Reflow at home

Most people modify a toaster over to be a reflow oven. Also, the hotplate method is known to work wonders (also modified hotplate).

Ummmmmm, toasted cheese open source hardware sandwich, arrrrrrrrrrrrrrgggggggggggggllllllllllllllllllllllllll. Forgive my drooling.

@ architect - Just saw this thread. My laser (that should be able to do mylar) should be here next week, hope to have my platform for it built week after that. If you want to try the plastic route, let me know, can definitely do it cheaper than $25, assuming you supply the design file :wink:

@ stevepresley - Very nice. I will keep that in mind for sure. Thank you!

I learned that heating a board with hot air or hot plate results in thermal stressing the board/components as there is no equal heat spreading. Reflow oven seems to be the way to go. Iā€™m sure you have a spare FEZ for controlling the reflow temperature curve :wink:

Never had luck with hot air anyway as it always blows away my componentsā€¦

Donā€™t blow so hard then :smiley:

Absolutely, uneven heating can be an issue. I would only use hot air to reflow a small chip, i wouldnā€™t consider using it for all my SMT work. I hand solder all my passives and itā€™s only tricky bits like that dratted MPR121 that I needed to reflow with air (in the other order, reflow with air then grab the soldering iron)

For many years I have used a heat gun, recently I have been using a DeWalt D26950 as you can adjust the heat settings. I have used this to remove and replace anything from BGAs to QFNs.

For metal stencils you can look at :http://www.quickstencil.com/Prototype-Stencils/Prototype-Stencil-Kits.aspx

Never used them before, but $99 for a metal stencil is cheapā€¦ :slight_smile:

As to sockets and hot air. I have found it to be a ā€œno-goā€. The flowing hot air focuses on, and picks on, the sharp plastic edges and starts melting the socket way before the pcb begins to reflow.

We have a cheap toaster oven in the office for our protos. Works like a charm. Put in the pcb. Turn the oven to max. Wait for the solder to flow, while keeping an eye on things. When the solder flows, turn off the oven. I have not tried a Gadgeteer socket in it yet, but the plastic bases of SMD Alu caps survive without a mark.

We donā€™t have nice profiles and all that, but it beats soldering 500+ parts per board by hand.

This looks interesting:

http://www.ebay.com/itm/T-962-INFRARED-IC-HEATER-REFLOW-WAVE-OVEN-BGA-T962-n-/250721222768

Thoughts?

I have looked @ the t962 for quite sometime. If you search around you will find some reviews. I have never found a good/great reviewā€¦ The general consensus is that its OK.

@ Architect - That is interesting. Is there is convection one like that? From personal experience convection is better. I was told that infrared works better on exposed solder pads as opposed to cover pads, i.e. BGAs and thermal pads.

@ Michael - There is some circulation of hot air:

The price is very attractive. If I would try to get something as close with cheap toaster oven, thermocouple, controller and time to put everything together and test it I might get something similar but probably will cost more. I am seriously considering it. Looking at the reviews.

I got a convention oven for Christmas a few years back. Has a big oven style space with two racks (and rotisserie which Iā€™ve never used) and a sliding tray at the bottom do to a pizza.

You can pick them up for $200 bucks now, so maybe with the thermocouple, it would be close to the price point of the IR unit you talked about

http://www.amazon.com/gp/product/B005HHEY8A/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B005HHEY8A&linkCode=as2&tag=dsaxmancom-20

Which route did you end up going?

Iā€™ve decided to try GE toaster oven first.

Please update the thread with your experience.

I tested a B&D infrawave oven this weekend, it works, but I am not satisfied with the results. I may need to keep playing with the settings.

I will. What was wrong with the results?

I am not getting a nice clean reflow on even soic-8 ICs, even to the point of burning the boards up. The passives look fine.

P.S. I am wondering if my paste is too old.

i have a T-962 for more than a year now and i am very happy with the resultsā€¦ Of course the type of solder paste used has a big influence on the results. Especially the melting temperature. The PCBā€™s i made are all small. about 3" x 2" i do not have experience with larger sized PCBā€™s

At http://www.tinyclr.com/forum/topic?id=5600&page=5 you can see a pcb thats soldered with the this T-962

The solder paste I used is S62-HF3+ an ultra-fine pitch from Cobar http://www.cobar.com/flux_products.asp?group=14&id=253