Packaging techniques for optical transmitters/receivers

• US 4,911,519 A
• Filed: 02/01/1989
• Issued: 03/27/1990
• Est. Priority Date: 02/01/1989
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.), Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: AT&T, Inc.
• Inventors: Robinson, Steven D., Burton, William H.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): PALMER, PHAN T H
• Application Number:
  US07/305,249
• Time in Patent Office: 419 Days
• Field of Search: 350/96.15, 350/96.17, 350/96.20, 250/227, 250/552, 357/17, 357/19, 357/30, 357/74, 357/80
• US Class Current: 385/14
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4245 Mounting of the opto-electronic elements
• CPC Class Codes: G02B 6/4246 Bidirectionally operating package structures
• CPC Class Codes: G02B 6/4265 of the Butterfly or dual inline package [DIP] type
• CPC Class Codes: G02B 6/4269 with heat sinks or radiation fins
• CPC Class Codes: G02B 6/4277 Protection against electromagnetic interference [EMI], e.g. shielding means shielding of electric apparatus H05K9/00, of instruments G12B17/00
• CPC Class Codes: G02B 6/428 containing printed circuit boards [PCB]
• CPC Class Codes: G02B 6/4292 the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements

Abstract

Advanced packaging techniques are utilized to provide updated packaging for optical transmitters and receivers. In particular, the hybrid integrated circuit (HIC) used to form either the transmitter or receiver circuitry in the prior art has been replaced by a plastic dual-in-line package (DIP). The DIP includes specialized leads (prongs) formed through the short end of the DIP to provide direct connection to the optical device. These end-prong leads thus significantly decrease the parasitic capacitance associated with conventional DIP connections. A capacitor may be molded into the DIP across the power supply leads to provide filtering for the package. Thermal dissipation is provided by two separate means in this package. First, the leadframe of the DIP is formed to include relatively long leads which extend through the bottom of the package to carry away the heat generated by the integrated circuit and the DIP itself may be disposed on a thermally conductive substrate which will also dissipate heat generate by the integrated circuit. Second, the metal cover of the package is attached to the optical device by a thermally conductive epoxy to provide a heat path for the optical device. Molded plastic piece parts are utilized to form the optical sleeve and an optical frame assembly.

Claims

1. An optical communication arrangement comprising

a semiconductor optical device;

mounting means for said optical device including a pair of electrical leads extending therefrom;

an optical sleeve comprising a plastic material which is capable of being molded, said optical sleeve including a central bore for insertion of an optical fiber assembly;

a connector frame assembly comprising a plastic material identical in composition to said optical sleeve, said frame assembly including a bore formed through a endwall thereof for insertion of said optical sleeve, said connector frame assembly further comprising an optical fiber connector port, said connector port appropriately shaped by means of molding;

a plastic dual-in-line package for housing an integrated circuit required to operate said semiconductor optical device, said dual-in-line package including a pair of end-prong leads for connection to the pair of electrical leads extending from said mounting means, said dual-in-line package further comprising a plurality of relatively long leads extending from both sides of said package;

a bottom support plate disposed under said dual-in-line package in a manner such that the plurality of relatively long leads pass through a plurality of associated holes formed in said bottom support plate, said leads being utilized for connection to external circuitry; and

a metallic cover plate disposed to contact said connector frame assembly such that said dual-in-line package and said optical sleeve are fully encased.

2. An optical communication arrangement formed in accordance with claim 1 wherein the plastic material forming the optical sleeve and the connector frame assembly comprises a liquid crystal polymer material.

3. An optical communication arrangement formed in accordance with claim 1 wherein the metallic cover plate comprises nickel-plated copper.

4. An optical communication arrangement formed in accordance with claim 1 wherein the bottom support plate comprises an epoxy glass material.

5. An optical communication arrangement formed in accordance with claim 1 wherein the end-prong leads of the dual-in-line package include U-shaped ends and are bent upwards to attach to the pair of electrical leads extending from said mounting means.

6. An optical communication arrangement as in claim 1 wherein the arrangement comprises an optical transmitter including a transmitting optical device, with a thermal epoxy utilized to attach the metallic cover plate to the transmitting optical device so as to provide a path for the dissipation of heat generated by said transmitting optical device.

7. An optical transmitter as defined in claim 6 wherein the transmitting optical device comprises an LED.

8. An optical transmitter as defined in claim 7 wherein the LED comprises an AlGaAs LED.

9. An optical transmitter as defined in claim 7 wherein the LED comprises an InGaAsP LED.

10. An optical transmitter as defined in claim 7 wherein the LED comprises an edge-emitting LED.

11. An optical transmitter as defined in claim 6 wherein the transmitting optical device comprises a semiconductor laser.

12. An optical communication arrangement as in claim 1 wherein the arrangement comprises an optical receiver including a photosensitive optical device, the dual-in-line package further including a bypass capacitor inserted across a pair of power supply leads, and the metallic cover plate connecting to an electrical ground plane formed on the bottom support plate.

13. An optical receiver as defined in claim 12 wherein the photosensitive optical device comprises a PIN photodiode.

14. An optical receiver as defined in claim 13 wherein the PIN photodiode comprises a silicon photodiode.

15. An optical receiver as defined in claim 13 wherein the PIN photodiode comprises an InGaAs photodiode.

16. An optical receiver as defined in claim 12 wherein the photosensitive optical device comprises an avalanche photodiode.