表面处理工艺对比
表面处理工艺直接影响电路板的成本、可制造性、品质与可靠性。以下对比 Sunking 提供的各类工艺。
表面处理是 PCB 制造的最后工序之一，用于防止裸铜氧化并提供可焊接表面。选择合适的工艺是一项关键的材料决策。若不确定哪种工艺适合您的项目，欢迎联系我们协助选型。
| 特性 | HASL | HASL (LF) | ENIG | ENEPIG | HARD GOLD | SOFT GOLD | SILVER | OSP | WHITE TIN |
|---|---|---|---|---|---|---|---|---|---|
| 沉积方式 | Dipped | Dipped | Immersion | Immersion | Electrolytic | Electrolytic | Immersion | Dipped | Immersion |
| 工艺控制 | Poor | Poor | Fair | Fair | Fair | Fair | Fair | Poor/Fair | Fair |
| 工艺成本 | Low | Low | Medium | High | High | High | Medium | Low | Medium |
| 焊盘平整度 | Dome | Dome | Flat | Flat | Flat | Flat | Flat | Flat | Flat |
| 薄板适用 | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| 热循环次数 | 2 | 3 | 2 | 2 | 2 | 2 | 2 | ~2 | 2 |
| 储存期 | 1+ yr | 1+ yr | 1+ yr | 1+ yr | 1+ yr | 1+ yr | 9-12 mo* | 9-12 mo* | 9-12 mo* |
| 操作要求 | Normal | Normal | Normal | Normal | Normal | Normal | Critical | Critical | Critical |
| 露铜 | No | No | No | No | Yes | No | No | Yes | No |
| RoHS 合规 | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| 细间距 SMT | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| BGA & μBGA | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| 倒装芯片 (Flip Chip) | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| 引线键合 (Wire Bonding) | No | No | Yes (Al) | Yes | No | Yes (Au) | No | No | No |
| 接触 / 连接器 | No | No | Yes | Yes | Yes | No | No | No | No |
| 可靠性 | High | Low/Med | High | High | Med/High | High | Med/High | Med/High | High |
| 焊点完整性 | Excellent | Good | Good | Good | Poor | Poor | Excellent | Good | Good |
| 厚度 | 25–2000 μin | 25–2000 μin | 3–10 μin Au / 150–200 μin Ni | 1–2 μin Au / 8–15 μin Pd / 100–150 μin Ni | 30–50 μin Au (23K) / 100–150 μin Ni | 30–50 μin Au (24K) / 100–200 μin Ni | 6–18 μin | 8–24 μin | 25–60 μin |
μin = 微英寸。* 需特殊储存条件。表中为典型值，具体项目请咨询我们。