Shields on White Goods

Challenge

Etch silicon and silicon oxides deposition from aluminum thin film coating system shields.

 

Deposition

Silicon and Silicon Oxides

 

Substrate 

Aluminum

 

Results

We were able to protect the aluminum substrate coating shields and remove the silicon and silicon oxides that are deposited. 

 

One of our clients, involved in cleaning precision parts, asked us to demonstrate a process of etching silicon and silicon oxides deposition from aluminum coating system shields of one of the largest white goods consumer products manufacturer.

 

Prior to our solution, blasting cleaned the shields, but there would always have issues with blasting media being trapped on the shields. The blasting media particles embedded and the subsequent cleaning, caused not only outgassing issues for pump down which delayed production, but also caused arcing during the pre-treatment and coating processes. Often, because of this the process had to be stopped, their parts taken out, and the source feed of Silicon had to be cleaned, which added to the cost of production, by the loss of feed stock (Silicon).

 

We were called to develop wet etching technology to avoid the blasting and the consequently provide some savings rather than losses.

 

What were the facts?

• The silicon and silicon oxide deposition would dissolve in a mix of two acids.

• This mix would dissolve the substrate (aluminum precision shield) almost instantly due to aluminum’s’ sensitivity to most of etching chemicals.

• During our studies of the problem, we found nothing else that would remove the deposition, leaving the substrate shield intact.

 

It was obvious we had to reach into our previous R&D and try another approach. Since we typically cannot protect the substrate by the etching mixture itself, we needed to use a surface protectant that would allow the etching agents to work on deposition, and preserve the shield’s surface at the same time.

 

Our new patented solution, at this point, was the best choice we could make to provide the necessary solution. With a few experiments, we found a group of chemical compounds that allowed the aluminum stay unaffected even under the action of strongest etching agents.

 

Further experiments proved that many other sensitive surfaces are protected by our surface protectants, as well.

 

We helped to scale-up our technology at our client’s facility and the end customer improved their productivity because there are no production losses due specifically from the arching issues.