A little mole-hill cooling off dead planar hey !? ; Steve ; I've been crying
my full vision out by the time I got to the end of this episode of that saga
:
If Jack didn't invite You to that legend convention ; he's got it all inside
out .
Takin' about classics !
Thanks for the show ; lokkin' forward to next episode
paul
PS
I definitely think (or so) that yo' deserve a public acclamation :
so all you loose and agile : let's give Steve cheers for his tireless
efforts keeping the Net wet with tears !
Do you concur Ladies & Gents ???
Just type : Hoy ! ; or certified substitute
AND HIT THE BUTTON ! please
> ----------
> From: Stephen R. Gregory[SMTP:[log in to unmask]]
> Sent: Friday, 8 January 1999 8:41
> To: [log in to unmask]
> Subject: [TN] Assy: I CAN Rework this BGA Socket!
>
> Hey ya'll!!
>
> SUCCESS! I was able to get that monster off!...(Now I just gotta' be
> able
> to get it back on right...hehehe) If you remember, the whole reason I had
> to
> rework it was because somehow they got the hole positions wrong in the
> board
> for the two alignment pins at the bottom of the socket, which caused the
> socket to be soldered one row off on the board. I'm still trying to get to
> the
> bottom of how that happened (I haven't forgotten your request Roger, still
> workin' the issue...).
>
> But I called CTI this morning and talked to them about trying to
> rework
> this thing. I was told that they have heard of people reworking this
> socket,
> but it's pretty much been hit and miss, and trying this, or trying that.
> They
> said the one company that they know of who have got it down is SCI. I
> guess
> they build a lot of product that uses this socket and they've had their
> rework
> equipment modified to do this socket...you know, special preheater,
> nozzle,
> etc.
>
> But, getting back to how I did it, it was a "Steve's start-up company
> mode special". Don't laugh too much, 'kay? Sometimes when you don't have
> all
> the things you want, you gotta make do with what you have...and I think if
> you
> use common sense, and take things slow, you can do just about anything
> anybody
> else can....maybe not as fast, but you can do it.
>
> My rework system is one of them fancy Hakko 850's...you know, the
> full-
> vision (your own two-eyeballs), hand held unit. The nozzle I used was a
> 36mm
> square one that's normally used for QFP's...this one matched the basic
> shape
> of the pins in the socket. I had to take the cam lever, and the "Z-lok"
> cover
> off to expose more of the pin's surface to absorb the heat. I also used my
> trusty Fluke multimeter (it has a temperature function which you can plug
> a
> thermocouple into and see temps real-time) and threaded the tip of the
> thermocouple into the socket where it could tell me how hot it was getting
> down around the solder joints.
>
> I was pretty liberal with the flux bottle, and really coated things to
> help me
> with heat transfer. Turned the Hakko on and watched my Fluke. It took
> about
> two and a half, to three minutes for me to indicate around 210-220 degrees
> centigrade inside the socket, and then I tested the socket with my
> tweezers
> gently at the corner to see if it would move, it moved easily, and I
> pulled it
> up without a hitch! Didn't even lift a pad!! YEEE-HAW! Not bad 'fer a
> in-gun-
> ear, huh? Usually, you don't want to let us get anything sharp or hot in
> our
> hands...(GRIN). The board had a little mole-hill where the socket was
> until it
> cooled back down and straightened out. The socket was actually in pretty
> good
> shape too, the plastic didn't degrade a bit.
>
> Now, I just gotta figure out how to get this puppy located back over the
> pads
> accurately without those guidepins, I gotta clip them off...I'll let ya'll
> know how that goes...
>
> -Steve Gregory-
>
> ################################################################
> TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
> ################################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in the body:
> To subscribe: SUBSCRIBE TechNet <your full name>
> To unsubscribe: SIGNOFF TechNet
> ################################################################
> Please visit IPC's web site (http://www.ipc.org) "On-Line Services"
> section for additional information.
> For technical support contact Hugo Scaramuzza at [log in to unmask] or
> 847-509-9700 ext.312
> ################################################################
>
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
