1.The vendor shall provide a wax bonding system with a second chuck for the silicon wafer". I need clarification. What is the purpose of the second chuck? Is the purpose to process a minimum of two wafers simultaneously?

(A)The specific application being considered is one where the device wafer has surface that are sensitive to oxidation. We do not want to heat the part in air. The SOW describes one method of keeping the product wafer cool prior to pump out of the system. Vendor can describe how their system works and technical representative can make an assessment as to whether the method would be acceptable. Basically, we do not want to heat the device wafer or plunge the device wafer into hot wax with air/moisture present. Any method that achieves that is acceptable.

2. The chuck shall have alignment marks for placement of the silicon wafer". Again, I need clarification. Generally for wafer bonding, wafers are attached to a completely round glass carrier. Since the glass carrier is completely round, no alignment can occur. Does NASA intend to use a different type of carrier?

(A)We have an application where we use a glass wafer with a flat and align it to the wafer flat. So the thought was the chuck could have a line for the wafer flat to assist with wafer placement. The vendor can propose alternate methods if that is more convenient.

 
3. The vendor shall provide a 1L supply of wax suitable for spin coating of glass substrates". What is the required bonding temperature for this wax?

(A)The typical melting point for our wax is 121 C, softening point at 71 C. But we will also take vendor's recommendation for void free wax bonds.

 4. The vendor shall provide three references that can be contacted that can describe the system delivered by the vendor to their institution". This request may be difficult as most owners of Logitech bonders are commercial and may be unwilling to disclose manufacturing techniques to third parties. If contact is made, what questions might be asked?

(A) If references are contacted, we ask for overall satisfaction with the tool, interaction with the vendor, and maintenance issues and how they were resolved.

 5.The SOW states computer programmability. Is that feature necessary?

(A)Computer programmability" is an overstatement. The expectation is that the hotplate will be programmable to ramp temperature up and down in a well controlled way but this does not need to be through a computer interface.