Another JLCPCB issue

you can download the partslist as xls,

Yes, I know. I was scraping it to get more information, also specifically historic price data, because prices today is just a snapshot, and the deals on LCSC when a component price drops, is difficult to see if that is a real drop, or just for LCSC to get rid of stock

I download that XLS and convert it to a TSV file. Then I use a bash function to `grep` the text file. Works very quickly and easily. I can think to improve it, but it's a good start:

function jlc { egrep -i "$@" ~/Downloads/JLC*tsv | less -S }

CH

Naah, just a dig. All the noise here (from many parties) about how crap JLC is, when you could just read instead. Never mind.

Oh BTW, I did find one part where the JLC visualiser showed it still rotated, even though my footprint and parts list was correct. It turned out that the 3d view for that part was rotated from what is on the actual feeder. JLC were very surprised, and fixed it quickly. So it does pay to check the render.

CH

Does anyone here use JLCPCB for production? They have prices on Xilinx Spartan 6 devices that I would have trouble getting even if I bargained with Xilinx directly. Some of the images I've seen of boards made by them make me cringe, but it's the sort of thing that can be worked out I suppose. I would not consider them normally as my CM gives me pretty good prices, but the Xilinx prices are amazing! I also see an Altera part in a FBGA-169, 1.0mm pitch BGA which would fit my board much better than the 256 pin package offered by Xilinx.

The Altera part has 3.1 GHz transceivers. Does anyone know if they can be used with a differential input with straight clocking at that speed without the 8B/10B stuff? I want to simply sample a differential input into a shift register without any formatting.

Dang, it would be neat to go on a tour. I've used some much smaller outfits and they were okay, just a few machines and some sharp girls deftly doing what the machines can't do economically.

I am working on a device, where I intend to use JLCPCB as EMS

I am a little worried about them pulling parts off their list, but sofar the list just seem to be growing and little taken off

I have stored their excel list at regular intervals, so when I get time I could write a script to find how many parts they have pulled off the list

I have benchmarked other suppliers. Some of them take 25% margin to source the components, but on the positive side they do double sided SMD, so the PCB cost is reduced. Like any engineering task, there is tradeoffs

Someone was just telling me they get 10 4x4" boards assembled for $100. Not $100 each, $100 for the lot including assembly and the parts!!! I'm getting boards made in the US for $70 EACH. Of course I don't know what parts he is using while my parts cost alone is some $40-$50, although I've never priced it out in detail. Still, it would appear JLCPCB is amazingly inexpensive.

They are off the mark sometimes. One part on my board is around $1 @ 1000 from TI. JLCPCB wants $3.32 at that quantity. Another part that is about $2 at many sources is nearly $4 at JLCPCB. Then there is the fact that they don't even carry other parts I need. So they are not a very universal solution. DK Red would not have that problem if they start doing the assembly thing.

Are you saying JLCPCB does not assemble double sided? I had not seen that. I see they only indicate "Single sided placement". Definitely out then.

One other observation. I use a third party search service to find parts on JLCPCB. They take you to the LCSC detail page for pricing. This is not always the same as the JLCPCB detail page. Strange. This is not a company you want to rely on for much.

Now if Digikey adds assembly to their DK Red PCB fabrication with access to the millions of line items, it would be amazing! It would have the potential to put all the other makers out of business.

Hopefully if DK has assembly, the file formats would be a lot better documented.

...

+1. All the annoying little parts, purchased in small qty and mounted at better than full-reel prices, without having to find space to store the reels? I'm very happy to complete the assembly with the few parts they don't source for me.

CH

Really? You want to hand solder 10s of thousands of parts on thousands of boards?

Why would you not use contract assembly? Manufacturing is a low margin, pain in the ass. I did my own procurement for a while and will never do it again.

Simple. I wouldn't use JLC for orders of thousands. But for prototypes or small orders they're just fine.

Heh. I'm awaiting a shipment of five boards from them, with a total of

850 robot-placed 0402 components on them. Thank you cheap robots :-) (I'll solder the remaining connectors et al myself)

JLC recently added through hole parts including connectors...

I thought I saw that they charge for soldering by the pin.

The small passives come on the tape at right angles to the axis of the tape. For reasons of stacking the feeders next to each other, the tapes point at the board. So, the normal relation of the part to the board is "horizontal".

Most P&P machines consider rotation relative to how the part comes out of the tape, so that makes horizontal zero degrees.

Jon

So how is the designer supposed to know how they orient the board relative to the machine? Or relative to the reels?

Which direction is +90 degrees and which direction is -90 degrees? 180 degrees I think I can figure out.

It seems to me the board designer should just worry about specifying the rotation of the part relative to the board and nothing else. The machine operator can worry with how the board is placed and where the reels are located. Somebody has to define the positive/negative rotation direction though.

A basic part of the design - solderability - determines the transport of your pattern on an automated fab.

This may not be much of an issue with 100% reflow, but if ANY wave operation is expected, it is a primary consideration in panelization, location of registration detail, component-to-board edge clearances, etc etc etc.

You design for manufacturability.

RL