>Date: Mon, 16 Sep 1996 23:56:03
>To: "Jeffery L. Hempton" <[log in to unmask]>
>From: Poh Kong Hui <[log in to unmask]>
>Subject: Re: ASSY:Solder Wicking,Fine Pitch Leads
>
>At 07:09 AM 9/19/96 -0500, you wrote:
>>We are seeing instances of solder wicking up our fine pitch leads and
>>causing minimal solder left in the joint to wet the board. What do most
>>companies do about solder wicking up fine pitch leads? What can be done to
>>minimize this phenomenon?  Does anyone have suggestions that have been
>>successful for you? 
>>Some background process info:
>>We profile at approximately 215-220 degrees c.
>>We are using RMA solder paste.
>>We are baking our boards (multilayer) prior to reflow soldering. They are
>>cool for the print cycle.
>>We are over 183 degrees c for approximately 70-80 seconds.
>>We are using a Vitronics 722 IR oven.
>>
>>Any comments would be appreciated!!! Thanx!
>>----------------------------------
>>Jeffery L. Hempton              Phone: (219) 429-7335   Fax: (219) 429-4688
>>Hughes Defense Communications                           Mail Stop: 25-31
>>1010 Production Road, Fort Wayne, IN 46808-4106
>>Email: [log in to unmask]
>>
>
>Hello Jeffrey,
>
>I have the same problem once, and I don't know what is the cause.
>However, I resolve it by  increasing the conveyor speed, as to reduce 
>the "heat soaking" time of the board in the oven and increase the temperature 
>of the bottom Reflow zone, so that the temperature of the board and the pad 
>is higher than the lead of the component. 
>
>I know it work well for me, but I not sure whether it works for you. Maybe 
>you can give a try.
>
>
>
Poh Kong Hui 
Nera Electronics
Fax: (65) 7765492

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