Re: HARI Systems Design
Ed, that is what I am saying ... there are things within the board construction
that can be done to get a 1.5% tolerance on impedance with no cost adders or at
least in the 1.01x range over standard fr4 practises. You keep saying that the
only way to get a cheap board is to live with 20% tolerance and live with the
way things have always been done. This is just not true.
Edward Chang wrote:
> I appreciate many issues you brought up to draw attentions in debating the
> HARI feasibility and cost-effectiveness. I did not say that PCB technology
> can not be improved. What I said is the PCB technology has been here for
> over half a century; as a result, most of the major technical breakthroughs
> have been done before. Mature technology still makes improvement, but in
> slower pace. Lately, Most of the new improvement for PCB equipments are
> focusing on cost-effectiveness; for example, speed, automation, auto test,
> There are many special PCB manufacturing techniques in industry; for
> example, 25-layer lamination (Unisys used time to time), 10% impedance
> control, optical PC runs using polymer type material, sub-5-mil pitch and
> width, special dielectric material for high frequency path to minimize
> loss,......etc, which I have been involved time to time, and are expensive.
> Here, we are trying to use the commonly available manufacturing techniques
> in US and oversee for cost-effectiveness to meet 3xGbE pricing target.
> Ed Chang
> NetWorth Technologies, Inc.
> -----Original Message-----
> From: Joel Goergen [mailto:goergen@xxxxxxxxxx]
> Sent: Wednesday, November 24, 1999 7:13 AM
> To: NetWorthTK@xxxxxxx
> Cc: edward.chang@xxxxxxxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
> Subject: Re: HARI Systems Design
> Ed and others that agree with Ed's statement below .....
> I have and always will disagree with the statement below. You assume the
> car can
> not be improved every year, but it is. You assume network equipment will
> have no
> more features next year, but they will. I believe it is called progress.
> I work very closely with the pcb industry and it has always facinated me
> designers and qualifiers hurt themselves by over-looking 'innovative
> Your world of board design hasn't changed in years because you have chosen
> not to
> change it. I bet some thought fiber would never change, yet don't we now
> have a
> newer grade of mm?
> It is absolutely untrue that pcb geometry is a mature technology. The real
> technology, well, that is yet to come.
> So, I assume we agree to disagree.
> NetWorthTK@xxxxxxx wrote:
> > Joel:
> > Thanks for comment. I believe the circuit issue is equally important to
> > other issues. Therefore, I think I should clear some disagreements we
> > The PC board layout technology is a mature technology, and the people
> > involved in the PCB business are all familiar with all the pros and cons
> > issues. The issue here is more of the cost-effective issue than the
> > technical feasibility issue.
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