29.3.08

circuit board building materials

garolite materials (such as FR4/G10)

there are many choices when it comes to board building material. the classic choice is FR4/G-10 also known as epoxyglass, among other names. one of the names for this material is garolite. FR-4/G-10 is simply one grade of garolite. the following information on garolite grades was taken from mcmaster.com:

there are two main attributes we want with this material: electrical insulator and flame retardant.

the following grades of garolite meet both of these specifications

XX
LE
CE
G-9
G-10/FR4

here is a list of properties for each material:

grade CE garolite: compared to grade XX garolite, grade CE offers higher impact strength. it's a cotton-cloth laminate with a phenolic resin binder.

grade G-9 garolite: this woven-glass fabric laminate has a melamine resin binder for superior strength. it retains its shape and size, plus is good for use in wet conditions. rated for flammability.

grade G-10/FR4 garolite: a glass-cloth laminate with epoxy resin binder, this material is the flame-retardant version of standard G-10 garolite. it offers excellent strength and low water absorption. rated for flammability.

grade LE garolite: similar to grade XX and CE garolite, grade LE is lightweight and strong. it offers lower water absorption than Grade CE so it can hold its shape better for tighter tolerances. it's a fine weave cotton fabric with a phenolic resin binder.

grade XX garolite: like all garolite, grade XX is lighter than metals but dense and strong. it's a paper-based laminate with a phenolic resin binder that absorbs less moisture than grade CE or LE Garolite. good for use as a template board or for gasketing and gears.

garolite is often available in convienent 3" wide pieces for those who don't have the equipment to cut large sheets. it is also available in many colors.

GP03 ( red swirl )

this has become a favorite in the marshall building community. it is an electrical grade fiberglass and it often referred to as "red swirl" material. this is also available in 3" wide pieces and is only available in red. there is no mention of its flammability rating. if you choose to use this kind of board, protect your self with some rubber gloves, etc. as the fiberglass causes slivers easily and they don't feel good and are difficult to get rid of.

fiber board (vulcanized fiber)

this is the kind of material used in the old fender amps. It is very thin and flexible and is usually fitted with eyelets rather than turrets. It is usually mounted to the chassis with a same-sized sheet of fish paper between the eyelet board and the chassis.

choosing mounting hardware

eyelets

eyelets are are a simple and very cost effective way to make connections on your circuit board. they mount nearly flush with the surface and are hollowed out. simply place all the connections in the hole and flow in some solder. buy these in bulk (100+) to bring their cost down to pennies each, if possible.

turrets

turrets are available in many varieties. a basic turret mounts firmly into circuit board material and has a post for mounting components and wires to. sometimes this post is hollowed out and sometimes it is not. some turrets have vertical slots, some have double or even triple stacked posts. turrets provide a lot of mounting space and make it easier to unsolder components. buy these in bulk (100+), if possible, to bring down their cost. you'll be glad you have some extras around.

3 comments:

Anonymous said...

Is the G-10 the only one in that list thats presently UL rated?

David B said...

A search for garolite by rating at mcmaster.com listed these as meeting UL specs:

UL 94HB - Grade CE, Grade G-10, Grade G-11, Grade LE, Grade XX, Graphite-Impregnated, Phenolic

UL 94V0 - Grade G-7, Grade G-9, Grade G-10/FR4, Copper-Clad (One Side) G-10/FR4, Copper-Clad (Both Sides) G-10/FR4, Grade G-30 Glass Polyimide, GP03 (red swirl)

PCB said...

Thanks for such an informative article and the extensive explanation, it's been very useful.