plating, anodizing, & finishing Q&As since 1989
Au (gold plating) thickness problem
October 21, 2010
Hi! I'm Joven from Philippines. We used to have a reel-to-reel plating process here that our problem is mainly on Au thickness problem which is always changing, that we cannot control the uniformity on the product, which I mean on top part have low deposits and and bottom were high, or sometimes the other way..any idea how? our masking shield used here got some bubbles also inside the AU bath..neither I would think it is on our rectifier problem.
Your reply will be appreciated..thanks.
Plating Tech - Manila
October 24, 2010
Not sure if you're referring to acidic hard gold (e.g. gold-cobalt) or strike gold plating. If so, the cathode efficiency used to be low and significant amount of hydrogen gas will evolve around cathode.
Different thickness was due to uneven current distribution (high current density area will have higher plating thickness). Proprietary chemical suppliers used to add in additive to suppress plating rate at high CD area to narrow down thickness deviation between high and low CD region.