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March 2018

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Subject:
From:
SALA GABRIELE <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, SALA GABRIELE <[log in to unmask]>
Date:
Wed, 7 Mar 2018 12:01:00 +0100
Content-Type:
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Hi,
I do not think actual technology adopt this technique .

0402 suitable for reflow generally can withstand temperature (very short contact/immersion time)  of wave solder

The very difficult process step would be the bonding of 0402 before wave.
To dispense very small adhesive dots under the 0402 could be possible but obtaining  a  very low quality yield.
Kind of adhesive and dispenser precision would be the key. After curing adhesion strength would be very low....

By the way the very low chip bonding strength would not be suitable to withstand the PCBA handling before wave and against the pressure of the solder wave itself.
Do not forget differences between Resistor and Capacitor chip. Bottom of R no gap to host adhesive dot. Bottom of C have a bit more gap but in my opinion not enough to host enough amount of adhesive without spread on pads, etc.
Etc....
My suggestion is to avoid fighting this kind battle....

Just my 0,25 cent

Gabriele


-----Messaggio originale-----
Da: TechNet [mailto:[log in to unmask]] Per conto di Yow GawChern
Inviato: mercoledì 7 marzo 2018 11:15
A: [log in to unmask]
Oggetto: [TN] 0402 suitable for solder wave?

Hi,

I would like to ask, for current technology, is surface mount chip size 0402 (1005) suitable for solder wave process?

Is there any recommendation to do it?

Regards,
Yow


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