I have 2 shops telling me that they can't do it. They can fill the inner blind via and the core, but not the L1-L2 via. I'm using a construction 2+8+2 construction w/ stack vias and a core from L2-L7. Can anyone recommend a good fab for HDI designs? Thanks, -oscar On Mon, May 19, 2008 at 3:25 PM, Douglas Stanley <dstanley@xxxxxxxxxxxx> wrote: > We use a 5 mil drill and a 10 mil pad on both inner and outer layers. > > > ------------------------------ > *From:* icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto: > icu-pcb-forum-bounce@xxxxxxxxxxxxx] *On Behalf Of *O Migs > *Sent:* Monday, May 19, 2008 3:21 PM > *To:* icu-pcb-forum@xxxxxxxxxxxxx > *Subject:* [PCB_FORUM] Re: copper filling of micro vias. > > What is your minimum drill size? We are using 12pad 5drill from L1-L2, > L2-L3. > > Regards, > > -oscar > > On 5/19/08, Douglas Stanley <dstanley@xxxxxxxxxxxx> wrote: >> >> We do boards every day that are 3 and 3 with microvias in pad. The board >> shops completely fill the hole with copper and then plate over it. They then >> planerize the copper so the pad is flat. I think it's pretty standard >> nowadays. We simply add a note to the fab drawing to plate the microvia >> closed and to "repad" so the surface is flat. >> >> >> Douglas G. Stanley >> PC Board Designer, Sr. Staff >> Broadcom Corporation- Irvine, CA >> dstanley@xxxxxxxxxxxx >> (949) 926-5889 >> >> >> ------------------------------ >> *From:* icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto: >> icu-pcb-forum-bounce@xxxxxxxxxxxxx] *On Behalf Of *O Migs >> *Sent:* Monday, May 19, 2008 9:58 AM >> *To:* icu-pcb-forum@xxxxxxxxxxxxx >> *Subject:* [PCB_FORUM] copper filling of micro vias. >> >> Hi All, >> >> Does anyone know the requirements to copper fill or epoxy fill a >> microvia? microvia is via in pad. Is there an alternative? >> >> I have a design that requires a fanout of 3.5 mil trace and 3mil airgap >> out of a finepitch bga. >> >> -oscar >> >> ____________________________________________________ >> oscar miguelino | lead pcb engineer | *OQO*, inc. >> 583 shotwell street | san francisco, ca 94110 >> >> *(this message constitutes confidential information proprietary to OQO, >> Inc.)* >> >> >