I am trying to come up with a better solution for an operation that is causing wrist and thumb pain for our operators. As part of a rework process for a microelectronics circuit board, a faulty part is removed from the board. The operator then has to manually scrape a patch of heat-cured adhesive off the board using a sharp exacto-knife/chisel-type tool. This patch of adhesive is relatively small (~1/4 inch square) and the work is done under a microscope as precision is extremely important. The posture of the hand is very similar to the traditional pen/pencil grip.
Even with padding build up on the tool and an icing and stretching program, pain is continuing. I’ve explored using a chemical and an automatic tool, but this would cause contamination of the part and/or the cleanroom this is performed in. Essentially, our only viable option from a quality standpoint is to manually scrape the boards. Right now, we’re limiting time at the task and rotating people frequently, but I’m wondering if anyone has dealt with something similar and found a solution? Or, since this operation is somewhat similar (albeit with more force involved) to handwriting, does anyone have a recommendation for a pencil grip/holder that I could try?
Sorry for the novel, and thanks in advance for any advice.
Would it be possible to weaken the adhesive force first by chilling the patch with a block of dry ice or a drop of liquid nitrogen before scraping? Maybe worth an experiment.
Frederick Grose, MPH, CIH
As an occupational therapist I deal with handwriting all the time. My favorite device for gripping a writing utensil when someone has weakness or no grasp is the Wanchik Writer device. It holds the pen/pencil in a normal writing postition, yet no real grasp is required. The motion and force come from the wrist and other arm muscles, which are usually stronger and able to handle repetive motion. Supporting the arm as much as possible is important however to prevent shoulder and elbow problems. You can see a picture and view ordering information on the following website:
I do not know if this will accomodate the tool you are using, but it is adjustable and possibly it can be modified for the tool. The "typer" has an extended piece already that could be modified to be the scraper.
Hope this helps.
Here are a few ideas:
* Before the days of computer aided drafting, draftsmen had to do a lot of erasing and for this they had a tool like a small hand drill but it contained a 1/4 inch diameter rod of eraser rubber instead of a drill. This saved a lot of finger ache. The closest thing to that for your application may be a Dremel tool with a small grindstone.
* This also sounds somewhat like precision wood carving and cleaning teeth. Can you use any of the chisels etc as used for carving wood? See http://www.leevalley.com for some of the ones available (see especially the Henry Taylor Palm Set. Your operators may find that they can grind a standard tool so it is small enough to do their job. Also check out the picks etc. used by dental hygienists.
* You could try an engraving tool with the point ground to a chisel shape. It would create swarf, but you must already have a small vacuum cleaner system for collecting the bits that you now shave off.
* A two handed pull-towards you paint scraper with a curved blade? One hand gets used for pulling, and the other for applying pressure, and control is improved. Something like a Bahco / Sandvik Ergo Scraper 650 but grind the blade down from its regular width to 3/16 inch or so.
* For the tools that you now use, lengthen the handles so that the operators can use both hands on the handle and thus use the whole upper body instead of their just the muscles in their hands.
I will rephrase the physics equation: Work = Force x Distance, to be Work = Force x Other Input.
To get the same amount of work output with the goal to decrease the force involved (employees muscles and finger dexterity), the second function (Other Input) must increase.
What "Other Input" would I recommend? In the medical field, when removing tape from a patient’s skin, the hospital uses adhesive remover. It’s an isopropyl alcohol-based solvent that chemically breaks down the adhesive qualities of the bonding agent.
In this situation, it might be possible to apply a non-destructive solvent that would reduce the bonding qualities of the resin adhesive and make removal much more easy to perform.
Thank you everyone for all the great ideas! A couple of things that make this challenging are that no power tool (dremel) can be used due to the clean-room, no-dust requirements. Also, there are other parts on the board that are sensitive to chemicals. We’re going to try the Wanchik’s Writer to see if that works. I ordered one – quite the crazy looking contraption!
Katie, please let us know how it works. Some training of the users will need to be provided as well as using the device. For example, the arm should be supported as much as possible, and encourage use of the whole arm. No pinch should be needed when using the Wanchik, although out of habit, folks may still want to do this. The wrist should be in a neutral position (not flexed or extended more than ten degress.
It’s a great little tool, so hopefully it helps.
Kathleen Shanfield, OTR/L
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