Hi, i’ve checked the requirements for the “special” deal at golden phoenix which i’m assuming BatchPCB is using. They mention 7 mil seperation and minimum drill size of 15 mil.
In the batchPCB FAQ 8 mil seperation is mentioned and minimum drill size of 20 mil
My TQFP-PT64_N smt IC has 7 mil seperation between pins. I wonder if this is a problem preventing me from using batch PCB.
also since golden phoenix mentions 15 mil minimum drill size, again assuming batchpcb is using golden pheonix then would 15 mil drill size be acceptable.
Please correct me if i’m wrong. But if 7 mil separation is not allowed then it is a inconvenient restriction on boards which use 64+ pin packages.
Please correct me if i’m wrong. But if 7 mil separation is not allowed then it is a inconvenient restriction on boards which use 64+ pin packages.
Yep, that’s correct. You could cheat a little by making the pads 1 mil narrower. That should get enough clearance to pass the board house’s clearance rule for low cost PCBs. The pads should still be larger enough to solder on the chip.
I work on PCB layouts that have much higher density parts and pay for the much smaller clearances.
steinar96:
Hi, i’ve checked the requirements for the “special” deal at golden phoenix which i’m assuming BatchPCB is using. They mention 7 mil seperation and minimum drill size of 15 mil.
BatchPCB doesn't use any of the advertised Gold Phoenix specials. They have their own deal worked out with the limitations that are stated on the BatchPCB website.
steinar96:
Please correct me if i’m wrong. But if 7 mil separation is not allowed then it is a inconvenient restriction on boards which use 64+ pin packages.
Ok, you're wrong! :mrgreen: There are plenty of 64+ pin packages that have 0.5mm pitch which is manufacturable through BatchPCB. 0.4mm pitch parts (which I'm guessing you are using) are just a hair too small for BatchPCB limitations so you will have to find a larger pitch part or use a different PCB service.
waltr:
You could cheat a little by making the pads 1 mil narrower.
If it’s a 0.4mm part which is roughly 15.7mil, the BatchPCB restrictions will most likely reject it since you need a minimum of 8mils for the pad and 8mils for the space between them. 0.3mils isn’t a lot but it is enough to get rejected by the DRC.
I should point out that if you use the 4-layer BatchPCB service, you get 6mil spacing and 13mm holes which will certainly work in your application. It just costs more than the 2-layer service.