LOW STRESS CAVITY PACKAGE
First Claim
1. A method for packaging integrated circuit devices, comprising:
- providing a leadframe having a number of leads suitable for use in packaging an integrated circuit die, each lead having a first surface arranged for connection with an associated bond pad on an active surface of the die and a second surface opposite the first surface, the second surfaces of the leads being adhesively secured to an adhesive film;
reflowing solder between the first surfaces of selected leads and selected bond pads on the active surface of the die to form solder joint connections that physically and electrically connect the die with the leadframe;
dispensing a viscous thermosetting material substantially around the periphery of the active surface of the die such that the viscous thermosetting material substantially fills any gaps between the solder joint connections between the active surface of the die and the adhesive film, wherein the viscous thermosetting material, the solder joint connections, the active surface of the die and the adhesive film define a cavity between the active surface of the die and the adhesive film that isolates selected regions of the active surface of the die from stresses; and
encapsulating at least portions of the die, leads, solder joint connections and the adhesive film with a molding material, wherein the viscous thermosetting material, the active surface of the die and the adhesive film substantially prevent molding material from entering the cavity.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to methods and arrangements for forming a low stress cavity package. Particular methods may be performed with existing packaging equipment. In one such method, a leadframe laminated with adhesive film is provided. Integrated circuit dice are connected to the leadframe by reflowing solder between bond pads on the active surface of each die and the leadframe. A viscous thermosetting material is dispensed around the periphery of the active surface of each die. The thermosetting material fills gaps between the solder joint connections and the adhesive film. As a result, the thermosetting material, solder joint connections, each integrated circuit die and the adhesive film define and seal a protective cavity between the active surface of the die and the adhesive film. Portions of each die, leads, solder joint connections and adhesive film are encapsulated with a molding material that is prevented from entering the sealed cavity.
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Citations
14 Claims
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1. A method for packaging integrated circuit devices, comprising:
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providing a leadframe having a number of leads suitable for use in packaging an integrated circuit die, each lead having a first surface arranged for connection with an associated bond pad on an active surface of the die and a second surface opposite the first surface, the second surfaces of the leads being adhesively secured to an adhesive film; reflowing solder between the first surfaces of selected leads and selected bond pads on the active surface of the die to form solder joint connections that physically and electrically connect the die with the leadframe; dispensing a viscous thermosetting material substantially around the periphery of the active surface of the die such that the viscous thermosetting material substantially fills any gaps between the solder joint connections between the active surface of the die and the adhesive film, wherein the viscous thermosetting material, the solder joint connections, the active surface of the die and the adhesive film define a cavity between the active surface of the die and the adhesive film that isolates selected regions of the active surface of the die from stresses; and encapsulating at least portions of the die, leads, solder joint connections and the adhesive film with a molding material, wherein the viscous thermosetting material, the active surface of the die and the adhesive film substantially prevent molding material from entering the cavity. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An integrated circuit package, comprising:
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an integrated circuit die having an active surface and a back surface opposite the active surface, the active surface including a sensitive region; a plurality of leads, each lead having a first surface and a second surface opposite the first surface; a plurality of solder joint connections that mechanically and electrically connect the first surfaces of selected leads with associated bond pads on the active surface of the die; an adhesive film adhesively secured to second surfaces of the leads; a viscous thermosetting material that substantially fills any gaps between the solder joint connections between the active surface of the die and the adhesive film, wherein the viscous thermosetting material, the solder joint connections, the active surface of the die and the adhesive film define a cavity between the active surface of the die and the adhesive film that isolates the sensitive region on the active surface of the die from stresses; and a molding material that encapsulates at least portions of the die, leads, solder joint connections and the adhesive film with a molding material, wherein the viscous thermosetting material, the active surface of the die and the adhesive film substantially prevent molding material from entering the cavity. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification