JLCPCB ordering tip

[Demon]

(Just a head's up to the next guy.)

I thought that ordering in panels was cheaper than single PCBs. Turns out I was wrong; I suppose they spread out our single panels wherever they have empty slots in their production run.

At least, that's the observation I made using a 6" x 9" (15cm x 20cm) layout I uploaded (I wanted to see the price difference between 2 layers and 4 layers). It might be different with small circuits, I didn't try it.

Also, I get a "large panel" surcharge when I use panels of this dimension, even when choosing 2 x 2.

20 PCBs, 2 layers:
- single, $ 3.73 ea.
- 2 x 2, $ 7.70 ea.

20 PCBs, 4 layers:
- single, $ 6.24 ea.
- 2 x 2, $ 10.27 ea.

100 PCBs, 2 layers:
- single, $ 2.24
- 2 x 2, $ 5.09

100 PCBs, 4 layers:
- single, $ 3.96
- 2 x 2, $ 6.54

Nothing fancy, just two 14-pin headers and a 28 pin smd PIC spread out across the surface.


EDIT: I think I know where the savings from panels comes from, it's probably when you use their assembling service and you don't use basic parts (they're preloaded on the machine). A technician has to go to inventory and load reels of "extended parts" on the machine.

[Ioannis]

I think the charge on a panel is for the whole panel.

In your first example

20 PCBs, 2 layers:
- single, $ 3.73 ea.
- 2 x 2, $ 7.70 ea. <-- here I think is for the panel, the 4 pcbs, Not each one.

Maybe I am wrong, have not tested right now.

Ioannis

[Demon]

Those prices are for each individual circuit. I was careful not to use panel prices and mix apples with oranges. I wanted to get a better idea on batches of 100 instead of small prints.

And I was testing the idea of a single motherboard in the background, instead of wires from MCP23017 to the PICs.

[Demon]

I was checking prices on JLCPCB for a MCP23017 circuit, and I noticed something when I entered their part numbers.

Did you know you can buy parts from other customers when JLCPCB doesn't have enough stock?




I have to do some tests tomorrow (2:30 am here). I'm going to try using all parts at 0 inventory, and see if I get deals.

But this might be an easy way for us peasants to get even better priced components.

[Ioannis]

Regarding passives, like R's and C's, there are millions of brands and types available (but not on stock all the time).

It gives me headache everytime I have to do an assembly by JLCPCB...

But on the other hand, this option is nice. Can you order also from Mouser Digikey etc?

Ioannis

[Demon]

...But on the other hand, this option is nice. Can you order also from Mouser Digikey etc?

Ioannis

Yup, you can pre-buy parts from suppliers by JLCPCB.

Pre-order the required components in advance to ensure sufficient components are ready anytime.

Place a PCBA order with confidence at any time when your design is ready.

I just did a test with intentionally insufficient JLCPCB stock, but the prices were still twice as high, even for headers, resistors and capacitors.

It "might" come in handy for more expensive ICs, I don't have a circuit ready yet with a PIC, but I'm not holding my breath.

[Demon]

If you keep messing up the "comma-separated" file prep like I do (the SAVE feature from Open Office is not smooth), consider using a script if you are I.S. savvy.

This is what I do to prepare PCBs for JLCPCB with parts:

- generate gerbers from PCB editor.
- generate drill files from PCB editor.
- generate component placement file from PCB editor.

- generate BOM from Schematic editor.
- generate CPL from Schematic editor (script downloaded from web).

The CPL script corrects the column names, removes unnecessary columns and overrides Rotation of ICs and Jumpers (you list them in a parameter file). I also tweaked the BOM and CPL scripts to save my files in a subfolder.

The nice thing about this is that I don't have to think. I just generate the files, run the 2 scripts, pass it through JLC once to see what needs to be rotated, edit the parameter file, and generate it again, and it's ready for JLC.

[Demon]

I don't have the same definition of stacked and staggered as JLCPCB.

[Demon]

I was curious to see how compact I could design a circuit to debounce switches, as well as see how much it costs at JLCPCB.

- total of 47 input lines,
- debounced using Bourns technique (10K / 0.1uF),
- Schmitt triggered and inverted (74HC14),
- 16F1946 TQFP-64,
- ICSP,
- driven from a master PIC via USART,
- busy lines to control communication (1 for master, 1 for slaves).

Ended up 158mm wide x 30mm tall (I was thinking of placing them vertically around the enclosure).




Got it priced at JCPCB to know what is the cost associated with assembling a circuit such as this:

5 PCBs, $80CAD + shipping
20 PCBs, $230CAD + shipping

[Ioannis]

If you have a local service for assembling the pcb's I think cost for the semiconductors will be significantly lower.

Will not hurt asking.

Ioannis

[Demon]

The prices for ICs and labour are much higher here in Canada:

16F1946 TQFP-64 in CAD funds

JLCPCB $2.90
Digikey $4.85-5.31
Mouser $4.45-4.68
Newark $4.54


If I have the PCBs fabricated in China, shipped to a local place for assembly, I'd pay shipping twice, and run the possibility of one supplier blaming the other for screw-ups.


I'm using:

- 0603 SMDs,
- TSSOP 74HC14,
- TQFP-64 PICs,
- 0.2mm traces,
- 0.2mm clearance,
- 0.5mm x 0.3mm VIAs.

I doubt I can expect small shop to compete with China.

[Ioannis]

From my experience, the chips that were in stock by JLC were double or triple the price from Mouser. The others that were not in stock were cheaper...!

But since I wanted only 20 assembled PCB's and none locally would do it, I just let JLC do the job.

Are you sure all components are available by JLC?

Ioannis

[Demon]

Yup, first thing I do is match all components on JLC's inventory for a given footprint and input price, JLC part # and Manufacturer part # in my symbol editor (Kicad), as well as if it's a Basic part or Extended part. My design depends on availability at JLCPCB, that's why I select PICs that are currently available.

I'm not looking forward to the day I have to start looking for compatible PICs because they are out of stock. New IC prices are just insane, even if we get to stock direct from Malaysia.

[Demon]

I'm pretty sure we get hit with "engineering", "setup" and "stencil" fees everywhere.

I tried to limit the "extended components fee" by using Basic components when possible (resistors and capacitors), but that's impossible to completely avoid.

I'm not sure what "manual assembly" and "hand-soldering labor" involve, but I think it's assembling the headers.

I'm willing to pay for board cleaning to make sure I get nice circuits.




The only way I an think of to get this cheaper is to do it myself, and there's no way I could match JLCPCB's precision. I don't think I'm going to get less than $80 for over 800 components installed on 5 PCBs. Just those 775 resistors and caps would take me forever.




If there's a better alternative for Canadians, I'd love to hear it.

[Demon]

...I'm not sure what "manual assembly" and "hand-soldering labor" involve, but I think it's assembling the headers. ...

Yup, confirmed. I removed headers from BOM and CPL and those 2 fees went away, as well as an extra $3 or so for cost of headers about $13 + tax reduction).


Anyways, I've decided to install the headers myself cause they're the easiest component to manually install.

I'll be using 90deg headers, and they have to be exactly perpendicular with the board. I noticed that the last set that was manually installed by JLCPCB were slightly off.

[Ioannis]

SMD's that many is impossible to do it manually in reasonable time and with no errors!

When production is low and you have through hole components, these are assembled by hand. And this costs...

Ioannis

[Demon]

Tip: When you think you're doing something wrong and spend countless hours trying to generate a 3D model on JLCPCB:




Stop tearing out your hair, browse the part and check the 3D model in inventory:




And if this is empty, you're done nothing wrong.




Complete brain fart on my part. I had created a new symbol in Kicad and copied over an SOIC-20 footprint. I was certain I had messed something up in the process.

I gave up, went to bed, and it dawned on me before I fell asleep.
....argh.....

[Demon]

Got a lots of tracks? Consider the over/under ™ technique:

[Ioannis]

I have to say you have done amazing progress on many different tasks, dealing with this project, giving tips for all!

Ioannis

[Demon]

Thanks, but don't fool yourself.

I post this for me when I forget in 2 days and come back here and Search.

[Demon]

Save on setup fees. Select Basic Parts whenever possible. It's cheaper than using Extended Parts.

[Demon]

I had copied over a TO-263 footprint from the public library in Kicad, then checked up in the datasheet from JLCPCB cause I thought the IC was unusually large.

It turns out the size of the TQFP-64 threw off my perspective, and the IRFZ44N really was 15mm tall (datasheet still is backwards though)

[Ioannis]

Well, you got a giant TO-263 at 15 inches!

Ioannnis