Sample of Solder supplied with PCB by supplier - What is this sample for?

L

LesPiles

Hello,


My question is this : when we receive PCBs from our supplier, he gives us a solder sample. This solder sample (stuck in epoxy) is something that annoys us because we never know if we should keep it, and especially why we should keep it. Added to the certificate of compliance, it makes a lot to manage.

What are these samples? Should we keep them? Is there some part of an IPC standard that tells PCB providers to ship their products with solder samples?

Thank you in advance!

François
 
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D

DrM2u

Re: Sample of Solder supplied with PCB by supplier. What is this sample for?

There could be a number of reasons WHY the supplier sends you samples:
- your organization asked for it in the past and the practice continues
- it could be an obscure part of your 'suplier quality manual' or requirements
- it is part of the supplier's common practice
- it is part of some applicable regulatory requirement
- who knows?!?

Anyway, if the sample is not needed and/or required by your organization then you can:
- ask your supplier to retain it as part of their inspection/production records
- ask your supplier not to prepare and send the sample

As far as what the sample is, I suggest that you ask your supplier for clarification if no one within your organization knows. I am not aware of all the applicable regulations and requirements for PCB's.
 
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D

David Hartman

Re: Sample of Solder supplied with PCB by supplier. What is this sample for?

The only reason I can see for receiving the sample (other than what has already been stated) would be so that you can proof the solder composition (provided that it is not entirely covered by the epoxy). With the move to Pb-free solder, and the many varieties available, this may be the suppliers method for allowing you the opportunity to validate the composition of the solder used on the PWB.
 
W

wilddogintheyard

For PCB sample ...i have used this company called pcbfinpo before...i think they are also the manufacturer but not 100% positive....

the thing bothers me is that all the manufacturer we can find online all located in Asia or more specifically China...and they are wellknown for its poor quality ...ok maybe not all...but it is not too difficult to meet one that drives you nut...

Ok...good news is i found this pcbfinpo (pcbfinpo.com) a while ago and tried with them a few times....both quality and time consume is perfect...all u have to do is go on their website and quote it yourself as long as you have the gerber file along with the specs....you can get the instant online quotation for small volume orders ...and purchase them ...i got my order like 2 or 3 days after...amazing ...

i believe their office is somewhere in the states...the only time i got their message is the day i got my DHL online tracking number...there is no more back and forth discussion...they know what exactly to do...hey i can't say my time worth a lot here...but i appreciate the time saving part.. the only down part is you still have to get to them personally when you want bigger amount of orders such as mid-volume or MP...any of you out there knows where can I buy for MP with doing it All-By-Yourself-Online-Quotation? :cool:
 

Wes Bucey

Prophet of Profit
Re: Sample of Solder supplied with PCB by supplier. What is this sample for?

Hello,


My question is this : when we receive PCBs from our supplier, he gives us a solder sample. This solder sample (stuck in epoxy) is something that annoys us because we never know if we should keep it, and especially why we should keep it. Added to the certificate of compliance, it makes a lot to manage.

What are these samples? Should we keep them? Is there some part of an IPC standard that tells PCB providers to ship their products with solder samples?

Thank you in advance!

François

The only reason I can see for receiving the sample (other than what has already been stated) would be so that you can proof the solder composition (provided that it is not entirely covered by the epoxy). With the move to Pb-free solder, and the many varieties available, this may be the suppliers method for allowing you the opportunity to validate the composition of the solder used on the PWB.
Four years ago, I wrote this post
In my high tech contract machining business, I normally added a clause to each contract (since we were making custom products to a customer's design):
[we] will forward the exact First Article sample together with a list of the instruments used to measure each parameter together with the measurements so recorded so customer may independently check dimensions replicating the instrumentation used. [we] will send test samples of final inspection together with the inspection sheets listing the instruments and dimensions checked with the results for customer to confirm, hold, and maintain.

[we] will maintain test coupons of each lot of material together with physical and chemical properties analysis in a permanent file for any future reference which may be required.


We gave the product samples to the customer, since it was his design. We retained the material "coupons" [a six to ten inch bar of the material] together with a laboratory analysis of a similar coupon cut from the same bar from a specific lot of material because we often would use the same material for multiple customers since we specialized in making aerospace and medical device components from some "exotic" materials like titanium or specialty stainless steel alloys.

We were silent on "in-process" inspection because the dimensions and other characteristics during in-process were often merely internal to our Control Plan and had no relationship to final characteristics of finished product.
I presume the supplier is doing something similar with the solder - he attests the solder is something and provides a test coupon for the buyer to make (or have made elsewhere) its own analysis to confirm the attestation, either randomly or every time. Sealed in epoxy to prevent contamination!

From my point of view, I would keep these samples indexed and identified with the other quality records for the organization's standard retention period of such records. It's a good reference point for tracing root cause if any field samples of your PCBs come back with failed solder joints.
 
J

Jonny147

I used to work in a PCB supply company. If they are bare printed circuit boards you are purchasing (i.e. not built with components). Then the sample is probaby a microsection of a finished PCB - this will show copper thickness,pth integrity,build etc. They should keep one of these samples themselves. If you don't want one why not let them know, it would mean less work for them and i'm sure they don;t want to produce extra microsections if they are not required
 
P

pcbman

I was just browsing for relevant posts for my project and I happened to stumble upon yours. Thanks for the useful information!
 

Mikishots

Trusted Information Resource
Re: Sample of Solder supplied with PCB by supplier. What is this sample for?

The only reason I can see for receiving the sample (other than what has already been stated) would be so that you can proof the solder composition (provided that it is not entirely covered by the epoxy). With the move to Pb-free solder, and the many varieties available, this may be the suppliers method for allowing you the opportunity to validate the composition of the solder used on the PWB.

It seems reasonable, but a bit odd; if I was concerned about the solder content, I would have the solder on the PCB tested, not some separate sample that may or may not have been used on that PCB.

I have come across one instance (only one, mind you), where a board purported to be RoHS compliant came with a small sample sliver that was confirmed through XRF to be lead-free. However, the solder on the PCBA was 63/37.:nope:
The explanation from the fab house (mainland China) was first that we were mistaken, then changed to "oh, we made a simple logistical error" when presented with the reports.
 

Wes Bucey

Prophet of Profit
Re: Sample of Solder supplied with PCB by supplier. What is this sample for?

It seems reasonable, but a bit odd; if I was concerned about the solder content, I would have the solder on the PCB tested, not some separate sample that may or may not have been used on that PCB.

I have come across one instance (only one, mind you), where a board purported to be RoHS compliant came with a small sample sliver that was confirmed through XRF to be lead-free. However, the solder on the PCBA was 63/37.:nope:
The explanation from the fab house (mainland China) was first that we were mistaken, then changed to "oh, we made a simple logistical error" when presented with the reports.
Yeah! that can happen in any country. There was a famous [infamous?] situation a few years ago where a manufacturer in eastern USA was making titanium tubing for US aircraft and simply used Xerox copies of the original lab analysis of the titanium from the very first shipment for every subsequent shipment regardless of where they got the titanium. It was never explained why the government receivers never noticed the date on the analysis was five years old and that every one was identical. It's an old story from 2005 - I didn't find a complete readout in a short search, but here's an excerpt of an AP story.
MARYCLAIRE DALE, Associated Press Writer
AP Online
06-08-2005
Dateline: PHILADELPHIA
A military supplier and two of the company's workers were charged Tuesday with falsely certifying material for the V-22 Osprey aircraft.

Federal prosecutors, however, said the material wasn't to blame for two deadly crashes involving the helicopter-airplane hybrid.

Anco-Tech Inc., located in Dearborn Heights, Mich., manufactured titanium tubing for use in the tilt-rotor aircraft. The company certified that the tubing met the military's standards, even though it was never tested or incompletely tested, federal prosecutors said Tuesday.

"Tests were skipped, protocols were …
 
Re: Sample of Solder supplied with PCB by supplier. What is this sample for?

Hi

I used to be involved in solder analysis in the 1980s. We used to ask for a sample of about 1.0 gm from the batch melt for analysis of impurities. Impurity analysis, both by conventional and instrumental (that includes XRF) from solder rods supplied used to be inconsistant from sample to sample; we understood that the problem was due to the migration of impurities to hotter zones during the solidification of the solder, XRF being a surface analysis method will not be able to give the concentration of impurities in the molten solder used for soldering. We use to test the complete 1.0 gm sample for impurity analysis and maintsined impurity levels in our solder baths.

Regards

Ramakrishnan
 
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