Technetters,
Firstly, thanks so much for your input!
We use:
- Heller Oven Profiles, most of them are 8-9 zones.
- Solder Paste Type: Water Soluble, Sn63Pb37 - P3
type.
- Board: 6 layers; thickness is equal or less than
0.05"
I agree with Mr. Krug that we should look for a
nominal oven profile that would satisfy about 80% of
the product profiles. However, to short through 7000
of them, it would be A LOT.
Also, there will be so much resistance to this change,
Q.A. will blame on different outcome, Production would
do the same thing until ... they reach a comfortable
zone. By having a scientific method, I may be able to
convince them and have them cooperated much easier
than shorting through 7000 to find the commonalities
among them.
A typical profile at here is:
100 - 140 - 160 - 175 - 170 - 190 -235 -255
where process windows are:
30-150 degree: 50 - 140 sec.
150-183: 50-120 sec
above 183: 40-80 sec
Depending on the products and panel layout (maximum
panel size: 7" x 12")the temperature for each zone can
be changed +/-20.
Again, I am looking for a scientific way that will not
only satisfy the product quality requirement (all
class 2) but also acceptable from strict people base
on what they called: Logical/scientific thinking.
Thanks,
Stacy
--- "Krug, Dick" <[log in to unmask]> wrote:
> I have seen the same issues and have reduced the
> number of different
> profiles dramatically. When working for an OEM
> which had similar PWB layer
> counts, similar component densities and only one
> solder paste, we got down
> to 1 profile per oven model. Now in the contract
> world, we are up to only 7
> oven profiles after over a year of our reduced
> profile initiative; RMA
> Standard, RMA Heavy, RMA Light, RMA Standard
> Nitrogen, RMA Heavy Nitrogen,
> RMA Medium Heavy and Cure. We use the same profile
> on RMA paste and WS
> paste, and both the Sn63Pb37 and Sn62Pb36Ag2 alloys.
>
>
> Using our paste suppliers' "nominal" profiles and a
> "typical" (obviously a
> judgment call) assembly, we defined the profile we
> wanted to match. After
> several iterations (because we wanted an "exact"
> match) we had our RMA
> Standard profile which is used on ~80% of all
> assemblies. All other
> profiles are variations because RMA Standard is not
> acceptable.
>
> Each oven model has different zone settings and
> speeds, but the same profile
> name.
>
> The profile we "matched" is as follows:
> Time Temp
> (sec) (deg C)
> 0 25
> 30 49
> 60 73
> 90 97
> 120 121
> 150 145
> 180 169
> 210 184
> 240 215
> 270 183
> 300 120
> 330 60
>
> Dick Krug
> Sypris Electronics
>
> -----Original Message-----
> From: My Nguyen [mailto:[log in to unmask]]
> Sent: Wednesday, January 16, 2002 1:17 PM
> To: [log in to unmask]
> Subject: [TN] Way too many Product Oven Profiles
>
>
> Good morning Techneters,
>
> I am working on oven profiler consolidation project.
> Currently, we have 540 Product Profile for each
> oven.
> For 13 oven machine, we have 7020 profiles. That is
> way too many for a memory manufacture!
>
> We currently use water-soluble solder and no clean
> solder. We know that for each product, the pre-heat
> zone, soak-zone, re-flow zone, and temperature could
> be a bit different from one Solder Paste Manufacture
> to other, or from one Solder Paste type to others,
> or
> even from single side, to double side.
>
> HOWEVER, for memory, the width, length, thickness,
> and
> number of ICs, resisters, capacitors, and others are
> limited to a certain number, i.e, PCB height is less
> than 1.7 inches; PCB thickness is equal or less than
> 0.05 inch; PCB length follow the spec. of 5.25" for
> DIMM, DDR, RIMM, 2.66" for SODIMM, 4.25" for 72 Pin
> SIMM, etc.
>
> I have heard that out there, there is a way to
> reduce
> from 1000s down to 10-100 oven profiles based on
> Mass/Density. And of course, there are many other
> scientific ways that I have not heard of. Please
> help
> me! What would be the best method you recommend or
> you
> have successfully tried to reduce the number of oven
> profiles down to a control/reasonable numbers?
>
> Your advice and suggestion are greatly appreciated.
>
> Stacy
>
>
> __________________________________________________
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