February 2009

Basic PCB Repair Tool Kit

by Andy on February 23, 2009

We found this video on Youtube from The Science Channel show How It’s Made. You’ll get to see how PCB boards, specifically video cards, are made. If you’ve never had a chance to see how a circuit board is made, and you’re a little bit of a “tech geek” like us, we think you’ll like this video. It’s a pretty cool process to watch. Thought it was appropriate for today’s post.

Before you get started repairing a circuit board there are a few things you should have on hand. These are some of the most used tools and materials for any PCB repair job however your particular job may require more or less. For instance, sometimes it is advised to gently heat the circuit board to prevent any component from going through thermal shock because of heating just one area of the board. A PCB heater didn’t make it on the list because we didn’t feel it was as heavily utilized as the other tools.

Consult a professional and/or your spec sheets before attempting to repair any circuit board.

1. ESD Workstation – Of course, you want to make sure you’re working on a safe workspace. Take care to make sure your workstation is ESD safe. You don’t want all your hard work to be in vain when you repair your PCB just to have it zapped by static.2. Magnifying Equipment – Like the doctor ready to perform an intricate operation, the circuit board tech needs to be able to see every fine detail. You can accomplish this with a headband style magnifier with light or with an illuminated magnifier on an arm that you can clamp down onto your workstation. The pro may be using a binocular stereo-zoom microscope for repairs.

3. Soldering – A good soldering iron or station is obviously necessary when repairing your circuit board. Depending on your needs, you can find soldering irons from professional stations and industrial irons to lightweight and cordless irons.

4. Desoldering Equipment – Removing old solder can get messy if you don’t have the right tools. Typically you’ll have a desoldering pump that, when the old solder is melted using a soldering iron, heat gun or butane torch, is easily sucked up into the pump. You can find desoldering guns with pump combos that make things a little easier. Another method is using a desoldering braid. These come in spools of braided specially treated fine copper threads that act as a wick and soak up the molten solder then solidify in the wick.

5. Drilling and Grinding Tools – In case you need to re-drill the connecting holes on your board, a micro drill or precision drill system will be very handy. Plus, dragging out the old bulky hand drill can be too much for the board to handle and completely destroy your circuit board. A good micro grinding tool is very helpful when removing dried epoxy or solder.

6. Eyelets with Eyelet Press – Eyelets are needed to repair through holes to connect wires to the board. They are crimped down onto the board using the eyelet press. They are used frequently when repairing boards and come in various sizes so make sure you have several different sizes on hand. The inside diameter should be 0.003” – 0.035” larger than the diameter of the component lead.

We’ll finish out with a video that shows how a circuit board was repaired for a Hoshizaki Machine. You’ll notice he uses several of the tools mentioned above.

Want to make your life a little easier? Check out our 415 piece PCB repair starter kit!

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All-Spec Stat-Crete Installation Instructions: Part 1

by Andy on February 19, 2009

This is part one of a three part series with instructions on how to install All-Spec’s new Stat-Crete 2-part epoxy paint.

Here are a few features of the dissipative epoxy paint:

Surface resistivity: <10⁷ Ohms² Max/Cm² @ 40% relative humidity
Static decay rate of <0.2 seconds using FTMS 101B, method 4046
Works on a wide range of concrete and ceramic surfaces
Resistant to abrasion and many chemicals and solvents
Available in a variety of sizes and colors

How to Install 2-Part Epoxy Paint on Existing Tile Floor

1. Remove existing finish with the All-Spec Eliminator floor stripper, a cold water floor stripper

Using cold water, mix 16 ounces per gallon of the floor stripper for routine stripping, 32 ounces for medium build-up or 128 ounces for heavy build-up. Mop on the solution and let stand for five minutes. Using a wet vacuum or automatic scrubber remove the finish; be sure to remove any residual floor finish by light rinsing or mopping. Let the floor completely dry before applying Stat-Crete.

Note: All-Spec Eliminator is not for use on older linoleum tile floors or asphalt tile. The stripper may remove the dye, especially from dark colored tiles.

2. Create a conductive floor using the All-Spec Stat-Crete epoxy paint

Add the pre-measured catalyst to the epoxy base and stir until the catalyst has been completely mixed in. Let the mixture stand for five minutes. Using a short nap roller, apply a thin, uniform layer of the dissipative epoxy. Allow the first coat to dry for 5-7 hours before applying a second coat. It is important to mix only the amount needed for immediate use and the paint should be used with six hours of initial mixing. Freshly painted floors can withstand light traffic after 12 hours of curing but maximum durability wont be achieved until five to seven days after painting.

Note: Avoid using this paint in areas that are frequently exposed to standing water.

3. Seal and Protect Dissipative Floor with All-Spec’s Stat-Seal

Vacuum the floor to remove any loose dirt or dust; then wash the floor with All-Spec’s Stat-Clean. Once the floor is dry, apply thin uniform coats and allow the sealer/finish to dry for about 30 minutes before allowing people to walk on the floor.

4. Maximize ESD protection with All-Spec’s Stat-Coat, a static dissipative floor finish

In temperatures of 60°F or warmer, use a synthetic finish mop to apply thin, uniform coats of the finish. Optimum appearance is achieved by waiting 30-45 minutes between each of the three to five recommended coats of finish. Avoid application in high humidity as this can extend drying times.

To maintain dissipative properties, sweep the floor everyday with an untreated mop to remove any sand or dirt that may scratch the floor. Damp mopping the floors on a regular basis is also a good idea to remove any substances that could decrease the conductive properties of the coating.

If you have any questions about All-Spec’s Stat-Crete, please contact our customer service by phone (1-800-537-0351) or email customer service.

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Creating an ESD-Safe Workstation

by Andy on February 3, 2009

If you’re working in an environment where ESD (electrostatic discharge) is something you absolutely must avoid, it’s very important to have a proper ESD Safe workstation. Knowing exactly what ESD is and having the right tools can make all the difference in protecting your sensitive electronic components.

So, what is ESD? Electrostatic discharge is simply the static that builds up in your body which is then discharged when you touch something conductive.

Technically it’s the equalization of the difference in electrical potential of two objects.

That “shock” you feel when you walk across the carpet and touch your dog, is a great example of ESD. It’s especially worse during this time of year when the air is dryer, seems everything you touch shocks you.

That tiny little shock costs the electronics industry millions every year. It is estimated that 60% of all electronic device failures are due to static buildup and/or discharge.

Integrated circuits used to make circuit boards can be damaged by anywhere between 100 and 1,000 volts. The amount of static you buildup just by walking over carpet can be as high as 35,000 volts!

What to do? One of the most common ways to combat ESD is through the use of dissipative or conductive mats, sometimes referred to as ESD mats. These are made with materials that whisk away static from anything that touches it, much like a sponge soaks up a spill, and will typically carry the charge off the mat and through a ground wire.

Your workstation should, at the very least, include a floor mat and a table mat. They typically come in one to three layers. A dissipative rubber, vinyl, or industrial elastomer top layer and conductive middle layer are what you will commonly find in most ESD mats. Sometimes a third dissipative bottom layer will be found that will also feature a non skid surface.

Check to make sure your mats come with a good ground cord and grounding system as well.

An ESD wrist strap is also part of an ESD Safe workstation. This is a simple two-part device that connects a person’s skin to a ground. This is useful as an added measure as this device constantly dissipates any charge further preventing any discharge.

A very useful tool in an ESD Safe workstation is the Static Monitor. These devices constantly monitor the connection and static levels of the person assuring a static free workspace.

If you do a lot of walking or standing you may look into heel straps or grounds that use the moisture in your shoe as a connection to the body and a conductive rubber tread as a connection to an ESD mat or floor.

Add an ESD awareness sign and you’ve got a complete ESD Safe Workstation!

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