Overview of Status of Analysis, Design, Fabrication, Tests, etc.
We have ordered some of the preliminary parts for fabricating our non co-fired design on our own while concurrently sending out our co-fired design to various companies for quotes
Accomplishments from Previous Week
Chemically etched copper plated PCB board with circuitry using a laser printer and Ferric Chloride
Confirmed that circuitry design can be produced with laser printer precision and therefore should be easily do able with thin or thick film technology
Confirmed that electrical connection will be maintained from the Chip to the pads
Purchased fired Aluminum Nitride from Stellar Ceramics
came up with new design that doesn't need to be co-fired
found company that will make us a "L" bracket or sell us the materials to make it (will have quote on "L" bracket and material on Monday 4/30)
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Begin machining Aluminum Nitride in the campus machine shop
Get AlN "L" Bracket (place order for bracket or material to be shipped)
if bracket can't be made or machined in a quick turn around time look into different method of attaching (adhesion or press fit L bracket together.)
Apply neccessary revisions to co-fired design per sponsors request and investigate a final producer to produce design for sponsor.
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Cu is ok to use for traces
finish co-fired design for him to get produced, find him a producer, and submit design to producer
Sponsor verified we cannot use Kovar for pins in co-fired design, so alternative metal will need to be used for pin outs.
Talked about design options for the BCu design.
Said that PCB is ok to use for layer with traces as long as during testing the chip doesn't heat up too much.
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Talked about changing of design to make sure that we have something that is completed by the end of the class. (04/23) changed design so that it isn't co-fired and the turn around time is much less.
Place chip directly on traces to maintain electrical contact instead of using bumps. (04/23) changed design and checked thermal expansion deformations to make sure that electrical contact will be maintained.
Order AlN and we will be reimbursed for our purchase (email 04/27). Placed order for AlN (order will be shipped on Monday and should be here on Wednesday or Thursday)
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
Risks and Areas of Concern
Whether we are able to use the same chemical etching used on PCB on AlN
Investigate feasibility of machining off copper from substrate instead of chemically etching them off
Resources or Information Required but not Available
AlN young's and shear modulus at 4K to calculate shear stress between Cu traces and AlN substrate.
Schedule
Budget (list amount spent and amount remaining)
Spent: $121.20 of $1000.00
Radioshack = $20.33
2 x PCB boards = $8.38+ tax
16 Oz Ferric Chloride = $10.49+ tax
Fed Ex Office = $1.55
8 Sheets of photo paper = $1.44+ tax
CVS = $7.73
2x Nail Polish Remover = $7.17+ tax
Disposable gloves = $3.19+ tax
Stellar Ceramics = $91.59
4.5''x4.5''x.070'' Aluminum Nitride Substrate = $91.59
Remaining: $878.80 of $1000.00
Progress on Report and Webpage