Homebrew PCBs

Hi!

I am a newbie in homebrew PCB.  I know that there are many types of 
PCBs available, such as paper phenol and epoxy.  What are their 
characteristics?  Which one is the best and which one is the worst?  
As a newcomer, which one should I try first?

Thanks!

Mark

hi

i am from europe sp i do not know the correct names for the boards at your 
location.

paper phenol is one of the cheapest boards.
it is made of paper/cardboard like material soaked in phenol resin to make 
it solid, prevent soaking with water, increase dielectric
properties, etc.
epoxy boards are most time glass fiber with epoxy resin.
a good quality is known as FR4. this is very solid material, you may not be 
able to break it without tools.
i think those "fr4" may be a category number like "cat5, 4, 3" with cables 
but i am not sure.

anyways most shops only sell "paper phenol resin type" and "glass fiber 
epoxy fr4" so you don't need any other.

there is also some strange "teflon" material available, sold for high 
frequency circuits (really HF).
expensive, i did not need until now. i think it is white.


it is hard to tell which one to try first, i only use fr4 material.
but that is because i didn't have to buy in small quantities at a shop at 
high price.

the paper phenol resin material is easy to cut and drill. but its 
mechanical stability is a bit less.
it is easier to bend/break and it doesn't resist too much heat (but 
enough...).
i was told it is no longer used. this is wrong, a lot of cheap equipment 
(tv etc.) uses this material.
it is also a bit cheaper than fr4 if you buy it in a shop..


the glass fiber reinforced (is that what FR means? fiber reinforced? WHERE 
ARE THE EXERTS??) material
is much stronger, the glass fibers make hss drill bits and saws blunt very 
fast.
but you can drill a couple of holes with cheap hss bits if you need.
you can also cut it with a normal jigsaw blade, or better with a diamond 
equipped one for cutting ceramics.
but if you really want to work with it you may want carbide drill bits and 
a carbide bladed table saw.


the qualities of paper phenol board vary a lot. but if you don't have the 
right tools please buy it.
you may also buy samples of fr4 to see if you like it more.
if you can use carbide drill bits and cut the boards please buy fr4. i find 
it worth the prize.
i also use fr4 a lot when i need "sheeting" for mounting purposes etc.
i used aluminium sheeting (2mm or so) in the past for this occassions but 
fr4 is very nice for this.


to answer your questions:
best is glass fiber expoy resin type (teflon/ceramic for HHHF).
worst is cheap quality paper resin (which is brittle when drilling already 
because of bad/little resin).

try both.
start with paper resin for easy mechanical work but make one pcb fr4 also.

hope this helps a bit. but i guess there is lot of information on the web 
which is more exact...


regards
stefan


On Mon, 07 Jul 2003 09:04:07 -0000, Mark Farnell <farnell_mark@...> 
wrote:

> Hi!
>
> I am a newbie in homebrew PCB.  I know that there are many types of PCBs 
> available, such as paper phenol and epoxy.  What are their 
> characteristics?  Which one is the best and which one is the worst?  As a 
> newcomer, which one should I try first?
>
> Thanks!
>
> Mark
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
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>
>
>
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>
>
>

In a message dated 7/7/2003 4:05:37 AM Central Standard Time, 
farnell_mark@... writes:

> paper phenol and epoxy.  What are their characteristics?  Which one is the 
> best and which one is the worst?   As a newcomer, which one should I try 
> first?


Farnell:

Someone "in here" with far more wisdom on this topic than me will probably 
have already answered, but as I was a "newcomer" once, and have never opened a 
PCB shop in the years, since, so perhaps I can address your question with some 
empathy:  

Paper-based phenolic, similar to "Bakelite", is just as the name indicates, 
layers of paper impregnated with phenolic-plastic, making a reasonably tough 
insulating layer upon which copper film may be applied on one or both sides, for 
making PCB's.  It is "good enough" for radios and low-end home-entertainment 
gear, etc., but I wouldn't want to find it as the "motherboard" material in a 
$1000 PC or stereo!  It can loose its electrical insulative properties when 
overheated, as the carbon in it has a tendancy to separate chemically from the 
other elements in the phenolic.  I don't really know enough about the chemistry 
to explain that further than that.  But carbon is a fair conductor of 
electricity when not chemically combined (see "carbon rod" in flashlight cells, 
etc.), so this is not the swiftest stuff to use, but it's a few % cheaper than FR4..
.

FR4:  Here, "FR" means "Fire Retardant".  I think you are probably right 
about the number following that, the "4" indicating the grade.  FR4 is the most 
common "glass epoxy" type of PCB stock in use, today.  A couple decades or more 
back, a material which LOOKED about the same, "G-10" was the "green stuff", 
but it is not as good, so FR4 found favor and nudged out G-10, I understand.  
The "green stuff" has glass fibers in it to strengthen it.  It is only 
coincidental that the initials can also stand for "Fiber Reinforced", but this is NOT 
what the "FR" means, as I said in the first line in this ¶.

If you can ONLY buy "new stock" by the square foot, I imagine it is possible 
the old paper-based phenolic may be a few pennies cheaper.  But SO much FR4 is 
being made and used, these days, for EVERYTHING, that its price is probably 
close to cheapest.  It may BE, for all I know!  I don't know simply because I 
make SO few PCB's myself, anymore, that I can get ALL the FR4 I need free of 
charge from the nearest professional PCB house, when I go there in clean 
clothing and beg.  They said, once, that their machinery can't handle a "panel" 
smaller than 4" wide, so the last 4" or so of a panel gets "wasted", and they 
gladly give it to po' ignernt folk who beg sweetly.  

Now, for a "newbie", the ONLY "advantage" I can imagine for paper-based 
phenolic is that it might be kinder to small saws and drill-bits than FR4.  If you 
saw FR4 with a woodworking bandsaw (or ANY kind, for that matter, not having a 
diamond-impregnated blade $$$!!!), the blade will go dull after 1" (that's 
2.54 cm for our European friends!).  Oh, a bandsaw blade might continue to cut 
FR4 for some time, but after that first couple of cm, it won't do well on wood, 
ever again!  And HSS drill-bits will go totally dull in FR4 after, what, half 
a dozen holes, and quit working at all after 20?  Professional solid-carbide 
PCB-drill-bits are simply the ONLY way to go, and they MUST be used in a 
rather FINE drill-press, preferably with some clever means to prevent the slightest 
sliding-about of the "blank", once you have it located exactly where you want 
the drill to go.  As carbide is VERY brittle, though harder than ANYTHING but 
diamond, and if that blank "wiggles" at all, you will SNAP a $2 bit!  

Some of the mail-order firms one can fine "in the back pages" of various 
electronic hobby magazines offer carbide "regrinds" from time to time quite 
reasonably, and if you GRAB a box of 50 of diameter, say, 0.75-1.0 mm, and/or an 
assortment from, say, 0.6 to 6 mm SOLID-CARBIDE micrograin professional PCB 
drill-bits, if you can find same for less than $0.75 (£0.50), you will have an 
investment that can live for months, if you generally work carefully.  Now, HSS 
bits WILL tolerate a little "wiggle", but simply won't last long (unless you 
regrind every few holes, and  then they would get shorter so fast as to be of 
questionable use at all!)    Oh, carbide PCB bits all have 1/8" dia shanks!  Yes, 
even those used in Metricdom:  3.175 mm. dia.  It might be easier to find a 
high-speed "quill" with only an 1/8" collet, rather than a tiny adjustable 
3-jaw chuck which would be necessary for the HSS bits of various diameters.  

Look in the PC web-site's "FILES" section for  "Home Made PCB Equipment."  
Double-Click on that, then see the third file from the top.  Double-click on it. 
 There you see my CNC  PCB-drill run by a PET comptuter (still working fine 
after its birth in 1976!)  (The top-two files are discussion of what I did to 
power the 400 Hz quill-motor).  That's what laziness will inspire!  Questions?  
Lotsa luck and fun!

...P.S:  Farnell?  Any relation to the firm of that name in UK that sells 
electronic goodies?  Or, just coincidence?

Jan Rowland


[Non-text portions of this message have been removed]

Jan,
You forgot one thing that's important enough to mention.
Dielectric values for paper  and FR4... FR4 runs about 4-5 and paper
about somewhere arount 1.8-2.5
So if the circuits demand it (RF etc) this may be a deciding factor.
hansw

JanRwl@... wrote:

>  In a message dated 7/7/2003 4:05:37 AM Central Standard Time,
> farnell_mark@... writes:
>
> > paper phenol and epoxy.  What are their characteristics?  Which one
> is the
> > best and which one is the worst?   As a newcomer, which one should I
> try
> > first?
>
>
> Farnell:
>
> Someone "in here" with far more wisdom on this topic than me will
> probably
> have already answered, but as I was a "newcomer" once, and have never
> opened a
> PCB shop in the years, since, so perhaps I can address your question
> with some
> empathy:


[Non-text portions of this message have been removed]

In a message dated 7/7/2003 3:40:39 PM Central Standard Time, 
hans@... writes:

> Dielectric values for paper  and FR4... FR4 runs about 4-5 and paper
> about somewhere arount 1.8-2.5
> So if the circuits demand it (RF etc) this may be a deciding factor.
> hansw
> 

Thank you, Hans!  But I am too STOOPID to think about stuff like that!  
Besides, I think TX uses lethal injection, now and no longer die electric...  (was 
that a BAD one, or what???)


[Non-text portions of this message have been removed]

good one.... !
hansw

JanRwl@... wrote:

>  In a message dated 7/7/2003 3:40:39 PM Central Standard Time,
> hans@... writes:
>
> > Dielectric values for paper  and FR4... FR4 runs about 4-5 and paper
>
> > about somewhere arount 1.8-2.5
> > So if the circuits demand it (RF etc) this may be a deciding factor.
>
> > hansw
> >
>
> Thank you, Hans!  But I am too STOOPID to think about stuff like that!
>
> Besides, I think TX uses lethal injection, now and no longer die
> electric...  (was
> that a BAD one, or what???)
>
>
> [Non-text portions of this message have been removed]
>
>
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