Flexible PCB SMT Stencil fixture

FPC is also called flexible circuit board. Flexible circuit board is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film, referred to as flexible PCB or FPC, it has the characteristics of high wiring density, light weight and thin thickness. Mainly used in mobile phones, notebook computers, PDAs, digital cameras, LCM and many other products.

Compared with the traditional rigid board, flexible is the biggest feature of FPC. The flexible circuit board is not well aligned when the SMT, therefore, a carrier fixture will be made to fix the FPC to complete the silk screen printing, mounting, reflowing etc. processing processes.

Carrier fixture is required to fully support FPC, which can be reused, high temperature, no deformation, poor thermal stress, workability, and large size. At the same time, the design of the tool requires precise positioning and convenient operation. There are three main materials:

1. Durostone, the scientific name of glass fiber reinforced plastic, is characterized by excellent high temperature resistance, continuous working temperature up to 350 °C, instantaneous maximum temperature resistance up to 400 °C, heat transfer rate is very low, can relieve the intense impact of heat on FPC, at the same time, it can conduct heat out to reduce heat stagnation, it is made of special resin and can withstand cyclic thermal shock, it can be used continuously at working temperature.

2. Bakelite, chemical name is phenolic plastic, has good insulation, corrosion resistance, and lower cost, but its high temperature heat resistance is poor, easy to deform when repeated use.

3. Aluminum plate, low cost, high heat absorption, but poor process ability.

In comparison, durostone though has higher cost, but its good performance and reusable frequency are the best choice for SMT carrier fixture in high-end FPC products under double-sided reflow process.