Surface treatments cover all areas with exposed copper to protect the solder pads from oxidation or to improve signal transmission on the board. We have our own lines for all common surface treatments ENIG, immersion tin, LF HAL, PbSn HAL, galvanic Au. For other surface treatments we can use external specialists.
A traditional PCB surface treatment that continues to find significant application despite its limitations is HAL (Hot Air Solder Levelling). Gatema PCB offers both HAL with lead solder (Pb37Sn63) and ROHS compliant tin solder (Sn99+). The solder is regularly regenerated and its composition is verified by OES directly at the supplier.
Immersion silver has best usage in HF applications. Because of missing Nickel is ideal for high frequency signals. Silver is better conductor than Au or Cu. It is easily solderable finish – IAg thickness is only 0,1 µm so even flatless is great. Silver is better conductor than Au or Cu. It is easily solderable finish – IAg thickness is only 0,1 µm so even flatless is great. Because of this characteristics it is commonly used for high construction classes of the printed boards too.
Gold is an ideal element for top PCB cover. Given that gold doesn´t form oxides, the temperature and storage conditions have nearly no effect on its durability or condition compared to other finishes. Excellent adhesion is result of practically instant dissolution of gold into the solder. Nickel layer needs to be coated between copper and gold layers to prevent their mixing and therefore causing problems with soldering. This finish is suitable for AI wire bonding.
Chemical tin bath excludes thin and even layer of pure tin selectively on copper surface and in plated holes. Tin layer acquired by this process meets all modern final PCB´s finish requirements.
