Dear Sunil,
the same problem has been found in our company, and we solved it though
below mentioned methods.

1) increase pre-heat tempreture to 160¡æ
2)increase the spraying flux
3)only use single wave solder, not double wave solder


Best Regards


Qu Zenglong

Industrial Engineering Department
Production Division
BISC, China
Tel: 0086-10-64346323
Fax:0086-10-64367731
e-mail: [log in to unmask]

> ----------
> From:         Sunil Gupta[SMTP:[log in to unmask]]
> Reply To:     TechNet E-Mail Forum.;[log in to unmask]
> Sent:         Wednesday, May 05, 1999 11:49 AM
> To:   [log in to unmask]
> Subject:      [TN] Icicle formation on wave soldering
> 
> While wave soldering the mixed technology boards I am facing the problem
> of
> icicles being formed on the solder side. The icicles are only on SMDs
> (capacitors and resistors, there are no other SMDs)  while not observed on
> lead thru components. The machine parameters are:
>    Bath temperature: 245 deg C
>    Conveyor speed: 1m per minute
>    Fluxing thru foam fluxer
>    PCB temperature before soldering: 100 deg C
>    Preheat zone length: 1.5 m
> 
> The problem got solved by heating the boards at 60 deg C and than passing
> them thru the fluxing and soldering.
> 
> I want to eliminate the Icicle problem and also remove the requirement of
> baking.
> Can you give me ideas.
> 
> regards
> 
> Sunil Gupta
> Manager Process Engineering
> Tata Telecom Ltd.
> 
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