You may want to address why 88 ohms is needed, seems incredibly high.
Chris Heard
3Com Corp
----- Previous Message ----------------------------------------------------
To: si-list @ silab.Eng.Sun.COM @ SMTP1
cc:
From: LinJohn @ mail.dec.com (John Lin - TAO) @ SMTP1
Date: Tuesday July 29, 1997 10:52 AM
Subject: [SI-LIST] : BackPlane stackup
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hi,
Can somebody tell me about if it is feasible to have the
stackup configuration, as following, for a backplane design ?
---------------------------------Ground plane
1
35 mils
----------------------------------Signal
2
35 mils
-----------------------------------Ground Plane
3
15 mils
----------------------------------- Signal
4
The total thickness is 93 mils.
Doing so is to match the impedance of microstrip( layer 4) to
Stripline (layer 2) impedance to the value of 88 ohms.
I am afraid that the manufacturing cost will increase greatly
compared to the following.
---------------------------------- Ground
Plane
27 mils
---------------------------------- Signal
33 mils
---------------------------------- Signal
27 mils
----------------------------------- Ground
Plane
The total thickness is 93 mils.
Thanks in advance,
JOHNLIN
CAE Engineer of EDA Department
Digital Equipment Corp. Taiwan Branch
Email: [email protected]
TEL: 1-886-3-3900000 ext. 2565