Patterned contact

Abstract

A chip having at least one electrical contact having a first end proximate to the chip and a second end removed from the chip, the second end including a pattern configured to facilitate penetration of the at least one contact into a malleable contact on another chip, the pattern comprising a non-planar surface having a perimeter and a surface area, the surface area being larger than a planar surface of an identical perimeter.

1 . A method comprising:
 electrically connecting a first chip to a second chip by joining a first electrical contact and a second electrical contact at a temperature below a melting point of a malleable material of the second electrical contact to form a mechanical and electrical connection between the first and second electrical contacts;   wherein the first chip includes the first electrical contact comprising a proximal end and a distal end with respect to the first chip; and   wherein the distal end has a shape projected in a plane parallel to the first chip such that the distal end is configured to facilitate penetration into the second electrical contact of the second chip.   
     
     
         2 . The method of  claim 1 , wherein the projected shape comprises a cross. 
     
     
         3 . The method of  claim 1 , wherein the first electrical contact is one of multiple electrical contacts, wherein each of the multiple electrical contacts has an elongated shape and an axis along the elongated shape, and wherein the multiple electrical contacts are arranged about a point so that the axes of at least two of the multiple electrical contacts pass through the point. 
     
     
         4 . The method of  claim 1 , wherein said joining a first electrical contact and a second electrical contact comprises penetrating a rigid material of the first electrical contact into the malleable material of the second electrical contact. 
     
     
         5 . The method of  claim 1 , wherein at least one of the first or second electrical contacts comprises:
 a base portion; and   multiple individual elements disposed over and extending from the base portion;   wherein each of the multiple individual elements has a cross-sectional area measured parallel to the respective first or second chip that is smaller than a cross-sectional area of the base portion.   
     
     
         6 . The method of  claim 5 , wherein the multiple individual elements comprise two elements stacked together, and wherein one of the two stacked elements has a perimeter similar in shape, but different in length, compared with another one of the two stacked elements. 
     
     
         7 . The method of  claim 6 , wherein a first of the two stacked elements rests on a surface of a second of the two stacked elements. 
     
     
         8 . The method of  claim 7 , wherein the first of the two stacked elements and the second of the two stacked elements are arranged to have an equal distance between corresponding points on the perimeters of the first and second stacked elements. 
     
     
         9 . The method of  claim 1 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes at least two bumps. 
     
     
         10 . The method of  claim 1 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a pyramid. 
     
     
         11 . The method of  claim 1 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a truncated pyramid. 
     
     
         12 . The method of  claim 1 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a shape having a point at the distal end. 
     
     
         13 . The method of  claim 1 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a first geometric shape physically connected to a second geometric shape. 
     
     
         14 . The method of  claim 13 , wherein the first geometric shape is different from the second geometric shape. 
     
     
         15 . The method of  claim 13 , wherein the first geometric shape has a first width at a widest portion thereof, and wherein the second geometric shape has a widest portion that is narrower than the first width. 
     
     
         16 . The method of  claim 13 , wherein the second geometric shape extends beyond a peripheral boundary of an integrated circuit (IC) pad located beneath the second geometric shape, and wherein the first geometric shape is within the peripheral boundary of the IC pad. 
     
     
         17 . The method of  claim 1 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a post-in-a-well configuration. 
     
     
         18 . The method of  claim 1 , wherein the first electrical contact comprises two layers, wherein one of the two layers includes one of a first metal or a first alloy, and wherein the other of the two layers includes one of a second metal or a second alloy different from the first metal or the first alloy. 
     
     
         19 . A method comprising:
 electrically connecting a first chip to a second chip by penetrating a rigid material of a first electrical contact into a malleable material of a second electrical contact at a temperature below a melting point of the malleable material of the second electrical contact to form a mechanical and electrical connection between the first and second electrical contacts;   wherein the first chip includes the first electrical contact comprising the rigid material having a proximal end and a distal end with respect to the first chip; and   wherein the distal end has a shape projected in a plane parallel to the first chip such that the distal end is configured to facilitate penetration into the second electrical contact of the second chip.   
     
     
         20 . The method of  claim 19 , wherein the first electrical contact comprises two layers, wherein one of the two layers includes a first metal or a first alloy, and wherein the other of the two layers includes a second metal or a second alloy different from the first metal or the first alloy. 
     
     
         21 . The method of  claim 19 , wherein said electrically connecting a first chip to a second chip comprises deforming the malleable material of the second electrical contact at the temperature below the melting point of the malleable material to surround a portion of the rigid material of the first electrical contact with the malleable material. 
     
     
         22 . The method of  claim 19 , wherein at least one of the first or second electrical contacts comprises:
 a base portion; and   multiple individual elements disposed over and extending from the base portion;   wherein each of the multiple individual elements has a cross-sectional area measured parallel to the chip; and   wherein each of the cross-sectional areas of the multiple individual elements is smaller than a cross-sectional area of the base portion.   
     
     
         23 . The method of  claim 22 , wherein the multiple individual elements comprise two elements stacked together, and wherein one of the two stacked elements has a perimeter similar in shape, but different in length, compared with another one of the two stacked elements. 
     
     
         24 . The method of  claim 23 , wherein a first of the two stacked elements rests on a surface of a second of two stacked elements, and wherein the first of the two stacked elements and the second of the two stacked elements are arranged to have an equal distance between corresponding points on the perimeters of the first and second stacked elements. 
     
     
         25 . The method of  claim 19 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a pyramid. 
     
     
         26 . The method of  claim 19 , wherein the distal end comprises a pattern configured to facilitate penetration of the first electrical contact into the second electrical contact, and wherein the pattern includes a truncated pyramid.