nozzle size

[HB9EVI]

so I'm looking for the right nozzle to de/solder a 208-pin QFP; I just got a 28x28 nozzle which turned out to have a too wide spacing likely going to cause tombstoning of all the surrounding caps.

[Ian.M]

And your question is?

If you gave the make and model of the hot air tool you are using, the dimensions of the QFP and the distance to the nearest of the surrounding caps you'd probably get a more useful response.

Toombstoning isn't the end of the world - just measure the offending cap with a cap meter in case you damage it and need to replace it, desolder it and refit it correctly.

[martin1454]

Tombstoning is cause you are heating to much to wide, so either you have to turn down the temperature or use a smaller nozzle.

Do you use a underheater for soldering? If so, try to reduce the airflow/temperature a little bit on you hot air station

[HB9EVI]

sorry for not being precise enough; so far: nothing happened yet; the nozzle I got seems to be for QFP 32x32 - this is actually the width between the slots, but it's declared as 28x28
the rework station is a Xytronic LF-852D-ESD; I got confused; but when studying their website only the A1129B matches

seems to be clear now, thanks anyway...

[Ian.M]

You are aware that QFP packages come in different pin pitches and therefore different sizes for the same pin count?  You still haven't told us the 208 pin QFP package size.  I assume the nozzle sizes above are in mm.

According to their website A1129B should measure 29mm between the inside edges of the slots: http://www.xytronic-usa.com/shop/category.aspx?catid=29