Whats CEM-1 Material?

[Overclocked]

Exactly as the title says, What is it? Its used in PCBs, and its cheaper than FR-4. Is it easier to cut? Is there any difference between FR4 and CEM-1?

 

[dknguyen]

I think they are the same thing:

**broken link removed**

"FR4 OR CEM-1" rather than "FR4 and CEM-1"

 

[hjames]

**broken link removed**

CEM-1 is mostly paper with some glass. FR-4 is glass only. Both are epoxy based.

 

[Overclocked]

Speaking of PCBs, How can I cut PCBs? I used a hacksaw but the cuts came out crooked. Then I started using a sharp knife to score the board and then break it apart.

 

[Nigel Goodwin]

Some people on these forums use bandsaws - and have probably bought them just for that!.

 

[hjames]

I've got something that looks like the 12" tabletop shears in this link:

**broken link removed**

The edges are crufty, but chopping PCB's goes a heck of a lot faster.

 

[Russlk]

I use a metal cutting fiber disc on my table saw. It makes a smooth cut and I don't have to file the edges. I bought a mini table saw from Harbor Freight, it worked good but did not last long.

 

[Sceadwian]

A dremel tool with a side cutting drill bit could be used to hand route a board but the cut's only going to be as good as your hand. Sanding afterwards should neaten it up.

 

[RadioRon]

I use large sheet metal shears, the hand held kind, that cost little money, like this one:

 

[hjames]

I think I've seen someone use a fiber cutoff wheel in a dremel tool with good results - the edges were pretty clean, if you don't mind the dust.

The best tool depends on quantity though - I was just messing with some simple LED boards yesterday, and I diced up a 12"x13" panel into about 80 12" strips using the shears. It was pretty ugly, but I couldn't begin to imagine doing it with any other method.

 

[Sceadwian]

I doubt breathing the glass/resin dust from cutting a PCB is healthy for you, make sure you have a good particulate dust mask!

 

[Shax]

I use a small water cooled electric diamond tile saw.
Cost me £29.95 about 5 years ago. Cuts real straight and fast. And as a bonus, there is no harmful fibreglass dust to worry about.

Piccy attached!!

 

[Nigel Goodwin]

I use a small water cooled electric diamond tile saw.
Cost me £29.95 about 5 years ago. Cuts real straight and fast. And as a bouns, there is no harmful fibreglass dust to worry about.

Cool idea!.

 

[David Wu]

Email address removed - Moderator

CEM-1 Composite material composed of woven glass fabric surfaces and paper core combined with epoxy resin. Primarily used in the printed circuit board industry. Easy punching and excellent electrical properties and higher flexural strength than paper based grades. CEM-1 provides excellent mechanical and electrical properties, and punches well up to .093″.

CEM-3 is very similar to FR4. Instead of woven glass fabric a ‘flies’ type is used. CEM-3 has a milky white color and is very smooth. It is a complete replacement for FR4 and has a very large market share in Asia. It is a kind of flame retardant epoxy copper-clad plate glass material, is generally used in electronics with double sided and multilayer pcb boards. And CEM – 3 is a new printed circuit substrate material developed based on FR – 4. In recent years, CEM-3 is used to replace FR-4 in Japan, even more than the FR – 4 dosage.

FR-4 copper clad laminated sheet，use glass fiber cloth as substrate material, immersed with epoxy resin, bake into prepreg sheet, combined several prepreg sheets single side or double sides with copper foil, hot pressing, curing, then forming CCL.
FR-4 Copper clad laminated sheet has excellent thermal stability and machinability, widely used in the manufacture of printed circuit board (PCB) for television sets, computers, communications equipment and other electronic products.

 

[JonSea]

Tile shears for floor tile, like a paper cutter on steroids, make for pretty decent cuts. Here are a couple that Home Depot has; I have one similar to the gray one.

 

[Sinedup]

I use a small benchtop table saw, but as mentioned above, the fine dust is a problem.
I've added a plexiglass 'guard' on a swing-arm that can temporarily screen (some) dust.
A pair of G-clamps holds a Hoover Aquavac's open hose end nearby to also suck away airborne particles.
I like Shax's water-cooled diamond saw.
Shopping soon..

 

[Jarsine chen]

Cem-1 and Fr4 have big different for material. You know Fr4 price is high But It is Glass plate and cem-1 use paper as material basis.
BTW, You said about how to do cut boards.
Actually. You can add one V-cut line in your design drawings. Then Vendor will manufacture V-cut lines in order to you can easier to cut.
I am vendor from china. If yuo have any requirements. You can private chat to me.

 

[BobW]

Note that this is an eleven year old thread that was resurrected by a spammer.

 

[JonSea]

Note that this is an eleven year old thread that was resurrected by a spammer.

Sorry, didn't note the date on the thread.

 

[hyedenny]

"Note that this is an eleven year old thread that was resurrected by a spammer. "

...and it's just as relevant, provocative, and interesting as it was 11 years ago. I don't understand why some people get so excited about that.

My experience with paper composite PCB board is not good! Sometimes it will absorb moisture and when you try to solder it, steam will build up underneath the copper and cause the copper to pop off and delaminate from the substrate. Radio shack used to sell that junk.