ProtoBoards

At Farnsworth Electronics, Inc. we supply DATAK PROTOBOARDS which are for quick and easy circuits.
Ideal for those "one only" circuits, pre-production prototypes etc. All DATAK Protoboards have copper

on one side and matching printed pattern on the opposite side to make parts placement easy.

Copper pads are drilled and ready to solder. These board are available in the less costly Phenolic

substrate and with an FR-4 substrate for high frequency RF circuits.

We've got one of our featured vendors, Philmore Manufacturing's catalog available online.

Click here to see the catalog.

Click here for instructions and tips

Jumper wire "PUSH-IN" PROTOTYPE CIRCUIT BOARDS (NO SOLDERING)
For prototype design, testing and modification of circuits. These breadboards will accept the leads of

nearly any electronic components (up to 0.032") in the 0.1" x 0.1" grid of solderless tie points, dual inline

packages, or DIP’s such as I.C.’s plug in for very fast assembly and modification of circuitry. Solid wire

jumpers plug in for interconnections. Contacts are a durable alloy with nickel plating; body is made of

ABS polymer. Breadboards have indexing numerals on each row and column to speed assembly and

eliminate errors. Ideal for the educator and in the designers lab also.

Standard Premier® PC boards

Datak Premier® series Special Board types

PC Developing & Etching Tray

# 12-515, 8X6inch

# 12-570, 5X7inch

# 12-810, 8X10inch

# 12-1114, 11X14inch

For developing positive boards or etching boards with Ferric Chloride etchant. NOT for use with

the negative developer!

DRILL BITS for PC board holes, two bits per package, except sets # 12-530 and # 12-550

These are the common sizes used to drill lead holes for components in the copper pads. Holes should

be just a bit larger than the lead sizes.

LAB PC Board ETCHING TANK SYSTEM

Like the tanks used by the big producers, except designed for a modest pocketbook and intended for use

by users that make a few boards at a time. Etching (with Ferric Chloride Etchant) is vastly more effective

when the solution is warm or very warm, agitated and full of air bubbles (oxygen acts much like a catalyst).
The Datak Etching tank system includes a heater to keep the solution warm and a pump assembly

(110-120 volts AC) to both agitate and insert oxygen. The System is intended for use on a bench top.

# 12-700 Complete Lab Etch Tank (does not include the Ferric Chloride Etching solution).

# ER-12 Power Etch pump and tubing. Includes submersible distributor and may be used in your own tank.

# 12-704 Replacement hose.
# 12-702 Replacement Heater (110-117 Volts

FERRIC CHLORIDE ETCHING CONCENTRATE for etching copper PC boards

# ER-3 1/4 lb. Etchant Powder Concentrate
# ER-21 one pound Etchant Powder Concentrate.
# ER-22 two pound Etchant Powder Concentrate.

Supplied in a dry powder form for mixing with ordinary tap water. Convenient in several ways, ships and

stores easily and when mixed with water the process creates heat. When used freshly made, the solution

will not have to be pre-heated. The 1/4 lb. package will produce 1 pint of solution which will etch about

200 square inches of 1 ounce (standard) copper board. Heavier copper, such as 2 ounce, will require

proportionally more etchant. Tip: Always etch in a plastic or glass container (never metal).  Always use

very warm etchant solution. One method of warming the solution is to place its container in a bucket

of HOT water. After about fifteen minutes, the solution will be ready to use. Be SURE to loosen the cap

so that the expanding head pressure is released when the bottle/solution is heating.//Always mix by

adding the powder to water; there is much heat generated during mixing and the water can absorb

the excess heat. (Adding water to the powder is a MISTAKE!)

LIQUID ETCHING SOLUTION, ferric chloride for etching copper PC boards

A High quality Ferric Chloride Etching Solution, our preferred solution for all PC board etching.
A quart of solution will etch roughly 980 square inches of standard PC board material.

# 12-2038 Ferric Chloride Etching liquid Solution 32 ounce bottle
# 12-2039 Ferric Chloride Etching liquid Solution 32 ounce bottle

Exposure Frames

Metal frame with slide-in glass and wood trays; holds the positive "art" tightly against board during

exposure to light source. Two sizes are available.

# ER-10 for up to 9" X 12" Boards
# ER-56 for up to 5" X 6" Boards

Direct Etch RESIST PENS

Pen is filled with a lacquer that may be used directly on the copper board to touch up breaks,

add a hand-drawn feature etc; ink will resist etching. May also be used on clear films used for

positives to touch up or manually add a trace etc. Black Ink.

Fine Point Pen # ER15
Extra Fine Point Pen # ER25

# SWS02

Wire kit contains several different lengths/colors of insulated wires. These are pre stripped and ready for

insertion into any of the Solder-free boards in this group, and of course may be used with solder type

boards as well. 22AWG copper hook-up wire; ten pieces of each color in storage box.

Instructions and Tips

INSTRUCTIONS for USING the DATAK PREMIER series POSITIVE ACTING PRINTED CIRCUIT BOARDS:
Premier Positive boards have a dielectric constant of 3.6 @ 1 MHz.

POSITIVE PRESENSITIZED PC BOARDS

The Positive Method is the easiest to use of the various methods for making a PCB. Although the negative

method may cost less, the Positive method's fewer steps and time savings more or less offset any savings

in material costs. Positive PC Boards... What are they? The boards are standard, 1 oz. copper PC boards

with a Fiberglas substrate. The copper is coated with a light-sensitive chemical that is often called a

photo-resist or a sensitizer. When this coating is exposed to enough light, the coating will rinse away

in a developer solution, exposing the copper beneath. The copper is then etched, leaving untouched the

copper pads and traces that are your circuit. Positive boards are available in a number of sizes ranging

from 2inch x 4inch up to 12inch X 12inch and with the photo resist, or sensitizer and copper on one or

two sides. Before use, you may want to cut the PC board to size. The ideal cutting tool is a sheet metal

shear. Please be careful if using a paper cutter as there is a different pull and 'feel' when cutting a board

and fingers could be "dragged" into the blade and severely injured if you do not hold the board very,

very securely. Be sure to Score the protective film with a sharp knife on the line where you will be shearing

the PC board. Or, score it with a cut on either side of the line where it will be sheared. Scoring the

protective plastic film will prevent the plastic from pulling resist from adjacent areas during the shearing.

(Use an Xacto, or other very sharp knife for scoring.)

Develop the board:
        While the board is being exposed, prepare a tray of developer solution.  Use either Datak

# 12-402 or 12-406 liquid concentrate only. Mix the Datak developer 1 part of concentrate to 10* parts

water. NOTE: mix with warm water. A cold developer is not going to work. The temperature should be above

room temperature (about 100 to 110 degrees F), Use glass or a plastic photographic tray

(never metal). Use just enough developer to cover the board (1/4" to 3/8" deep is usually good).

After exposing, place the PC board in the tray and rock the tray gently until the copper is fully exposed

in areas to be etched. It will be obvious to you when the copper is bare; be sure that there is no haze

or film remaining. Rinse a developed board in cold water for a minute. Tap water is fine.  Cold water

stops the process and 'sets' the resist; after immersion in clean cold water, normal room lighting will not

affect the resist further.

Final notes: Here are some helpful tips for users of the positive PC boards:
    1. Store used developer in a plastic or glass bottle. Plastic is best as you may squeeze most of

the air out of the bottle and cap tightly. Do this because the developer will react, over time, with

the carbon dioxide in the air and decompose.
    2. You can use the developer until it simply does not perform; then flush it down the sink with a

fast cold water chaser. Storing developer in a refrigerator can help to keep it fresh for very long periods. 
    3. If the board proves to be tough to etch, you probably did not develop it long enough and some

resist residue remained behind. Or, said residue can also be caused by too short an exposure time, too

weak a light source and so on.
   4. Etchant may be reused and stored in a plastic or glass bottle; use only a plastic (not metal) cap.
When etchant is obviously taking much too long to etch, it has expired and a fresh batch is needed.
   5. We strongly recommend that all PC board drilling be done with a drill press. Accurate drilling with

a handheld drill is nearly impossible.

EXPOSURE and DEVELOPING:
    Step 1. Work in very subdued light with no sunlight or fluorescent light entering the room. A yellow

25 watt 'bug light" bulb provides a good safelight; or use a low wattage (15W) incandescent bulb at a

distance from the PC Board.
        Cut the PC board to size and then remove the plastic protective cover from the PC board with a

peeling motion, rolling it back off of the resist. Roll the cover slowly, with a steady pressure. Pulling 'up'

on the film may remove some resist from the PC board.   
       Place the board, resist side up in a Datak exposure frame or under a heavy piece of glass. Place

your positive on top of the sensitized coating on the PC board and sandwich the two in the exposure

frame.

The Exposure Frame: This device will be familiar to you if you have ever made photographic prints.

The frame is simply a holder for a board and piece of glass. With your positive in place on top of a

precoated board, put the two in the frame under the glass and slide into the frame. The frame will

hold the PC board and your positive tightly together during exposure.

Expose the PC board
        Expose the board, held in the frame, to the light of a 100 watt white light bulb. Best results

will result if the bulb is in a hooded, reflector type lamp shade. By this, we mean the kind that is white

inside and reflects light.
        EXPOSURE TIMES: A single 100 watt bulb at a distance of 12" for a ten minute exposure time is

recommended for boards up to about 6" X 6" (or smaller) in size. We suggest using a fairly "young" bulb,

one with less than ten hours of use.
        Exposure for PC boards larger than 6" X 6" may require either using two bulbs, side by side

(about 2" between them). Very large boards, about 12" X 12" can be done either by exposing the two

halves of the board separately or placing three bulbs in a triangular pattern (which can be a bit tricky).

You may cover half a board with cardboard, expose for ten minutes and then expose the other half while

covering the exposed half.     Another technique for exposing larger boards is to suspend the bulb from

its power cord and let it swing in a circle for roughly fourteen or fifteen minutes (at the 12" distance).

Etching the PC Board:

Your are now ready to etch the board. We suggest using Datak Ferric Chloride etchant. It is messy

and we warn against using this etchant in a home environment (except out of doors) as it can stain

almost anything, including counter tops, floors etc.. Ferric Chloride is not an acid, not especially

dangerous in small amounts and is actually used in some garden fertilizers. We DO recommend using

goggles to protect your eyes from splashes. And use with good ventilation; some people find the fumes

very irritating to the throat and lungs.

This author steps into the garden to etch boards; the plants do not seem affected at all. Disposal of

expired etchant can be done simply by flushing down a drain with a couple of minutes of cold

running water. Local Laws may require other disposal methods so please check for your location.
        Use Datak bottled Ferric Chloride etchant or Datak powdered concentrate, which is then

mixed with water following the instructions on the package. Warm the etchant before use. (You can

warm the etchant by placing its storage bottle in a bucket of hot tap water for about fifteen minutes.)

Hot etchant works best, but warm will work. Cold etchant may not get the job done. You can use the

etchant in a couple of ways.

One, place the etchant in your photographic tray and not too deep (never a metal tray; use glass or

plastic). Place the board, face up, in the etchant and then agitate the tray almost constantly, including

some rocking.

It is important to keep the etchant moving on the surface of the copper. Check periodically to see if

the etching is complete; be sure to etch all exposed copper. Time varies, but you should be close to f

inished in not more than fifteen minutes.
    This author prefers using a large mouth plastic jar for etching. Placing about 3/8" to 5/8" deep

etchant in the jar with your PC board and placing the lid on the jar. This permits swirling and some

gentle shaking back and forth which will etch a board very quickly. A left over jar from many foods

from Cashews to Biscotti have a large enough mouth and a plastic lid (never use a metal lid).

Monitor the etching progress by tipping the jar to see if copper has been completely removed

from areas not protected by the resist. DO NOT over-etch; undercutting will occur and narrow traces

and pad diameters. We expect small 2" x 4" boards and smaller to be finished in around seven minutes.

The time required to etch is affected by the warmth of the etchant (warmer the better), the amount

of swirling action, oxygen that gets into the solution while swirling and, of course, if the etchant is

new or has been used before. When ETCHING IS COMPLETE, you may rinse the board in a flush of tap

water, dry with paper towels and proceed to drilling the pads. When you wish to remove

the remaining resist, use a fingernail polish remover. Inspect the copper during drilling. (If there any

breaks in lands (traces) or pads, you can bridge them with a small copper wire and solder).

Looking for Negative Instructions? Send us an email or give us a call.