Electronics Forum | Tue Feb 11 15:17:49 EST 2020 | emeto
Your profile should be close to this.
Electronics Forum | Tue Feb 11 09:26:57 EST 2020 | astarotf
Hi everyone I have problems welding QFN components in a 10-zone reflux oven, we cannot make a welding fillet that covers the entire QFN pin. Currently we use paste T4 - 63Sn / 37Pb. I enclose the curve of the oven profile. Any help or support on this
Electronics Forum | Tue Feb 11 10:31:20 EST 2020 | emeto
Values and range definitions on your profile attachment are for LF paste not for Tin Lead. Please recheck and redefine, so we get the correct values. Also, which location is the QFN?
Electronics Forum | Tue Feb 11 10:41:30 EST 2020 | dunks
We had this problem at my old job. My understanding (from googling this problem previously) is that the exposed leads on the side of the qfn are not tinned and are not required/designed to have a fillet. Someone correct me if I'm spouting lies.
Electronics Forum | Tue Feb 11 10:59:31 EST 2020 | dontfeedphils
I was going to say, technically it's BTC, so I don't believe it needs a fillet, only evidence of wetting.
Electronics Forum | Tue Feb 11 11:42:06 EST 2020 | slthomas
Yep....I just looked at a copy of IPC-610-G and am not 100% sure but I think it's Note 5, Table 8-16, pg. 8-96.
Electronics Forum | Tue Feb 11 13:03:05 EST 2020 | astarotf
Evtimov The areas analyzed are a standard oven curve according to the pasta we are using. The channels used are only for measuring the oven temperature profile, not in detail of the QFN component sector.
Electronics Forum | Tue Feb 11 17:04:43 EST 2020 | astarotf
hello robgd3 Thank you for your contribution based on your experience and I see that it is very useful for my case, since it is very similar, we will begin to analyze the points mentioned.
Electronics Forum | Tue Feb 11 17:05:53 EST 2020 | astarotf
Evtimov thank you very much for sharing this profile, we will perform tests with this curve to see behaviors in the oven and pasta.
Electronics Forum | Wed Feb 19 12:30:19 EST 2020 | emeto
Sebas, Curve you attached is using different temp table. We need valid data to evaluate.
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