Author Topic: Professional assembly mishaps  (Read 29690 times)

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Offline gnif

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Re: Professional assembly mishaps
« Reply #75 on: December 16, 2017, 06:49:35 am »
maybe you should firstly answer my questions. have you checked the site registration date, as  you believe i have been there for 3 years. 
i have answer your questions with "left".

I suggest you stop here, I have had a look at your post history and issued you a warning. Your activity is very suspicious. Any further plugs for Makerfabs will incur a ban on your account.
 
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Offline EEVblog

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Re: Professional assembly mishaps
« Reply #76 on: December 16, 2017, 06:58:50 am »
Shill confirmed:
https://www.eevblog.com/forum/beginners/which-stores-do-you-guys-usually-purchase-from/msg1284806/#msg1284806

Quote
depends on what do you want to buy
1. for components IC: digikey/mouser;
2. for components common used such as LED: aliexpress/ebay/amazon
3. for instruments: alibaba;
4. for hardware modules: sparkfun/seeed

personally in the past half a year i orders some simple modules such as OLED/power supply from a store makerfabs DOT com, really good experence, their products has much higher quality than other China sellers that on aliexpress/ebay, and feedback me quickly when any problems encountered.

among many other posts about makerfab.
He's now banned. We get countless PCB house shill accounts and spam on the forum, it's almost plague proportions.
 
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Online Kean

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Re: Professional assembly mishaps
« Reply #77 on: December 16, 2017, 07:11:04 am »
this is "Manufacturing & Assembly" and the post  for "assembly mishaps", i think this is a good place to share my  experience, and caught as a "shill" |O

Yes, and some of your posts had some good info - but you continually went on about your "vendor".
I would not have cared one bit if you mentioned makerfab in every post if properly disclosed (others might have...).

I didn't specifically want you banned, you brought that upon yourself.
 

Offline gnif

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Re: Professional assembly mishaps
« Reply #78 on: December 16, 2017, 07:11:54 am »
Shill confirmed:

Good call, I didn't have time to read through his posts in detail, was just going to watch his reaction and see.
 

Offline wraper

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Re: Professional assembly mishaps
« Reply #79 on: December 16, 2017, 11:35:57 am »
this is "Manufacturing & Assembly" and the post  for "assembly mishaps", i think this is a good place to share my  experience, and caught as a "shill" |O

Yes, and some of your posts had some good info - but you continually went on about your "vendor".
I would not have cared one bit if you mentioned makerfab in every post if properly disclosed (others might have...).

I didn't specifically want you banned, you brought that upon yourself.
I wouldn't mind this myself. Actually I would not mind if he admitted he's from makerfabs and stopped pretending to be their customer. What pissed me the most is attitude when presented with evidence.
 

Offline olkipukki

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Re: Professional assembly mishaps
« Reply #80 on: December 16, 2017, 12:05:14 pm »
Not sure if anybody will bother to reply here after above "mishaps", but I will try  :-//

My questions are really simple:

Who is paying bills for these mishaps and what usually assembler contract says about that?
 

Online Kean

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Re: Professional assembly mishaps
« Reply #81 on: December 16, 2017, 12:19:34 pm »
Yes, sorry for the diversion.  I was finding this topic really interesting.

I'd guess the cost of these mistakes will depend on the contract with the assembler.  But I guess even if you're not paying for fully tested PCBA, they still have to rectify/rework these kinds of glaring errors.
 

Online Kean

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Re: Professional assembly mishaps
« Reply #82 on: December 16, 2017, 12:24:50 pm »
Here is a couple of contributions...
1. A capacitor that was poorly placed, but strangely didn't tombstone
2. A connector that must have been hand placed, as it was the wrong pin count and horizontal instead of vertical.  I think they picked up a spare connector from the PnP reject box, but didn't verify it was the right one
 

Offline wraper

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Re: Professional assembly mishaps
« Reply #83 on: December 16, 2017, 02:09:51 pm »
Here is a couple of contributions...
1. A capacitor that was poorly placed, but strangely didn't tombstone
Actually most likely it was placed completely fine. SMT pad layout with a huge gap between pads is just asking for such trouble to happen during reflow. Doing so is certainly against recommended pad layouts.
« Last Edit: December 16, 2017, 02:15:10 pm by wraper »
 

Online Kean

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Re: Professional assembly mishaps
« Reply #84 on: December 16, 2017, 02:47:51 pm »
Yes, you could be partly right there.  In this case I didn't design the board nor the footprints.  I just took the project over, made some minor changes on various boards, and had a couple of batches made up for the client.  I've since designed a lot of new add-on boards for the client with my own footprints... and written a lot of new firmware & apps for them.  That said, that particular 0805 footprint has been used on a bunch of designs without further issues.  I believe the footprint may also in use at a large UAV company (unrelated to my clients products).
 

Offline hermit

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Re: Professional assembly mishaps
« Reply #85 on: December 16, 2017, 03:57:57 pm »
Had an easy one on the Kicad forum I reported.  He used his real name and he was listed on their marketing page.  Some are just too easy.  As someone else mentioned, if they were contributing AND transparent I wouldn't have a problem with them if their shilling was at least helpful to the current situation.
 

Offline james_s

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Re: Professional assembly mishaps
« Reply #86 on: December 16, 2017, 05:10:46 pm »
I love the upside down IC.

I worked for a ISO9000 certified company for a few years. It was mostly BS, we had a bunch of processes to follow and had to read all these process control documents and sign off that we had read them. There was no assurance at all that the process was good or made any sense, just that it was documented and followed. I had to read and sign off on a bunch of process documents that had no relation whatsoever to the job I performed. One I recall involved dealing with politicians and foreign diplomats and what actions could constitute bribery. As if any of the engineers were ever in a position to negotiate with foreign diplomats and politicians.
 

Offline SeanB

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Re: Professional assembly mishaps
« Reply #87 on: December 17, 2017, 10:08:06 am »
I would say the capacitor was placed poorly, with most of it being on the one pad, if placed slightly left on the paste it would have soldered fine.

The connector I can believe, as likely they used only the central pins from the battery, ignoring the rest, so having no pads on the one would not be an issue as it likely was an unused internal cell temperature sensor.
 

Offline plazma

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Re: Professional assembly mishaps
« Reply #88 on: December 17, 2017, 10:17:18 am »
Many PCBA factories don't use AOI for small volumes. It requires a lot of work to program. Common faults may be programmed if there are more production runs.
 

Online Kean

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Re: Professional assembly mishaps
« Reply #89 on: December 17, 2017, 10:21:25 am »
The connector I can believe, as likely they used only the central pins from the battery, ignoring the rest, so having no pads on the one would not be an issue as it likely was an unused internal cell temperature sensor.

The board with the battery connector is for a submersible datalogger.  It should have a 6 pin vertical connector for the battery (including thermistor as you surmised).  The 7 pin right angle connector was used on a completely different set of boards (submersible sensors) produced at the same time.  I had to swap the connector to make it usable.  Thankfully one was like this in the batch.

Many PCBA factories don't use AOI for small volumes. It requires a lot of work to program. Common faults may be programmed if there are more production runs.

For sure!  But they always make a point of telling you they have the capability even if they don't plan to use it on your job.  ;D
 

Offline wraper

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Re: Professional assembly mishaps
« Reply #90 on: December 17, 2017, 11:32:43 am »
I would say the capacitor was placed poorly, with most of it being on the one pad, if placed slightly left on the paste it would have soldered fine.
This is not how tombstoning works, it does not require inaccurate placement. In this case because pads are very large with a very high distance between them, it was pulled horizontally with a terminal to the center of the pad instead of just lifted vertically and hanging above the pad like here:
 

Offline bd139

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Re: Professional assembly mishaps
« Reply #91 on: December 17, 2017, 12:08:00 pm »
I had one of those the other day on a cheap Chinese switcher module. It was on the input side of the unit so it still worked reasonably well, enough to pass QA  :palm:
 

Offline Mr. Scram

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Re: Professional assembly mishaps
« Reply #92 on: December 17, 2017, 12:12:52 pm »
I love the upside down IC.

I worked for a ISO9000 certified company for a few years. It was mostly BS, we had a bunch of processes to follow and had to read all these process control documents and sign off that we had read them. There was no assurance at all that the process was good or made any sense, just that it was documented and followed. I had to read and sign off on a bunch of process documents that had no relation whatsoever to the job I performed. One I recall involved dealing with politicians and foreign diplomats and what actions could constitute bribery. As if any of the engineers were ever in a position to negotiate with foreign diplomats and politicians.
ISO9000 is primarly about a quality control system being in place, not about actual quality being the result of it. That's the mistake many people make.
 
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Offline julianhigginson

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Re: Professional assembly mishaps
« Reply #93 on: December 17, 2017, 09:36:16 pm »
Who is paying bills for these mishaps and what usually assembler contract says about that?

Usually if you can prove CM fault with a local CM, they will make good at their own expense. This is less likely to happen with a cut-price overseas CM.

My most recent board run was a multi board (8 design) prototype job (X10) done with an overseas CM, selected for speed purposes more than anything else.  We paid for them to buy Digi-Key and mouser to my BOM, but when boards arrived, I had one case of a tantalum cap being the wrong voltage... And so obviously not what I listed in the BOM... So I pulled and replaced those parts myself... Noting that while the boards all basically work we have no guarantee on the correctness of any part on them... They worked fine as prototype, but that issue just killed them for any future production build of these PCBAs..
 

Offline HalFET

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Re: Professional assembly mishaps
« Reply #94 on: December 18, 2017, 08:08:56 am »
I would say the capacitor was placed poorly, with most of it being on the one pad, if placed slightly left on the paste it would have soldered fine.
This is not how tombstoning works, it does not require inaccurate placement. In this case because pads are very large with a very high distance between them, it was pulled horizontally with a terminal to the center of the pad instead of just lifted vertically and hanging above the pad like here:


The one in that image is rather nasty. That's one that AOI and even XRay might not pick up!
 

Offline CJay

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Re: Professional assembly mishaps
« Reply #95 on: December 18, 2017, 01:04:14 pm »
I love the upside down IC.

I worked for a ISO9000 certified company for a few years. It was mostly BS, we had a bunch of processes to follow and had to read all these process control documents and sign off that we had read them. There was no assurance at all that the process was good or made any sense, just that it was documented and followed.

Yup, that's my experience too, we had BS5750 and later ISO accreditation, it's all about the documentation, if you state you take each board and pray over it while anointing it with the grated peel of 1000 lemons they will approve your process but woe betide you if you only grate the peel from 999 lemons and someone spots your non compliance.

 

Offline bd139

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Re: Professional assembly mishaps
« Reply #96 on: December 18, 2017, 01:30:08 pm »
 
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Offline Mr. Scram

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Re: Professional assembly mishaps
« Reply #97 on: December 18, 2017, 02:28:52 pm »

It might be shit, but at least you know you're getting shit every time!
 

Offline HalFET

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Re: Professional assembly mishaps
« Reply #98 on: December 18, 2017, 10:40:39 pm »

It might be shit, but at least you know you're getting shit every time!

Quality!!!
 

Offline AF6LJ

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Re: Professional assembly mishaps
« Reply #99 on: December 19, 2017, 06:34:01 pm »

It might be shit, but at least you know you're getting shit every time!
Having the flow of reliable shit has nothing to do with quality, that shit is needed to keep our profit margins high.
Sue AF6LJ
 


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