BGA rework - what type of heating? - Page 1
Forum section: electronics / beginners

author: Shock
author_rank: Super Contributor
timestamp: July 16, 2015, 07:08:54 am
content: Still Looking for AdviceLooking at designing a BGA rework station and have questions for anyone who has experience with different heating systems and the pros and cons between them.1. What advantages do you get from element/direct air flow over a ceramic system for underside preheating?2. Would an element covered with ceramic tiles make an effective preheater?3. Is hot air favored over IR, what are the differences in operational terms (aside from glasses)? Is IR worth even bothering with?I'm not focused on the temperature and control side at this stage but let me know your thoughts, even if comparing differences in commercial stations. Cheers.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: July 16, 2015, 07:17:46 pm
content: I recently did a lot of research on this topic since I needed a BGA rework station for replacing BGAs on my prototype boards. My BGAs range from small ones (15x15mm) to mid-size FPGAs (say 35x35mm). I looked at the Ebay variants, which are all IR but eventually got a Zephyrtonics ZT-7 hot air rework station with the "big grid" preheater air bath.The reason I chose the ZT-7 is that it has correct temperature control, will not burn PCBs or cause delamination etc. They are normally quite pricey but I found a new one on Ebay for 1/3 or the new price. I have not yet used it for removing large FPGA BGAs but it works just fine for the smaller BGAs.You may be able to get IR to work with a bit of effort but I did not dare to go that route since my boards are prototype boards that I only have one or two of. Best not to skimp on proper tools. Perhaps someone else can give feedback on IR systems.

author: Shock
author_rank: Super Contributor
timestamp: July 19, 2015, 01:55:18 pm
content: Bump

author: stevenhoneyman
author_rank: Regular Contributor
timestamp: July 19, 2015, 06:30:52 pm
content: I'd also like to know the answer to this. I've been limiting myself to qfn for 'real' boards and deadbugging the occasional bga-only part for testing/evaluation due to a lack of reflow oven or any specialist BGA stuff. (oh and cheap Chinese PCB limits are the other reason!)

author: Shock
author_rank: Super Contributor
timestamp: July 28, 2015, 04:17:32 pm
content: Bump

author: stevenhoneyman
author_rank: Regular Contributor
timestamp: July 28, 2015, 05:09:18 pm
content: I'll share what I've learnt from a quick look around (and therefore may be completely incorrect!) seeing as nobody else has replied.Quote from: Shock on July 16, 2015, 07:08:54 amPeople that use direct contact preheaters (seems to be all of the improvised/DIY jobs) suggest that it discolours boards.Ceramic tiles seem to be one solution that is used. Sand is another.Quote from: Shock on July 16, 2015, 07:08:54 amHot air is used in large setups often just because it was what was available at the time and they don't want to buy new equipment.IR is good for larger components, not so good for smaller.IR does not melt plastic bits (apparently) so makes it good for connectors and stuff as well.Hot air is easier to control.Personally I think I'll get an IR preheater and use my current hot air kit and see how it goes. A lot of people say it's not the equipment, it's whether you know what it's doing and what it should be doing to solder correctly, which is why some of the "xbox repair crew" manage it with a 2kw paint stripper!