Place in Western Europe (If possible BeNeLux area) that can bond LCP to FR4

[TheUnnamedNewbie]

Hi guys,

I have a research project I'm working on that involves rigid flex PCB stackups. The in-house group can do the patterning, via drilling and etching on an LCP substrate.

We have used the pure flexible structures without any rigid layers, and verified that the concept we are working on is promising. However, we now want to take it to the next step and include flip-chip dies onto the structures. In order to be able to connect these flip-chip dies we need a rigid layer (hence the FR4). We want to continue manufacturing the LCP layer inhouse for reasons I can't go into right now. So what I am looking for is a place where I could ship these flex layers that could then bond them onto FR4 substrates. We need to be able to have cutouts in the FR4 (quite large ones). We don't need any traces on the FR4, it is just their to form the rigid layers in the concept. We do need alignment of the LCP layer to the FR4 since we need the cutouts in the FR4 to match up with structures on the flex layer.

Does anyone know of a place that could provide this as service? How hard is it to do this yourself, if you can get a hold on the substrates? (could I EG order cheap boards without any silkscreen and solder-mask from your run-of-the-mill supplier, and get bondlayers and manualy bond them?).

I myself operate out of Leuven, Belguim. I would prefer the supplier to be local for shipping time reasons (We have about a month to do this or we miss an important paper deadline).

[SaabFAN]

From how you describe it, it seems you could do it by just using some superglue or epoxy to glue an FR4-Chunk in place.
If you need it only for a small number of prototypes, I see no problem with that method. Unless you have some specific requirements that cannot be met that way.

[TheUnnamedNewbie]

From how you describe it, it seems you could do it by just using some superglue or epoxy to glue an FR4-Chunk in place.
If you need it only for a small number of prototypes, I see no problem with that method. Unless you have some specific requirements that cannot be met that way.

Thanks for your reply.
I have considered this, but there are two things that worry me.

The flip-chip dies will be mounted using stud-bumps made with gold, and not soldered down. These bumps are 28 um tall. As a result the substrate needs to be quite rigid and flat, and I don't know how well I can get the tolerances I need. I can play around with this and see how it goes.

[free_electron]

contact Isola to get your hands on substrates.
For the bonding you will need a multilayer press ( heated press )

Try ACB circuits or Vermeulen Printservice in the netherlands (aarle-rixtel) ( the are close to eindhoven ) they may want to help you out. they love 'experimental stuff '

Any ship that can make flex boards should be able to fuse an Fr-4 stiffner. LCP is not really special.