Burning Phenomenon: Poor conductivity -> Device repair. Weak agitation -> Review spray pump settings / Nozzle cleaning, filter replacement. Poor adjustment of shielding plate -> Device repair. Low bath temperature -> Device repair. High current density -> Reduce current density. Low additive concentration -> Add additives. High additive concentration -> Dummy plating / Activated carbon filter tr..

Void Defect: Weak agitation -> Review spray pump settings / Nozzle cleaning / Filter replacement. Weak agitation accelerates detachment near the hole's opening, making voids more likely to form. If the nozzle and filter inlet are blocked, agitation weakens, leading to void formation. High current density -> Reduce current density. High current density accelerates detachment near the hole's openi..

Stripping: After electroplating, the photosensitive film DFR is removed using a dedicated stripping agent of Amin-based chemicals for fine circuit formation First, the dry film swells and strips Stripped dry film fragments cannot withstand internal pressure and break apart Residue on the bottom is removed through additional stripping spray process Improper stripping that leaves DFR behind can in..

Next, let's learn about the main mechanisms for each circuit fabrication process. Major Mechanisms for Each Circuit Fabrication Process Front Side - DFR Adhesion (Lamination) - Photolithography - Stripping - Etching - AOI Front Side: Removal of foreign substances from the substrate surface before adhering the photosensitive film DFR (Rinse - Acid Rinse - Rinse) DFR Adhesion (Lamination): Adhesio..

Continuing from our previous session, let's further explore the PCB drilling process. Drilling Process 1. Principles of Drilling Process The process of machining PTH (Plating Through Hole) for interlayer circuit connectivity in the stacked panels and NPTH (Non Plating Through Hole) for alignment marks and assembly of fixtures. CNC (Computer Numerical Control) Drilling involves the use of automat..

The key terms of the pressing process are as follows: Heating Rate: This refers to the speed at which heat is raised over a certain period. It is necessary for prepreg forming since heat is required for the process. 1st Step Heat: This is the point where actual prepreg forming occurs. The temperature at this point is determined using viscosity data. Appropriate pressure should be applied at this..