Optimizing Modified Semi-Additive Process Parameters for Sub-30 Micron Feature Generation
Sub-30 micron mSAP feature generation requires controlling seed layer thickness, LDI resist profiles, plating additive dynamics, and flash etch undercut.
IPC-TM-650 Peel Strength
Bond Tenacity
Mechanical testing of the adhesive force between a copper foil and its underlying dielectric substrate follows a standardized industry procedure. The ipc-tm-650 peel strength test determines the amount of force required to strip a wide trace from the laminate surface. This measurement is taken after the board has undergone thermal stress to simulate the conditions of a soldering cycle.
Test Execution
A specialized machine pulls a copper strip at a ninety degree angle while measuring the resistance in pounds per inch. The test must be performed on both the as received material and after the material has been exposed to chemicals or heat. Because thin traces are more likely to lift during rework, a high base peel strength is necessary for long term reliability.
If the foil separates too easily, the circuit traces may delaminate during the assembly process or while the device is in use.
Delamination Risk
Minimum values for this strength are specified by the laminate manufacturer and verified by the fabricator. High temperature resins and specialized copper treatments are used to enhance the bond for demanding applications. This test remains the primary way to verify that a material can withstand the thermal shocks of lead free soldering.