PCB News - How long can the PCB circuit board be stored, what is the baking time and temperature

How long can the PCB circuit board be stored, what is the baking time and temperature

After the PCB circuit board is manufactured, there will be a shelf life. If the shelf life is exceeded, the PCB board needs to be baked. Otherwise, it is easy to cause the PCB to burst when the PCB board is produced online in the SMT workshop. Let’s take a look at the editor from Shenzhen Circuit Board Factory!

The storage time of the PCB board, as well as the temperature and time of using the industrial oven to bake the PCB board are all regulated by the industry.

1. The specification of PCB circuit board management and control

1. PCB unpacking and storage

⑴PCB board sealed and unopened manufacturing date can be directly used online within 2 months;

⑵The PCB board manufacturing date is within 2 months, and the unpacking date must be marked after unpacking;

⑶ PCB board manufacturing date is within 2 months, after unpacking, it must be online and used within 5 days.

2. PCB board baking

⑴ If the PCB board is sealed and unpacked for more than 5 days within 2 months of the manufacturing date, please bake it at 120 ±5°C for 1 hour;

⑵If the PCB board is more than 2 months from the manufacturing date, please bake it at 120 ±5 degree Celsius for 1 hour before going online;

⑶If the PCB board is 2 to 6 months past the manufacturing date, please bake it at 120 ±5°C for 2 hours before going online;

⑷If the PCB board is 6 months to 1 year beyond the manufacturing date, please bake it at 120 ±5 degree Celsius for 4 hours before going online;

⑸The baked PCB must be used up within 5 days (put into the IR REFLOW), and the PCB must be baked for another hour before it can be used online after it is used;

⑹If the PCB is more than one year from the manufacturing date, please bake it at 120 ±5 degree Celsius for 4 hours before going online, and then send it to the PCB factory for re-spraying tin before going online.

3. PCB baking method

⑴Large circuit boards(16 PORTs and above, including 16 PORTs) are placed horizontally, a stack of up to 30 pieces, open the oven within 10 minutes after the baking is completed, take out the PCB, and lay it flat for natural cooling (pressing anti-plate bay fixtures)

⑵Small and medium-sized circuit boards(8PORT and below 8PORT included) are placed horizontally. The maximum number of a stack is 40 pieces. The number of vertical type is unlimited. Open the oven and take out the PCB within 10 minutes after the baking is completed. Bay fixture)

2. Storage and baking of circuit boards in different regions

The specific storage time and baking temperature of PCB circuit boards are not only related to the production capacity and production process of the PCB manufacturer, but also have a great relationship with the region.

The PCB made by OSP anti-oxidation process and pure immersion gold process generally has a shelf life of 6 months after packaging, and it is generally not recommended to bake for OSP process.

The preservation and baking time of PCB circuit boards have a lot to do with the region. In the south, humidity is generally heavier, especially in Guangdong and Guangxi. There will be "returning to the south" weather in March and April each year. It is rainy every day, and it is very humid at this time. PCB must be used up within 24 hours when exposed to the air, otherwise it is easy to oxidize. After normal opening, it is best to use it up in 8 hours. For some PCBs that need to be baked, the baking time will be longer. In the northern regions, the weather is generally dry, the PCB storage time will be longer, and the baking time can also be shorter. The baking temperature is generally 120 ± 5 degree Celsius, and the baking time is determined according to the specific situation.

For PCB storage time, baking time and temperature, specific problems need to be analyzed in detail, and specific choices need to be made on the basis of PCB management and control specifications, according to the production capacity, craftsmanship, region and season of different Shenzhen circuit board manufacturers.