Quality Related
Quality Related
Liang Dar's recommended baking methods in the finished product inspection specification are shown in the table below.
Surface Finishing | Not Yet Unpacked Preservation Period | Baking Temperatures After Expiry (℃) | Recommended Baking Time (HR) | Attention |
Immersion Sn | 6 months | 105 ~ 125℃ | 4 ~ 6 hrs | Baking can affect solderability and it is suggested to conduct solderability tests after baking. |
Immersion Ag | 3 months | 105 ~ 125℃ | 4 ~ 6 hrs | Baking in an environment contaminated with sulfur or chloride can lead to corrosion. Ensure the oven is clean from such contaminants. |
Electroless Nickel Immersion Gold (ENIG) | 12 months | 105 ~ 125℃ | 4 ~ 6 hrs | Oxidation may penetrate the thin gold layer and oxidize the nickel layer. Baking in a low-oxygen environment, such as a vacuum or an inert gas like nitrogen, helps prevent oxidation. |
Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG) | 12 months | 105 ~ 125℃ | 4 ~ 6 hrs | |
Organic Solderability Preservative (OSP) | 6 months | 105℃ | 1 hr | Non-stacking baking method |
Hot Air Solder Leveling (HASL/HAL) | 12 months | 105 ~ 125℃ | 4 ~ 6 hrs | Tin thickness being less than 0.77 µm (30 µ") may lead to intermetallic compound (IMC) formation and impact PCB solderability. |
Refer to IPC-A-600 2.1.3 guideline (See attached image): The product is considered acceptable without penetrating more than 50% of the distance to the closest conductor or 2.5mm whichever is less.
- Tin lead – 235 ± 5 ℃, 5 ± 1sec。
- lead-free – 255 ± 5 ℃, 5 ± 1sec。
- More than 95% of the PAD surface has good wetting properties
- The durability of IPC Class 1,2 and A surface coatings - Solder shall fully wet the wall area of the plated through holes, and plug holes less than 1.5 mm diameter.
- The durability of IPC Class 3 and B Surface Coatings - The solder shall have fully wetted the walls of the hole. There shall be no non-wetting or exposed base metal on any plated-through hole.
See J-STD-003C Figure 4-4 for effectiveness of solder wetting of plated through holes – Class 3 below 3.0 mm.
See J-STD-003C Figure 4-5 for effectiveness of solder wetting of plated through holes - Class 3 below 3.0mm.
A. Acceptable conditions B. Defective conditions