45
off and use cleaning needle to clean the nozzle
3.
Current nozzle size is not suit to component , change another one
4.
Surface uneven on the component, replace with a qualified one
5.
Component is sticking to the bottom tape;
6.
Burrs on tape hole stuck component;
7.
Component’s pin get stuck in the corner of the den;
8.
Gap between components and tape package hole is not big enough , uncover the plastic tape
and upside down to check if the components can fall down or not.
9.
Plastic adhesive tape is too sticky or flimsy and then can not be unfolded. Or plastic adhesive
tape has been tore down from edge side.
10. Pick up position offset. Actual Feed box is offset from Feeding center,check X, Y, Z data and
do reprogram.
Placement offset
Solutions:
1.
Programming issue(some components’ positions are inaccurate),amend the coordinates;
2.
If all components are offset, please modify fiducials.
3.
The components’ thickness setting errors,modify components information on Footprint
Library
4.
Pick height is too high that causes components being dropped. Please reset the Pick Height
value
5.
Pick height is too low that causes slide problem during placement
6.
High speed issue. Lower the speed to achieve a more accurate rotation and placement effect.
5.2.4.Related issues during Solder paste printing process
1. Stencil Printing Technology
Screen printing technology refer to using ready-made stencil, directly contact to the printer in a
certain way, make the solder paste evenly flow on the stencil and then leak into the mesh through
the holes. When getting the stencil away, solder paste had been covered to the printed circuit board
solder graphics
corresponding, thus complete the solder paste printing on the PCB.
2.Inspecting of solder paste printing
Printing process is one of the key working procedure to ensure the quality of surface mounting.
According to the statistics,under the premise of guaranteed quality about components and
PCB,correctly PCB design, 70% of the surface quality problem caused during printing process. In
order to ensure the quality of SMT assembly, it is necessary to strictly control the quality of the
solder paste printing.
The amount of solder paste printing requirements are as follows:
