Photonic integrated circuit chip packaging

Abstract

A localized hermetic sealing of a photonic integrated circuit component chip mounted in a photonic integrated circuit device chip to protect a chip-to-chip interface from contamination, thereby enhancing functionality and reliability. A covering lid mounted on or over the component chip is hermetically sealed to the device chip surrounding the component chip forming a localized hermetically sealed area.

We claim: 
     
         1 . A photonic integrated circuit (PIC) chip device comprising: 
       a component PIC chip including a component waveguide;
 a device PIC chip for receiving the component PIC chip, and a device waveguide optically coupled with the component waveguide; 
 a covering lid, for covering the component PIC chip; and 
 a hermetic seal between the covering lid and the device PIC chip forming a localized hermetically sealed area around the component PIC chip. 
 
     
     
         2 . The device according to  claim 1 , wherein the covering lid is integral with the PIC component chip. 
     
     
         3 . The device according to  claim 2 , wherein the covering lid comprises a ledge extending from around an end of the component PIC chip. 
     
     
         4 . The device according to  claim 3 , wherein the device PIC chip includes a pit; and wherein the component PIC chip is mounted in the pit; and wherein the hermetic seal is provided between the covering lid and an upper surface of the device PIC chip. 
     
     
         5 . The device according to  claim 1 , wherein the covering lid is separate from the PIC component chip. 
     
     
         6 . The device according to  claim 5 , wherein the covering lid includes a cavity for receiving an upper portion of the component PIC chip. 
     
     
         7 . The device according to  claim 5 , further comprising a thermally-conductive heat spreader between the device PIC chip and the covering lid for dissipating heat from the device PIC chip. 
     
     
         8 . The device according to  claim 1 , further comprising a first electrical connector on the component PIC chip, and a second electrical connector on the device PIC chip; wherein the first and second electrical connectors are connected within the localized hermetically sealed area. 
     
     
         9 . The device according to  claim 8 , wherein the first electrical connector extends from one end of the component PIC chip; and wherein the second electrical connector extends from a bottom of a pit extending into the device PIC chip. 
     
     
         10 . The device according to  claim 9 , further comprising an electrically conductive bonding material between the first and second electrical connectors bonding the component PIC chip in the pit. 
     
     
         11 . The device according to  claim 1 , wherein the hermetic seal comprises a thermally conductive metal to dissipate heat from the component PIC chip to the device PIC chip. 
     
     
         12 . A method of assembling a photonic integrated circuit (PIC) device comprising:
 mounting a component PIC chip onto a PIC device chip;   aligning waveguides on the component PIC chip with waveguides on the device PIC chip;   fixing the component PIC chip to the device PIC chip; and   hermetically sealing a covering lid to an upper surface of the device PIC chip around the component PIC chip, thereby providing a localized hermitically sealed area around the component PIC chip.   
     
     
         13 . The method according to  claim 12 , wherein the covering lid is integral with the component PIC chip. 
     
     
         14 . The method according to  claim 13 , wherein the covering lid comprises a ledge extending from around an end of the component PIC chip. 
     
     
         15 . The method according to  claim 14 , wherein the device PIC chip includes a pit for receiving the component PIC chip; and wherein the hermetically sealing step includes hermetically sealing the covering lid to an upper surface of the device PIC chip. 
     
     
         16 . The method according to  claim 13 , wherein the component PIC chip includes a substrate in or on which the waveguide is formed; and
 wherein the method further comprises removing a portion of the substrate to form the ledge.   
     
     
         17 . The method according to  claim 12 , wherein the hermetically sealing step includes mounting a separate covering lid over the component PIC chip. 
     
     
         18 . The method according to  claim 17 , wherein the covering lid includes a cavity for receiving an upper portion of the component PIC chip; and wherein a thermally conductive heat spreader is mounted in the cavity for dissipating heat from the component PIC chip. 
     
     
         19 . The method according to  claim 12 , further comprising connecting electrical connectors on the component PIC chip to electrical connectors on the device PIC chip within the hermetically sealed area. 
     
     
         20 . The method according to  claim 12 , wherein the hermetically sealing step is conducted under vacuum or any required inert gas atmosphere.