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Christmas Star project

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Visitor

Well-Known Member
Well looks like I am maybe a "NO SMT ASSEMBLY" unless a green star is ok.

NOTE: smt assembly ONLY on green boards. Asked JLCPCB

Geez oh grief. How can the fact the JLC's assembly service will make only green boards be unknown to you?????

Once again, you have made me truly regret wasting my time trying to help.

At the risk of opening a very large can of worms, you could have boards assembled by JLCPCB. My only relationship with JLC is that I'm a satisfied customer.

Let's assume your board is 100mm × 100mm or less. The cost for board assembly breaks down like this:

1. Cost for 10 boards, engineering services and stencil: $13.50

2. Cost of components (per board): ~$3
JLC only has the PIC18F46K22-I/PT in stock. It's the big brother of the 18F43K22, with much more memory. It's $1.95 for 10+ pieces. The resistors, caps and LEDs would be pennies each at most. Probably less that a buck a board.

3. Cost for "extended" parts: $3 total.
The PIC is an extended part, meaning there's a charge to set up a pick&place machine with it. With careful selection, all of the other components should be available on the "basic" list.

4. Cost per pin for soldering: $?
This is some insignificant amount that I never even notice on my builds.

5. Shipping – DHL: $17

So for roughly $65, you'll receive 10 boards with [only] the surface mount parts installed.

Read this carefully: soldermask option is green. SMT parts are soldered to one side of the board only, and through-hole parts are your responsibility. Only parts in-stock and in their SMT library will be installed, and parts not on the basic list incur a $3 setup charge, which should only be for the PIC if other parts are selected carefully. Parts not in stock or not in their library won't be installed.

You're paying essentially $8.50 to have a lot of 10 boards assembled and getting a break on component costs buying though them.

If you want to do this, I'd recommend using JLC's free EasyEDA software – it will make it easier to provide BOM and pick&place files in the proper format. It's easy to use with a simple learning curve.

I have used this service for several boards and have been extremely pleased with the results. But be absolutely clear on one thing: For a successful build, it's entirely up to you to select components from their library and in-stock, and to be aware that only surface mount parts are part of the service.

View attachment 126305
 
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Visitor

Well-Known Member
In case you neglect to open the full quote, let me make it easy for you.
Screenshot_20200922-140902_Edge.jpg


This was spelled out clearly when I suggested having them assembled. Before I wasted so much time helping you with EasyEDA. CLEARLY SPELLED OUT.

Screenshot_20200922-140902_Edge.jpg
 

MrDEB

Well-Known Member
yes blue but would prefer the smaller LEDs
The green solder mask? is this not the color of the board?
going to inquire about how easy to solder 0805 LEDs or what it would cost to have made at Elcrow?
 

Visitor

Well-Known Member
yes blue but would prefer the smaller LEDs
The green solder mask? is this not the color of the board?
going to inquire about how easy to solder 0805 LEDs or what it would cost to have made at Elcrow?

10× more +at Elcrow.

Do you not understand soldermask??? Apparently not. Better do so of that research you claim to do on how boards are made and what the layers of the board do / are for.
 

Visitor

Well-Known Member
Soldermask it the layer on top of the tracks. It insulates the track, helps prevent solder bridges between pads and gives the board whatever color it is. The FR-4 board substrate is a light grayish-green color and not typically seen.

How can you not understand that soldermask is what gives the boards their color after specifying soldermask color on every board you've ordered.
 

MrDEB

Well-Known Member
So solder mask gives the boards color, not the actual board.
I have an inquiry over at Elecrow with same project .
 

Visitor

Well-Known Member
JLC's assembly service is unique. It's a limited service that will assemble boards using components only from their list. The "basic" parts are always loaded on their pick & place machines, while the "extended" parts are loaded as needed. A board will be stuffed by running through rows of pick & place machines, and parts placed from the machine which has those parts loaded. This assembly-line service, using mostly parts always loaded in the machines makes the cost incredibly low.

Full-service assemblers (i.e., everybody else) operate completely differently. You supply the BOM and they will offer substitutions using what they have in stock, and will find and order the necessary parts (much more labor equals much more cost). When they have all the needed parts, they will load all of those parts into a pick & place machine (full custom setup every time --> more labor equals more cost). There's also more time involved, because a machine has to be set up for a specific board. It may only take a minute to stuff ten boards, but it may take half an hour to set up the pick and place machine to do that (tying up resources --> greater cost).

You will be shocked when Elecrow quotes a price. I'm certain it's going to be more than 10 times what JLC asks.
 

MrDEB

Well-Known Member
Am I missing something>
the boards are first laser printed then etched.
then the solder mask is applied (color) then the board is assembled.
Maybe I should order the boards then have them assembled?
 

Visitor

Well-Known Member
Am I missing something>

Pretty much every pertinent point.

You've never watched a video on how boards are made? I am quite sure I have posted links of this in response to your posts before.


Maybe I should order the boards then have them assembled?

You mean order boards, get them in your hands, and then ship them somewhere to be assembled? Why on earth do you think that makes any sense?!?!?
 

gophert

Well-Known Member
Most Helpful Member
Am I missing something>
the boards are first laser printed then etched.
then the solder mask is applied (color) then the board is assembled.
Maybe I should order the boards then have them assembled?

A photo-mask is printed on clear acetate or PET film (from your gerber files).
A photo-resist is applied to the copper-clad FR4.
The copper is drilled (from your gerber/drill files).
The printed acetate is placed in front of the PHOTO-resist and exposed to UV light.
The photo resist is developed to reveal the copper that needs to be etched.
Then copper is etched.
...
...
...
 

MrDEB

Well-Known Member
got quote from Elecrow ==$300 including shipping!!
Will have a look at link
No I was hoping to have boards made by JLCPBC and have them assembled there but I guess I am outa luck
YES their website shows multiple colors but only green if you want them to assemble.
Makes no sense, they fabricate PCBoards in multiple colors but only assemble if they are green.
 

gophert

Well-Known Member
Most Helpful Member
Try PCBWay.com. They will do any color mask plus multiple colors of silk screen. Their prices are now closer to jlcpcb and they do assembly.
They will order parts from Digikey or other local distributors in China.
 

Visitor

Well-Known Member
Makes no sense, they fabricate PCBoards in multiple colors but only assemble if they are green.

Next time you go to Costco, buy yourself a giant box of CLUE. Better make it two.

When JLC makes boards, your board (one copy) is put on a panel with many other boards (as gophert explained for your 2' first design). Ten panels are made, and all the different designs are cut apart. A panel won't be made until there are enough boards to fill it. If a color is unpopular, it may take some time to fill a panel.

As you have seen, JLC's assembly service is incredibly cheap, because it's a limited, specialized service. They can do this because it's a hands-off to the maximum extent possible as I explained above. To make their process efficient, they don't mess with different colors of soldermask. They do the setup process for a new order, put it on a panel and move on. If they allowed different colors of soldermask, extra effort would be required to sort orders to different streams.

Sorry you didn't get the message about only green soldermask being available but I did point this out when I suggested using the assembly service. The fact that you have never connected the color of the board to soldermask color despite selecting soldermask color on every board you've ordered is beyond belief.
 

MrDEB

Well-Known Member
took some time off this project and have reached a viable solution.
position the 66 LEDs within the white silkscreen areas then using pinstripe tape mask the silkscreen/LEDs off, spray the board blue then apply a light sprinkle of glitter.
remove tape and should be done hopefully.
first need to contact PCBway for quote.
 

Pommie

Well-Known Member
Most Helpful Member
I have no idea why you want a blue star on a green tree. However, why not paint around the LEDs with PVA glue, sprincle blue glitter on it, wait until glue dries and remove excess glitter. You can of course replace the PVA with blue paint.

Mike.
 

MrDEB

Well-Known Member
you say around the LEDs? Do you mean to paint over the LEDs with PVA glue?
can't see a green Star on top of a Christmas tree. Stars are blue or white in my neck of the woods.
 
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