CLP270M-TR View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

CLP270M-TR

OVERVOLTAGE AND OVERCURRENT PROTECTION FOR TELECOM LINE

STMicroelectronics 

CLP270M

A new technology available today is IMS - an

Insulated Metallic Substrate. This offers greatly

enhanced thermal characteristics for surface

mount components. IMS is a substrate consisting

of three different layers, (I) the base material which

is available as an aluminium or a copper plate, (II)

a thermal conductive dielectrical layer and (III) a

copper foil, which can be etched as a circuit layer.

Using this material a thermal resistance of 8°C/W

with 40 cm2 of board floating in air is achievable

(see fig. 39). If even higher power is to be

Fig 39 : Mounting on metal backed board

dissipated an external heatsink could be applied

which leads to an Rth(j-a) of 3.5°C/W (see Fig. 40),

assuming that Rth (heatsink-air) is equal to Rth

(junction-heatsink). This is commonly applied in

practice, leading to reasonable heatsink

dimensions. Often power devices are defined by

considering the maximum junction temperature of

the device. In practice , however, this is far from

being exploited. A summary of various power

management capabilities is made in table 1 based

on a reasonable delta T of 70°C junction to air.

Fig 40 : Mounting on metal backed board with an

external heatsink applied

Copper foil

Insulation

Aluminium

Copper foil

FR4 board

Aluminium

heatsink

The PowerSO-10 concept also represents an

attractive alternative to C.O.B. techniques.

PowerSO-10 offers devices fully tested at low and

high temperature. Mounting is simple - only

conventional SMT is required - enabling the users

to get rid of bond wire problems and the problem to

control the high temperature soft soldering as well.

An optimized thermal management is guaranteed

through PowerSO-10 as the power chips must in

any case be mounted on heat spreaders before

being mounted onto the substrate.

TABLE 7 : THERMAL IMPEDANCE VERSUS SUBSTRATE

PowerSo-10 package mounted on

1.FR4 using the recommended pad-layout

2.FR4 with heatsink on board (6cm2)

3.FR4 with copper-filled through holes and external heatsink applied

4. IMS floating in air (40 cm2)

5. IMS with external heatsink applied

(*) Based on a delta T of 70 °C junction to air.

Rth (j-a)

50 °C/W

35 °C/W

12 °C/W

8 °C/W

3.5 °C/W

P Diss (*)

1.5 W

2.0 W

5.8 W

8.8 W

20 W

22/24

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