PCB Fabrication - Endless Noob Questions

[BobW]

I've now designed my very first PC board, and am in the process of reviewing it. One thing that occurred to me is that I created a couple of custom pads and wasn't paying attention to whether the hole sizes were standard drill sizes. It's no problem to go back and change them, but my question, is: Is there a set of standard drill sizes that should be used?

Edit: Changed the title of the thread to reflect the inevitable divergence.

 

[ronsimpson]

Where are you going to get the boards made? Most places have a list of drills they like.
Many places have "low cost boards" that must be, rectangle, 1 oz copper, ...…. and these 10 drill sizes. (for the low cost boards they will change your drills to the next bigger standard size, if you allow them to)
Bottom line; to the board house's website and see what they do for the best price.

 

[BobW]

Actually, I don't know where I'm going to get them made yet. I'm open to suggestions. This would be for a non-commercial product, and I'd be looking for the lowest cost. The board, in its current state is single sided, dimensions are 2.25" x 3.25" (55mm x 85mm). In another thread, I'd mentioned that learning to use PCB software was one of my New Year's resolutions, and coincidentally, someone had contacted me to see if I'd ever designed a PCB for one of my projects. So, that was the circuit that I chose as my first PCB design project. So, at this point, I have a tentative design, and that's as far as I've got.

 

[BobW]

I may give https://jlcpcb.com/ a try. It has good reviews on this forum:

Good service from PCB manufacturer.

As most of you on here know, I usually build projects on veroboard, however in my new job which includes R&D, designing, prototyping etc. I needed to be using PCB's. I'm not sure where I saw the link, I'd presume it might have been on these forums?. Anyway, the company, in China, is at...

www.electro-tech-online.com

I don't see anything about drill sizes on their site though. Maybe someone who's dealt with them can comment?

 

[Visitor]

JLCPCB is good. Elecrow is another source I have used many times with excellent results.

Ten boards of 100mm × 100mm should cost $5 (which is unbelieveable) for 2 layers with soldermask and silkscreen on both sides.

Elecrow offers v-score at no extra cost for one design on a panel.

 

[BobW]

V-score is so the boards can snap apart?

 

[ronsimpson]

single sided

There is very little single sided happening now. Some board houses charge the same price.
Through hole parts do better on a double sided board. The board and solder are stronger.

 

[BobW]

Yes. I noticed that JLCPCB has no price difference for single or double. So, I'll go with double which will be nice to get the solder pads on the top side, and plated through holes.

 

[Visitor]

V-scoring allows boards to snap apart. They also do internal routing, which allowed me to make 10 boards on a panel with straight sides (the v-score) with rounded ends (internal routing).

 

[KeepItSimpleStupid]

I don't know what you have to do for finished size on a plated hole.

 

[MaxHeadRoom78]

I have used PCBway for nice cheap well made boards.
Being in Canada, I use metric sized for mounting holes etc, if a plated through hole, then allow 0.2mm plating = 0.4m for dia.
Max.

 

[BobW]

I'm not as concerned about the size reduction due to plating, because there's usually ample room for the component leads. Still it's good to know how much effect the plating has.
I normally use metric too, but considering that I'm still working with a lot of through-hole components that are on a 0.1" grid, imperial dimensions seemed to be the way to go. Plus, when I fired up DipTrace, it was set to imperial dimensions by default. However, the pad holes for the library components are based on metric drill sizes. For example, there are a lot of 0.0394" holes. I realized afterwards that this is just a 1 mm hole. So I'll probably be okay if I stay with common metric sizes.
I check out PCBway. Thanks for the tip.

 

[MaxHeadRoom78]

I check out PCBway. Thanks for the tip.

The one thing I liked was the options for shipping, most of the others I had tried had either gone to just DHL or Hong Kong mail and DHL.
The problem is that regular Chinese mail often takes over a month and DHL expensive..
PCBway have three options, one in between the other two that is by air to US & Canada.
I am not really in a hurry, but do not want to wait for ever.!
It is Chinese new year right now, so not a good time, but I think PCBway have a deal for new customers, especially.
Max.

 

[Visitor]

Datasheets for many components include a suggested PCB footprint with drill sizes accounting for plating thickness.

EasyEDA makes having the proper pattern pretty simple. Select a part, say a 555 timer in the schematic and the appropriate footprint will be selected. The only caution I have, particularly with user-donated parts, is the verify the footprint against the datasheet.

 

[MaxHeadRoom78]

All the footprints in Kicad PCB I have used have been the correct size.
Max.

 

[BobW]

One thing that I noticed immediately is that, for most through-hole components, the outer diameter of the surrounding pad is very small compared to the hole. This isn't an issue for plated through holes, but if I was going to have a single sided board, I'd be worried that the pad wouldn't survive the component installation and soldering process. When I was doing my own toner transfer on single sided boards, I made generously large pads, so they wouldn't pull away. I understand that on modern board designs, the smaller pads reduce the amount of copper that has to be plated, and allow components to be placed closer together. Anyway, it's a bit of a learning curve, but not as bad as I'd feared.
I even managed to generate a 3D image.

 

[BobW]

I think the original drill size question has been well answered. And I can see that I'm going to have several other questions before I send my design off to be fabricated. So, I changed the thread title to reflect this.

The next question relates to panelling. I've managed to get my board size down to 45x85mm which is less than half the size limit for the special prototype rate at PCBway and JLCPCB. I used DipTrace's Panelize function to put 2 copies of the board into the gerber files but I'm confused about whether PCBway and JLCPCB will charge extra for this, or just ignore the fact that the board outline layer shows two outlines instead of one, and make them as a single board (with no V-scoring and no depanelizing, which is fine with me).

 

[gophert]

Two things, your fonts size look like the printed size may be way too small to read. Print it to paper to make sure you can read it before submitting it.

jlcpcb.com gave me an $8 discount on DHL shipping (first order customer appreciation discount). The boardsturned out great. They also have a Gerber file viewer you can use to make sure the bottom side is oriented correctly. Note, Gerber file should be created with bottom side "non-mirrored" for jlcpcb.com.

 

[BobW]

I assume non-mirrored means that all layers line up when viewed together?

 

[gophert]

Yes, when you upload to their site, make sure the through holes are not duplicated and all looks right on the viewer.