Multi-chip stacked devices

Abstract

A multiple stacked die device is disclosed that contains up to four dies and does not exceed the height of current single die packages. Close-tolerance stacking is made possible by a low-loop-profile wire-bonding operation and thin-adhesive layer between the stacked dies.

What is claimed is: 
     
       1. A multiple-die low-profile semiconductor device comprising: a. a lead-frame paddle supported by a lead frame;   b. a controlled, first, thin-adhesive layer of about 0.001 inches affixing a first die above the paddle;   c. a plurality of thin wires having a first low-loop wire bond to a plurality of first .[.diebonding.]. .Iadd.die-bonding .Iaddend.pads, said wire bond having a wire height above the bonding pad of about 0.006 inches, and a second wire bond to a plurality of adjacent lead-frame lead fingers;   d. a second thin-adhesive layer of about 0.008 inches affixing a second die above the first die;   e. a second plurality of thin wires having low-loop wire bonds to a plurality of second die-bonding pads and second wire bonds to the plurality of lead fingers;   f. two additional dies affixed above the second die by additional subsequent layers of adhesive of about 0.008 inches and having additional thin wires bonded to additional bonding pads and lead fingers; and   g. an .[.encapsulated.]. .Iadd.encapsulation .Iaddend.layer surrounding all dies, adhesive layers, and thin wires wherein a total encapsulated package height is about 0.110 inches.   
     
     
       2. A multiple-die low-profile semiconductor device comprising: a. a lead-frame paddle supported by a lead frame;   b. a controlled, first, thin-adhesive layer of about 0.001 to 0.005 inches affixing a first die above the paddle;   c. a plurality of thin wires having a first low-loop wire bond to a plurality of first die-bonding pads, said low-loop wire .[.ball.]. bond having a wire height above the .Iadd.first die.Iaddend.-bonding pads of about 0.006 inches and a second wire bond to a plurality of adjacent lead-frame lead fingers;   d. a second thin-adhesive layer of about 0.008 to 0.010 inches affixing a second die above the first die;   e. a second plurality of thin wires having low-loop wire bonds to a plurality of second die-bonding pads and second wire bonds to the plurality of lead fingers;   f. an .[.encapsulated.]. .Iadd.encapsulation .Iaddend.layer surrounding all die adhesive layers and thin wires wherein a total encapsulation-layer height is about 0.070 inches. .Iadd.   
     
     
       3.  A multiple-die low-profile semiconductor device comprising: a. a lead-frame paddle supported by a lead frame;   b. a controlled, first, thin-adhesive layer affixing a first die above the paddle;   c. a plurality of thin wires having a first low-loop wire bond to a plurality of first die-bonding pads and a second wire bond to a plurality of adjacent lead-frame lead fingers;   d. a second thin-adhesive layer affixing a second die above the first die;   e. a second plurality of thin wires having low-loop wire bonds to a plurality of second die-bonding pads and second wire bonds to the plurality of lead fingers;   f. two additional dies affixed above the second die by additional subsequent layers of adhesive and having additional thin wires bonded to additional bonding pads and lead fingers; and   g. an encapsulation layer surrounding all dies, adhesive layers, and thin wires and having a height of about 0.110 inches. .Iaddend..Iadd.4. The semiconductor device as recited in claim 3 wherein the paddle is downset from the lead fingers and selected lead fingers are formed up thereby providing for additional space within the device and shorter thin wires, respectively. .Iaddend..Iadd.5. The semiconductor device as recited in claim 4 wherein the thin wire is gold, and the first low-loop bond is a ball bond and the second bond is a wedge bond. .Iaddend..Iadd.6. The semiconductor device as recited in claim 3 wherein a low-loop bond wire height above the bonding pad is about 0.006 inches and the second and subsequent thin-adhesive layers are about 0.008 inches. .Iaddend..Iadd.7. The semiconductor device as recited in claim 6 wherein the first   
     
     
        thin-adhesive layer is about 0.001 inches. .Iaddend..Iadd.8.  A multiple-die, low-profile semiconductor device comprising: a. a lead-frame paddle supported by a lead frame;   b. a controlled, first, thin-adhesive layer affixing a first die above the paddle;   c. a plurality of thin wires having a first low-loop wire bond to a plurality of first die-bonding pads, said low-loop wire bond having a wire height above the bonding pads of about 0.006 inches and a second wire bond to a plurality of adjacent lead-frame lead fingers;   d. a second thin-adhesive layer of about 0.008 to 0.010 inches affixing a second die above the first die;   e. a second plurality of thin wires having low-loop wire bonds to a plurality of second die-bonding pads and second wire bonds to the plurality of lead fingers; and   f. an encapsulation layer surrounding all die adhesive layers and thin wires. .Iaddend..Iadd.9. The semiconductor device as recited in claim 8 wherein the first thin-adhesive layer is about 0.001 to 0.005 inches. .Iaddend..Iadd.10. The semiconductor device as recited in claim 9 wherein a total encapsulation layer height is about 0.070 inches. .Iaddend..Iadd.11. A multiple-die, low-profile semiconductor device comprising:   a lead-frame paddle supported by a lead frame;   a first adhesive layer affixing a first die above the paddle;   a plurality of wires having first wire bonds to a respective plurality of first die-bonding pads and second wire bonds to a respective plurality of adjacent lead-frame lead fingers;   a second adhesive layer affixing a second die above the first die;   a second plurality of wires having first wire bonds to a respective plurality of second die-bonding pads and second wire bonds to a respective plurality of lead fingers;   two additional dies affixed above the second die by additional subsequent layers of adhesive and having additional wires bonded to additional respective bonding pads and lead fingers; and   an encapsulation layer surrounding all dies, adhesive layers, and wires and having a height of about 0.110 inches. .Iaddend..Iadd.12. The semiconductor device as recited in claim 11, wherein the paddle is downset from the lead fingers and selected lead fingers are formed up thereby providing for additional space within the device and shorter wires, respectively. .Iaddend..Iadd.13. The semiconductor device as recited in claim 12, wherein the wire is gold, and the first bond is a ball bond and   
     
     
        the second bond is a wedge bonds. .Iaddend..Iadd.14.  The semiconductor device as recited in claim 11, wherein a bond wire height above the first and second die-bonding pads for all but the uppermost die is about 0.006 inches and the second and subsequent adhesive layers are about 0.008 inches. .Iaddend..Iadd.15. The semiconductor device as recited in claim 14 wherein the first thin-adhesive layer is about 0.001 inches. .Iaddend..Iadd.16. A multiple-die, low-profile semiconductor device comprising: a lead-frame paddle supported by a lead frame;   a first adhesive layer affixing a first die above the paddle;   a plurality of respective wires having first low-loop wire bonds to a plurality of first die-bonding pads, said low-loop wire bonds having a wire height above the bonding pads of about 0.006 inches, and second wire bonds to a plurality of adjacent lead-frame lead fingers;   a second adhesive layer of about 0.008 to 0.010 inches affixing a second die above the first die;   a second plurality of respective wires having first wire bonds to a plurality of second die-bonding pads and second wire bonds to a respective plurality of lead fingers; and   an encapsulation layer surrounding all die adhesive layers and wires. .Iaddend..Iadd.17. The semiconductor device as recited in claim 16 wherein the first adhesive layer is about 0.001 to 0.005 inches. .Iaddend..Iadd.18. The semiconductor device as recited in claim 17 wherein a total encapsulation layer height is about 0.070 inches. .Iaddend..Iadd.19. A multiple-die, low-profile semiconductor device comprising:   a lead-frame paddle supported by a lead frame;   a first die affixed above the paddle;   an adhesive layer having a thickness and affixing a second die above the first die; and   a plurality of wires having first wire bonds to a respective plurality of first die-bonding pads and second wire bonds to a respective plurality of lead-frame lead fingers, the first wire bonds having loop heights above the first die of less than the thickness of the adhesive layer. .Iaddend..Iadd.20. The semiconductor device of claim 19, further including a second plurality of wires having first wire bonds to a respective plurality of second die-bonding pads and second wire bonds to a respective   
     
     
        plurality of lead fingers. .Iaddend..Iadd.21.  The semiconductor device of claim 20, further including two additional dies affixed above the second die by additional subsequent layers of adhesive and having additional wires bonded to additional respective bonding pads and lead fingers, the wires bonded to at least those affixed die below the uppermost die having loop heights above the die to which those wires are bonded of less than the thickness of the adhesive layer affixing the die above. .Iaddend..Iadd.22. The semiconductor device of claim 19, further including an encapsulation layer surrounding all dies, adhesive layers, and wires. .Iaddend..Iadd.23. A multiple-die, low-profile semiconductor device comprising: a lead-frame paddle supported by a lead frame;   a first die having bonding pads at the periphery thereof and affixed above the paddle;   an adhesive layer having a thickness and affixing a second die above the first die, said adhesive layer leaving the first die peripheral bonding pads uncovered; and   a plurality of wires having first wire bonds to a respective plurality of first die-bonding pads and second wire bonds to a respective plurality of lead-frame lead fingers, the first wire bonds having loop heights above said first die of less than the thickness of said adhesive layer. .Iaddend..Iadd.24. The semiconductor device of claim 23, further including a second plurality of wires having first wire bonds to a respective plurality of second die-bonding pads and second wire bonds to a respective plurality of lead fingers. .Iaddend..Iadd.25. The semiconductor device of claim 24, further including two additional dies affixed above the second die by additional subsequent layers of adhesive and having additional wires bonded to additional respective bonding pads and lead fingers, at least the dies below the uppermost having peripheral bond pads, the adhesive layers leaving the peripheral bond pads uncovered, and the wires bonded to at least those affixed dies except the uppermost die having loop heights above the die to which the wires are bonded of less than the thickness of the adhesive layer affixing the die above.   
     
     
        .Iaddend..Iadd.     The semiconductor device of claim 23, further including an encapsulation layer surrounding all dies, adhesive layers, and wires. .Iaddend.