Several of my previous posts relate to LEDgoes, the first product of OpenBrite, LLC, which ran a very successful Kickstarter campaign. Stacy & I designed this product (which requires a great deal of custom hardware), though we are in fact two software engineers by trade & schooling. She has experience, though, with manufacturing various audio components from voice coils and cables to amplifier circuits, has worked with Ray Samuels on some of his designs, and she even took a class in D/A and A/D integrated circuit design. Nevertheless, through the Kickstarter experience, we embarked on a whole new world when it comes to scaling up production on circuit boards.
You Can't Pick Your Parents, But At Least Pick Your Partner
Selecting the right assembly company is crucial. Many companies can produce the hardware for you from end-to-end, source the parts for it, test it, and even help out in the design phase. Some of these companies can do everything in-house, and others will sub-contract certain pieces of it such as obtaining raw PCBs or solder stencils from other vendors. There are websites that list PCB assembly houses by the hundreds throughout the USA, but often it is hard to find reviews for them because most companies ordering hardware have known the same suppliers and manufacturers for many years and have no reason to write reviews.
Originally, we elected to go with one of these "end-to-end" services which would source parts for us, order PCBs, and then handle assembly and testing themselves. Interestingly, this presented us a huge tax advantage too, since our hands were free of any inventory: we licensed them to produce our design for free, paid them their contracting fee, and intended to split the profits from sales (which they would be handling) later. Not only that, but we thought it'd be great to kickstart a local assembly business consisting of two friends of ours from the local Makerspace looking to move out of the corporate world. Unfortunately for us, we did not really research their work ethic ahead of time. This resulted in an inordinate amount of delays: one of them (who basically had all the assembly experience) started neglecting the company since shortly after we placed our work order, thus causing it to become very unprofitable. (The latest drama revolves around their website, which this person is supposed to be in charge of; it has been down for approximately two weeks as of this writing.) As such, the other person had to continue working their corporate job while conducting LEDgoes assembly and test. When your reputation and brand is on the line, it is important to work with suppliers and vendors who do not shrink from their responsibilities, because their lack of responsibility will negatively affect your image too. An actual business with a large staff and years of experience is the only way to go in order to handle hardware manufacturing, even if you think a small group of friends with their own startup is fully capable. There is just no replacing trained, fully dedicated staff who have an established business process and are already familiar with the nuances of their own equipment.
What To Look Out For
Always take a tour of the facilities if available. Make sure the pick & place is nice -- it needs optics, trays/guides, and the ability to support enough reels to make your product. (Your components don't always have to be on reels -- tape alone is usually sufficient -- but reels will save the production engineer a bit of trouble.) Good optics mean better quality & less rework, since the chips will align squarely with the pads and nothing will be even 1 or 2 degrees tilted coming out of the reel or tray.
The reflow oven needs to be proper and big enough to hold your panels. It might look like a giant microwave oven with an LCD screen in front allowing you to control the temperature profiles for the specific solder paste you're using. If there's no window, no LCD, and no fan inside to ensure even heat distribution (so all the solder reflows as expected), run away like the wind. No proper reflow oven in sight = no business doing business.
They should have a proper way to clean the boards. And, if a substantial amount of through-hole work is required, a professional assembly company will handle that with a huge wave soldering machine. (Not even the entire volume of Partnerboards we had to produce warranted turning on and setting up the wave soldering machine, according to their sales representative, but they were still able to do all the through-hole work on 45 5" x 7" panels in a single day.)
You Shouldn't Be Surprised By...
Engineering support can be troublesome. If you prototyped something and it doesn't scale up, or when you want to expose features that aren't really supported by the kit, you may end up referring to either vague documentation or support "engineers" who barely know V = IR (ahem, TI, ahem...) One of our friends who used to work at CircuitCo lamented on TI's engineering support: to paraphrase, "They would always start by blaming the inductor, but once you would find the real cause, they would go 'Oh yeah, that...'"
Legitimate companies take a dang long time to get moving, unless you're paying for some premium rush service. For instance, I contacted a company about assembly on December 9 to begin discussing a quote. They took a 2-week holiday for Christmas/New Year's, while I worked on legitimate engineering diagrams for them, and they finally gave me the quote on January 14. (In case you've been wondering what else I've been doing besides posting here... :-P) My board house, too, always seems to take toward the upper end of their time estimate (typically 2 or 3 weeks) to finish a job. Once upon a time, I paid them an extra rush fee to finish a job a week earlier than the low end of their usual estimate (i.e 1 week), and it ended up coming back right on the low end of their usual estimate (i.e. 2 weeks). However, they are local, I can drive to pick up PCBs (or get issues fixed fast if there's a problem), and usually when I'm there, I get in a conversation with the lady in front about other ideas I have and what they could do to make it possible. The only really fast job was from the company that made my solder stencil. Then again, I probably could have laser-cut my own (which is all they did) if I had 4-mil aluminum and an appropriate frame on hand, and if the laser on the laser cutter at the local Makerspace had a small enough kerf width.
The China Syndrome
Don't forget that the Chinese New Year usually means most Oriental suppliers are on vacation throughout a good chunk of the month of February. However, this isn't the main point of this section.
Most of my vendors are in fact local, but I did end up ordering certain things from Alibaba & AliExpress. I have not had a bad experience with a single one of my Chinese vendors -- they all shipped out what they promised, even if it took a little longer than expected to produce. I tend to stay up until about 1 or 2 PM Shanghai time anyway (sometimes all the way until it's time for them to go home) to seal the deal. Keeping the conversation flowing on Skype always helps, especially if they are the slightest bit unclear on what you want. However, one of my suppliers was so good that we only needed a short email exchange before he was clear on what I wanted, and delivered it within a few weeks. For a shot at above-average service, be friendly & get a little personal over Skype or email. Ask how their weekend went, if they have any kid(s), what they like to do besides work, etc. But before engaging in any business from Ali.*, make sure they've been verified and have good ratings from other buyers for the products you're specifically asking for. And even if such is the case, you may still get fakes -- I got fake FTDI chips, though they still work fine for the most part (a bit more sensitive to ESD, and a very slightly different IC package shape).
In all, I learned a great deal about manufacturing through the second phase of the Kickstarter experience, and I had quite a bit of fun putting some of the panels together myself in the interlude between using two different contract assemblers. However, now that my supply chain seems to be taking shape finally, I intend to only experience the thrill of manufacturing prototypes, and save the rest of my time for design work. Nevertheless, this knowledge will help me communicate more effectively with manufacturers in the future.