Hot air or oven? - Page 1
Forum section: electronics / repair

author: url
author_rank: Newbie
timestamp: March 22, 2019, 09:09:23 am
content: Hi GuysI have a hot air station and do basic reflows (repairs) using that.Where something like a laptop motherboard or TV main board needs a chip reflowed (I am not yet brave enough to remove a BGA and redeploy!), I have been using my hot air station.I have been thinking about buying a reflow oven.Would an oven be better than my current hot air station approach?I personally feel that with the hot air station I can target just the component that needs it without stressing the whole board unnecessarily.On the flip side, at least with an oven, the correct temperature approach/curve would (should!) be attainable that using a hot air station would not give.Thoughts?David

author: SilverSolder
author_rank: Super Contributor
timestamp: March 22, 2019, 05:50:51 pm
content: Sometimes it can be good to pre-heat a board, not to the point where the solder melts, but hot enough that it becomes easier to use the hot air.The heating can be as simple or as fancy as you like, in principle. Oven, hot plate, whatever floats your boat!

author: url
author_rank: Newbie
timestamp: March 22, 2019, 07:16:23 pm
content: Thanks SilverSolder.... I had not considered that.I am trying to weight up the cost and value of a T962A or if I stick to my CSi 825++ .... we all love tools/kit so the allure of an oven is appealing.... just need to make sure its something that "gives me something" or improves what i do if you know what I mean.I have looked and liked the look of a DIY oven, but the UK options seem slim, and I fear I would spend as much as a 962 in the end!David

author: Deepak
author_rank: Regular Contributor
timestamp: March 22, 2019, 08:42:03 pm
content: Quote from: url on March 22, 2019, 07:16:23 pmOvens aren't all sunshine. The T962 series are pretty dodgy as-is, and there are aseries of modificationsyou'll want to make to the unit, which will add to the total cost of ownership. MSL also becomes a bigger concern than with localized heat. For repair specifically you'll need to look out for through-hole based plastic connectors and remove them - otherwise they'll turn into smoking craters during the reflow process.Therearebenefits to an oven for sure, just make sure that if you invest in it you'll actually be able to put it to use.

author: TheNewLab
author_rank: Frequent Contributor
timestamp: March 23, 2019, 08:21:55 am
content: Excellent advise guys.question is DIY being considered or not?Looking through all the DIY builds, you can collect the mistakes and weaknesses and make one that's better.I would also consider how often you intend to use it.

author: Psi
author_rank: Super Contributor
timestamp: March 23, 2019, 10:09:52 am
content: For repair i would think a board pre-heater would be of more use.It would make your repair reflow job easier with hot air.Not much point using a oven unless you are soldering all parts onto a board, or are reflowing many boards at once.

author: url
author_rank: Newbie
timestamp: March 23, 2019, 12:59:36 pm
content: Quote from: TheNewLab on March 23, 2019, 08:21:55 amGood call!I used to be pretty much immersed in repairs in my spare time, but time went elsewhere, and now I want to get back into it...as well as construction within my hobbies.DIY is appealing, but the UK oven market appears much smaller than the US where a lot of designs spring from. I did read the whole "oven selection" thread on here and it was excellent.Perhaps I am getting lazy in my old age - the "appeal" of a T962A with mods is ease... I dont want it to become a project in itself! It could be fun though!

author: url
author_rank: Newbie
timestamp: March 23, 2019, 01:02:47 pm
content: Quote from: Psi on March 23, 2019, 10:09:52 amI think that sums it up then in reality - a pre heater is the way to go... for repairs , which is the majority of what I will do.I had wondered if the thermal expansion of part of a board would be detrimental - hence the over was a thought in the first place.I have to confess that I bought a T862 awhile ago and other than check it works (looking for the common reported issues) I have never used it! The intent there was to use the board heater to help - but many reviews now think its underpowered and inffective.David

author: wraper
author_rank: Unknown
timestamp: March 23, 2019, 03:38:21 pm
content: QuoteBGA "reflow" is not a repair in 95+% of cases. It's kicking a dead chip in hopes it will become zombie which will be going for a few weeks-months. Offering this "service" to customers is dishonest as minimum.QuoteWhen there is an actual soldering issue (rare cases), you need to reball the chip anyway.Reflow oven has no use for repair.

author: url
author_rank: Newbie
timestamp: March 23, 2019, 04:28:05 pm
content: Quote from: wraper on March 23, 2019, 03:38:21 pmOk - in my experience, "weeks or months" is usually the exception rather than the rule, and for the record, I have never taken any money for any repairs - the circumstances where I donate my time is to help those that may not have the skills nor the cash to otherwise get items repaired...nor indeed replace them.So - what kit do you suggest I buy to do proper remove and replace BGA devices?What do you have yourself?