Anyone familiar with contract manufacturing industry practices? - Page 1
Forum section: electronics / general

author: mpmarquez
author_rank: Newbie
timestamp: April 23, 2025, 03:54:47 am
content: I recently worked for a contract manufacturer in Florida. They fabricated PCBAs for customers where the PCB was fabricated by another company and they populated the SMDs and other parts. Before they sent the PCBAs to the customer they had to test them on test fixtures designed and made by the customer and made sure they passed.My experience has been working for a company that designs its products, some assemblies might be built on site and others contracted out, but the product is tested by the company usually on full sized test stations with professional test and measurement equipment where the hardware configuration/connections are well documented and the software (often LabView/TestStand) is available to read and debug.But at the contract manufacturer I worked for the customer provided the test fixture and hardware usually in a small box with the software running on an Arduino board.There was no documentation provided for exactly what the test fixture was measuring in any specific test or any info on what calculations the software was doing. Usually you couldn't pause the tests so it would run from one test to another even if one test failed. This was fine if you just want an operator with no experience to test if something passes or failed. However there would be many boards that failed and these test fixtures were no help at debugging exactly what was failing or even provide any detailed logs. I was told that this was standard in the contreact manufacturing world.I couldn't understand why the customer would not provide any details on the test fixtures while at the same time they provided schematics and gerbers of the actual device under test (DUT). I would think that the DUT/product was the thing they would be concerned about giving to much info about and that the test fixture just served the product. To me the DUT and the test station form a system and you need to know what is going on with both when in debugging mode.I would find myself approaching the problem as if I had to reverse engineer the test fixture so I could then try to isolate the problem on the DUT. So I looked at it as trying to understand the operation of the test fixture and DUT circuit. But I was told that this is not how it is done in contract manufacturing. If something failed they would just kind of "throw spaghetti at the wall" by removing and replacing components until the PCBAs passed. One problem I found with this method was in the process of reverse engineering the test fixtures it appeared to me that there was usually not anything wrong with the PCBAs/DUTs and it seemed to be problems/glitches with the test fixtures where it seemed that the same exact unit would sometimes pass and other times fail.So I tried to get the management of the contract manufacturer to contact the customer (since I wasn't allowed to do that myself) to relay what I was finding with the test fixtures but they were uncomfortable with doing this telling me that the customer can just take their business away and go to another contract manuafcturer. Which is exactly what happened. A customer that accounted for 80% of their business got angry about the contract manufacturer's inability to ship units that they basically pulled almost all their business. I just couldn't understand the logic behind this. I wanted to be able to resolve problems for the benefit of both my employer and the customer but I got the impression that they were locked into a zero sum game with each other.Is this anyone else's experience in the industry?Edited: Added breaks to break up wall of text

author: Psi
author_rank: Super Contributor
timestamp: April 23, 2025, 04:07:27 am
content: yes, Just yes.Contract manufactures are often though of as a black boxes that only requires money to get an output that meets the requirements.And this is reinforced by the fact that the money they charge is so high. The... "we're paying you a lot, figure it out"..One downside for contract manufactures is that the people/companies who hire them are more likely to be startups/non-technical.eg, Just a shit ton of investor money and an idea or prototype.So they often don't have much of an internal technical team to build high quality prod equipment.You really want to figure this out at the start and make designing prod equipment part of the contracting agreement if it looks like they will be shit at it for the exact reason you described. Bad 3rd party prod equipment makes you look bad.And of course there's the usual problems where non-technical people in management make engineering decisions, or decisions that effect engineering, and totally screwing themselves and the company due to lack of understanding. That's a bit one.

author: hwasti
author_rank: Contributor
timestamp: April 23, 2025, 07:22:32 pm
content: There is another bigger problem here.A business, ANY business, if it lets one customer be responsible for 80% of its revenue, is in serious trouble. If that customer walks, fails or has a downturn, the business can fail faster than you can ask "what happened?"Also, paragraphs are your friend. Use them liberally.

author: hwasti
author_rank: Contributor
timestamp: April 23, 2025, 07:32:10 pm
content: Quote from: Psi on April 23, 2025, 04:07:27 amA hard disagree on this.Based on my experience, a majority are companies that do not have enough volume to justify having an in-house manufacturing setup. If you look at long term clients, such companies comprise a vast majority. These companies can have qualified and competent engineering teams, but do not generate a large volume on the products they make. This is very common in defense, aerospace and other industries with high ticket items.

author: GridWork
author_rank: Contributor
timestamp: April 24, 2025, 06:01:23 pm
content: Sending complex assemblies to contract manufacturers seems like it is a thing. My employer is looking at outside sources to build very complex Hi-Rel boards that require extensive testing and tuning. The expectation is also that wherever will be an order of magnitude cheaper than in house. They are expecting the supplier to just suffer the yield costs and have all of the expertise to assemble the boards, test, populate the "select at test" parts, conformal coat, pot (if required), perform the temperature testing and deliver fully functional boards that can just be assembled at the box level. All of the prior, cheaper than we can do in house, with the volume being around 20-40 board sets per year (less than 6 boards per set).I think that it would be extremely challenging at best (I've been doing this type of stuff for over 2 decades by now). I'd love to hear continued thoughts on this matter.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 24, 2025, 06:46:26 pm
content: Paragraphs.

author: Psi
author_rank: Super Contributor
timestamp: April 24, 2025, 10:57:03 pm
content: Quote from: hwasti on April 23, 2025, 07:32:10 pmyeah sorry, I kind of mess up what i was trying to say.

author: mpmarquez
author_rank: Newbie
timestamp: April 24, 2025, 11:40:29 pm
content: One of the guy's I worked with mentioned that often between the customer and contract manufacturer there is another company whose expertise is developing prototypes and working out the wrinkles before going into mass production. He said a lot of customer's skip this step to save money.

author: Psi
author_rank: Super Contributor
timestamp: April 27, 2025, 01:44:55 am
content: Exactly.