Ceramic substrate prototyping? A search for options. - Page 1
Forum section: electronics / rf-microwave

author: CNe7532294
author_rank: Regular Contributor
timestamp: March 18, 2018, 05:29:31 am
content: Lately I've been getting into RF specifically microwave and millimeterwave tech. I recently watched a video on PCB prototyping as a source of inspiration.I was just wondering if there are any equivalents for prototyping with ceramics. The why I would need this is due to heat concerns along with RF signal integrity. I'm trying to figure out where to start.I know that I will face a lot of differences between ceramics and PCBs. It can also be very pricey too. Still, even though right now I'm just semi-serious about this I thought perhaps it would help to start a discussion on this. If this has been discussed here or on another board please point us in that direction as well (ie. Manufacturing & Assembly board?).My questions are the following:Are there companies working with ceramics that I could have access to as an individual?Can they plate gold traces for me based on what I specify per design?Can they introduce thin and thick film resistors for me as per design?Can they wire bond for me?What would be the costs I'm looking at if I cared for a budget?Currently I myself have access to discrete components, bonding material for said components (solder and epoxy), a + airflow hood acting as a clean room cabinet, and wire bonding equipment. I could order the substrates themselves but I would still need someone to plate them for me. Another alternative worth mentioning is a 3-5%? ceramic fiberglass subtrate (I forgot what to call it).

author: phenol
author_rank: Regular Contributor
timestamp: March 18, 2018, 10:36:30 am
content: maruwa and kyocera in japan, elceram in Czech Republic...I have used Maruwa Al2O3 substrates with 100um glass overglaze for thick film hybrids. The smooth glazed surface allowed deposition of mirror-like 0.8um Au layers (with Au pastes and screen printing) enabling etch feature size of 10um or even smaller with more or less standard pcb etching methods.

author: CopperCone
author_rank: Super Contributor
timestamp: March 18, 2018, 02:14:02 pm
content: but, you can buy ceramic (i.e. nitride or al oxide) PCBs that are blank, which I assume you can etch if you photomask them.However I got stuck on drilling holes in them, it looks like carbide MIGHT be able to do it. Also you would need to get a VIA solution, I am finding copperset kits to be very hard to find.Can you tell us about wire bonding equipment? is it affordable to own as a hobbyist?

author: rhb
author_rank: Super Contributor
timestamp: March 18, 2018, 02:48:57 pm
content: For a hobby effort you should consider silkscreening. The setup cost is very nominal even if you buy stainless steel screen which will give you very precise results using photoemulsion and mylar films.Locating a source of inks may be a problem, but you can always make your own with a file, sieve and gold or silver bar. Not quite sure what to suggest as a binder, but a little experimentation should find a suitable choice. You'll want to use a container that is flooded with an inert gas. You can experiment using brass to get the process worked out before you use gold or silver. An electric stove burner from a scrapped stove and some refractory to surround it is all you need.Look for for some hobbyist books on ceramics and enameling and check out the ceramic and jewelry suppliers. I suspect some of them sell gold and silver inks in small quantity. Rio Grande jewelers supply would be the first place to look.Have Fun!Reg

author: phenol
author_rank: Regular Contributor
timestamp: March 20, 2018, 08:45:20 am
content: Heraeus and Tanaka make all sorts of pastes for thick film, including copper and RuO2 resistors. You would need inert atmosphere to fire copper, though. Ag and Au worked surprisingly well directly on a kitchen stove, but if you heat it too rapidly, the evaporating/burning fillers will crack the metal. Typical firing temperature for gold is 800C+ in a 1-hour trip thru a belt furnace.Vias are made with a CO2 laser.As for bonding equipment, i'm on the lookout for a new one and they are usually in the $ 6-digit domain.

author: rfeecs
author_rank: Frequent Contributor
timestamp: March 20, 2018, 06:07:53 pm
content: For microwave/millimeter wave, here is a possible place to go:http://www.thinfilm.com/index.htmlThey have a design rule document you can request.You give them your CAD file and they give you back circuits. They make the masks, so there will be a tooling charge. If you have vias, they do laser drilling. Another tooling charge and a longer lead time. They process per your requirements, dice the individual circuits and package and ship. Quality is excellent in this industry, it's a given.An example of pricing for small quantity: 2 masks conductor and resistor $600, 100 finished circuits $750. So $13.50 each. These are tiny circuits, something like .250" x .125".As an example of trying to do it cheaply, you can buy metalized substrates with conductor and resistor layers already deposited. If you have a simple circuit with low tolerance requirements, you can use a film mask and etch it yourself. Then you still have to dice it, so you need a dicing saw. I don't see this as a hobbyist thing.I'm not trying to give a sales pitch. I'm not affiliated with them. There are other companies that do the same thing.Here's is an obviously promotional video: