Replacing BGA components with hot air.

[Spork Schivago]

Re: Replacing BGA components with hot air.

Looking at my rework station, the bottom plates are 600W and there are 4 of them.
Yours don't sound large enough to heat a whole board.

Yeah, I was afraid of that. So it looks like I'm back at trying to find some plans on how to build a nice large 2,000 watt preheater. They do make a bigger preheater, the only problem is it runs off 240, not 120VAC. In my house, it'd be a bit of a challenge to get 240VAC in that room. We'd have to run new wire from the breaker box. The wire that's in the walls isn't even that good. 14-2 I think. We have a lot of 20AMP breakers in there. I wanted to put a higher amperage breaker in for the work room. I have some stuff that could probably benefit for it. I'm afraid to have everything turned on at once. I talked to some electrician to see if it was possible, but he said because of the gauge of the wire we had, we couldn't go any larger without replacing the wire in the walls.

I'm not sure if it's 14-2 or not. I just remember him saying some number like that.

[stj]

Re: Replacing BGA components with hot air.

no, that sounds very small, the ones i'm used to can heat a whole ps3 and then some.

[diif]

Re: Replacing BGA components with hot air.

Looking at my rework station, the bottom plates are 600W and there are 4 of them.
Yours don't sound large enough to heat a whole board.

[Spork Schivago]

Re: Replacing BGA components with hot air.

If I have it on low, 120 mm x 60 mm
If I have it on high, 120 mm x 185 mm

It has a K-type thermocouple, the preheater I mean. No thermocouple connections for the hot air rework station.

[stj]

Re: Replacing BGA components with hot air.

what's the surface area?

[Spork Schivago]

Re: Replacing BGA components with hot air.

Thanks Stj! You've been more than helpful getting me going in the right direction. I'll keep you guys posted on how my progress goes. It might take a bit before I get to work on it though.

So, do you think the preheater would be large enough or should I work on building my own?

[stj]

Re: Replacing BGA components with hot air.

actually, if your using more than 1 you want the rs485 comms.

here is a software manual

[stj]

Re: Replacing BGA components with hot air.

well the controllers need a solid-state relay, for driving the heaters.
other than that, i think they can have a serial port.
(make sure you know the correct part number for the rs232 version.)

[Spork Schivago]

Re: Replacing BGA components with hot air.

you mean wiring, or programming?
wiring is in the pdf.

Both. I would think that programming would be already taken care of and built into the controllers, right? I'd still want to have some way of hooking it up to a PC to control / watch temps. So I'm sure there'd be some programming involved. After I'm done working on these two PCs, I'll study the PDF. I just glanced through the first pages. I'll read the whole thing and maybe I'll have a better understanding.

[stj]

Re: Replacing BGA components with hot air.

you mean wiring, or programming?
wiring is in the pdf.

[Spork Schivago]

Re: Replacing BGA components with hot air.

exactly.

Good to go! Now, is it all powerful enough? I believe the hot air rework is around 650 watt. The preheater is 600 watt. I don't think the 600 watt is enough for the preheater. I was talking privately on here to one of my friends and he says some of these high end units have over 4kW total power (preheater and the top heater).

I wouldn't mind making a new preheater. 2,000 watt would be my goal. From my friends suggestion, I'd implement zones. Just figuring out how to do it, that's the trouble. Would I be able to use those control units you linked me to earlier? Or would I have to design a PID controller myself or use someone elses design? So many questions. I wish I could find a nice how-to that involved using those controllers you linked to Stj.

[stj]

Re: Replacing BGA components with hot air.

That's what I was thinking. It's just like when I do SMD type work. I preheat the board so it doesn't warp. I thought maybe for BGA though, they might need the whole board preheated and then extra heat on the bottom where the chip was going. It was a stupid thought though. Thanks for clearing it up for me.

some do have a 3rd heater that blows up under the chip.

[stj]

Re: Replacing BGA components with hot air.

Grab the PC400/410/900 controllers and hook them up to my Weller WHP-3000 preheater / Weller WHA-900 hot air blower motor?

If so, this would make it so I wouldn't have to design a custom circuit board for the hot air rework station blower motor, right?

exactly.

[Spork Schivago]

Re: Replacing BGA components with hot air.

The whole of the bottom of the board gets heated. I cover any delicate parts like plastic connectors with aluminium/kapton tape.

Bottom heat is required for two reasons, having cold parts of the board and very hot causes warping and cracking and it also requires more effort from the top heater.

That's what I was thinking. It's just like when I do SMD type work. I preheat the board so it doesn't warp. I thought maybe for BGA though, they might need the whole board preheated and then extra heat on the bottom where the chip was going. It was a stupid thought though. Thanks for clearing it up for me.

[Spork Schivago]

Re: Replacing BGA components with hot air.

...
personally i would just get a couple of pc400/410/900 controllers off ebay - they are designed for it.

Grab the PC400/410/900 controllers and hook them up to my Weller WHP-3000 preheater / Weller WHA-900 hot air blower motor?

If so, this would make it so I wouldn't have to design a custom circuit board for the hot air rework station blower motor, right?

[diif]

Re: Replacing BGA components with hot air.

When you say bottom heat, do you just mean the whole board gets preheated or do you mean the bottom board gets preheated and then there's concentrated heat where the BGA chip is on the bottom and on top as well?

The whole of the bottom of the board gets heated. I cover any delicate parts like plastic connectors with aluminium/kapton tape.

Bottom heat is required for two reasons, having cold parts of the board and very hot causes warping and cracking and it also requires more effort from the top heater.

[stj]

Re: Replacing BGA components with hot air.

it's doable if your pre-heater is big enough and you fit your air unit into a drill-press type frame over it.

your not pre-heating under the chip btw, your pre-heating the whole board to avoid warping or cracked joints caused by hot and cold area's

personally i would just get a couple of pc400/410/900 controllers off ebay - they are designed for it.

[Spork Schivago]

Re: Replacing BGA components with hot air.

i would not try that, you wont have profile control.

the proper units can raise and lower the heat in timed stages.

Hey! I think I saw some people using those controllers in their home made BGA rework stations. I was wondering if I should maybe purchase some of those to use in my attempt for a homemade hot air BGA rework station.

[Spork Schivago]

Re: Replacing BGA components with hot air.

i would not try that, you wont have profile control.

the proper units can raise and lower the heat in timed stages.

Right. I should have explained the original question a bit more in detail. The idea was if I could safely replace BGA components with hot air, I wanted to use my preheater and the Weller WHA900 Hot Air station parts and modify it into a BGA rework station. I wanted to use the hot air blower motor and redesign the circuit board, so I'd have profiles.

The first step would be designing the board that controls the motor to make it digital. Then I'd want to add some K-Type thermocouples. Finally, somehow hook it up to a PC to control it remotely so I could use profiles. Instead of saving up a lot of money and buying a BGA rework station. I'd still be able to use it manually for SMD type work. I just wanted to know if it was possible. I know it'd be a lot of work, but it could be very fun and one heck of a learning experience.

I believe these things have a PIC in them. The preheater does at least and I can control that remotely via an RS232 connection. My soldering station and "talk" to the preheater and I have the protocol information for the preheater. I thought I could implement the same protocol on the hot air rework station so the hot air could talk to the preheater and vice-versa and the computer could control both.

What do you think?

[stj]

Re: Replacing BGA components with hot air.

i would not try that, you wont have profile control.

the proper units can raise and lower the heat in timed stages.