- 15
- Nov
PCB pressing common problems
PCB 緊迫的常見問題
1. White, revealing the texture of the glass cloth
問題原因:
1. The resin fluidity is too high;
2. The pre-pressure is too high;
3、加高壓的時機不對;
4、粘合片樹脂含量低,膠凝時間長,流動性好;
解決方案:
1、降低溫度或壓力;
2. Reduce pre-pressure;
3、貼合時仔細觀察樹脂流動情況,待壓力變化和溫度升高後,調整開始施壓時間;
4. Adjust the pre-pressure\temperature and the start time of high pressure;
二、起泡、起泡
問題原因:
1、預壓低;
2、溫度過高,預壓與全壓間隔過長;
3、樹脂的動態粘度高,加滿壓的時間來不及;
4. The volatile content is too high;
5、粘接面不干淨;
6. Poor mobility or insufficient pre-stress;
7、板溫低。
解決方案:
1、增加預壓;
2、降溫、增加預壓或縮短預壓週期;
3. The time-activity relationship curve should be compared to make the pressure, temperature and fluidity coordinate with each other;
4. Reduce the pre-compression cycle and reduce the temperature rise rate, or reduce the volatile content;
5、加強清洗處理的操作力度。
6. Increase the pre-pressure or replace the bonding sheet.
7、檢查加熱器是否匹配,調整燙印機溫度
3、板面有凹坑、樹脂、皺紋
問題原因:
1、LAY-UP操作不當,未擦乾的鋼板表面有水漬,導致銅箔起皺;
2、壓板時板面失去壓力,造成樹脂流失過多,銅箔下缺膠,銅箔表面起皺;
解決方案:
1、仔細清潔鋼板,將銅箔表面抹平;
2、排版時注意上下板與版面對齊,降低操作壓力,使用低RF%薄膜,縮短樹脂流動時間,加快加熱速度;
Fourth, the inner layer graphics shift
問題原因:
1、內紋銅箔剝離強度低或耐溫性差或線寬太細;
2. The pre-pressure is too high; the dynamic viscosity of the resin is small;
3、壓機模板不平行;
解決方案:
1、改用優質內層覆箔板;
2、降低預壓或更換膠紙;
3. Adjust the template;
Five, uneven thickness, inner layer slippage
問題原因:
1. The total thickness of the forming plate of the same window is different;
2. The accumulated thickness deviation of the printed board in the forming board is large; the parallelism of the hot-pressing template is poor, the laminated board can move freely, and the entire stack is off the center of the hot-pressing template;
解決方案:
1.調整到相同的總厚度;
2、調整厚度,選擇厚度偏差小的覆銅板; 調整熱壓膜板的平行度,限制層壓板的多響應自由度,力求將層壓板放置在熱壓模板的中心區域;
六、層間錯位
問題原因:
1、內層材料的熱膨脹和粘合片的樹脂流動;
2. Heat shrinkage during lamination;
3、層壓材料與模板的熱膨脹係數相差較大。
解決方案:
1、控製膠粘片的特性;
2、板材已預先熱處理;
3.使用尺寸穩定性好的內層覆銅板和粘合片。
七、板材曲率、板材翹曲
問題原因:
1. 不對稱結構;
2、固化週期不足;
3. The cutting direction of the bonding sheet or the inner copper clad laminate is inconsistent;
4、多層板採用不同廠家的板材或粘合片。
5、多層板後固化、洩壓處理不當
解決方案:
1. Strive for symmetrical wiring design density and symmetrical placement of bonding sheets in lamination;
2、保證固化週期;
3. 力求切割方向一致。
4. 有利於在組合模具中使用同一廠家生產的材料
5. The multilayer board is heated to above Tg under pressure, and then kept under pressure and cooled to below room temperature
八、分層、熱分層
問題原因:
1. High humidity or volatile content in the inner layer;
2. High volatile content in the adhesive sheet;
3. Pollution of the inner surface; pollution of foreign substances;
4. The surface of the oxide layer is alkaline; there are chlorite residues on the surface;
5、氧化異常,氧化層結晶過長; 預處理沒有形成足夠的表面積。
6. Insufficient passivation
解決方案:
1. Before lamination, bake the inner layer to remove moisture;
2、改善存儲環境。 膠紙從真空乾燥環境中取出後,必須在15分鐘內用完;
3、改進操作,避免接觸粘接面有效面積;
4、加強氧化操作後的清洗; 監測清洗水的PH值;
5、縮短氧化時間,調整氧化液濃度或操作溫度,增加微蝕,改善表面狀況。
6.遵循工藝要求