How to store printed circuit boards? When you receive circuit boards but do not put them in use at once, PCB storage is the thing you need to consider.
Part 1: Printed Circuit Boards Storage Conditions
Generally, PCB boards are in the environment of:
- Temperatures 12℃ to 40℃
- Humidity rate smaller than 75%RH
- No corrosive gas, sun, rain, dampness, heat, mechanical damage, heavy loads
Part 2: PCB Board Storage Time
The PCB storage time depends on the boards and their packages.
- Moisture-proof packaging: packaging using moisture-proof packaging materials and desiccant. Generally, if a humidity instruction card is inside the packaging, we consider it moisture-proof packaging.
- Normal packaging: packaging without a humidity card, such as bubble bags, corrugated packaging, etc.
|
PCB boards
|
Packaging
|
Storage time without rechecking
|
Maximum storage time
|
|
Heavy-copper PCB
|
Moisture-proof packaging
|
12 months
|
12 months
|
|
Heavy-copper PCB
|
Normal packaging
|
3 months
|
9 months
|
|
Normal PCB
|
Moisture-proof packaging
|
12 months
|
12 months
|
|
Normal PCB
|
Normal packaging
|
6 months
|
12 months
|
|
Aluminum PCB
|
Normal packaging
|
6 months
|
12 months
|
|
OSP PCB
|
Normal packaging
|
3 month
|
9 months
|
Below are the regulations regarding PCB storage time.
1. PCB boards stored beyond the maximum storage time are scrapped.
2. The storage time of the rechecked heavy-copper PCBs, normal PCBs, and aluminum PCBs lasts 3 months. When it reaches the storage time, PCBs should be checked again. PCBs can be rechecked for at most 2 times.
3. OSP (organic solderability preservative) PCBs should be returned to the PCB factory for recheck, and the packaging should be marked for a recheck.
Part 3: Can PCB Boards within Storage Time Be Soldered Without Processing?
It depends.
If PCBs have been stored for more than 6 months and are still within the maximum storage time, the PCB boards need to be baked before PCB assembly.
PCB baking depends on the storage time and surface finish types.
Below are some regulations about the baking of PCBs stored beyond 6 months.
|
PCB surface finish and storage time
|
Processing of PCB boards
|
|
Hard gold plating, 6 to 8 months
|
Baking at 130℃ for 3 hours + citric acid cleaning
|
|
Hard gold plated plating, 8 months to maximum storage time
|
Baking at 130℃ for 1 hour + citric acid cleaning
|
|
HASL or lead-free HASL, 6 to 8 months
|
Baking at 130℃ for 3 hours + water cleaning
|
|
HASL or lead-free HASL, 8 months to maximum storage time
|
Baking at 130℃ for 1 hour + water cleaning
|
|
Immersion silver, or immersion silver + gold plating, 6 to 8 months
|
Aluminum foil cover + baking at 120℃ for 2 hours
|
|
OSP, or OSP + gold plating, 6 to 8 months
|
Baking at 130℃ for 2 hours + OSP processing again + copper thickness check
|
|
OSP, or OSP + gold plating, 8 months to maximum storage time
|
Baking at 150℃ for 1 hour + baking at 110℃ for 4 hours + OSP processing again + copper thickness check
|
Part 4: One-Stop PCB Manufacturing with PCB Storage Processing Hassles
PCBONLINE is a one-stop advanced PCB manufacturer that leaves you no worries about PCB storage.
PCBONLINE, founded in 1999, provides PCB manufacturing, component sourcing, PCB assembly, PCB design, conformal coating, and box-build PCB assembly.
PCB manufacturing, components sourcing, PCB assembly, and tests are all completed under one roof.
One-on-one engineering support and free DFM, DFT, and DFX.
Reduce the project manufacturing costs from appropriate PCB design.
Spray conformal coating to lengthen the PCB lifespan and better storage condition.
From manufacturing to transportation, the whole process can be tracked, including PCB storage conditions.
PCBONLINE is an ISO, IATF, REACH, UL, RoHS certified PCB/PCBA manufacturer. If you have PCB needs and hate PCB storage issues, please feel free to contact PCBONLINE to provide hassle-free one-stop services.
Conclusion
We had better assemble printed circuit boards as soon as possible when they are manufactured. But if we can't because of electronic components shortage, project stranded, etc, PCBs should be properly stored for a while. If you don't want to experience PCB storage issues such as PCB expiration, recheck, baking, or return to work, please send your Gerber and BOM to the one-stop electronic manufacturer PCBONLINE by email at info@pcbonline.com.
