Browse Prior Art Database

High Reliability Variable Load Time Controllable Vibration Free Thermal Processing Environment

IP.com Disclosure Number: IPCOM000106752D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 4 page(s) / 143K

Publishing Venue

IBM

Related People

Anderson, TM: AUTHOR [+7]

Abstract

This disclosure describes a new design for a vibration free thermal processing chamber that provides high tool reliability and precise highly flexible temperature versus time "profile" control with a wide capability range. It is fundamentally different from the prior art designs in that "cost, performance, and reliability-optimized" heating and cooling regions each having time variable and controllable load/temperature surfaces are shuffled to and away the stationary, vibration-isolated product. This allows sizable improvements in existing-art problems of reliability, cost, performance, throughput and process consistency.

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High Reliability Variable Load Time Controllable Vibration Free Thermal Processing Environment

      This disclosure describes a new design for a vibration free
thermal processing chamber that provides high tool reliability and
precise highly flexible temperature versus time "profile" control
with a wide capability range.  It is fundamentally different from the
prior art designs in that "cost, performance, and
reliability-optimized" heating and cooling regions each having time
variable and controllable load/temperature surfaces are shuffled to
and away the stationary, vibration-isolated product.  This allows
sizable improvements in existing-art problems of reliability, cost,
performance, throughput and process consistency.  Some potential uses
of the chamber are the attachment of solder features to discrete
components, reflow of solder to attach electronic devices to MCMs,
adhesive curing, and selective reflow of solders in multi-level
packaging.

      The concept is shown in Fig. 1.  In general, the chamber
consists of a time variable and controllable load heating surface 101
and a time variable and controllable load cooling surface 102
connected to a positioning device (not detailed), and a vibration
isolated product carrier (or "pallet") 103 all enclosed in a
containment vessel 104.  The translation device serves to position
the proper heat exchange surface for direct exposure to the product
and/or carrier.  The heating surface can be isolated from the cooling
surface by a thermal barrier 105 composed of air gaps, radiation
shields, and/or low conductivity material.

      With the proposed design, the product is loaded into a position
directly exposed to the heating plate.  Energy is delivered to the
heating surface in such a way as to drive the product temperature
along the ramp up region of the specified time-temperature profile.
Near the end of the dwell period the product is translated to a
position exposed to the cooling surface.  At this point cooling is
provided to achieve the desired temperature ramp down.  A key
strength of this concept is the design freedom to optimize the
separate heating and cooling components for maximum performance,
reliability, consistency, and cost effectiveness.

      Alternatively, the product could be affixed to a translation
stage and shuttled underneath stationary heating and cooling surfaces
(Fig. 2).

CLAIMED ADVANTAGES

o   The product and carrier are held stationary throughout the reflow
    process to minimize vibration and the attendant chip to substrate
    motion (in contrast to the stick-slip motion of a belt, which
    generates repetitive vibration transients that act on the
    product).

o   A novel configuration for the positionable heating and cooling
    components is to have the heat exchange devices mounted to a
    vertical shaft and rotated into or out of position.  With this
    configuration, the wiring and manifolds necessary to...