A few “smart pills” for manufacturing short-run electronics

Written by Daniel Price

Uh-oh. Here come the hard decisions. You knew you’d have to make them as soon as you were put in charge of the company’s first-time IoT project

Now you’re facing the manufacturing tiger. You have made it through the engineered prototype and proof-of-design phases of your new IoT product and now have a product that works as it is supposed to. More or less.

Admittedly, the assembly and fit-and-finish of this product were done at your office and it was a messy business — file to fit, bash to close, paint to hide. The PCB didn’t snuggle into the mechanical encasement quite as planned, so John took the prototype back into the shop for a chat, dragged out the Dremel, and made sounds like a dentist putting in a crown. More than a few wire jumpers found their way onto the board, and a trace or two on the PCB had to be cut — but hey, now that the little fella is tucked inside the encasement, no one can see that. It looks great in the PR photos.

Now you are gearing up for your engineering validation test run (EVT — the first stage in the production ramp of a new product). This means that you are going to have to trust a contract manufacturer (CM) to handle the complexities of your product build and assembly, and without resorting to the Dremel.

Risks hover over the prototype at this point — mainly design changes to the PCB (corrections from the mistakes on the engineered prototype). The engineers seem confident, but committing to manufacture on a batch of non-functional PCBs would be a major setback to the program. If nothing else, it risks a late-to-market launch of the new product. And these days, market timing is (almost) everything. Budget has reared its ugly head, too. The materials cost for half a dozen prototype PCBs, and John’s time with the Dremel, were chicken feed compared to the manufacturing bill you are about to receive for your EVT. Yikes.

Does this sound like what you’re up against?

Factory-Short-Run

The table below shows how we at Breadware weigh our own production decisions for the first PCB manufacturing batch of a new product. We’ve worried through this exact scenario hundreds of time. This is our guide to getting through the wilderness of short-run production.

We see five general decisions you must make (your own situation may include more, but rarely fewer):

  • Geography — where to manufacture
  • Turnkey or kitted
  • Testing needs
  • Manufacturing capability
  • Lead time required

The table highlights the various considerations you should work through to come up with answers to the above decisions.

Your Considerations

1. Price

Price can make the difference between breaking even and breaking down. You have a budget for your manufacturing run. Once you make sure that your essentials are covered, your primary goal often becomes one of minimizing the manufacturing price.

In evaluating price, lead time will play often play the most important role. Next, is geography. Manufacturing in the United States will almost certainly be more expensive than manufacturing in China. However, the decision is not that simple. Geography affects shipping costs — all parts must reach the manufacturer, and assembled goods must get back to you. Ease-of-contact also plays a part. What is the time difference between your location and the manufacturer, and is that going to result in days lost in a conversational back and forth? Such delays will cause indirect price increases.

2. Quantity

How many devices are you planning to make?  The quantity you’re building may determine if you want to request a kitted or turnkey order. For lower quantities (less than 1000 units), procuring parts yourself and shipping them to the manufacturer may make sense. For larger orders, you may not want to deal with kitting your own parts, and can justify placing a turnkey order. Another item related to quantity is the availability of your parts. Take a pass through your bill of materials and make sure that your supplier can provide the quantity of parts you need — you don’t want your product delayed for two weeks because of lack of availability for a connector. As good practice, you should also go through all the parts on your BOM and ensure that none of the parts are marked for an upcoming end-of-life. If so, it is strongly recommended to swap them out for your upcoming design; making changes later when you have your runaway success and your production volumes are bigger will only be harder.

3. Quality

Geography can affect quality in a few different ways. Many manufacturers have an “open door policy” where you can come and see your board manufactured. Of course, this is harder to do the farther away your manufacturer is located.

The larger manufacturers in China are going to build what you ask them to build. This usually good; but if you have made a mistake in your board, this can cause a problem. Manufacturers who are more local may offer more support and service and be able to offer design reviews before beginning the manufacturing.

4. Complexity/Tolerances

Different manufacturers offer different tolerances to which they can build. Manufacturers have specialties. They address their areas of expertise on their web sites. For example, the closeness or tightness of components on a PCB is called pitch. (Think of pitch as how closely your airplane seat is positioned to the one in front of it.) If you have tight tolerances for your PCB — say, it must fit into a small space, and thus the components must be close together without crosstalk on the traces — you may be excluding manufacturers that can't meet that tolerance. Typically, the higher-precision/higher-tolerance manufacturers will be more expensive. But you are paying for that higher level of precision.

5. Certifications

IoT devices communicate to the Internet by definition, but very few of them are hard-wired. Most of them communicate wirelessly and therefore use the public airways. Regulation of those airways varies from country to county. Different manufacturers may offer different certification capabilities for different environments and countries — if the manufacturer does not offer these certifications in-house, they may know nearby electrical testing labs that can offer the certifications. It doesn't hurt to ask. Geography plays a part in that a manufacturer may not be skilled in the certifications required by some distant country.

6. Time/Lead Time

“Time is money,” said Benjamin Franklin. He was right. Time in production plus shipping time (geography, again) equate to time-to-market, where time really is money. You will need to factor in the lead times of your supplier, shipping times, fabrication time, assembly time, testing time, and perhaps certification time. You can speed up any of these steps — but it will probably cost you.

7. Expertise/Experience

If you’re coming to device manufacturing with less experience than you might want, you’ll rely more on your manufacturer. You’ll want a manufacturer with good customer support/service. Lead times and even pricing become (a little) less relevant. Better to get a working device than a fancy paperweight, right? Ask the manufacturer if they can do 100% testing, and if they can provide you with a turnkey service.

Once you’ve surmounted the engineering validation test, you’ll be tooling up. This means investing $10–15K each in the manufacturing tools for injection molding for your mechanical pieces, as well as investing in the electrical circuit testing rig. Finally, you’ll navigate the certification process for your design validation test (DVT) and production validation test (PVT). Breadware will be releasing a series of articles to cover each of these stages.

Apple2

Remember even at the manufacturing stages, everyone makes mistakes along the way. The resin cases for the first hundred or so Apple II computers arrived from the manufacturer more gray than beige — and beige had been the color specified in the order. So, Steve Jobs went into the back room with some spray paint to make those cases right. Hopefully, your worst manufacturing mistakes also will require only a can or two of Krylon.


Learn more tips like this at HardwareCon 2018, the Bay Area’s Premier Hardware Innovation Conference on April 19th-20th.  Experience two full days of keynotes, panels and workshops focused on the most important topics around building a successful hardware company. Get" class="redactor-linkify-object">http://www.hardwarecon.com/">G... your tickets here now if you want to meet the hottest startups, investors and industry leaders across the global hardware ecosystem.

About The Author

Daniel Price

Daniel Price

CEO at Breadware

Breadware is a company whose mission is to reduce the time, cost, and risk of bringing IoT hardware to production. Daniel is an author on eight patents and has experience at all stages of the electronics development cycle. Prior to founding Breadware, Daniel was the Director of Electrical Engineering for MotoCrane, a robotics company specializing in providing state-of- the-art filming tools to the cinematography industry. Daniel is a Rhodes scholar and holds an MBA and MSc in Biomedical Engineering from Oxford University as well as BS degrees in Electrical Engineering/Computer Science and Bioengineering from UC Berkeley.

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