User`s manual

Lake Shore MTD Series Cryotest System User’s Manual

Introduction 1-7

1.1.9 PRECISE MONITORING AND CONTROL OF TEMPERATURE OVER A WIDE RANGE

Select from Lake Shore’s full line of temperature controllers and sensors to complete system

operational requirements. Shown is the Model 330 temperature controller, which offers Autotuning of

Proportional, Integral, and Derivative (PID) parameters, front panel programming. The temperature

sensor is a Lake Shore DT-470 series silicon diode which produces an accurate and repeatable

measurement from 1.4 K to 475 K.

1.2 HARDWARE DESCRIPTIONS AND FUNCTIONS

The following are definitions of the primary components of a typical MTD Cryotest System. The list is

presented in alphabetical order.

BAYONET COUPLING: Ladish

flange used to securely connect transfer line to MTD-150 cryostat.

CHIP CARRIER CLAMP ASSEMBLY: Secures the chip carrier in the device socket and against the

cold pedestal. It may also be used to hold the fixed aperture disks and optical filters. It is spring

loaded to ensure good thermal contact between the ceramic substrates on the device package and

the cold pedestal. All interior optical surfaces are vapor-blasted and black-anodized to minimize

optical reflections.

COLD PEDESTAL: Mounted to the center of the cold plate. Makes direct thermal contact to the DUT.

Indium foil or Apiezon

“N” grease is used between the cold pedestal and the ceramic substrates on

the DUT to assure good thermal contact.

COLD PLATE: Mounted to the second stage heat exchanger, it provides a cooled mounting surface for

the interface board, cold pedestal, fanout board and chip carrier clamp assembly through the cold

pedestal.

CRYOSTAT (MTD-100): Continuous flow two-stage cryostat which operates with either LHe or LN

any attitude and incorporates a female bayonet type coupling which mates to the transfer line male

bayonet coupling. Consists of two main sections; cold finger (inside vacuum chamber) and main

body (outside of vacuum chamber). See Figure 1-4.

First Stage

Exhaust Heater

Connector

Bayonet Flange

Exhaust Port

Temperature

Sensor Both Stages

Heaters

Both Stages

Second Stage

C-MTD-1-04.eps

Figure 1-4. Typical MTD-100 Cryostat Profile