Processing instructions for Printed Circuit Boards

Following storage conditions aid avoiding an additional humidity absorbtion of PCBs and preserving an optimal solderability.

Recommended storage conditions:

• storage temperature 18-22° C
• relative humidity 30-50 %
• no direct sunlight
• no contact with the skin
• clean ambient air

Acceptable shelf life of PCB surfaces:

• HAL SnPb / lead-free: approx. 12 months
• immersion silver, gold: approx. 12 months
• immersion tin: approx. 6 months

General remarks:

• printed circuit boards shall remain in the protective transport packaging until assembly
• avoid contact of the PCB surface with the skin
• printed circuit boards, removed from its transport packaging, can be stored for a maximum of one week, if stored stacked between layers of chlorine-free paper

The processing of printed circuit boards demands a high degree of process stability.

Our printed circuit boards are already tempered during the manufacturing process, but neither delivery conditions (rain, temperature, etc.) nor storing conditions are optimal after dispatch.

For further processing, we therefore recommend a prior tempering of the printed circuit boards, especially after a longer storing period. This procedure raises the process stability considerably .

Accomplishment: Free-standing or horizontal in a circulating air oven.

Processing must take place directly after tempering (4 - 48 h), as the hygroscopic property of the base material persists.

Printed circuit boards with immersion tin surface react with a faster growth of the intermetallic phase to a higher temperature (artifical aging). This can have a negative impact on the solderability.

Therefore, we recommend you to cooperate with an experienced, skilful assembly partner when processing immersion tin surfaces.