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;   at least two semiconductors thermally coupled to said heat spreader;   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.   
     
     
       2. A semiconductor module according to  claim 1 , wherein said semiconductors are electrically coupled to one another in series, and where said semiconductors are capable of being electrically coupled to a transmission channel. 
     
     
       3. A semiconductor module according to  claim 2 , wherein a final semiconductor in said series, remote from said transmission channel, is electrically coupled to said termination resistor. 
     
     
       4. A semiconductor module according to  claim 1 , wherein one semiconductor of the 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. 
     
     
       5. A semiconductor module according to  claim 1 , wherein a resistance value of the termination resistor is selected such that an impedance of said termination resistor substantially matches an impedance of a transmission channel and a signal source to which said termination resistor is connected. 
     
     
       6. A semiconductor module according to  claim 1 , wherein said termination resistor's form of termination is selected from a group consisting of: parallel termination, Thevenin termination, series termination, AC termination, and Schotty-diode termination. 
     
     
       7. A semiconductor module according to  claim 1 , wherein said termination resistor is thermally coupled to said heat spreader. 
     
     
       8. A semiconductor module according to  claim 1 , wherein said termination resistor is bonded directly to a side wall of said heat spreader. 
     
     
       9. A semiconductor module according to  claim 1 , wherein said two semiconductors are mounted on opposing side walls of said 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 flexible circuit at least partially attached to said heat spreader. 
     
     
       12. A semiconductor module according to  claim 11 , wherein said flexible circuit is a flexible dielectric tape. 
     
     
       13. A semiconductor module according to  claim 12 , wherein said flexible circuit is bonded directly to said side wall of said heat spreader. 
     
     
       14. A semiconductor module according to  claim 1 , wherein said 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 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;   thermally coupling said semiconductors to a heat spreader; and   electrically coupling a termination resistor to at least one of said semiconductors.   
     
     
       18. A method according to  claim 17 , initially comprising electrically coupling said semiconductors in series, where said semiconductors are capable of being electrically coupled to a transmission channel. 
     
     
       19. A method according to  claim 17 , further comprising 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 to a separate transmission channel. 
     
     
       20. A method according to  claim 17 , including bonding said termination resistor directly to a side wall of said heat spreader. 
     
     
       21. A method according to  claim 17 , including mounting said two semiconductors on opposing side walls of said 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 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. 
     
     
       24. A semiconductor module, comprising:
 a heat spreader comprising a first vertical member spaced apart from a second vertical member and a horizontal member joining the first vertical member and the second vertical member to define an inverted channel between the first and second vertical members;   at least two semiconductors each containing integrated circuitry, wherein each semiconductor of the semiconductors is thermally coupled to a respective one of the first and second vertical members;   a flexible circuit bonded to at least a portion of a surface of the inverted channel defined by the heat spreader, wherein the flexible circuit is electrically coupled to the semiconductors; and   a plurality of electrical contacts including a first set of electrical contacts disposed on a portion of the flexible circuit that is proximate to an end of the first vertical member and is remote from the horizontal member, and a second set of electrical contacts disposed on a portion of the flexible circuit that is proximate to an end of the second vertical member and is remote from the horizontal member, wherein the plurality of electrical contacts are configured so that a signal enters at the first set of electrical contacts and exits at the second set of electrical contacts.   
     
     
       25. The semiconductor module of claim 24, wherein the flexible circuit is flexible tape. 
     
     
       26. The semiconductor module according to claim 24, further comprising a termination resistor electrically coupled to the integrated circuitry of at least one of the semiconductors, where the termination resistor is thermally coupled to the heat spreader. 
     
     
       27. The semiconductor module of claim 26, further comprising one or more additional termination resistors, wherein each respective semiconductor contains integrated circuitry that is electrically coupled to a distinct termination resistor. 
     
     
       28. The semiconductor module according to claim 26, wherein one semiconductor of the semiconductors is not connected to the termination resistor, and an additional termination resistor is electrically coupled to the one semiconductor not connected to the termination resistor. 
     
     
       29. The semiconductor module according to claim 26, 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. 
     
     
       30. The semiconductor module according to claim 26, wherein the termination resistor is thermally coupled to the heat spreader. 
     
     
       31. The semiconductor module according to claim 26, wherein the termination resistor is bonded directly to a side wall of the heat spreader. 
     
     
       32. The semiconductor module according to claim 24, wherein the heat spreader has an inverted “u” shape. 
     
     
       33. The semiconductor module of claim 24, further comprising a fastening mechanism for removeably anchoring the semiconductor module to a circuit board. 
     
     
       34. The semiconductor module of claim 33, wherein the fastening mechanism includes clamps. 
     
     
       35. The semiconductor module of claim 24, wherein the plurality of electrical contacts are an array of bond pads. 
     
     
       36. The semiconductor module of claim 24, wherein the plurality of electrical contacts are an array of metal points. 
     
     
       37. The semiconductor module of claim 24, wherein the semiconductors are bonded to the heat spreader using a bonding adhesive with thermal expansion properties similar to those of the semiconductors and the heat spreader. 
     
     
       38. The semiconductor module of claim 24, wherein the flexible circuit contains a plurality of electrically conductive leads. 
     
     
       39. The semiconductor module of claim 24, wherein at least portion of the flexible circuit that is bonded to the heat spreader is bonded using a bonding adhesive with thermal expansion properties similar to those of the flexible circuit and the heat spreader. 
     
     
       40. The semiconductor module of claim 24, wherein the portion of the flexible circuit that is bonded to the heat spreader is also bonded to the semiconductors. 
     
     
       41. The semiconductor module of claim 24, wherein the semiconductor module is configured to connect to a pin grid array (PGA) socket that in turn connects to a circuit board. 
     
     
       42. The semiconductor module of claim 24, further comprising shielding to protect the semiconductors from electromagnetic interference. 
     
     
       43. The semiconductor module of claim 24, wherein the two or more semiconductors are connected to one another by electrical leads in the flexible circuit. 
     
     
       44. The semiconductor module of claim 24, wherein the semiconductor module is a memory module. 
     
     
       45. The semiconductor module of claim 24, wherein each semiconductor is connected to a distinct transmission channel and each transmission channel is separately terminated. 
     
     
       46. The semiconductor module of claim 24, wherein the first and second vertical members of the heat spreader are substantially perpendicular to the circuit board when the plurality of electrical contacts disposed on the flexible circuit are removeably coupled to the corresponding electrical contacts on the circuit board. 
     
     
       47. The semiconductor module of claim 24, wherein a signal path length from a first semiconductor to the first set of electrical contacts is substantially the same as a signal path length from a second semiconductor to the second set of electrical contacts. 
     
     
       48. The semiconductor module of claim 47, wherein a distance between the first set of electrical contacts and the first semiconductor is substantially equal to a distance between the second set of electrical contacts and the second semiconductor. 
     
     
       49. The semiconductor module of claim 24, further comprising:
 a first base member joined to an end of the first vertical member that is not joined to the horizontal member, wherein the first set of electrical contacts are disposed on a portion of the flexible circuit that is coupled to the first base member; and   a second base member joined to an end of the second vertical member that is not joined to the horizontal member, wherein the second set of electrical contacts are disposed on a portion of the flexible circuit that is coupled to the second base member.   
     
     
       50. The semiconductor module of claim 49, wherein the first base member and the second base member are parallel to the horizontal member and remote from the horizontal member.