TECHNET Archives

November 1999

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Lum Wee Mei <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Mon, 22 Nov 1999 12:33:54 +0800
Content-Type:
text/plain
Parts/Attachments:
text/plain (86 lines)
Out of curosity, why is HAL not recommended for controlled Zo?

Thanks.

Brian Ellis wrote:

> Hi!
>
> I do not recommend HAL for UHF boards: the flux residues are damn hard
> to remove and the hygroscopicity of them may be limitative, especially
> if you do decide on an FR-4. You may also care to consider 35 µm copper
> (1 oz) on the inner layers for a better connection to through
> holes/vias. Does the fact that 2 x 1080 is specified suggest controlled
> impedance? If so, be prepared to find the high resin:glass ratio will
> give a slightly higher dielectric constant than a more usual build. Also
> HAL is definitely NOT recommended for controlled Zo.
>
> Brian
>
> Ko Adeline-FSGA2298 wrote:
> >
> > > Hi there,
> > >
> > > My engineer is asking me to design a 900Mhz 4-layer brd using the
> > > following information.
> > > As this is my first time doing such a high freq brd.
> > > I wish to know,  is this PCB material perform excellent in high freq.
> > >
> > > PCB Info
> > > Top layer     --> 1/2 oz copper
> > > Prepreg       --> 2 X 1080
> > > Layer 2               --> 1/2 oz copper
> > > Prepreg               --> 2 X 7118
> > > Layer 3               --> 1/2 oz copper
> > > Prepreg       --> 2 X 1080
> > > Bottom                --> 1/2 oz copper
> > >
> > > Brd finishing thickness : 0.031" +/- 0.005"
> > > Material : FR4.
> > > Plating : Tin / Lead  63/37 HAL
> > >
> > > Thanks & Best Rdgs
> > > Adeline Ko
> >
> > ##############################################################
> > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> > ##############################################################
> > To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
> > the body:
> > To subscribe:   SUBSCRIBE TECHNET <your full name>
> > To unsubscribe:   SIGNOFF TECHNET
> > ##############################################################
> > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
> > information.
> > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
> > 847-509-9700 ext.5365
> > ##############################################################
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
> the body:
> To subscribe:   SUBSCRIBE TECHNET <your full name>
> To unsubscribe:   SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
> information.
> If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
> 847-509-9700 ext.5365
> ##############################################################

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

ATOM RSS1 RSS2