Fab houses capable of BGA and micro, buried and blind vias? - Page 1
Forum section: electronics / general

author: MarkS
author_rank: Unknown
timestamp: July 14, 2023, 06:44:40 pm
content: I'd like to play around with BGA packages. Unfortunately, the fab houses I know of have very tight limits on BGA pitch and none of them support anything other than standard through hole vias. I realize that going this route would incur a much greater cost, but I'm not willing to even attempt a design if I cannot get it manufactured.Are there any fab houses that can do this and in the small production runs of JLCPCB and PCBWay?

author: asmi
author_rank: Super Contributor
timestamp: July 14, 2023, 07:06:24 pm
content: It depends on the pitch. I'd say 0.65 mm and up are very doable with JLCPCB process (they can do down to 0.09/0.09 mm traces, 0.15 mm drills and 0.25/0.3 mm via pads, but latter for additional fee), and they can also do via in a pad (which I recently tested and found very useful) - and even do so at NO EXTRA CHARGE for 6+ layer PCBs. You only need microvias for 0.5 mm pitch and below, or very large devices with many hundreds of balls.You can check out a project in my signature for an example of a 4 layer board designed around JLCPCB process which contains 1 mm and 0.8 mm pitch BGAs. I've also almost completed a 10 layer design which is going to contain a rather large 484 balls BGA and use via in a pad, also intented to be manufactured by JLCPCB, and since BGA pitch is rather large 1 mm, I've managed to get it done using only 0.1/0.1 mm traces and 0.2/0.4 mm vias to save a bit of money on manufacturing - they have quite a jump between 0.2 mm drills and 0.15 mm ones, but if needs must, of course you can take a step down. I've limited myself to 0.2 mostly because I wanted to see if I can actually get it done, knowing that an option to step down the drill size is still there should I absolutely need it. That design breaks out every single ball out of 484 ones, and it also contain a large 64 bit DDR3 interface to an SODIMM socket, so I needed all the routing space I can get, but in the end it worked out beatifully.

author: MarkS
author_rank: Unknown
timestamp: July 15, 2023, 05:48:36 pm
content: Quote from: asmi on July 14, 2023, 07:06:24 pmSome of the BGA parts I've looked at in the past that interested me were 0.5mm pitch and below. I think they were microcontrollers or FPGAs and not very complicated chips, just only available in fine pitch. I'd like to open up my possibilities. I'd just like to have some options available to me and right now they don't exist.

author: asmi
author_rank: Super Contributor
timestamp: July 16, 2023, 01:09:19 am
content: Quote from: MarkS on July 15, 2023, 05:48:36 pmWell, let me know if you find anything - I could use something like that as well.

author: mon2
author_rank: Frequent Contributor
timestamp: July 16, 2023, 10:49:27 am
content: Your specs are leading you into HDI specs. Respectively, search out pcb shops who can support HDI PCBs in low volume. We have used a few for our 0.4 and 0.35mm ball pitch designs in 4L for our WLCSP packaged devices (ICE40UL, etc.).Will post the vendor names later but Kingford PCB was selected for one project. Their offer was around $1200 usd lower than the highest competitor. Asked them if they understood the complexity of our design and Kingford replied with 'yes, this a HDI board and we work with these constraints normally. It is not a premium service to them'. We started our business relationship with them after seeing their 40++ layer pcb in a showcase in HK made for AMD. It was at a past HK Electronic fair we attended. The board was drop dead gorgeous. Crazy to think for the same specs and qty, others demanded a large price spike. You will always pay more for HDI so do attempt to design without the need but WLCSP and BGA devices sometimes cannot avoid such layouts. That is, HDI is when you need to use laser drilled vias, blind and buried vias, resin filled and copper topped pads, thin pcb traces with thin spacing. I am the logic designer for our many projects and will need to ask our PCB designer if you require the exact specs of our past designs.These days, we just cannot avoid HDI pcbs for our pending Gowin / Efinix / STM32 / Ambiq based layouts.Fairly sure Jet PCB will support HDI as well but will post the others we have used once fully awake here.Update:1) Attached are more names of PCB shops we have dealt with in the past with HDI support in low and fair volumes (1k-2k lots).QuoteNot tested but claim to be supporting of HDI:QuoteWe are constantly receiving broadcasted emails from offshore PCB vendors but recommend that you consider to request the above for quotes. Upon interest, can share PCB brokers that will farm out your HDI pcb to the best shop and support you if there are any QC issues. We have such contacts to allow us to source from Suntak and other tier 1 shops in China who frown upon low volume purchases of PCBs (ie. $500k EAU is too low of a dollar value for Suntak to work with us for PCB sourcing).

author: MarkS
author_rank: Unknown
timestamp: July 16, 2023, 11:54:12 pm
content: It looks likePCBWaycan do most of what I need! I just watched a Phil's Lab video and he showed they do HDI boards! I had no idea! The price is, of course, ridiculous, but it's good to know there's an easily available option.

author: asmi
author_rank: Super Contributor
timestamp: July 17, 2023, 12:58:43 am
content: Quote from: MarkS on July 16, 2023, 11:54:12 pmYeah, I knew about them, but >500 USD for a ten 10x10 cm 6 layer PCBs is kind of insane. Of course it's not US-based fab-insane, but still pretty close out there.

author: stone
author_rank: Contributor
timestamp: August 03, 2023, 10:19:52 am
content: Are you looking for this kind of IC substrate?

author: Kean
author_rank: Unknown
timestamp: August 03, 2023, 11:37:09 am
content: Quote from: stone on August 03, 2023, 10:19:52 amWhat is that last photo? Is that for bare silicon wire bonding? Argh, I can't believe I wrote "silicone" instead of "silicon". It really bugs me when others do that.

author: stone
author_rank: Contributor
timestamp: August 03, 2023, 12:42:45 pm
content: Yes

author: stone
author_rank: Contributor
timestamp: August 03, 2023, 12:48:51 pm
content: wire bonding