Pre impregnated material is a sheet-like material composed of resin and carrier. Among them, the resin is in the B-stage, under the action of temperature and pressure, it has fluidity and can quickly cure and complete the bonding process, and together with the carrier, forms an insulation layer. Commonly known as semi cured sheet or adhesive sheet. To ensure the high reliability and quality stability of multi-layer printed circuit boards, it is necessary to conduct quality testing on the characteristics of semi-solid chips (test layer pressing method). The characteristics of electroplating semi cured chips on circuit boards include two parts: pre lamination characteristics and post lamination characteristics. The characteristics before lamination mainly refer to: resin content%, fluidity%, volatile content% and gel time (S). The circuit board prototype manufacturer will share with you the characteristics after lamination, including electrical performance, thermal shock performance, and flammability. Therefore, in order to ensure the high reliability of multi-layer printed circuit boards and the stability of lamination process parameters, it is very important to detect the characteristics of the pre lamination printed circuit board electroplating semi cured sheets.

1. Determination of resin content (%): (1) Preparation of test piece: Cut into 100 pieces at a 45 ° angle according to the fiber direction of the circuit board electroplated semi cured sheet × 100 (mm) small test block;

(2) Weighing: Use a 0.001 gram balance to weigh Wl (grams);

(3) Heating: Heat and burn at a temperature of 566.14 ℃ for 60 minutes, then weigh W2 (grams) after cooling;

(4) Calculation: W1-W2 resin content (%)=(W1-W2)/W1 × one thousand and two

Quality inspection method for electroplating semi cured sheets of circuit boards

Determination of resin flow rate (%): (1) Preparation of test piece: Cut the fiber direction of the electroplated semi cured sheet of the circuit board into 100 pieces at a 45 ° angle × 100 (mm) pieces of approximately 20 gram test pieces;

(2) Weighing: Use a 0.001 gram balance to accurately weigh W1 (grams);

(3) Heating and pressurization: Adjust the temperature of the heating plate of the press bed to 171 ± 3 ℃. When the test piece is placed in the heating plate, apply a pressure of 14 ± 2Kg/cm2 or more, heat and pressurize for 5 minutes, cut off the flowing glue and weigh W2 (grams);

(4) Calculation: Resin flow rate (%)=(W1-W2)/W1 × one thousand and three