soldering is further extended for two-sided boards, as components are mounted on both the top and bottom surfaces. After the soldering step for each component type, the connections are inspected and if any issues are discovered, then rework is performed to correct them.

Cleaning
Cleaning is performed to remove any excess debris from the board’s surface(s). Alcohol or deionized water is effective at removing most contaminants.

Depanelization
Depanelization, which is the separation of the multi-board panel into individual units or PCBs, is the final major task and should not be overlooked. Inefficient panelization or panel design can result in significant waste and additional cost.