JLCPCB SMT Assembly Service

[danie1]

I got an email reply in case anyone else is wondering. They'll only assemble stuff that's in stock at the time of order and there's no way to get them to hold the pcb or part stock for you.

They also said that one of the parts I'm waiting on (MAX31855) they "won't buy" - it's an extended part that's still listed in the parts DB and is in stock at LCSC. I dunno if they listed it by mistake or there's some temporary procurement problem. I love the idea of getting jlc to assemble a few boards for prototypes but it's not as useful if listed parts might never get restocked for some reason.

[snoopy]

When I upload the files it shows some of the components are missing for instance only 2 out of 5, 100 ohm resistors are shown in the LCSC parts list even though 5 designators are specified in the BOM.

Anyone come across this ?

cheers

[danie1]

When I upload the files it shows some of the components are missing for instance only 2 out of 5, 100 ohm resistors are shown in the LCSC parts list even though 5 designators are specified in the BOM.

Anyone come across this ?

I haven't come across it but one thought, is your BOM grouped so all the designators for the same component are on the same line or one line per designator? If the latter I wonder if you are running afoul of some unspecified line limit in their parser. All the BOMs I've successfully used are grouped and I've had some lines with 20+ copies of the same component.

[snoopy]

When I upload the files it shows some of the components are missing for instance only 2 out of 5, 100 ohm resistors are shown in the LCSC parts list even though 5 designators are specified in the BOM.

Anyone come across this ?

I haven't come across it but one thought, is your BOM grouped so all the designators for the same component are on the same line or one line per designator? If the latter I wonder if you are running afoul of some unspecified line limit in their parser. All the BOMs I've successfully used are grouped and I've had some lines with 20+ copies of the same component.

It's a CSV file and multiple designators of the same component type are separated by commas

[danie1]

Hmm, mine is CSV but multiple components of the same type are space separated:

Code: [Select]

Reference, Quantity, Value, Footprint, Datasheet, LCSC Part Number, Part Number
R7 R9 R20 R21 R10 R11 R12 R13 R18 R14 R15 R27 R28 R29 ,14,"10k","Resistor_SMD:R_0402_1005Metric","~","C25744","0402WGF1002TCE"


[snoopy]

Hmm, mine is CSV but multiple components of the same type are space separated:

Code: [Select]

Reference, Quantity, Value, Footprint, Datasheet, LCSC Part Number, Part Number
R7 R9 R20 R21 R10 R11 R12 R13 R18 R14 R15 R27 R28 R29 ,14,"10k","Resistor_SMD:R_0402_1005Metric","~","C25744","0402WGF1002TCE"


For some reason it doesn't like if I specify the LCSC part number. When I eliminate this column all of the components are counted for but it doesn't automatically find a match to the LCSC column.

EDIT: The missing components are not in the Pick and Place file. For some reason Altium is not dealing with the Variant properly.

[Kentxu]

I have sorted many of the parts in the Excel file to make it much more convenient to use.
Hope you like it. "jlcsmt_parts_library_4.zip" 1.4MB

http://s000.tinyupload.com/?file_id=35614263837265853771

Thanks for the spread sheet list of Basic Parts. Much easier than looking on the JLC page.

Does anyone know of an Altium library of the Basic Parts?

[aix]

Not sure if this has already been posted (doesn't seem to be): https://dubiouscreations.com/2019/10/21/using-kicad-with-jlcpcb-assembly-service/

[aix]

I've been trying to place my first assembly order, and I can't for the life of me get the placement preview to work.  It just displays the bare PCB with no parts on it.

All the BOM parts have been matched & confirmed.  The board is simple enough that there are no unselected parts.

The BOM and CPL files look as follows (generated by the tool I linked to earlier):

"Comment","Designator","Footprint","LCSC Part #"
"100nF","C1","C_0402_1005Metric","C1525"
"CEM9288","Q1","SOIC-8_3.9x4.9mm_P1.27mm","C180872"
"100","R1","R_0402_1005Metric","C25076"
"1K","R2","R_0402_1005Metric","C11702"

Designator,Val,Package,Mid X,Mid Y,Rotation,Layer
C1,100nF,C_0402_1005Metric,113.665000,-84.836000,90.000000,top
Q1,CEM9288,SOIC-8_3.9x4.9mm_P1.27mm,106.426000,-84.963000,90.000000,top
R1,100,R_0402_1005Metric,113.665000,-86.741000,270.000000,top
R2,1K,R_0402_1005Metric,110.236000,-88.138000,180.000000,top
U1,DW01,SOT-23-6,111.125000,-85.725000,180.0,top


I can't tell whether it's a data problem or a rendering issue.  I tried two browsers (Chrome and Safari), with identical results.

I've emailed JLC support but thought I'd also ask here in case any of you have any ideas.

[danie1]

I had a play about with your BOM & CPL and comparing them to mine and all I can conclude is the preview is really buggy.

If I have less than 5 components in the CPL it will complain about missing "Rotation" in the cpl but with 5 it accepts it fine.
If I have exactly 3 components in the BOM the components show up but are offset from their correct position.
If I have 1 or 2 components in the BOM, they don't show up (or maybe they are offset off the screen, who knows!

I couldn't get your BOM or CPL to work. I've uploaded my working BOM and CPL files if you want to try fiddling with them. Note my headings, column order and when fields are quoted seems to differ from yours but I did try copying to yours and they still didn't work...
BOM: https://gist.githubusercontent.com/cs2dsb/5d1a9c116d87ef6e14e72c607210122a/raw/8a8ab6349df5067707ad016da14f6e9999e8cf25/bom.csv
CPL:  https://gist.githubusercontent.com/cs2dsb/5d1a9c116d87ef6e14e72c607210122a/raw/8a8ab6349df5067707ad016da14f6e9999e8cf25/cpl.csv

I generated mine manually in kicad, I wrote up instructions for myself here if that's any use: https://github.com/cs2dsb/zcssr/blob/master/docs/generating_gerbers_and_fab_outputs.md. Any scripts or other files it refers to in there are in that repository somewhere.

[aix]

Thanks danie1, let me play with this further (and thanks for sharing your tooling/workflow).

[aix]

Wait a minute, I just noticed that the BOM file only has four parts instead of five.  It's missing U1.  I wonder if this might be contributing to the problem.

edit: Nope, fixing that by hand made no difference at all.

[aix]

JLC support got back to me saying, in effect, "check your files — there's probably something wrong with them."  Turns out their support team don't have access to unsubmitted orders; I was hoping they'd just look at the pending order I referred them to and troubleshoot from there.  Oh well.

I sidestepped the problem by submitting a different, more complex, design.  This renders in preview, but I am now hitting "The part C84635 is no longer sold, please refresh the page."

C84635 is SS34, a basic part of which they have 11K in stock.  I'd be willing to throw $3 at fixing this; however, choosing a different SS34 gives the same error.  I am not really sure what's so special about this diode. 

[jonroger]

After I got my files formatted exactly like their examples, it worked fine.    It's going to change my prototype designs - common parts placed by JLCPCB on one side, uncommon parts placed by hand on the other side.

[aix]

I've just placed my first order.  The preview looks good, but I am seeing lots of "Cannot find this Pad in your PCB" messages in JLCPCB's DFM Analysis.  The original & corrected part placement look identical.

It sounds like this might be a useful tool if it can detect some placement errors.  Not really sure what to expect from it or what I need to do to my Gerbers to get it to work.

Any thoughts?

(In case it matters, I use KiCad.)

[aix]

Hm, and now practically all the passives I have in my test design are gone from the basic catalogue.  I am talking 100nF 0603 ceramics, 1K & 10K resistors (in all sizes except 1206) etc.

Most of them are still available as extended, though one part (a ferrite bead) I picked from the catalogue just a few hours ago is completely gone.

[aix]

And the quoted pricing is messed up. As in: component cost x component count x board count doesn't add up and isn't even consistent across different parts on the same board.  Some parts are off by as much as a factor of ten.

I'm guessing a bad software push that hopefully gets fixed before long?

[thinkfat]

Some parts have a MOQ.

[aix]

Ah, that explains the apparent price discrepancy.  Thanks.

Since I posted the last message, more parts have disappeared from the basic catalogue.  There's no longer an AMS1117-3.3 in the basic catalogue and the STM32 part I chose a few hours ago has also gone extended.

I wonder what's going on there.

[aix]

Is there a way to see a part's MOQ when browsing the catalogue?  (I.e. without uploading a design that uses the part.)

Also, one of the more expensive parts I tried using seemed to have an MOQ of 7.  Isn't that a bit silly, given that there's no way to have seven boards made?  (Only 2, 5, 10, etc.)

[ve7xen]

There will be some waste with Extended Parts due to loading the tape into the machine. It's not clear exactly how this is calculated, but you will definitely have to buy more parts than are placed.

[aix]

I think that's completely reasonable.  But it would be nice to see the MOQ upfront so that I can factor it in when deciding which parts to use on my boards.

[steenerson]

Some parts have a minimum quantity that shows up in their parts search, where it'll only show pricing for 50+ quantity etc. Other parts show pricing for 1+ in the parts search, but then on the screen after you upload the BOM and CPL files where you select components, you can click on a component detail and it'll say something like this:

Qty:1-199 - Unit Price: $0.0221
*For qty≤20,charges a fixed fee $0.0221

Which as far as I can tell, it means if you order just 5 they adjust the unit price by a factor of 4 so that you pay for 20. The only place I see that note listed is in the part selection process which you don't see until you've uploaded the gerbers/BOM/placement files and it's kind of a pain to go back and change things.

It's not usually a lot of money but it's annoying if you try to actually track BOM cost in spreadsheets and check your invoices against it.

[OwO]

I can still see all the 0603 caps and AMS1117-3.3 in the basic library: https://www.sz-jlc.com/portal/smtComponentList.html (note "扩展库" means extended library), so I'll say it's the English version of their website that is broken. AMS1117-3.3 is listed as "very popular" so it's probably not going to be removed any time soon.

[aix]

I have to say that I find the formatting on the Chinese site so much more useable!  And you're right, is still lists all the parts that have been disappearing on me.  I've emailed JLC to let them know.