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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


AMP Mictor

Zanolli

#15652

AMP Mictor | 2 June, 1998

Is anyone familiar with assembly procedures for the AMP� straddle mount Mictor connector? If so are there any suggestions to solve difficulty in slitting through the ground pin PTH barrels� and applying paste as reccommended?

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haran

#17745

AMP Mictor | 1 October, 2001

What is the main problem in running Mictor connector in SMT? What should be the stencil opening for the through hole lead?Is there any way we can eliminate touch up for the through hole lead as I understand from others that the main problem in running the Mictor connector is having good barrel coverage.Pls help.

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#17752

AMP Mictor | 1 October, 2001

We do not assemble with these connectors any longer, we replaced them with a connector from somebody er other, like Teka [one of the pioneers of solder-flux bearing lead technology and a supporter to SMTnet], Samtec, Advanced Interconnections, Mill-Max, etc. that offer through-hole connectors with solder bearing leads that liquefy during typical reflow processing of printed circuit boards. But if life works the way it normally does, the above is not going to help you with the problem you have � RIGHT NOW!!!!

AMP Mictor connectors come in 50 and 25 pitch versions. And boyeee are they expensive � BIG $$$. The 25 pitch Mictors are a pain, because: * Tough to paste / reflow, because there's little room for printing any substantial amount of paste on the inner rows of pins. The 25-pitch seems to have an untenable relationship between spacing between leads and pin thickness. * Connectors are somewhat fragile, as is any fine pitch component, and must be treated accordingly.

Understand that this is biased talk, because we gave-up, rather than fight this problem. Pasting a 25-pitch connector is tough, because the designer probably used all available real estate between the connectors for pads [not that there�s much there anywho]. * Over-printing paste between the pins of rows causes bridging, just like THAT!!! * Pins on the outside will accept a teardrop-shaped paste over-print. This can have quite a bit of material, providing someone didn�t brick wall another component next to the Mictor. * Pins in the inside will take oval over-printing that is oriented 45� to the rows of pins.

Places to find more information on paste-in-hole are: * http://www.smta.org/knowledge/proceedings_abstract.cfm?PROCEEDING_ID=586 * http://www.alphametals.com/products/solderpaste/pin-in-paste.html * http://www.itm-smt.com/articles.html * http://www.bobwillis.co.uk/ * Amp connectors used to have some good stuff, but I can�t find it.

� but they really won�t be able to help you much, because you have too little real estate and too much hole to fill. But wuttdahay?

We used a slitting tool that AMP developed, and it seemed to work fine for us. We would: * Slit the boards. * Deposit paste on the connector through hole barrels and SMT pads on the secondary of the board. * Place secondary side SMT components and reflow. * Clean and inspect secondary side SMT. * Deposit paste to the primary side SMT and connector through hole barrels. * Install the Mictor connector. Don�t get too aggressive about jamming it through the holes, because the hole probably is blocked with the reflowed solder paste from the secondary side. * Apply liquid flux to the secondary side Mictor pins [now resting on a �crown� of solder from bottom side SMT assembly]. * Place primary side SMT components and reflow. * Clean and inspect primary side SMT.

Get Amp Application Specification 114-11004 covering the use of Mictors. I looked for it on the AMP site, but got very confused. Your sales rep probably can get you a copy, if you can�t find it either.

Most if our rework was bridging [plus a few poor seatings]. So, we used: * AirVac [A SRT or any of the other fine rework stations would do the job, also] to remove and replace Mictor connectors, both the straddle mount and the right angle �back-plane� style. * Leister tool to hit and �clean-up� connector bridges. [We struggled in try to understand bridging with too little solder. We think it went back to: A �too many things wrong about the situation to get good flow� situation. And solder, being ornery by its very nature, would vasty prefer to bridge at the nice, warm pins; rather than flow down the dark, cool through holes.]

ps: Next time, please open a new thread, rather than posting to a tread that's over three years old. Tks. ;-)

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Garry Barrows

#18350

AMP Mictor | 5 December, 2001

I assembly boards that have 200 each of the MICTOR connectors. The boards are .300" thick. I have 100% solder fill in the holes. I also have developed a rework process so I can remove and replace the connectors if the they get broken by my customer. If you have any question or would like more info. Phone 214-576-8143 email garry.barrows@flextronics.com or gbarrows1@juno.com

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