REDUCING THERMAL EXPANSION EFFECTS IN SEMICONDUCTOR PACKAGES

• US 20110229702A1
• Filed: 05/27/2011
• Published: 09/22/2011
• Est. Priority Date: 10/18/2005
• Status: Active Grant

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Aizpuru, Jose Joaquin, Johnson, Christopher William, Hawkins, Bobby Marion
• Granted Patent: US 8,809,125 B2
• Time in Patent Office: Days
• US Class Current: 428/212
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01S 5/02232 Liquid-filled housings
• CPC Class Codes: H01S 5/02253 using lenses
• CPC Class Codes: H01S 5/0232 Lead-frames
• CPC Class Codes: H01S 5/024 Arrangements for thermal management
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/4998 Combined manufacture including applying or shaping of fluent material
• CPC Class Codes: Y10T 428/24917 including metal layer
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

Reducing effects of thermal expansion in electronic components. An electronic device can include a support, such as a leadframe. An electronic component can be supported by the support. A first flexible layer can cover the electronic component. A second more rigid layer can cover the first layer. The first layer can be made from a material that is more flexible than the second layer thereby creating a mechanical buffer layer between the second layer and the electronic component such that the electronic component is protected from thermal expansion of the second portion caused by changes in temperature. The electronic component can be a laser. The first and second materials can be selected to disperse an optical emission from the optical transmitter.

Claims

1. A method for manufacturing an electronic device comprising:

coupling an electronic component to a support;

producing a first layer over the component; and

producing a second layer over the first layer, wherein the first layer includes a material that is more flexible than the second layer, and wherein the material of the first layer is selected to absorb stresses caused by thermal expansion of the second layer.

2. A method according to claim 1, wherein the support is a leadframe or a substrate, and wherein the electronic device is one of:

a laser, a vertical cavity surface emitting laser (VCSEL), a sensor, an optical transmitter, an optical receiver, a silicon chip, or a capacitor.

3. A method according to claim 1, wherein the first layer comprises silicone and the second layer comprises a first material and a second material, wherein the first material has a lower thermal expansion characteristic than the second material.

4. A method according to claim 3, wherein the first material is glass filler particles, the second material is a plastic material, and the second layer is produced by an injection molding process, a transfer molding process, or a pour molding process.

5. A method according to claim 1, wherein the first layer comprises a dye for identifying cracks in the electronic device.

6. A method for manufacturing an optical transmission device comprising:

coupling an optical transmitter to a support;

encasing the optical transmitter with a first material having a first refractive index;

encasing the first material with a second material having a second refractive index, wherein the second refractive index is greater than the first refractive index so as to disperse a width of an optical emission from the optical transmitter.

7. A method according to claim 6, wherein the first material is more flexible than the second material and the first material is selected to mechanically absorb stresses by deformation caused by expansion of the second material in response to changes in temperature.

8. A method according to claim 6, wherein the first material comprises silicone and the second material comprises an epoxy.

9. A method according to claim 6, wherein the second material includes a filler material, and wherein the thickness of the first material is selected to create an optical buffer between an emission cavity of the optical transmitter and the filler material.

10. A method according to claim 6, wherein the first material has a refractive index of about 1.4 and the second material has a refractive index of about 1.55.

11. An electronic device manufactured according to the method of claim 6.