Silicon Valley Computer SHUGART 706 User Manual download pdf (Page 61)

PC SERVICE

One of

the

most

difficult

tasks

in

build-

ing

any construction

project

featured in

Radio -Electronics

is

making

the

PC

board

using just the

foil pattern

provided

with the

article.

Well,

were

doing some-

thing about

it

We've moved all the

foil patterns to this

new

section

where they're printed

by

themselves,

full

sized,

with nothing on

the

back side of

the

page.

What

that means

for you

is

that

the

printed page

can be

used

directly to produce

PC

boards!

Note:

The

patterns

provided can be

used directly only

for direct positive pho-

toresist

methods.

In

order

to

produce

a

board

directly

from

the magazine

page,

remove

the page

and

carefully

inspect it under a strong

light

and/or on

a

light

table.

Look for breaks

in

the traces, bridges between

traces, and

in

general, all

the

kinds

of things you

look

for

in

the

final

etched board.

You

can clean up

the published artwork

the

same

way

you

clean up you

own artwork.

Drafting tape

and graphic aids

can fix

incomplete traces

and doughnuts, and you

can use a

hobby

knife to get

rid

of bridges

and dirt.

An

optional step, once

you're satisfied

that

the

artwork

is clean,

is

to

take

a

little

bit of

mineral

oil and

carefully

wipe

it

across the back of

the artwork.

That helps

make the

paper

transluscent. Don't

get

any on

the

front

side

of the paper

(the

side

with the

pattern)

because you'll con-

taminate the sensitized surface of

the

copper blank. After

the

oil

has

"dried" a

bit -patting

with

a paper

towel will

help

speed up the process -place

the pattern

front

side down on

the sensitized copper

blank,

and

make

the exposure.

You'll

probably

have

to use a

longer

exposure

time than

you

are used

to.

We can't tell

you

exactly

how long

an

exposure

time

you

will

need

as

it

depends

on

many factors but, as a starting

point,

figure

that there's a 50 percent

increase

in

exposure

time over

lithographic

film.

But

you'll

have to

experiment

to

find the best

method

for

you. And once you

find it,

stick

with it.

Finally, we would

like

to

hear how you

make out using our

method. Write

and

tell

us of

your

successes,

and

failures,

and

what techniques work best

for you. Ad-

dress your

letters

to:

Radio

-Electronics

Department

PCB

500 -B

Bi-

County

Blvd.

Farmingdale, NY

11735

A

C/D

w

2

U

z

TUNE IN THE

HIDDEN WORLD

of FM

radio with the SCA

receiver. Most of

the

components

mount on this single

-sided

PC board.

69

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 107 108

Comments to this Manuals

No comments