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LGA component rework process on SRT machine

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#86734

LGA component rework process on SRT machine | 4 June, 2021

Hi All, Do you have any experience for LGA component rework on SRT equipment? Please share how to re-soldering the LGA component to PCB pads. Thanks

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#86735

LGA component rework process on SRT machine | 4 June, 2021

We do this quote often with our older Summit machine. there are a few ways to do this. all of these are assuming you have parts on the boards already and are working around them. 1- if you have a good tech that can add solder to the pads on the PCB and hot air them to level prior to component install this is the quickest/easiest way. we then apply tacky flux and install the part and reflow, we end up with fewer voids in there joints. 2- Buy the mini kapton stencils for the specific component package you are working with, apply solder paste, install the part and reflow. the kapton stencil stays on the pcb. 3- if you have an EFT dispenser, apply solder paste to the pads of the PCB using a timed shot and needle tip this will yield the same volume of paste on each pad. 4- lastly i have used preforms and tacky flux in a pinch, when my rework/repair tech is not here i wick the pads myself, apply tacky flux and hand place (or machine place) solder preforms to the pads and set the part on the preforms/pads. oh and make sure if you are using the same part you removed, wick the pads on the component too! don't forget to bake your board and component before rework.

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#86739

LGA component rework process on SRT machine | 5 June, 2021

For Linear Tech LGA's we solder bump the LGA using a .30mm solder ball then reflow with a tacky flux. This will provide a void free solder joint and adds a little height to the solder joint in case you use a flux that you want to clean from under the BGA.

We use Amtech 4400 mildly active tacky flux. This is good for Lead Free Solder and washes out easily with warm water. For a No Clean Tacky Flux we use Kester RF-741.

We also make custom fixtures that can solder bump 9 to 12 LGA at a time if you have a lot of LGA's to bump.

Best makes Kapton Stencils that you can apply solder paste to the LGA or PCB and reflow to make a solder bump also or just install the LGA with Solder Paste. The disadvantage of installing LGA's and QFN's using solder paste is that you will always have some voids.

You can see our reballing demo here: https://youtu.be/7-M65u74oSo

We are a supplier of Reballing Fixtures, Solder Balls, Reballing Stencils, Amtech Fluxes, Chip Quik Products, JBC Soldering Stations, and BGA Rework Stations. We also have a large inventory of SRT Nozzles and provide SRT Service, Repair and Operator Training.

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