Warp compensated electronic assemblies
AssigneeFreescale Semiconductor, Inc.
InventorsWILLIAM H. LYTLE, Scott M. Hayes, George R. Leal
Life of this patent
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Abstract
An electronic panel assembly (EPA) includes one or more electronic devices with primary faces having electrical contacts, opposed rear faces and edges therebetween. The devices are mounted primary faces down in openings in a warp control sheet (WCS). Cured plastic encapsulation is formed at least between lateral edges of the devices and WCS openings. Undesirable panel warping during encapsulation is mitigated by choosing the WCS coefficient of thermal expansion (CTE) to be less than the encapsulation CTE. Thin film insulators and conductors couple electrical contacts on various devices to each other and to external terminals, thereby forming an integrated multi-device EPA.
Claims18
An integrated electronic assembly, comprising:
- multiple electronic devices having front faces with bonding pads thereon, opposed rear faces and edges extending between the front and rear faces;
- a substantially planar sheet having openings therein in which the multiple electronic devices are located and wherein the substantially planar sheet has a first coefficient of thermal expansion (CTE);
- plastic encapsulation in at least the openings in the substantially planar sheet coupling the electronic devices to the substantially planar sheet so that an initial electronic assembly is formed with the bonding pads exposed, wherein the plastic encapsulation has a second CTE relative to the first CTE such that the initial electronic assembly is substantially flat or has a convex warp;
- and
- interconnections extending to some of the multiple electronic devices of the initial electronic assembly thereby coupling some of the bonding pads to each other or to external terminals or both to form the integrated electronic assembly.
An electronic assembly, comprising:
- multiple electronic devices with primary faces where electrical contacts are located, opposed rear faces, and edges extending between the primary and rear faces;
- a perforated warp control sheet having a first surface and multiple openings therein sized to accept the multiple electronic devices and having a first coefficient of thermal expansion (CTE), wherein the multiple electronic devices are located in the multiple openings in the perforated warp control sheet so that gaps are located between the edges of the electronic devices and edges of the openings, and wherein the primary faces of the electronic devices are substantially co-planar with the first surface of the perforated warp control sheet;
- and
- cured plastic encapsulation material at least in the gaps, wherein a characteristic of the plastic encapsulation material is that a second CTE of the plastic encapsulation material is equal or greater than the first CTE, and wherein the characteristic that the second CTE is equal to or greater than the first CTE results in a panel containing the multiple electronic devices and the perforated warp control sheet that has a convex warp, wherein the primary faces are exposed at a first surface of the panel, and the first surface of the panel has a convex curve.
An integrated electronic panel assembly (IEPA) having multiple electronic devices, comprising:
- a warp control plane having a first surface and openings therein adapted to receive multiple electronic devices, wherein the warp control plane has a first coefficient of thermal expansion (CTE) less than a second CTE;
- the multiple electronic devices with first faces having bonding pads thereon, opposed rear faces, and edges extending between the first faces and rear faces, wherein the multiple electronic devices are located in the openings in the warp control plane with their bonding pads oriented toward the first surface, and wherein a gap separates the edges of each of the multiple electronic devices from each opening in the warp control plane;
- cured plastic encapsulation having the second CTE at least between edges of the multiple electronic devices and the openings in the warp control plane, wherein the cured plastic encapsulation substantially fixes the multiple electronic devices and the warp control plane in the encapsulation, thereby forming a panel of multiple electronic devices.
Dependencies are inferred from the claim text.