Small batch, large pcb, white soldermask suggestions

[yeah_indeed]

Hi everyone,

I hope I'm in the right subforum for this, if not let me know and I'll delete this post.

For a project I need to manufacture some large PCB's (12x48 cm / 4.72"x18.9"). The size is not because of components, but they are for an LED cube which has this size.
Now, we want the solder mask to be white, and we have small single unit sockets which fit the copper wire from which the cube is constructed. The mounting holes for these sockets need to be in between 1.96mm and 1.91mm.

At first we were going with PCBWay but I read they don't deliver reliable quality, especially with white silkscreen.
Does anyone have a recommendation on the service we can use?

[DerekG]

At first we were going with PCBWay but I read they don't deliver reliable quality, especially with white silkscreen.

We have had about 1500 boards (over 4 designs) manufactured by PCBWAY & all have been fine.

[yeah_indeed]

At first we were going with PCBWay but I read they don't deliver reliable quality, especially with white silkscreen.

We have had about 1500 boards (over 4 designs) manufactured by PCBWAY & all have been fine.

Good to hear, and they were white solder mask as well?

[DerekG]

Good to hear, and they were white solder mask as well?

I think you mean white silkscreen?

We have boards with white silkscreen from PCBWAY with a line thickness of 1.5mm. We have sent away 1.2mm line thickness, but they adjust that to 1.5mm unless you want to pay extra.

We have had the usual green solder mask plus red as well. The green is better for optical inspection due to the lower reflection.

The last batch of boards I have ordered with blue solder mask, so we will see how that compares to the green during optical inspection (different solder mask colours cost no extra).

The only problem we have had was the solder paste screen (stencil) was one up instead of two up (to match the panel). I took a photo & sent it to PCBWAY & it was replaced within 7 days via courier to Australia, all at no cost to us.

[printedcircuit]

do you mean the silkscreen quality from PCBWay is unreliable? as i know, the quality of the board is decent. there are few reported unclear silkscreen before. it is mainly due to unskilled worker as the silkscreen is made manually. i think that issue happen more than half year ago. the quality of PCBs from PCBWay  is better now.

[yeah_indeed]

Good to hear, and they were white solder mask as well?

I think you mean white silkscreen?

We have boards with white silkscreen from PCBWAY with a line thickness of 1.5mm. We have sent away 1.2mm line thickness, but they adjust that to 1.5mm unless you want to pay extra.

We have had the usual green solder mask plus red as well. The green is better for optical inspection due to the lower reflection.

The last batch of boards I have ordered with blue solder mask, so we will see how that compares to the green during optical inspection (different solder mask colours cost no extra).

The only problem we have had was the solder paste screen (stencil) was one up instead of two up (to match the panel). I took a photo & sent it to PCBWAY & it was replaced within 7 days via courier to Australia, all at no cost to us.

I actually mean that the whole board is white, with black text. That's white solder mask, right?

do you mean the silkscreen quality from PCBWay is unreliable? as i know, the quality of the board is decent. there are few reported unclear silkscreen before. it is mainly due to unskilled worker as the silkscreen is made manually. i think that issue happen more than half year ago. the quality of PCBs from PCBWay  is better now.

Yeah, I read it here https://www.eevblog.com/forum/reviews/pcbway-mini-review/
Also, to add, I see you are from PCBWay yourself, so I cannot trust that statement unfortunately. It is also hard to rely on reviews when you offer in store credit for positive reviews. Not the best representation for a manufacturer.

[DerekG]

I actually mean that the whole board is white, with black text. That's white solder mask, right?

Now I understand. You did not mention above that you wanted black text.

White does not cover the darker circuit board so well as it is more translucent. If you want a "good white" for your cube & not a "dirty white" you will need to ask that it be solder mask twice with the first layer allowed to dry before the second application.

Make sure you get a prototype first, otherwise the answer from many/most/all Chinese manufacturers will be "yes, we can do that" ............. but they will apply the white mask only once.

[yeah_indeed]

I actually mean that the whole board is white, with black text. That's white solder mask, right?

Now I understand. You did not mention above that you wanted black text.

White does not cover the darker circuit board so well as it is more translucent. If you want a "good white" for your cube & not a "dirty white" you will need to ask that it be solder mask twice with the first layer allowed to dry before the second application.

Make sure you get a prototype first, otherwise the answer from many/most/all Chinese manufacturers will be "yes, we can do that" ............. but they will apply the white mask only once.

Thanks for your reply. It doesn't have to be perfectly colored, so I think once is OK, it's just nice to not have a green board in this application, but the color doesn't need to be perfect. Thanks again, I think we'll check PCBway out again.

[Wilksey]

I had a white board with black text from Smart-Prototyping, and the white came out perfectly, with no issues with see through etc, mine was 10 x 10cm, that's the only time I have had a white board so can't comment on other manufacturers.

P.S. Not affiliated with any PCB house etc, just sharing my experience.

[yeah_indeed]

I had a white board with black text from Smart-Prototyping, and the white came out perfectly, with no issues with see through etc, mine was 10 x 10cm, that's the only time I have had a white board so can't comment on other manufacturers.

P.S. Not affiliated with any PCB house etc, just sharing my experience.

Thanks for your response, never heard of them. Unfortunately they have a 40cm limit I see. But thanks!

[Wilksey]

Never hurts to email them, they might be able to accommodate, you never know!

[DerekG]

I had a white board with black text from Smart-Prototyping, and the white came out perfectly, with no issues with see through etc

Normally solder mask is somewhat opaque so that you can still see the tracks underneath for visual inspection etc.

[Wilksey]

You can "see" the tracks, i.e. they are raised as per normal, but there was no I.S. visible through the mask as far as I remember.