Guy,
We agree that if all we had was J-STD-001C, 5.2 Solderability, we probably
would not be having this conversation.
. but we do have J-STD-001C, 5.4 Solderability Maintenance. We also agree
that 5.4 applies to components, parts, etc. that come from the stockroom,
kitting, component prep, sequencing, machine insertion, machine placement,
hand insertion, or similar areas up-stream of all soldering processes.
5.4 says that if you don't solder the components, parts, etc. that you
checked for solderability in 5.2 right away, but instead put them in a
stockroom, kitted them, prepared them, sequenced them, machine inserted
them, machine placed them, hand inserted them, or similar things; then you
need to check the solderability of every component, part, etc. that you did
those things to prior to starting a soldering operation on that component,
part, etc.
Dave Fish
----- Original Message -----
From: Guy Ramsey <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, July 05, 2001 6:07 AM
Subject: Re: [TN] J-STD-002 and -003 solderability testing...
> J-STD-001C 5.2 Solderablity: Electronic/mechanical components and wires to
> be soldered shall meet the requirements of J-STD-002 or equivalent . . .
I
> do not see a requirement for 100% solderability testing. I am not a
> proponent of 100% solderability testing.
>
> I submit that the standard requires you to "know" that the part you intend
> to use in production be solderable as defined in J-STD-002. I believe you
> can "know" this through statistical methods and sampling.
>
> I set up a sampling plan for our board suppliers that specified sampling
by
> date code. So, in the case where our supplier manufactured many different
> part numbers our testing requirements were reduced. We found the system to
> be effective (identified defective product and minimized inspection and
> test), and our customers approved the system.
>
> I think the part of the standard that might be getting you is 5.4
> Soderability Maintenance: . . . ensure that all componets, parts, leads,
> wiring . . . are solderable.
>
> But, I interpert this paragraph as addressing storage and handling. It
does
> not mention testing or inspection. This paragrah requires the manufacturer
> to "know" that storage and handling has not degraded the components to be
> soldered.
>
> The end item acceptability criteria in the J-STD-001 and IPC-A-610 assume
> that the materials and methods used conform to the requirements of the
> standard. This is not a version of process control it is a prerequisite
for
> compliance.
>
> A means by which we can provide assurance is SPC, rather than 100%
> inspection. One of the four essential techniques in Statistical Quality
> Control (from the Western Electric Handbook, 1956 based on Shewhart's
work)
> is Statistical Sampling Inspection.
>
> Guy Ramsey
> Senior Lab Technician / Instructor
>
>
> E-Mail: [log in to unmask] <mailto:[log in to unmask]>
> Ph: (610) 362-1200 x107
> Fax: (610) 362-1290
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]]On Behalf Of David Fish
> Sent: Wednesday, July 04, 2001 12:24 AM
> To: [log in to unmask]
> Subject: Re: [TN] J-STD-002 and -003 solderability testing...
>
>
> Guy,
>
> What makes 100% solderability testing of the components, wires, and boards
> referenced in J-STD-001, 5.2 a valid version of process control? If a
> mandated process step is process control, we sure have different
perceptions
> of process control. We think of process control as an organic element
that
> the process operator changes to maintain and improve quality. Yano,
> something out of Shewhart's work that started in the 1920s. Tell me, does
> IPC- 9191 "General Guidelines for Implementation of Statistical Process
> Control (SPC)" also suggest 100% sampling?
>
> You speak of managing risk and making business decisions. We appreciate
> that your comments speak to everyday processes within many companies.
What
> in J-STD-001 says that you can still be compliant after making business
> decisions that are not in compliance with the standard? We read it as
"all
> or nothing." We thought precluding making business decisions about the
> standard was the intent all the SHALLs when we went from rev B to rev C.
>
> Guy, you're correct, Mike's requirement for "objective evidence" is not
from
> J-001, 5.4 [or 5.2]. On the other hand, most quality systems require
> objective evidence to demonstrate that you do what you say you do [and
> obtain certification from outside auditors]. So if you say you comply
with
> J-STD-001, you need to be able to prove it!!! [The realization of a need
to
> demonstrate compliance is probably the inspiration for this thread. You
> know . "Lordy, how are we going to do THAT?"]
>
> On you opinion that 100% solderability testing is vital to obtaining 75%
> barrel fill, we only float [sacrifice] a single board in each lot and we
get
> GREAT barrel fill, well except in the cases of a couple of nasty ground
> planes, but we know we get cut some slack on those.
>
> Where are STC BIG dogs?
>
>
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