MCM-L

DESCRIPTION
MCM-L is a high density interconnect device. Generally consisting of glass reinforced laminates up to 22 layers with blind and buried via technology, this product allows interconnect and attachment of bare integrated circuit die. Using a refined subtractive process, fine line width and spacing technology along with small hole drilling can be achieved. Intermediate conformal packages (e.g. DIPs, Quad Flat Packs, PGAs, SMT) are eliminated which results in size, weight, and power savings. Multiple methods of attachment of the bare die promote flexibility and reduced cycle times. Military certification is available.

APPLICATIONS
MCM-L can be used where size, weight, and speed are of concern. When high density, low cost interconnections are required MCM-L packaging should be used. Space, military, commercial, automotive, and flight hardware are prime candidates for MCM-L. While limited to approximately 350 Mhz clock speed, most products can be designed into this lightweight subminiature package. Multiple methods of attaching the bare die are available, e.g. wire bond, TAB, flipchip.

MCM-L TYPICAL PROPERTIES

PHYSICAL PROPERTIES

Materials Types

Epoxy Glass

Polyimide Glass

Polyimide Cast Film (Kapton/Flex)

Bismaleimide Triazine Glass (BT)

Cyanate Ester Glass

Minimum Line Width

.0025"

Minimum Spacing

.0025"

Minimum Component Pitch

.005"

Minimum Via Drill Size

.004"

Minimum Via Pad Size

.012"

Minimum Pad to Via Ratio

2:1"

Minimum Dielectric Thickness

.0025"

Via Technology

Blind and Buried

CONDUCTIVE FINISHES

Tin

MIL-T-10727B

Nickel

QQ-N-290A

Wire Bondable Gold

MIL-G-45204C Type III Grade A

Tin/Lead

MIL-P-81728

Tin/Nickel

MIL-P-55640

ELECTRICAL PROPERTIES

Dielectric Constant Typical 50%-60% Resin Content Measured @ 100°C

Material Type

Dielectric Constant

Disipation Factor

1MHz

10 MHz

100 MHz

Epoxy Glass

4.5

4.3

4.2

.020-.025

Polyimide Glass

4.0

3.9

3.95

.010-.012

Polyimide Cast Film (Kapton/Flex)

4.0

3.7

3.6

.020-.030

Bismaleimide Triazine Glass (BT)

4.2

4.1

4.0

.011-.013

Cyanate Ester Glass

3.5

3.4

3.2

.005-.007

THERMAL PROPERTIES

Material Type

Tg (Glass Transition Temp) °C

Thermal Conductivity
 BTU/(hr)(ft)(°F)

Epoxy Glass

145

.25

Polyimide Glass

260

.30

Polyimide Cast Film (Kapton/Flex)

40

.13

Bismaleimide Triazine Glass (BT)

185

.25

Cyanate Ester Glass

245

.25

Thermal Core Types
CopperAluminumCopp er/Invar/Copper

Design and manufacture of prototype and medium volume
 production printed circuit boards and multichip modules