Joe Wackerman wrote:
> Here are the responses to my post on axial part age. There was a
> related
> post from John Gulley concerning the age of parts when they are
> received. I
> don't yet have an answer from my purchasing dept on how old a part can
> be
> when received. I suspect no one here has ever checked before. I think
> sometimes we're just glad we have SOMETHING.
>
> Just some background (so you'll remember 2 years from now when you
> read
> this). We are a low volume, high mix facility. We make about 7500 PCAs
> per
> month. We have about 150 different PCAs. I took a PCB inventory in
> 10/97
> and found 5 products I want to obsolete, 4 that I want to reduce order
> qty,
> and 13 with datecodes (DC) older than 12 months (10 of those were
> older
> than 18 months). This actually was not to bad. I re-introduced the
> workcells to First In First Out (FIFO) and purged some old stock. Not
> too
> painful.
>
> I then did an inventory of axial parts (we are quickly moving to
> surface
> mount), and started to see some reel (pun intended) problems. Looks
> like in
> the old days (late '80s) we ordered everything in 5000 reels (cheaper
> that
> way!). Out of about 200 P/N I found 28 with no stock younger than 4
> years.
> I found one part 11 years old. Many parts in the 2-4 year range. I am
> working on purging stock, changing our buying practices (qty),
> implementing
> a re-order based on last date ordered (if we haven't bought it in two
> years
> we need to!). We may be giving a lot of parts to the local JC.
>
> I've just started looking at our DIPs. A first look showed over 50
> parts
> with monthly usage less than 10. I haven't done a DC check yet.
>
> I had thought that our SM line could wait until last. But now that I
> know
> received parts can already be old, I will be looking into that soon.
>
> Here are the answers I received to my post on technet.
>
> From: "David D Hillman"<[log in to unmask]>
> To: [log in to unmask], [log in to unmask]
> Date: Fri, 24 Oct 1997 06:33:09 -0500
> Subject: Re: [TN] Axial Part Age
>
> Hi Joe - if only predicting solderability was that easy! The industry
> "norms", if there is really such a unit of measure, is that a majority
> of
> component manufacturers will state that the component solderability is
> good
> for 12 months and many will extend that out for 24 months. After that
> everyone becomes silent. Three forcing functions become part of the
> equation: 1) what is the condition of the component finish?; 2) what
> is the
> storage environment?; 3) what flux will be used during the soldering
> process? A good, thick tin lead surface finish(e.g. 120 microinches)
> can
> last for several years but a thin tin lead surface finish could
> oxidize or
> have intermetallic exposure problems within months. A gold finish
> could
> last indefinitely but if it has too much porosity then the basis metal
>
> oxidizes very quickly. The storage environment you mention is very
> benign
> but lack of humidity and temperature controls will impact the surface
> finish. Last, the flux used in the soldering operation may be active
> enough
> to overcome any surface finish oxidation/intermetallic problems that
> may be
> present. The interaction of these three variables is why getting a
> black&white answer to storage life prediction for a component finish
> is so
> tough. Steam aging is NOT a simulation of storage life but only a
> condition
> method that can be used to understand how robust a surface finish is
> (that
> is a widely misunderstood concept). The Alternative Finishes task
> group is
> going to be looking into conditioning methods for surface finishes in
> the
> next year including reassessment of steam aging (maybe we should say
> steam
> conditioning) so hopefully some good information will become available
> for
> the industry to use.
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
> ##########################
> #################################################
>
> All,
>
> 1. Are a majority of the Manufacturers or OEMs receiving
> components
> through Receiving with parts that have date codes as old as
> 9531?
>
> 2. Does anyone check the date codes of components as part of
> their
> Incoming Inspection?
>
> 3. If older than 12 months, how are you approaching the
> solderbility
> issues? Are you dispositioning the parts for rework, return
> to
> vendor or Use As Is?
>
> 4. Is it typical to receive components with date codes older
> around
> 9531, 9644, 9540, etc from the suppliers/distributers?
>
> 5. I've identified that some components that are very old (typ.
> older
> than 12 months) are having solderability defects (very
> random). I
> am having my Incoming Inspection identify the old components
> through an Expired Parts List. This sometimes helps me when
> identifying defects in mfg. Does anyone have a better method?
>
> 6. I'm not sure thie method is benefiting like I would want it
> to.
>
> Any input is appreciated.
>
> John Gulley
> Inet Inc.
> "A Smarter Vision"
> www.inetinc.com
>
> ####################
> ######################################################
>
> Date: Fri, 24 Oct 1997 10:12:58 -0500
> To: [log in to unmask]
> From: [log in to unmask] (Benjamin A Guthrie)
> Subject: TH part solderability concerns
>
> Hi Joe. I have a similar situation, where our mature products are
> bringing
> in sales without packaging updates, so we keep building old stuff
> along with
> the new. As a mostly-Military house, we buy parts after receiving a
> contract for a delivery schedule, and they don't get in the door
> without
> solderability sampling, so in-house solderability deterioration isn't
> currently a problem. I appreciate your proactive concern, though,
> because
> of diminishing suppliers and the aging on their shelves, which will be
>
> getting longer. Please keep the info exchange about this on Technet,
> so I
> can follow. thanks.
> --------------------------------------
> Hughes Defense Communications
> Benjamin A Guthrie Phone: (219)429-8324
> Mail Stop:25-31 Fax: (219)429-4688 Email: [log in to unmask]
> HDC, 1010 Production Road, Fort Wayne, IN 46808
>
> ###############################################
> ###########################
>
> From: Richard Hamilton -TEST <[log in to unmask]>
> To: 'Joe Wackerman' <[log in to unmask]>
> Subject:
> Date: Fri, 24 Oct 1997 09:30:46 -0700
>
> Joe,
>
> Caught your email on the TechNet list. You seem to be ahead of our
> plant
> in migrating to SM. We still are doing a very limited SM process
> (uProc
> only).
>
> My manager is asking for documented evidence that component pricing on
>
> SM is coming down, and TH is going up. Any idea where we can find this
>
> info? Any idea on where the two movements will cross (when?)?
>
> Any info would be appreciated.
>
> Richard Hamilton
> Clemar Mfg. / Rain Bird
>
> ****I have passed this one on to my purchasing dept.
>
> ####################################################
> #######################
>
> And finally my original post:
>
> Technetters- As the industry moves more and more toward SMT, our TH
> line
> continues to mfg mature products. The problem is that as qty rises on
> SMT,
> the qty are dropping on TH. We are seeing older and older parts on the
>
> shelf and would like to avoid solderability problems proactively. I
> understand that solderability can vary widely between manufacturers,
> parts
> and lots....but is there an industry standard for how long axial parts
> can
> sit on the shelf (reels in an air conditioned factory, 65-75F,
> 45-55RH)? I
> am looking for a broad guideline (something like: don't use anything
> older
> than X, test parts that are Y-Z, incoming test for new parts). Thanks
> in
> advance. Joe
>
> Joe Wackerman
> Sr. Mechanical Engineer
> Parker Hannifin
> Compumotor Division
> http://www.compumotor.com
> voice 707-584-2522
> FAX 707-584-8015
> e-mail [log in to unmask]
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV
> 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in the body:
> To subscribe: SUBSCRIBE TECHNET <your full name>
> To unsubscribe: SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
> additional information.
> For the technical support contact Dmitriy Sklyar at [log in to unmask] or
> 847-509-9700 ext.311
> ##############################################################
Joe!
Before You contact the local JC (Which I am assuming to mean Junk
Collector EMIAW((Excuse Me If I Am Wrong)), let me know what you have,
outside of reels that are worth a buck a piece on the market (i.e.
resistors).
As much as people love to talk about the demise of TH, when is the last
time you saw a post about chip cracking relating to through hole?
Never. I buy EVERYTHING. For Example, I was sitting on a HUGE lot of
LM1801 PDIP's. Used for everything from water detection to burgular
alarms. Last listed price from National was 18 cents. I just sold
40,000 at $1.80 a piece. My cost, was shipping and two hundred
dollars. Now granted, they sat, sealed in a temperature and humidity
controlled enviroment for 6 years but HEY! Imagine trying to
re-engineer a product. My cost difference - orignal price = $60,000.
Now if you have a High volume punch & Crunch Product and can't find
these, try getting an EE on board to redesign a product for less.
Probably won't happen EASILY.
So before you pitch, gimme a list.
Mark Ross
Reliant Electronics
(248)433-2287
(248)433-1369 Fax
(248)821-6663 Cell/Roaming Voice Mail
[log in to unmask] : Email
1288277567663mc653565355278991982:Genetic Marker Tag (as seen on
X-Files)
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
##############################################################
|
