Creating a product from start to finish - Page 1
Forum section: electronics / general

author: german77
author_rank: Regular Contributor
timestamp: February 09, 2018, 02:30:03 am
content: Hi this is my first time creating a product in 100+ quantity. I want to create a case and circuit board with components.I already have the schematics and component list for everything. And been able to make a few working prototypes. There are many places where they can make a 2 layer PCB. But I don't know anything about PCB assembly.Do I have to send them the PCB and components?Did they make the PCB and with a part list they get the components needed to make the assembly?What considerations do I need to have for the assembly?Recommended places for PCB assembly?Where I can found a case manufacture for my product?Info you may need to know:PCB- 2 layer, 1 side components, 100 x 150 mm, through hole and SMD components, less than 25 different components.Case- Just a box with holes for connectors, components can heat up but it's designed to stay cold most of the time.Budget- 3000 dollars, obviously it has to be cheap enough to be viable.Quality- Nothing fancy, just reliable for at least 2 years.Time- Max 1 month to get a finished product.I can do some steps by myself but they must not be time consuming or need special tools.I'm from México, no luck finding something in here, importing anything specially from USA doubles the price.I hope someone would guide me to make this product ready for mass production. Thank you for your attention.

author: rx8pilot
author_rank: Super Contributor
timestamp: February 09, 2018, 02:49:15 am
content: Look at the typical extruded aluminum case companies like Hammond. There are quite a few. Some of them offer machining and vinyl face printing.Send your Gerber files to a few PCB houses for quotes. You can have them source the parts or buy them yourself and send them a kit with extras.You have to be able to test and qualify the design well enough that you don't drive into a wall by having some little flaw that you have to fix on your dime. you also have to be very detailed with PCB assembly to ensure you get a good result. If you mess up and the boards do not work - you pay for the mistake and that can be pure pain. Don't ask me how I know.With low volume, low budget, and tight timeline as you say - good luck. I have a whole factory and might not be able to pull that off - even with off the shelf cases.

author: imidis
author_rank: Frequent Contributor
timestamp: February 09, 2018, 02:51:43 am
content: You mention 100+ but how many do you need?I can't be of much help, but quantity will make a difference on how you approach.In a lot of cases setup costs can be prohibitive on small runs.Spend wisely and be realistic.

author: rea5245
author_rank: Frequent Contributor
timestamp: February 09, 2018, 02:53:07 am
content: I've had PCBs manufactured and assembled in China. One company took care of both tasks. I sent them the Gerbers and the parts list. They ordered the parts from Digi-key and Mouser, so I didn't have to send them anything. I didn't have them do the case, so I don't know whether they would've done that.If I had wanted to send them the components, I'm sure we could've done it that way. But I liked the "turn-key" convenience of having them do all the work.My quantity was 30 boards and it took between 3 weeks and a month. One week of that was making the PCBs. I don't know whether they ordered the components while the PCBs were being manufactured, or if they waited until the PCBs were done before ordering the components.China is on its New Years break for the next week or two, so you won't be able to talk to them for a while.- Bob

author: imidis
author_rank: Frequent Contributor
timestamp: February 09, 2018, 02:56:30 am
content: What was setup cost?

author: Siwastaja
author_rank: Super Contributor
timestamp: February 09, 2018, 09:14:25 am
content: Recently, I have had quite good experience on PCB assembly from PCBWay. Everyone uses them for board manufacturing, but it was quite impossible to find actual testimonials for their assembly service - so I just took the bullet and tried them, and have been very happy.The first board was actually rather complex - I tried to get a quotation from a local, more expensive assembly house and it was a nightmarish discussion since they didn't even seem to understand the design files at all. No issue whatsoever with the Chinese! Everything was manufactured correctly, and out of 30 boards, about 400 components each, some 0.5mm LGAs, many 0.5mm QFNs, and 54-pin 0.5mm TSSOPs, and tightly packed 0402 passives, and some power components, 29 boards tested electrically perfect; one board had one solder bridge and one pad lacking a bit of solder.When sourcing the components, they add a bit more than you'd expect on the top of the actual component prices (around +30-+50%), so this offsets the insanely cheap setup cost (typically in range of about $500 even for a complex design). (Some extra is to be expected, since they need to order some extra components - also, this increase is to pay for the sourcing job. It's still a little bit more than I had expected.)Recently I sent them some components as well. No problem there. They are very responsive as well, and ask for confirmations (clearly written, with pictures) whenever I have forgotten to specify something, such as a LED polarity.This reply is not sponsored or paid by them. Just a happy customer. I'm sure there are even better assembly houses, but the low cost, good customer service, and the easiness of the process has been nice.Things to remember with any assembly service:- Make sure the components are built correctly so the centroid file works OK: i.e., the origin must be in the middle of the component, pin1 or cathode to the left, and so on.- In addition to P&P (centroid) file, you need to supply a basic excel BOM with quantity, designator list, and the order code- You also need to deliver an assembly drawing, unless your silkscreen is really complete. With today's integration levels, silkscreen typically cannot fit all the info in a clear manner: so this is basically a pdf file where each component outline is drawn, and the designator is inside this outline, and the pin1 / cathode / whatever extra information for orientation is clearly marked. This file is a must because, unfortunately, the standardization for the P&P files is a rather new thing, and kind of broken, so they can't trust the automated information of the pin orientation, and need to manually check each component. For example, some datasheets draw diodes cathode to the left, some cathode to the right, some draw them vertically. How do you translate this datasheet to the PCB library component?

author: josip
author_rank: Regular Contributor
timestamp: February 09, 2018, 11:55:34 am
content: Quote from: rea5245 on February 09, 2018, 02:53:07 amQuote from: Siwastaja on February 09, 2018, 09:14:25 amCan you attach hi-res PCB part, with 0402 / 0603 or QFP / QFN components?

author: Mr. Scram
author_rank: Super Contributor
timestamp: February 09, 2018, 12:03:01 pm
content: Quote from: rea5245 on February 09, 2018, 02:53:07 amI would be a bit wary of paying for original parts when the assembler orders them himself. You wouldn't be the first to get caught out with cheap or fake components.

author: rea5245
author_rank: Frequent Contributor
timestamp: February 09, 2018, 12:40:07 pm
content: Quote from: imidis on February 09, 2018, 02:56:30 amThey quoted ten dollars for "engineer start". All the other prices varied linearly based on the number of units they were quoting. So it looks like they didn't charge a setup cost (or they hid it in the per-unit cost).- Bob

author: rea5245
author_rank: Frequent Contributor
timestamp: February 09, 2018, 01:26:24 pm
content: Quote from: Mr. Scram on February 09, 2018, 12:03:01 pmI've done this a few times and experienced less than 5% DOA boards. I never thought to attribute it to counterfeit parts, but I guess it could be. I haven't seen any problems with the non-DOA boards.If we're not going to trust a company to order genuine parts, why would we trust it to use the parts we send them, rather than replacing them with counterfeits and selling the genuine parts?- Bob

author: german77
author_rank: Regular Contributor
timestamp: February 09, 2018, 04:03:59 pm
content: Thanks for your help. I would not worry about counterfeit parts, as long as they do their work. I will give a try to PCBWay as my current supplier is Digikey and Mouser. And while the new Chinese year is over, I would make the assembly files are as clear as posible.This is a small run, specially because my company is crying for this circuit and I want to test them and fix problems that can happen with time. But if it turns out well I will be making 10000+ without "limits" in budget and up to 6 months.If I run in to problems. I would let you know.

author: Mattylad
author_rank: Regular Contributor
timestamp: February 09, 2018, 05:44:27 pm
content: For the enclosure, I would look for an existing one, this will be far cheaper and quicker to obtain than anything being made specially for such a small quantity - tooling charges alone could wipe out your budget.