Basically I want to save some money and order 1layer boards and not 2layer but I cannot work out how to achieve this in Kicad 8. I have both copper layers in the design (top and bottom) but only really need one on the bottom for soldering and need the tracks on there obviously rather than the top. There’s a screw that I’ve put in with a pad to GND but I’m not sure if it’s really that necessary to have the pad on the top. I have a design made up in the pcb editor with both sides having copper layers but I can’t work out how to take off the top layer where the components will sit. I also don’t have any SMT components for the top. Is this the right thing to do and how do I go about doing it? If anybody could give me some direction I would very much appreciate it.
True single layer PCBs are simply not cheaper these days except for some very high volume cases, using paper/resin based PCB and punched, not drilled.
The big snag is that you don’t get plated through holes, so dry joints are all too common.
2 layer PCBs from the Chinese vendors are very chap.
Assuming that you don’t plan to order 10m² I think that if you don’t send top layer files to PCB manufacturer and tell them you want single layer PCB they will probably be able to do it for you. But they will do it by etching top layer from standard 2 layer laminat. It will be for them little higher costs than standard 2 layer PCB.
If you take a look at the Chinese Fabs you will find they are quoting around $2 for 1 to 4 layer boards up to 100mm x 100mm. They would make a 1 layer board by etching away one side of a 2 layer board. Most of your costs are on postage. You will get a better quality board if you use 2 layers - it will be easier to route and have better EMI performance.
A normal plated through hole fills with solder and the component lead is then welded by this solder to the barrel of the hole. This is strong.
A true single layer board only has solder above and outside of the pad. Any stress on the component lead and the pad is lifted off the pcb or the joint cracks.
IMO, the replies here are somewhat over the top.
I’ve used single-sided boards up through the 70s, 80s, 90s, 00s with no problems at all. Bare copper, untinned even. No soldering/reliability/quality issues.
But the argument that PCB fabs are laid out for PTH, double.sided production today holds.
Your board would probably need to be handled as a “special”, making it more costly.
I see no reason for not using standard, two-sided, PTH boards.
Over my working life, I’ve had a sideline of repairing electronic consumer goods. Many were, and still are true single sided boards. A current product that comes to mind is flat screen TVs. Most still have a single sided board for the power supply and a multilayer board for signal processing.
Dry joints still occur on the single sided boards after a period of use. Heat caused contraction and expansion together with automatic soldering and lead free solder are the biggest culprits. These commercial products recognize this problem (to this day) in part by using rivets for the large and heavy and heat prone components (I suppose a single sided board, a few rivets and a single solder pass, are still cheaper than a double sided board in some commercial products). The not so large or heavy components (high wattage SMPS resistors, amplifier modules etc. that have suitably large holes for hand stuffing) is where long term use with single sided boards causes problems, and where I still make a few “tax free ” dollars.
Again, I stress, this single sided board problem is really only in high usage, reasonably cheap, domestic consumer products, and, of course, some of the ultra cheap rubbish coming from a certain Asian country.
I did, at Clayton Vic. Au. Dry joints were a no extra charge, no option for pretty much all the TVs manufactured in the 1970s.
Philips CTVs were a great product. I made a lot of money out of repairing those from out of warranty to end of life, at round the year 2000. A lot more money than I did as a junior engineer working for them for about 6 years.
I suppose, to be fair, a compromise was struck over the PCB stuffing. It was all done by hand in those days, ad a larger hole meant quicker and easier parts placement, but more susceptibility to eventual dry joints.
In the 90s I worked with products using Paninsert through hole machines for bandoliered resistors. These required oversized holes. I’m not sure when these machines came into use.
Depending on the size if your board, your reasoning is just nonsensical these days.
100mm x 100mm board from China are, circa, $2 for 5 units. If yoh dont mind waiting you can get delivery for inder $5.
Anyway, temember Google is your friend (hint hint)
Found the dollowing lonk.whuch should get you stated
My experience was with low wattage and light parts in telephone sets. These do get a lot of dropping abuse, but the pcb was small and very well supported.
If you ae not designing for very high volumes or to use milling, forget about single sided
Unless you are trying to do millions of boards and prepared to have a punched
PCB you can not save money.
And the assembly image you share was of through hole components which are not the low cost way to make assembly.
Your approach will save approximately nothing on PCB and will likly add assembly cost and component cost.
Assuming you find a manufacturer that will make your single sided PCB for you . . . just don’t send them the Gerber for the top (component side) copper layer.
Do all your routing on the bottom side (non-component side), use wire links where you absolutely cannot find a route and have to cross tracks. Keep your tracks chunky for added strength and stability.
So as per your images and the fact you have Silkscreen on the component layer you would send the following gerbers:
So I do single sided PCB’s reasonably regularly and that is because of IMS. You just don’t send them the BOTTOM layer information, but you should talk to the fabricator to align on this
” dollars.
