Semiconductor module with serial bus connection to multiple dies

Abstract

A semiconductor module is provided which includes a beat heat spreader, at least two semiconductors thermally coupled to the heat spreader, and a plurality of electrically conductive leads electrically connected to the semiconductors. At least one of the electrically conductive leads is common to both of the semiconductors. The semiconductor module also includes a termination resistor electrically coupled to at least one of the semiconductors. A method of making a semiconductor module is also taught, whereby a plurality of electrically conductive leads are provided. At least two semiconductors are electrically coupled to the plurality of electrically conductive leads, where at least one of the electrically conductive leads is common to both of the semiconductors. The semiconductors are then thermally coupled to a heat spreader. Subsequently, a termination resistor is electrically coupled to at least one of the semiconductors.

1. A semiconductor module, comprising:
 a heat spreader comprising a solid block of heat spreading material having a substantially planar first side, a substantially planar opposing second side and a respective edge between the first side and the second side;  
 a flexible circuit including a first portion bonded to at least part of the first side of the heat spreader, a second portion wrapped around the respective edge of the heat spreader, and a third portion bonded to at least part of the second side of the heat spreader; 
 at least two semiconductors coupled to the flexible circuit and thermally coupled to said  the heat spreader, wherein one of the semiconductors is disposed at the first side of the heat spreader and another one of the semiconductors is disposed at the second side of the heat spreader; and, 
 a plurality of electrically conductive leads electrically connected to said semiconductors, where at least one of said electrically conductive leads is common to both of said semiconductors; and  
 a termination resistor electrically coupled to at least one of said semiconductors.  
 a plurality of electrical contacts disposed on the flexible circuit proximate to the second portion of the flexible circuit, where each of the plurality of electrical contacts is electrically coupled to at least one of the semiconductors via the flexible circuit, wherein the plurality of electrical contacts are configured to removeably couple the semiconductor module to corresponding electrical contacts formed in a slot on a circuit board when a portion of the semiconductor module, including the respective edge of the heat spreader, the second portion of the flexible circuit wrapped around the respective edge of the heat spreader, and the plurality of electrical contacts, is inserted into the slot. 
 
     
     
       2. A semiconductor module according to  claim 1 , wherein said  at least some of the semiconductors are electrically coupled to one another in series, and where said  the semiconductors are capable of being electrically coupled to a transmission channel. 
     
     
       3. A semiconductor module according to  claim 2 , further comprising a termination circuit electrically coupled to at least one of the semiconductors, wherein a final semiconductor in said series, remote from said  the transmission channel, is electrically coupled to said  the termination resistor  circuit. 
     
     
       4. A semiconductor module according to  claim 1 , wherein one  each semiconductor of the at least two semiconductors is not  connected to said termination resistor, and an additional termination resistor is electrically coupled to the one semiconductor not connected to said termination resistor.  a separate transmission channel, where each transmission channel is separately terminated. 
     
     
       5. A semiconductor module according to  claim 1 , further comprising a termination resistor electrically coupled to at least one of the semiconductors, wherein a resistance value of the termination resistor is selected such that an impedance of said  the termination resistor substantially matches an impedance of a transmission channel and a signal source to which said  the termination resistor is connected. 
     
     
       6. A semiconductor module according to  claim 1 , further comprising a termination circuit electrically coupled to at least one of the semiconductors, wherein said  the termination resistor's form of termination is selected from a group consisting of: parallel termination, Thevenin termination, series termination, AC termination, and Schotty-diode  Schottky- diode  termination. 
     
     
       7. A semiconductor module according to  claim 1 , further comprising a termination circuit electrically coupled to at least one of the semiconductors, wherein said  the termination resistor  circuit is thermally coupled to said  the heat spreader. 
     
     
       8. A semiconductor module according to  claim 1 , further comprising a termination circuit electrically coupled to at least one of the semiconductors, wherein said  the termination resistor is bonded directly to a side wall of said  the heat spreader. 
     
     
       9. A semiconductor module according to  claim 1 , wherein said  the two semiconductors are mounted on opposing side walls of said  the heat spreader. 
     
     
       10. A semiconductor module according to  claim 2 , wherein each of said semiconductors are bonded directly to said side wall of said heat spreader. 
     
     
       11. A semiconductor module according to  claim 1 , wherein said leads form part of a  the flexible circuit at least partially attached to said heat spreader  includes a plurality of electrically conductive leads electrically connected to the semiconductors, where at least one of the electrically conductive leads is common to both of the semiconductors. 
     
     
       12. A semiconductor module according to  claim 11 , wherein said  the flexible circuit is a flexible dielectric tape. 
     
     
       13. A semiconductor module according to  claim 12 , wherein said  the flexible circuit is bonded directly to said  the side wall of said  the heat spreader. 
     
     
       14. A semiconductor module according to  claim 11 , wherein said  the common electrically conductive lead is selected from a group consisting of a voltage supply node, a reference voltage node, and an electrical ground node. 
     
     
       15. A semiconductor module according to  claim 1 , wherein said heat spreader is a solid block of heat dissipating material. 
     
     
       16. A semiconductor module according to  claim 1 , wherein said heat spreader is “u” shaped. 
     
     
       17. A method of making a semiconductor module, comprising:
 providing a heat spreader comprising a solid block of heat spreading material having a substantially planar first side, a substantially planar opposing second side and a respective edge between the first side and the second side;  
   attaching a flexible circuit to the heat spreader including bonding a first portion to at least part of the first side of the heat spreader, wrapping a second portion around the respective edge of the heat spreader, and bonding a third portion to at least part of the second side of the heat spreader;   
 providing a plurality of electrically conductive leads; 
 electrically coupling at least two semiconductors to said plurality of electrically conductive leads, where at least one of said electrically conductive leads is common to both of said semiconductors;  the flexible circuit; 
 thermally coupling said  the at least two semiconductors to a  the heat spreader, wherein one of the semiconductors is disposed at the first side of the heat spreader and another one of the semiconductors is disposed at the second side of the heat spreader; and  
 electrically coupling a termination resistor to at least one of said semiconductors. 
 providing a plurality of electrical contacts disposed on the flexible circuit proximate to the second portion of the flexible circuit such that each of a plurality of electrical contacts is electrically coupled to at least one of the semiconductors via the flexible circuit, wherein the plurality of electrical contacts are configured to removeably couple the semiconductor module to corresponding electrical contacts formed in a slot on a circuit board when a portion of the semiconductor module, including the respective edge of the heat spreader, the second portion of the flexible circuit wrapped around the respective edge of the heat spreader, and the plurality of electrical contacts, is inserted into the slot. 
 
     
     
       18. A method according to  claim 17 , initially comprising electrically coupling said  at least some of the semiconductors in series, where said  the semiconductors are capable of being electrically coupled to a transmission channel. 
     
     
       19. A method according to  claim 17 , further comprising  wherein electrically coupling at least two semiconductors to the flexible circuit includes electrically coupling an additional termination resistor to the semiconductor not already connected to said termination resistor, where each of said semiconductors is capable of being electrically coupled  each semiconductor to a separate transmission channel, where each transmission channel is separately terminated. 
     
     
       20. A method according to  claim 17 , including electrically coupling a termination circuit to at least one of the semiconductors; and bonding said  the termination resistor directly to a side wall of said  the heat spreader. 
     
     
       21. A method according to  claim 17 , including mounting said  the two semiconductors on opposing side walls of said  the heat spreader. 
     
     
       22. A method according to  claim 17 , including bonding each of said semiconductors directly to a side wall of said heat spreader. 
     
     
       23. A method according to  claim 17 , wherein said leads form part of a  the flexible circuit at least partially attached to said heat spreader, said method including bonding said flexible circuit directly to a side wall of said heat spreader  includes a plurality of electrically conductive leads electrically connected to the semiconductors, where at least one of the electrically conductive leads is common to both of the semiconductors. 
     
     
       24. A semiconductor module according to  claim 1 , further comprising a fastening mechanism for anchoring the semiconductor module to a circuit board. 
     
     
       25. A semiconductor module according to  claim 24 , wherein clamps anchor the semiconductor module to the circuit board. 
     
     
       26. A semiconductor module according to  claim 1 , wherein the plurality of electrical contacts disposed on the flexible circuit are a linear array of electrical contact pads coupled to the heat spreader. 
     
     
       27. A semiconductor module according to  claim 26 , wherein the plurality of electrical contact pads are an array of bond pads. 
     
     
       28. A semiconductor module according to  claim 26 , wherein the plurality of electrical contact pads are an array of metal points. 
     
     
       29. A semiconductor module according to  claim 1 , wherein the flexible circuit is at least partially bonded to the heat spreader using a bonding adhesive with thermal expansion properties similar to those of the flexible circuit and the heat spreader. 
     
     
       30. A semiconductor module according to  claim 1 , wherein the plurality of electrical contacts are disposed at on a section the flexible circuit that is bonded to the heat spreader, and the section the flexible circuit having the plurality of electrical contacts disposed thereon is bonded to the heat spreader proximate to the respective edge of the heat spreader. 
     
     
       31. A semiconductor module according to  claim 1 , wherein the plurality of electrical contacts disposed on the flexible circuit are electrically and mechanically coupled to a section of the flexible circuit that is bonded to the heat spreader near an apex of the heat spreader. 
     
     
       32. A semiconductor module according to  claim 1 , wherein the first side of the heat spreader and the second side of the heat spreader are substantially perpendicular to the circuit board when the semiconductor module is coupled to the electrical contacts formed in the slot. 
     
     
       33. A method according to  claim 17 , wherein the first side of the heat spreader and the second side of the heat spreader are substantially perpendicular to the circuit board when the semiconductor module is coupled to the electrical contacts formed in the slot. 
     
     
       34. A method according to  claim 18 , further comprising electrically coupling a termination circuit to at least one of the semiconductors, wherein a final semiconductor in the series, remote from the transmission channel, is electrically coupled to the termination circuit. 
     
     
       35. A method according to  claim 17 , further comprising electrically coupling a termination resistor to at least one of the semiconductors, wherein a resistance value of the termination resistor is selected such that an impedance of the termination resistor substantially matches an impedance of a transmission channel and a signal source to which the termination resistor is connected. 
     
     
       36. A method according to  claim 17 , further comprising electrically coupling a termination circuit to at least one of the semiconductors, wherein the termination circuit's form of termination is selected from a group consisting of: parallel termination, Thevenin termination, series termination, AC termination, and Schottky- diode termination.   
     
     
       37. A method according to  claim 17 , further comprising electrically coupling a termination circuit to at least one of the semiconductors, wherein the termination circuit is thermally coupled to the heat spreader. 
     
     
       38. A method according to  claim 23 , wherein the flexible circuit is a flexible dielectric tape. 
     
     
       39. A method according to  claim 17 , wherein the flexible circuit includes a plurality of electrically conductive leads electrically connected to the semiconductors, where at least one of the electrically conductive leads is common to both of the semiconductors. 
     
     
       40. A method according to  claim 39 , wherein the common electrically conductive lead is selected from a group consisting of a voltage supply node, a reference voltage node, and an electrical ground node. 
     
     
       41. A method according to  claim 17 , further comprising mechanically coupling the semiconductor module to a fastening mechanism for anchoring the semiconductor module to a circuit board. 
     
     
       42. A method according to  claim 30 , wherein the fastening mechanism for anchoring the semiconductor module includes a clamp. 
     
     
       43. A method according to  claim 17 , wherein the plurality of electrical contacts disposed on the flexible circuit are a linear array of electrical contact pads coupled to the heat spreader. 
     
     
       44. A method according to  claim 43 , wherein the plurality of electrical contact pads are an array of bond pads. 
     
     
       45. A method according to  claim 43 , wherein the plurality of electrical contact pads are an array of metal points. 
     
     
       46. A method according to  claim 17 , wherein the flexible circuit is at least partially bonded to the heat spreader using a bonding adhesive with thermal expansion properties similar to those of the flexible circuit and the heat spreader. 
     
     
       47. A method according to  claim 17 , wherein the plurality of electrical contacts are disposed at on a section the flexible circuit that is bonded to the heat spreader, and the section the flexible circuit having the plurality of electrical contacts disposed thereon is bonded to the heat spreader proximate to the respective edge of the heat spreader. 
     
     
       48. A method according to  claim 17 , wherein the plurality of electrical contacts disposed on the flexible circuit are electrically and mechanically coupled to a section of the flexible circuit that is bonded to the heat spreader near an apex of the heat spreader. 
     
     
       49. A semiconductor module, comprising:
   a heat spreader comprising a solid block of heat spreading material having a substantially planar first side, a substantially planar opposing second side and a respective edge between the first side and the second side;        at least two semiconductors each comprising circuitry, where the semiconductors are thermally coupled to the heat spreader, and one of the semiconductors is disposed at the first side of the heat spreader and another one of the semiconductors is disposed at the second side of the heat spreader;        a flexible circuit including a first portion bonded to at least part of the first side of the heat spreader, a second portion wrapped around the respective edge of the heat spreader, and a third portion bonded to at least part of the second side of the heat spreader, wherein the flexible circuit comprises a plurality of electrically conductive leads that are electrically connected to the semiconductors, where at least one of the electrically conductive leads is common to both of the semiconductors;        a termination resistor electrically coupled to the circuitry of at least one of the semiconductors; and        a plurality of electrical contacts disposed on the flexible circuit proximate to the second portion of the flexible circuit, where each of the plurality of electrical contacts is electrically coupled to at least one of the semiconductors via the flexible circuit, wherein the plurality of electrical contacts are configured to removeably couple the semiconductor module to corresponding electrical contacts formed in a slot on a circuit board when a portion of the semiconductor module, including the respective edge of the heat spreader, the second portion of the flexible circuit wrapped around the respective edge of the heat spreader, and the plurality of electrical contacts, is inserted into the slot.