Browse Prior Art Database

Heat Spreader in Array Design to Minimize Processing Time

IP.com Disclosure Number: IPCOM000007584D
Original Publication Date: 2002-Apr-08
Included in the Prior Art Database: 2002-Apr-08
Document File: 3 page(s) / 122K

Publishing Venue

Motorola

Related People

R.Ibrahim: AUTHOR [+4]

Abstract

Traditionally, integrated heat spreaders are attached to the individual units one-by-one either manually or by pick and place equipment. This method is time consuming, and for array packages such as MAP BGA and QFN, the time taken for this method would depend on the number of units on each panel. The new method introduced here is that heat spreaders are made in array (panel) format, which can be gang-attached to the panels prior to package encapsulation. Separation of the heat spreader units occurs when panels are sawn into individual (singulated) units. This method significantly reduces processing time and simplifies the handling of heat spreaders, which is similar to handling of substrate panels or leadframes.

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Heat Spreader in Array Design to Minimize Processing Time

R.Ibrahim, LC Tan, KH Tan, Calvin Lo

Traditionally, integrated heat spreaders are attached to the individual units one-by-one either manually or by pick and place equipment.  This method is time consuming, and for array packages such as MAP BGA and QFN, the time taken for this method would depend on the number of units on each panel.  The new method introduced here is that heat spreaders are made in array (panel) format, which can be gang-attached to the panels prior to package encapsulation.  Separation of the heat spreader units occurs when panels are sawn into individual (singulated) units.  This method significantly reduces processing time and simplifies the handling of heat spreaders, which is similar to handling of substrate panels or leadframes.

BACKGROUND

Various heat spreader designs that improve package thermal performance are presently commercially available.  The differences in the designs are mainly to suit different types of applications, cost of assembly, and effectiveness in dissipating heat.  Traditionally, the heat spreader attachment process is performed in a unit-by-unit manner.  When packages are processed in a lower cost format such as in large array panels, heat spreader attachment is still be done in such a manner.  For packages such as MAP BGA or QFN where the number of units on one panel can easily exceed 100 units, the processing time for one panel is significantly long.

 

DESCRIPTION

This new method introduces heat spreaders produced in array or panel form that matches the array of the leadframe or substrate being processed.  The individual heat spreader units are connected with thin metal bars to form an array (Figure 1).  Slots are created to minimize metal burr during saw and singulation process.

                       Figure 1:...