Using SMT to Assembly PCB needs following steps:

1st Step: Solder Paste Application

Eternity EMS uses stencil to apply the solder paste.

We have a stencil made with openings or apertures the size and shape of the surface mount pads on your design. These stencils are often laser cut for precision and can be built from a variety of materials at different widths depending on the components to be soldered and the amount of paste required. The stencils can be plated and coated with materials that will make the aperture openings smooth and help with the even application of the paste. A squeegee is used to spread solder over the stencil and fill all of the apertures evenly in an operation that typically takes 16 to 46 seconds per board. Once the printing process is complete, the board is inspected with optical scanning equipment to verify the quality of the applied solder paste.

We use the lead-free and no-wash solder paste, which is eco-friendly and with high production efficiency.

2nd Step: Component Placement

There are 3 primary attributes that shall be considered in the component placement system: accuracy, speed and flexibility. Accuracy involves the aspects of resolution, placement accuracy and repeatability. Speed involves the aspects of equipment placement rate, de-rating strategy and production through-put. Placement rate is determined by machine type and the distance between components on a board. Flexibility involves the aspects of component variety, number of feeders and PCB size range.

The pick and place machine is often the most important piece of manufacturing equipment for placing components reliably and accurately enough to meet throughput requirements in a cost-effective manner.

Our pick and placement machine are industry-leading brands like YAMAH* and FUJ*, which supports us to provide manufacturing service to the PCBA of AMT machine and communication base.

3rd Step: Reflow Soldering

Circuit board assemblies need to be preheated to activate the flux in the solder paste. Then they need to be heated at a higher temperature to reflow the solder. A cooling step follows that allows the solder to solidify.

The preheating, heating and cool down cycles in the reflow machine are defined by the thermal profile.

4th Step: Electrical Testing

We can run a series of testing like reliability test ( temperature and humidity test, vibration test, drop test) and function test for PCBA and final assembled electronic product.

Based on 16 years in electronics manufacturing experience in the fields of Telecom, smart device, financial equipment, new energy, industrial control, automotive and medical products, we provide PCBA and box build manufacturing service to brands including Fortune Global 500 companies.

http://www.eternity-em.com/