What are the common reasons for shifting SMT chip processing components?
The reasons for different package shifts are common. The common reasons are:
(1) The reflow soldering furnace has too high wind speed (mainly occurs on the BTU furnace, and small and high components are prone to displacement).
(2) Transmission rail vibration and placement machine transmission (heavy components)
(3) The pad design is asymmetrical.
(4) Large size pad lift (SOT143).
(5) Components with small pins and large spans are easily tilted by the surface tension of the solder. The tolerance for such components, such as SIM cards, pads or stencil windows, must be less than the component lead width plus 0.3 mm.
(6) The size of the components at both ends is different.
(7) The components are unevenly stressed, such as the package's anti-wetting thrust, positioning holes or mounting slot.
(8) There are components that are prone to venting, such as tantalum capacitors.
(9) Solder pastes with high activity are not easily displaced.
(10) Any factor that can cause a license will cause a shift.
Handle for specific reasons.
The components show a floating state due to reflow soldering. If you need accurate positioning, you should do the following:
(1) Solder paste printing must be accurate and the stencil opening size should not be more than 0.1mm wider than the component leads.
(2) Properly design the pads and mounting locations so that the components can be automatically calibrated.
(3) When designing, the matching clearance of the structural member is appropriately enlarged.
The above is the industry consultation provided by smt patch processing factory Shenzhen Pengzexiang Technology Co., Ltd., I hope to help you! Please contact us if necessary: http://www.oem-pcb.com email@example.com