Part of the rigid-flex circuit board resource.
Do not use a universal bake recipe
Moisture handling depends on the material stack, finish, component population, storage history, and assembly process. A temperature and duration copied from another board may be inappropriate. Request the proposed supplier instructions for the actual construction and resolve conflicts with component or finish limits before heating a finished assembly.
Document storage and exposure
Record packaging condition, receipt date, storage environment, and the exposure period relevant to the assembly plan. Identify whether moisture-control packaging or other handling requirements apply to the proposed materials. Avoid assuming that an unopened package alone proves the circuit is ready for any reflow profile.
Review all parts of the stack
The flexible dielectric, coverlay adhesive, rigid bonding materials, and any stiffener adhesive can behave differently. Local construction changes may affect the process. Thermal properties on one laminate datasheet do not automatically establish limits for all interfaces or for the finished assembly.
Separate prevention from diagnosis
A bake may be a specified conditioning step, but it is not a universal repair for a manufacturing defect. If delamination or damage occurs, preserve samples and process records. Review moisture history, stack construction, reflow exposure, and inspection findings before assigning a cause.
Release a controlled handling instruction
Agree storage, conditioning when required, maximum exposure, reflow limits, and handling responsibility with the board and assembly partners. Include the instruction revision with the build records. Check that the planned process also fits the mounted components and test sequence.
Continue with the design guidelines, assembly review, prototype plan, or project RFQ.