I would recommend either 
a) Arlon HI-4093 Epoxy/Kevlar Chip Carrier Laminate (CTE: X=6; Y=6; Z=62 Below 130 degrees Centigrade). Tg is 130 degrees centigrade. It is MIL-S-13949H qualified and QPL listed.
b) Arlon HI-3003Q Quartz Polyimide (CTE: X=9; Y=9; Z=57 Below 260 degrees Centigrade). Tg is 260 degrees centigrade. Use if Tg of a) is too low.
c) Arlon HI-7293 Modified Epoxy/Kevlar Laminate (CTE: X=4-7; Y=4-7; Z=62 Below 180 degrees Centigrade). Tg is 180 degrees centigrade. Use if Tg of a) is too low and cost of b) is too high.
d) Dupont Thermount (a nonwoven aramid material) with a CTE of 7 (Z I am unsure of).
Arlon may be reached at (909) 989-7053
Du Pont may be reached at (800) 527-2601

I encourage you to purchase a copy of IPC-CC-110 (Guidelines for Selecting Core Constructions for Multilayer Printed Wiring Board Applications) and also discuss your specific needs with your laminate manufacturer.

I also suggest that you consider purchasing IPC-V-107 Standards for Printed Board Materials Manual which contains IPC-CC-110, IPC-T-50F (Terms and Definitions for Interconnecting and Packaging Electronic Circuits) as well as specifications of rigid laminates, metallic foil cladding and rigid prepreg.

Your concerns are well founded and the laminate industry can meet your needs if you do your homework.

Chris Taylor
Senior Printed Circuit Designer
LXE, Inc.
125 Technology Parkway
Norcross, GA 30092
voice: (770) 447-4224 X3242
fax: (770) 447-6928
e-mail: [log in to unmask]


----------
From:   Jeff McGlaughlin[SMTP:[log in to unmask]]
Sent:   Monday, August 11, 1997 2:10 PM
To:     [log in to unmask]
Subject:        [DESIGNERCOUNCIL] DES:Thermal Concern for SMT Board?

--Help!-- I am working on a design for an active antenna
mounted external to jet aircraft. I am concerned about the
CTE mismatch between ceramic and plastic components
(including 2 16-pin SOICs)  and  FR-4 laminate. Can anyone
suggest materials/vendors for this type of application?

Thank you for any input,

Jeffrey McGlaughlin
BFGoodrich Avionics Systems Inc.
1105 Schrock Road
Suite 800
Columbus Ohio 43229
(614)825-2232 (Voice)
(614)825-2037 (Fax)
[log in to unmask]