| SMT Assembly Procedure | |||||||
| Step 1. Materials Preparation | |||||||
| All components in BOM list,PCB bare boards, and stencils will be inspected before SMT assembly. All of these materials are from our long-term reliable supply chain with good quality. Bare boards and components will be baked in the oven in order to keep the excellent assembly effect when necessary. | |||||||
| Step 2. Solder Paste Printing | |||||||
| The solder paste are used to connect the components with the pads on PCB boards, and they play a very important role in SMT assembly quality control. Therefore we will inspect it before SMT procedure. And we use automatic solder paste printer to improve production efficiency, reduce defective rate and rework cost. | |||||||
| Step 3. SMT Placement | |||||||
| The printed bare boards are put into the pick& place equipments then the JUKI automatic high-speed machines will place the components on pads printed with the solder paste. The placement speed 42,000CPH. Maxim PCB size is 650mm*370mm. | |||||||
| Step 4. Reflow Soldering | |||||||
| The PCBs are put into the reflow soldering oven and the electronic components will be firmly fixed on the pads of boards. Our reflow soldering oven has 8 temperature zones and we always apply different temperature profiles for different projects.After pick & place machines, the PCBs are put into the reflow soldering oven where the solder paste will melt and solidify and the electronic components will be firmly fixed on the pads of PCB boards. PCBbee's reflow soldering ovens have 10 temperature zones and we always design and apply different temperature profiles for different PCBA projects. | |||||||
| Step 5. First article Inspection | |||||||
| After step 4, we will proceed the first article inspection which can find whether it is 100% consistent with the customer's request and whether the components are placed properly or not. We can find the problem in the first article inspection in order to guarantee the batch assembly 100% correct and reduce the rework cost and time. | |||||||
| Step 6. Automated Optical Inspection (AOI) | |||||||
| All PCB boards will be tested by AOI equipments after SMT production finished. It can effectively find the polarity errors, leaks, deviations, damage, empty soldering etc. It is a very critical step to ensure the quality control of SMT production. | |||||||
| Step 7. X-Ray Testing | |||||||
| As for the boards with BGA, CSP, LGA,QFP components etc, we usually use X-Ray tester to monitor the SMT assembly production process. It can find the soldering problems and prevent the occurrence of open circuit, short circuit, leaks etc. |
