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How I Made a Cheap PCB

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Re: How I Made a Cheap PCB

#61

Post by LeifCarrotson »

cillian64 wrote: post #34
bhickey wrote: post #18

Earlier quoted context omitted.

How do you feel about using a toaster oven? I've had some success using a DIY reflow oven and pick-n-place by hand. Haven't tried 0201's, but 0402 resistors and 5mm QFN packages go pretty well. Just don't use lead free solder.

I think the hate for lead-free solder is either a bit much, or outdated. I've used nothing but lead-free for both hand-soldered PTH and toaster-oven-reflowed SMT and get reliably excellent results. This is with cheap solder, dodgy HASL PCBs and a consumer toaster oven.

I don't know about cheap solder - I have done rework on lead-free boards that required an absurd amount of heat - but I love working with Sparkfun's special blend of 96.35% Sn, 3.0% Ag, 0.5% Cu, 0.15% Sb (Antimony): https://www.sparkfun.com/products/10243

Re: How I Made a Cheap PCB

#62

Post by LeifCarrotson »

VLM wrote: post #40
LeifCarrotson wrote: post #7

Earlier quoted context omitted.

The PCB business 5 miles away has US labor and associated costs. Compare the Chinese board to Advanced Circuits in the US - http://www.4pcb.com/ - you can't get anything without spending over $100.

4pcb is $33 each min 4 total $132 for 60 sq inches per board times 4 = 240 sq inches or 1548 sq cm for $132 dirtypcbs is $14 for qty 10 of 25 sq cm boards or 250 sq cm total. So 1500 sq cm of boards from dirtypcbs would cost about $14 times 6 or $84. Note that ethically, outsourcing to China is the modern version of handing syphillis blankets to indians. "Well, they're warm blankets, and they did ask for it, and anyt…

60 square inches per board is enormous, but they don't care because the material is cheap and the labor is about the same regardless of the board size. If you use their regular pricing that takes the area into account, it's still incredibly expensive.

Re: How I Made a Cheap PCB

#63

Post by schiffern »

jdietrich wrote: post #56
madengr wrote: post #3

Nice, instead of supporting the PCB business 5 miles away, send it to China. The copper not on your PCB is probably floating down some Chinese river, hence "Dirty PCB".

Copper is a valuable commodity. No Chinese board house will be foolish enough to waste it. With modern processes, it's simply a case of neutralising the etchant and filtering out the precipitated copper. "Dirty PCBs" are so named because they're not great quality. The solder mask and silkscreen aren't perfectly aligned and the minimum trace width is eight mil.

>Copper is a valuable commodity. No Chinese board house will be foolish enough to waste it. With modern processes, it's simply a case of neutralising the etchant and filtering out the precipitated copper.

Except that motivation will only results in removing just as much copper as it's economical to extract. They'd still discharge the remaining copper once it reaches concentrations too low to bother extracting (but plenty high enough to cause damage to biological systems).

This also ignores all the other stuff in the etching and rinse baths, which isn't exactly benign.

Re: How I Made a Cheap PCB

#64

Post by jpindar »

ZenoArrow wrote: post #35
alex_hitchins wrote: post #20

Earlier quoted context omitted.

Well, it is listed under "Ramblings". I don't think it was written as an article, it's just a blog post that could help out someone looking to do the similar.

> "Well, it is listed under "Ramblings"" My issue was with the word 'made'. If I see a title for 'I made x' I expect a little more than 'I ordered x'. I'm not going to make an article about 'How I made an iPad' if I just ordered one from Amazon.

I work in electronics manufacturing and if I said "we made a new board for this project", I would mean we laid it out and sent it out to be fabricated.

Re: How I Made a Cheap PCB

#65

Post by pgvoorhees »

god_bless_texas wrote: post #43

Anyone here use expresspcb.com and their own software? I've tinkered with Eagle and considered KiCAD but I am intrigued by the co with the software built into their design process.

I've used it an age ago. Don't bother. The software wasn't terribly sophisticated. The library support was OK at best. And the only thing it really does is make ordering a little easier. It's only slightly more work to use a FOSS tool and generate output which can go to and board house.

Re: How I Made a Cheap PCB

#66

Post by Grishnakh »

daniel-cussen wrote: post #24
diskcat wrote: post #19

Earlier quoted context omitted.

>Nice, instead of supporting the PCB business 5 miles away, send it to China. I don't see why he should support somebody who charges 5x the competitor. Im not gonna pay $20 for a jar of peanut butter because the factory owner lives 5 miles from me.

Ok, you aren't, but I might. And others too: witness the popularity of otherwise ineconomical farmer's markets, for instance. It supports local industry, which "keeps money in the family" to a large extent (and protects from predatory pricing down the road), and connects with the local industrial community more. You never know when they might know the person that can help you out with whatever glitch. Except when the…

Farmer's markets are popular because the food is higher quality. The reason for this is simple: it's fresher. You're buying it right after it was picked, and it was allowed to ripen fully before being picked. A lot of produce from grocery stores isn't like this: it's produced in other countries, or using methods to artificially ripen it after picking, so that it'll look ripe in the store.

It's simple biology and physics: if you want freshly-picked fruit, you have to get it nearby, unless you're going to pay $$$$ to have someone ship it to you by overnight shipping (and it's not economical to ship food that way).

How is some local farmer going to "help me out with whatever glitch"? He's busy running his farm. He doesn't live next door to me, he lives 20 minutes away. He might as well live across the country. But his food is probably going to be fresher and better quality than food at the supermarket that was shipped in from Central America.

Re: How I Made a Cheap PCB

#67

Post by bhickey »

cillian64 wrote: post #34
bhickey wrote: post #18

Earlier quoted context omitted.

How do you feel about using a toaster oven? I've had some success using a DIY reflow oven and pick-n-place by hand. Haven't tried 0201's, but 0402 resistors and 5mm QFN packages go pretty well. Just don't use lead free solder.

I think the hate for lead-free solder is either a bit much, or outdated. I've used nothing but lead-free for both hand-soldered PTH and toaster-oven-reflowed SMT and get reliably excellent results. This is with cheap solder, dodgy HASL PCBs and a consumer toaster oven.

Got any debugging tips? I had a lot of trouble with lead-free paste bridging on small pitch components.

Re: How I Made a Cheap PCB

#68

Post by stephen_g »

madengr wrote: post #3

Nice, instead of supporting the PCB business 5 miles away, send it to China. The copper not on your PCB is probably floating down some Chinese river, hence "Dirty PCB".

That's an overly hostile comment - and unrealistic - I'm guessing you're probably not in the electronics industry?

In many places there's only one reason a small company (let alone an individual) would buy a short run of PCBs locally - you desperately require it in two to four days and are willing to pay six times the price to get it.

It's not that people aren't willing to support local PCB manufacturers, it's just that the manufacturers know there's very money in cheap, small volume work outside China and focus on the profitable niches (like really fast turnaround), which usually makes them unaffordable for hobbyists.

Re: How I Made a Cheap PCB

#69

Post by stephen_g »

bhickey wrote: post #18
david-given wrote: post #11

Earlier quoted context omitted.

Do you know any places that do assembly as well? My soldering skills are approximately good enough to do 0.1 inch pitch pins about 90% of the time, which isn't really good enough for surface-mount, and most modern microprocessors don't come in anything else.

How do you feel about using a toaster oven? I've had some success using a DIY reflow oven and pick-n-place by hand. Haven't tried 0201's, but 0402 resistors and 5mm QFN packages go pretty well. Just don't use lead free solder.

Just don't use crap solder, actually... There are some good lead free solders available on the market now. Nihon Superior SN100C, for example.

The biggest problem I see with hand soldering is people not using enough flux (get a no-clean flux pen, they're amazing) and then just blaming the solder when they can't get it to flow... Reflow will do similar if you let the flux dry out (keep it in the fridge - I often put it in a zip-lock bag to try and really keep moisture out also).

Re: How I Made a Cheap PCB

#70

Post by ggoss »

bobadams5 wrote: post #47
jwr wrote: post #38

Several points: * KiCAD has become a great tool for designing boards, even fairly complex ones. And it's completely free, both in terms of freedom and money. Don't get locked into EAGLE, which is becoming increasingly obsolete (development is glacially slow) and will suddenly become quite expensive to use once you want a certain board size or a number of layers. * There are multiple PCB services in China, itead.cc, s…

Has KiCAD improved their schematic/footprint library management? Last time I tried to use it (2 or 3 years ago) it drove me crazy with how difficult it was to use. I've used Diptrace, KiCad, Altium, and Cadence Allegro and KiCad was by far the worst of these for handling parts.

I believe so, yes, though the degree to which this is true depends on whether or not you were using the beta at the time. The latest KiCad stable is worth a look if you haven't tried it in a while
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