Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


BENT LEADS ON FINE PITCH

GREG DENHAM

#12047

BENT LEADS ON FINE PITCH | 7 April, 1999

DOES ANY ONE KNOW HOW I CAN STRAIGHTEN BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM.

reply »

ScottM

#12048

Re: BENT LEADS ON FINE PITCH | 7 April, 1999

| DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM. | I use tweezers and picks. I place the component down on it's backside (legs up) and manually tweek them under a X4 or X8 magnification. The extent of the damage depends on if you can get the P&P to place it or if you have to manually install it. If only a few pins are bent, chances are I can make it work on the P&P but I have straightened 208 pin QFPs with 100% bent pins (container busted "open" in shipment) to be good enough for manual soldering. Patience and a stable hand helps...

I have also seen ads for straightening templates but I have not investigated them.

Hope this helps, Cheers, Scott

reply »

Frank Johnson

#12049

Re: BENT LEADS ON FINE PITCH | 8 April, 1999

Greg,

We at Beau Tech make all size picks and probes for straightening leads and other repair/rework tasks. Sounds like you can use a 10-MilProbe for your job. Please visit the Beau Tech web site at the following address www.beautech.com or call us for more details. Thanks. Frank.

| DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM. |

reply »

Matt Stackhouse

#12050

Re: BENT LEADS ON FINE PITCH | 9 April, 1999

| DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM.

Here is a neat trick if you have the equipment. If your company does any feature measurement of mechanical devices or you measure process capability of your pick and place you probably have a coordinate measuring machine (CMM). Many of these machines have a feature called "overlay". This feature allows you to compare one image to another or "overlay" one image on another.| The heavy flat glass backlit tables, high magnification cameras and the overlay feature make tweeking bent leads on QFP's a snap. You simply overlay the image of a set of "Perfect" leads overtop of the bent ones and Tweak the leads to match. You can bring the parts back to near perfection with a steady hand and a very fine probe. This came in really handy when a technician bounced a tray of QFP-300s by mistake.

reply »

Charles Stringer

#12051

Re: BENT LEADS ON FINE PITCH | 13 April, 1999

| | DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM. | | | I use tweezers and picks. I place the component down on it's backside (legs up) and manually tweek them under a X4 or X8 magnification. The extent of the damage depends on if you can get the P&P to place it or if you have to manually install it. If only a few pins are bent, chances are I can make it work on the P&P but I have straightened 208 pin QFPs with 100% bent pins (container busted "open" in shipment) to be good enough for manual soldering. Patience and a stable hand helps... | | I have also seen ads for straightening templates but I have not investigated them. | | Hope this helps, | | Cheers, | Scott | I have used a previous issue mask as a template. Just cut out the part of the foil for the device in question, Although in general the holes will be too narrow to slot the leads into they will be the right pitch and an excelent tool for checking the alignment of tweaked pins. Taking this one stage further..... You could have a pattern with apertures slightly wider than the pins etched into a redundant area of the foil or on a test coupon by your mask supplier. I have not tried this last approach but having just thought of it I intend to give it ago on our next screen. Watch this space

reply »

ScottM

#12052

Re: BENT LEADS ON FINE PITCH | 13 April, 1999

| | | DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | | | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | | | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM. | | | | | I use tweezers and picks. I place the component down on it's backside (legs up) and manually tweek them under a X4 or X8 magnification. The extent of the damage depends on if you can get the P&P to place it or if you have to manually install it. If only a few pins are bent, chances are I can make it work on the P&P but I have straightened 208 pin QFPs with 100% bent pins (container busted "open" in shipment) to be good enough for manual soldering. Patience and a stable hand helps... | | | | I have also seen ads for straightening templates but I have not investigated them. | | | | Hope this helps, | | | | Cheers, | | Scott | | | I have used a previous issue mask as a template. Just cut out the part of the foil for the device in question, Although in general the holes will be too narrow to slot the leads into they will be the right pitch and an excelent tool for checking the alignment of tweaked pins. | Taking this one stage further..... You could have a pattern with apertures slightly wider than the pins etched into a redundant area of the foil or on a test coupon by your mask supplier. | I have not tried this last approach but having just thought of it I intend to give it ago on our next screen. Watch this space | Good thought, thanks for the tip -- I'm going to give it a go...

Cheers, Scott

reply »

Stephen Oltmann

#12053

Re: BENT LEADS ON FINE PITCH | 14 April, 1999

A company in Santa Clara California specializes in repair of fine pitch using automated inspection and repair equipment. They guarantee their work and include bake and dry pack.

Go to http://www.sixsigmaservices.com/services.htm

| DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM. |

reply »

SMT, PTH, AOI,  and Test machines for sale - ECM Equipment

vacuum tweezers - manual pcb assembly