Printed Circuit Board
Purpose：Metallographic cross-sectioning is performed to examine voids, intermetallic compound (IMC) layers, and other potential defects in PCB solder joints. The specimen is prepared by sectioning using the Table Cut 200 automatic flatbed cutting machine, cold mounting with TJ2226 cold mounting resin, and grinding and polishing using the Alpha 610 automatic grinding and polishing machine. The detailed sample preparation procedure is described in the following preparation method.
Basic Guide：
Cutting：1.For PCB samples, select a DP electroplated diamond cutting wheel. The specific wheel specification should be selected according to the Trojan Cutting Guide.
2.Select non-pulse mode for cutting. The recommended maximum cutting speed is ≤ 0.25 mm/s.
Mounting：Mount the specimen using vacuum impregnation in combination with a high edge-retention cold mounting resin.
Grinding：1.Method 1：Grind with abrasive papers starting from P400 to approach the edge of the target area, use P1200 to grind to the target position, and perform fine grinding with P2000 and P4000.
2.Method 2:Grind with metallographic grinding papers starting from P400 until reaching the edge of the target area.
3.Continue fine grinding using a POS disc in combination with 9μm PD-WT polycrystalline diamond suspension, grinding to the target position.
4.After each grinding step, thoroughly clean the specimen, specimen holder, and hands.
Polishing：1.Before starting polishing, the polishing cloth, specimen holder, and hands must be thoroughly cleaned. This cleaning procedure shall be repeated after each subsequent polishing step.
2.Polishing discs used with different abrasive particle sizes must not be mixed.
3.After polishing, rinse the specimen with alcohol and dry the surface using a blower to remove residual water stains.
4.After each polishing step, examine the specimen under a metallurgical microscope to verify that the scratch size corresponds to the polishing particle size and that the scratches are randomly oriented.
5.After use, polishing cloths should be thoroughly cleaned with running water and a soft brush, drained, and stored properly.
6.Polishing cloths used for PCB samples shall be dedicated exclusively to PCB polishing and must not be used for polishing specimens of other materials.
