[DIY] BGA rework station

Forum for all DIY topics.

Re: [DIY] BGA rework station

Postby egberttheone » Sat Nov 23, 2013 3:04 pm

Ok so i limit the power to the top heater to 50% and now it works quite well.

Image

I have some old boards so did some try's and it worked perfectly.


Image

Came off really clean. :D

So i dicided to try and repair a GPU from a motherboard.
It came off perfectly without any fore, but it seems some pads are gone !? :?
Or is this black pad?

Image

Image

Are these unused pads or is this why the motherboard failed?
egberttheone
Valued Member
Valued Member
Progress to next rank:
20%
 
Posts: 32
Joined: Sat Aug 17, 2013 5:59 pm
Location: Netherlands
Has thanked: 7 times
Been thanked: 8 times

Re: [DIY] BGA rework station

Sponsor

Sponsor
 

Re: [DIY] BGA rework station

Postby domelec » Sat Nov 23, 2013 3:27 pm

there ripped off pads mate
they ripped off cos solder wasnt liquified enough or was too much heat causing the pads to lift
domelec
VIP Member
VIP Member
 
Posts: 222
Joined: Sat Oct 06, 2012 12:09 pm
Location: west yorkshire
Has thanked: 0 time
Been thanked: 5 times
Set up: scotle ir6000 v4, t8120 preheater and t835 ir, 853a preheater and 858d hot air

Re: [DIY] BGA rework station

Postby code0102stinks » Sat Nov 23, 2013 3:54 pm

What is the temp on top of your MB from preheat before you start top heat? On that graph, it looked too low, but don't k now if that graph
is showing just a test or what you actually used lifting that chip. Should have about 170-175C on top of the mb from preheat. And you should
use the nudge test on the bga chip to see when it is fully liquid. Reused test boards can have lifted pads due to previous tests too, but when
you believe you have your profile to the point the chip is fully loose, try lifting a chip that hasn't been cooked from previous testing. Be
gentle when trying to nudge. If all the balls are liquid but a few, then the chip can seem loose and move, but a pad will tear. Try a couple corners.
At first I got the impression from earlier pics it was small 22mm OD, but yours is the larger. As long as you are content with the fan in it, it
should worn good if you mod the netted nozzle.
code0102stinks
VIP Member
VIP Member
 
Posts: 705
Joined: Sun Dec 09, 2012 5:18 pm
Location: WA, US
National Flag:
United States of America
Has thanked: 78 times
Been thanked: 234 times
Set up: DIY Hot Air Top Heater and Nozzle. Modded T8280 Preheater

Re: [DIY] BGA rework station

Postby egberttheone » Sat Nov 23, 2013 5:33 pm

The pads are ripped off, but the pads that came off are unused by the PCB so it is not a lost battle.

i'm using 140 degree preheat as the datasheet of a flux manufacturer recommended.
170-175 degree seems like you will almost reflow the entire board? :tumbleweed:
egberttheone
Valued Member
Valued Member
Progress to next rank:
20%
 
Posts: 32
Joined: Sat Aug 17, 2013 5:59 pm
Location: Netherlands
Has thanked: 7 times
Been thanked: 8 times

Re: [DIY] BGA rework station

Postby code0102stinks » Sat Nov 23, 2013 6:41 pm

I was assuming it was lead-free which the law requires now on electronics. To remove a large bga chip on a 2-zone you need
much more preheat. 140C would be fine preheat on a 3-zone, but you need as much help as you can get from bottom heat
on 2-zone. Otherwise top heater has to do too much heating and damage chip.

Also, your tc placed by chip temperature reading will be much different than what these guys using IR. With HR the tc is mostly
reading the hot air temp rather than the pcb temp. When using IR, the tc will have a real temp of pcb since the pcb aborbs
heat from IR, then radiates it to tc to give a more accurate reading. With HR the only way you know what the actual pcb temp
is at the chip is when the solder becomes liquid and chip lifts.
code0102stinks
VIP Member
VIP Member
 
Posts: 705
Joined: Sun Dec 09, 2012 5:18 pm
Location: WA, US
National Flag:
United States of America
Has thanked: 78 times
Been thanked: 234 times
Set up: DIY Hot Air Top Heater and Nozzle. Modded T8280 Preheater

Re: [DIY] BGA rework station

Postby egberttheone » Sat Nov 23, 2013 11:23 pm

Thank you for sorting that out, the 2 pcbs i used for testing where old and i think not ROHS.
The motherboard is lead free, so i need to make a new profile for pb free rework.
:+1:
egberttheone
Valued Member
Valued Member
Progress to next rank:
20%
 
Posts: 32
Joined: Sat Aug 17, 2013 5:59 pm
Location: Netherlands
Has thanked: 7 times
Been thanked: 8 times

Re: [DIY] BGA rework station

Postby egberttheone » Tue Nov 26, 2013 7:13 pm

I have added the ability to load and save profiles.
I have come up with this profile.

Image

Pb free, soaking zone with pre-heater ramping up to 170 degree.

Image

Leaded solder rework profile
egberttheone
Valued Member
Valued Member
Progress to next rank:
20%
 
Posts: 32
Joined: Sat Aug 17, 2013 5:59 pm
Location: Netherlands
Has thanked: 7 times
Been thanked: 8 times

Re: [DIY] BGA rework station

Postby bartlet » Wed Nov 27, 2013 2:41 pm

the bottom temperature ?
bartlet
VIP Member
VIP Member
 
Posts: 139
Joined: Mon Aug 05, 2013 8:22 pm
Location: italy
National Flag:
Italy
Has thanked: 14 times
Been thanked: 12 times
Set up: scotle ir pro sc v4

Re: [DIY] BGA rework station

Postby egberttheone » Thu Nov 28, 2013 11:44 am

yes, the pre-heater. The temperature is measured from the top of the PCB.

Here is the result of the lead free profile.


Image

You can ignore the rapid cooling, the thermo couple was not covered with tape.
You can see that the top heater struggles to get the board to temperature.
Is it fast enough or can it potentially damage the chip in the process?
egberttheone
Valued Member
Valued Member
Progress to next rank:
20%
 
Posts: 32
Joined: Sat Aug 17, 2013 5:59 pm
Location: Netherlands
Has thanked: 7 times
Been thanked: 8 times

Re: [DIY] BGA rework station

Postby egberttheone » Sun Dec 08, 2013 10:45 am

Designed new PCB.

Added functions:

-Stepper motor controller for a Z-axis.
-Extra thermocouple input for control of the hot air temperature.
-Extra 230v fan output, if i want to switch to a bigger hot air fan.

Image

Going to send it out for production. :)
egberttheone
Valued Member
Valued Member
Progress to next rank:
20%
 
Posts: 32
Joined: Sat Aug 17, 2013 5:59 pm
Location: Netherlands
Has thanked: 7 times
Been thanked: 8 times

PreviousNext

Return to DIY Forum

Who is online

Users browsing this forum: No registered users and 1 guest