Electronics Corp.
These instructions are to be used to make fine resolution printed circuit boards by means of a photographic process utilizing a positive working photo resist.
BE SURE TO READ THE ENTIRE INSTRUCTIONS THOROUGHLY BEFORE PROCEEDING STEP BY STEP.
Materials
Needed
1.
BLACK
PLASTIC to protect
underside from light.
2.
4" x 6" GLASS (2 pcs.) to construct an exposure frame to expose the boards.
3.
FOUR METAL SPRING CLIPS
to hold glass and positive firmly against the board
4.
THREE 2-SIDED SENSITIZED BOARDS (2 boards 3x4.5" 1 board 4x6") to make
printed circuit boards
5.
PHOTO-FLOOD LAMP ( PC557 )
to expose board
6.
DEVELOPER ( D3-6 )
to wash away exposed resist
7.
TWO PLASTIC TRAYS
to hold photo resist developer and etchant
8.
ETCHANT ( PC199-6 )
to etch away unwanted copper
9.
TWO
FOAM SWABS to wipe down the boards
10.
.040"
DRILL BIT ( PC300-60 ) to drill holes for components
11.
SCOURING PAD to
remove photo resist after board is finished
12.
FLANGED PINS ( 10 PCS. ) for
registration of positive artwork
13.
PC50A REUSABLE EXPOSURE GUIDE to determine proper time and exposure rate
14.
PROTECTIVE
GLOVES to protect
your hands while handling boards and chemicals
15. INSTRUCTION SHEET to provide instructions on the recommended method to make a printed circuit board
CAUTION: Do not open the black pouch containing the sensitized boards until ready to expose to the light source. The positive developer should be premixed and ready to use at 68-72º Fahrenheit.
AVOID CONTACT OF ALL CHEMICALS WITH THE SKIN. PROTECTIVE CLOTHING, EYEWEAR, AND GLOVES ARE A MUST. EXPOSURE AND DEVELOPING REQUIRE SAFE-LIGHT CONDITIONS, (RED OR YELLOW LIGHT).
We recommend that you use a yellow or red 25W bulb for safe-light conditions. We suggest that you wear nylon gloves so as not to get fingerprints on glass or board. NITRILE or rubber gloves as well as Safety goggles should also be used when handling the chemicals in this Kit.
PROCESSING STEPS
| I. SET UP POSITIVE |
| II. EXPOSE BOARD |
| III. DEVELOP |
| IV. ETCH |
| V. REMOVE RESIST |
| VI. FINAL ASSEMBLY |
| VII. PROTECTING FINISHED SURFACES |
PRACTICE BOARD: To become familiar with the steps necessary to make a printed circuit board, we suggest that you make your first board for practice.
1.
Construct a contact frame by taking 2 pieces of plain plate glass, no
more than 1/8" thick, and prepare to sandwich the pc board in between the
glass with 4 spring clips. It is important not to use Plexiglas or any
other glass that contains UV blockers.
2.
Clean the positive artwork and the glass plates on the contact frame so
that they are free of dust and fingerprints.
3.
Set up #2
Photo-flood bulb in a fixture. Arrange the bulb so that it is 10"
above the contact frame.
4.
Exposure and developing require semi-dark conditions. No fluorescent or
incandescent lights should be within 15 feet and blinds should be pulled to
eliminate sunlight. If light is needed, a 25 watt yellow bulb should be used at
least 10 feet away from the work area. A yellow fluorescent bulb is also
acceptable, as well as a yellow fluorescent sleeve.
START SEMI-DARK CONDITIONS
1.
Under semi-dark conditions and holding the
board on the edges, slit open the black pouch containing the sensitized boards
while being careful not to touch the copper sides.
2.
Drill four corner holes through the positives and through the board.
This will insure proper registration of the layout onto the board.
3. Take the two glass plates and make a sandwich as follows, reading from the top down: glass plate, top positive, board, bottom positive, black plastic, glass plate; make sure all registration holes are aligned. Be careful that the positive faces up, appearing the same as the original layout. Secure the four edges of the contact frame tightly with the four metal spring clips. Place the clips so that they do not cover any of the required printed circuit wiring. Place the completed contact frame onto the black plastic. NOTE: THE BOTTOM POSITIVE MUST BE RIGHT SIDE UP WHEN THE BOARD IS VIEWED FROM THE BOTTOM.
4. Using the #2 500W Photo Flood bulb supplied, expose at a distance of 10 inches for 10 minutes. Make sure the positive is directly beneath the bulb. If a BL Fluorescent bulb is used, such as the PC557F, the time and distance could be reduced to 6 inches for 6 minutes. If other bulbs are used the exposure time and distance will vary according to their ultra-violet output. The distance and time can be determined by using the PC50A INJECTORALL Exposure Guide.
5. Another way is to use a sample piece of board and a test positive such as is supplied in this Kit. The #2 PHOTO FLOOD has a usable PC life for up to one hour. The bulb produces a carbon spot within the bulb itself which will block the necessary ultraviolet radiation and will render the bulb useless for exposing PC boards. The PC 557F has a usable life for up to 1000 hours.
6. Remove the black plastic and cover the top side of the board and expose the bottom side as in step 3. To insure proper development it is important to expose both sides of the board for the same amount of time.
BE SURE TO WEAR NITRILE OR RUBBER TYPE GLOVES WHEN HANDLING DEVELOPER.
CONTINUE SEMI-DARK CONDITIONS
DILUTE DEVELOPER WITH SEVEN PARTS DISTILLED OR FILTERED WATER
IMPORTANT: DEVELOPER MUST BE 25º C ( between 68-72º F ) TO WORK PROPERLY
1.
While the board is being exposed, pour the developer into tray. There
should be 3-4 inches of developer above the board. USE WITH
ADEQUATE VENTILATION. AVOID PROLONGED BREATHING OF VAPOR AND PROLONGED OR
REPEATED CONTACT WITH SKIN.
2.
Place the exposed board into the developer, copper side up.
3.
Rock gently for up to 2 minutes in the developer.
4.
After the first 5-10 seconds, an image should start to appear. If
an image does not appear until 25 seconds or more, it is time to change the
developer.
5.
Remove the board from the developer being careful not to touch the copper
face. Use a plastic rod as an aid. Handle the board by the edges.
6.
Wash the board in cool standing water for two minutes. This will stop the
chemical action of the developer. The developer may now be poured back into the
bottle.
DO NOT
USE FORCEFUL RUNNING WATER. THE BOARD IS NOW READY FOR ETCHING
7.
Inspect the pattern before etching. If there are any breaks in the
pattern, they can be touched up using our RESIST INK PEN.
CAUTION: Never use a metal tray, only glass or plastic. Severe burns can happen if aluminum is used.
AVOID CONTACT WITH SKIN. USE PROTECTIVE GLOVES, GOGGLES AND CLOTHING.
USE WITH ADEQUATE VENTILATION.
For detailed instructions, see instructions for
Sodium Persulfate ( part number PC200 ).
1.
Pour the etchant into a plastic or glass tray.
2.
Immerse the board in the etching solution. Inspect after 25
seconds. The etching process should have begun. This is readily viewable as the copper that is being etched
away will have a "new-penny" look.
If this has not occurred, it is quite possible that there is still a
slight residue of Photo-resist on the board.
Remove the board and rinse carefully and place back into the developer
for another 30 seconds. Rinse
carefully and replace into the Etchant tank.
Repeat if necessary. Immerse
in the Etchant tank until all of the unwanted copper is removed.
3.
Remove board and rinse in cool standing water for two minutes to
terminate the etching process.
END
SEMI-DARK CONDITIONS
After etching the board, the copper traces will still be covered with the Positive Photo Resist. The Photo Resist may be removed by using a fine Scotch Brite pad ( part number PC-SB ). The Resist may be left on to prevent the copper from oxidizing until ready to mount the components.
VII. PROTECTING FINISHED SURFACES
After all components are soldered to the board, spray copper with a protective coating. This will prevent oxidation of the copper and will protect the mounted components.
631-563-3388
631-563-3389
110 Keyland Court, Bohemia, NY 11716
800-878-7227
General Information: injectorall@mindspring.com
Copyright © 2003 Injectorall Electronics Corp.