Design journal
High-temperature sensor interface board review
Review a high-temperature sensor interface PCB by separating sensed temperature, local board exposure, measurement error and interconnect requirements.
Design journal
Why online estimates need clear assumptions
Read PCB online estimates using an explicit assumption register, quantity basis and sensitivity example before comparing them with reviewed quotations.
Design journal
DFM review questions for a specialty PCB
Organize specialty PCB DFM findings by decision owner, affected requirement and closure evidence, with a worked hole-size conflict example.
Design journal
ENEPIG selection questions for mixed interconnects
Evaluate ENEPIG for boards combining solder joints and wire bonds by specifying each interconnect, thermal sequence and qualification evidence.
Design journal
Aspect ratio as a process review input
Calculate through-hole aspect ratio with an explicit diameter basis and use the result to frame drilling, plating and qualification questions.
Design journal
Low-flow versus no-flow terminology
Translate low-flow and no-flow prepreg terminology into measurable rigid-flex bond requirements, without assuming that no-flow means zero movement.
Design journal
Finished thickness versus nominal core thickness
Avoid PCB fit and impedance errors by separating core thickness, pressed dielectric spacing and total finished thickness with a worked tolerance budget.
Design journal
Polyimide versus epoxy for a thermally cycled assembly
Compare polyimide and epoxy PCB candidates using the actual thermal cycle, interconnect geometry and validation evidence, rather than Tg alone.
Design journal
A PCB fabrication drawing completeness audit
Audit a PCB fabrication drawing with a requirement-to-file matrix and a worked conflict example before releasing an Arlon board for manufacture.
Design journal
Bare-board requirements before assembly quoting
Prepare a polyimide PCB assembly review that covers material-specific handling, thermal history, moisture exposure and traceable release evidence.