Begin forwarded message:
> From: Yuan-chia Joyce Koo <[log in to unmask]>
> Date: February 26, 2020 9:03:30 AM EST (CA)
> To: <[log in to unmask]>
> Subject: Re: [TN] Cleaning Course of Study
>
> (1) compatibility of cleaning solution to the device/assembly
> material usually is over looked. I saw many delamination edge of
> flex, peel off flipchip polymer on surface that protect die
> (instead glass passivation). (2) surface tension of cleaning agent
> that usually change after reaction with flux, with low profile
> device, such as QFN or flipchip, you might not clean under the
> device after "solution" used for a while... some can never be
> cleaned if it is large enough.. you need to use low residue or no
> residue flux instead... I found those details usually missed when
> design house is far away from MFG (sometimes, just next building,
> that is far enough for a designer to be insulated in their bubbles.
> apology to designer on TN... live in the next building ;-). With
> high speed (10GHz) and compact design (flipchip or QFN) low profile
> used more, it is a worry. (Vapor phase still too expansive).
> my 1.45 cents.
> jk
> On Feb 26, 2020, at 7:43 AM, Douglas Pauls wrote:
>
>> Good morning Technetians
>>
>> OK, so I have been thinking (and we know how dangerous that is) about
>> developing a course of study for someone to become a "cleaning
>> expert".
>> Something along the lines of starting with a new hire and
>> educating the new
>> hires up to my level. Courses would include things like flux
>> chemistry,
>> cleaning processes and chemistry, cleanliness measurement methods,
>> SIR
>> methods, etc. What items would you suggest be added to the course
>> of study?
>>
>> *Douglas Pauls *| Principal Materials and Process Engr | Advanced
>> Operations Engineering
>>
>> *COLLINS AEROSPACE*
>>
>> 400 Collins Road NE, MS 108-101, Cedar Rapids, IA 52498 USA
>>
>> *Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773
>>
>> [log in to unmask]
>>
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