Bond pad structure comprising multiple bond pads with metal overlap

Abstract

A bond pad structure comprising two bond pads, methods of forming the bond pad structure, an integrated circuit die incorporating the bond pad structure, and methods of using the bond pad structure are provided. Each of the bond pads comprise stacked metal layers, at least one lower metal layer and an upper metal layer. When the two pads are connected by a conductive material, they function as a single pad. The lower metal layer of one of the bond pads forms an extension that extends beneath the upper metal layer of the other of the bond pad. The lower metal extension functions to block the etching of a dielectric layer that is put down over the upper metal layers and the underlying substrate, for example, during a passivation etch to form the bond pad opening, to protect the substrate from damage.

1 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a test mode signal to a first bond pad of a die to supply said test mode signal to test mode function circuitry of the die configured to initiate a test mode in the die; the die comprising the first die pad and a second bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer overlying the die, each of the bond pads comprising an upper metal layer overlying and connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad connected to the test mode function circuitry, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    upon completion of the test sequence, disabling the connection of the first bond pad with said test mode function circuitry;    interconnecting the first and second bond pads with a conductive material to form a single pad unit; and    initiating an operational sequence in the die by applying an operational signal to at least one of the first and second bond pads of the single pad unit.    
     
     
         2 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by applying a signal to a first bond pad of the die to supply said test mode signal to test mode function circuitry of the die configured to initiate a test mode in the die; the die comprising the first die pad and a second bond pad, said bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of the bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad connected to the test mode function circuitry of the die, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    initiating a test sequence on circuitry of the die by applying a signal to the first bond pad to conduct said signal to the test mode function circuitry;    terminating the test sequence by applying a signal to the first bond pad to disable the connection of the first bond pad with said test mode function circuitry;    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit; and    initiating an operational sequence in the die by applying a signal to at least one of the first and second bond pads of the single pad unit to conduct said signal to the operational mode function circuitry.    
     
     
         3 . The method of  claim 2 , wherein the electrically conductive material to connect the first and second bond pads comprises a solder material.  
     
     
         4 . The method of  claim 2 , further comprising, after the step of connecting the first and second bond pads, attaching a bonding wire to the conductive material.  
     
     
         5 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a signal to a test mode bond pad of the die to conduct said signal to test mode function circuitry of the die configured to initiate a test mode in the die; the die comprising the test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and within a single opening of a passivation layer on the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and the test mode bond pad connected to the test mode function circuitry, and the operational mode bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test sequence by disabling the connection of the test mode bond pad with said test mode function circuitry;    connecting the test mode bond pad to the operational mode bond pad with an electrically conductive material to form a single pad unit; and    initiating an operational sequence in the die by applying a signal to at least one of said bond pads of the single pad unit to conduct said signal to the operational mode function circuitry.    
     
     
         6 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test mode on circuitry of the die by conducting a signal to a test mode bond pad of the die to conduct said signal to test mode function circuitry of the die configured to initiate a test mode in the die; the die comprising the test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer on the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and the test mode bond pad connected to test mode function circuitry of the die configured to initiate a test mode in the die, and the operational mode bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test mode by applying a voltage to the test bond pad to disable the connection between the test mode bond pad and said test mode function circuitry;    connecting the test mode bond pad to the operational mode bond pad with an electrically conductive material to form a single pad unit; and    initiating an operational mode in the die by applying a signal to at least one of said bond pads of the single pad unit to conduct said signal to the operational mode function circuitry.    
     
     
         7 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a signal to a test mode bond pad of the die to conduct said signal through a switching device to test mode function circuitry of the die configured to initiate a test mode in the die; the die comprising the test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer on the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and the test mode bond pad connected via the switching device to the test mode function circuitry, and the operational mode bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test sequence by applying a voltage to the test bond pad to disable the switching device;    connecting the test mode bond pad to the operational mode bond pad with an electrically conductive material to form a single pad unit; and    initiating an operational sequence in the die by applying a signal to at least one of said bond pads of the single pad unit to conduct said signal to the operational mode function circuitry.    
     
     
         8 . The method of  claim 7 , wherein the switching device comprises a fuse or an antifuse.  
     
     
         9 . The method of  claim 7 , wherein the switching device comprises a transistor.  
     
     
         10 . A method of testing and operating circuitry of a die, comprising the steps of: 
 applying a signal to a first bond pad of the die to conduct said signal to test mode function circuitry of the die to initiate a test sequence on circuitry of the die, the die comprising the first bond pad and a second bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer on the die, each of the bond pads comprising a plurality of interconnected and stacked lower metal layers connected to an upper metal layer, with at least one of the lower metal layers of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad connected to the test mode function circuitry, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    disabling the connection of the first bond pad with said test mode function circuitry to terminate the test sequence;    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit; and    applying a signal to at least one of the first and second bond pads of the single pad unit to conduct said signal to the operational mode function circuitry and initiate an operational sequence in the die.    
     
     
         11 . The method of  claim 10 , wherein the step of disabling comprises blowing a fuse.  
     
     
         12 . The method of  claim 10 , wherein the step of disabling comprises applying a voltage to the first bond pad.  
     
     
         13 . A method of testing and operating circuitry of a die, comprising the steps of: 
 applying a signal to a first bond pad of the die to conduct said signal to test mode function circuitry of the die to initiate a test sequence on circuitry of the die, the die comprising the first bond pad and a second bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer on the die, each bond pad comprising an upper metal layer overlying and connected to two or more stacked lower metal layers, the upper metal layer of the first bond pad overlying at least one of the lower metal layers of the second bond pad, and the first bond pad connected to test mode function circuitry of the die configured to initiate a test mode in the die, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    disabling the connection of the first bond pad with said test mode function circuitry to terminate the test sequence;    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit; and    applying a signal to at least one of the first and second bond pads of the single pad unit to conduct said signal to the operational mode function circuitry and initiate an operational sequence in the die.    
     
     
         14 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a signal to a test mode bond pad and test mode function circuitry of the die, the die comprising the test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer overlying the die, each of said bond pads comprising an upper metal layer connected to two or more stacked and interconnected lower metal layers, the upper metal layer of one of said bond pads overlapping at least one of the lower metal layers of the other of said bond pads, and the test mode bond pad connected to the test mode function circuitry, and the operational mode bond pad connected to operational mode function circuitry of the die configured to initiate an operational sequence in the die;    terminating the test sequence by disabling the connection between the test mode bond pad and the test mode function circuitry;    connecting the test mode bond pad to the operational mode bond pad with an electrically conductive material to form a single pad unit; and    initiating an operational sequence in the die by applying a signal to at least one of the test mode bond pad and the operational mode bond pad of the single pad unit, to conduct said signal to the operational mode function circuitry.    
     
     
         15 . A method of testing and operating circuitry of a die, comprising the steps of: 
 applying a signal to a first bond pad of the die to conduct said signal to test mode function circuitry of the die and initiate a test sequence on circuitry of the die, the die comprising the first bond pad and a second bond pad, said bond pads being unconnected and adjacently situated within a single opening of a passivation layer on the die, each bond pad comprising an upper metal layer conductively connected to a lower metal layer with an insulating layer situated between said upper and lower metal layers, and a lower metal layer of one bond pad extending underneath the upper metal layer of the other bond pad, and the first bond pad but not the second bond pad connected to said test mode function circuitry of the die, and the second bond pad but not the first bond pad connected to an operational mode function circuitry of the die;    disabling the connection of the first bond pad with said test mode function circuitry to terminate the test sequence;    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit; and    applying a signal to at least one of the first and second bond pads of the single pad unit to conduct said signal to the operational mode function circuitry and initiate an operational sequence in the die.    
     
     
         16 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a signal to the first bond pad and the test mode function circuitry;    initiating a test sequence on circuitry of the die by conducting a signal to a first bond pad and test mode function circuitry of the die, the die comprising separate first and second bond pads that are unconnected and adjacently situated within a single opening of a passivation layer on the die, each of said bond pads comprising a stacked upper metal layer connected to a lower metal layer, and an insulating layer situated therebetween, the metal layers of each bond pad connected by a conductive contact extending through the insulating layer, and the lower metal layer of one bond pad extending under the upper metal layer of the other bond pad, and the first bond pad but not the second bond pad connected to said test mode function circuitry of the die, and the second bond pad but not the first bond pad connected to an operational mode function circuitry of the die;    terminating the test sequence by disabling a connection between the first bond pad and the test mode function circuitry;    connecting the first bond pad and the second bond pad with an electrically conductive material to form a single pad unit; and    initiating an operational sequence in the die by applying a signal to at least one of the first and second bond pads of the single pad unit to conduct said signal to the operational mode function circuitry.    
     
     
         17 . A method of testing and operating circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a signal to a first bond pad to conduct said signal to test mode function circuitry of the die, the die comprising the first bond pad and a second bond pad, said bond pads being electrically separate and within a single opening in a passivation layer on the die, each of the bond pads comprising a stacked upper metal layer connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad connected to said test mode function circuitry of the die, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test sequence by applying disabling the connection of the first bond pad with said test mode function circuitry;    connecting the first bond pad with the second bond pad with an electrically conductive material to form a single pad unit;    connecting a bonding wire to the conductive material; and    initiating an operational sequence in the die by applying a signal to the single pad unit to conduct said signal to the operational mode function circuitry.    
     
     
         18 . A method of testing circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by applying a signal to a first bond pad to conduct said signal to test mode function circuitry of the die, the die comprising the first bond pad and a second bond pad, said bond pads being electrically separate and within a single opening of a passivation layer on the die, each of the bond pads comprising a stacked upper metal layer connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad connected to said test mode function circuitry of the die configured, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test sequence by disabling the connection of the first bond pad with said test mode function circuitry; and    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit, wherein applying a signal to the single pad unit conducts said signal to the operational mode function circuitry to initiate an operational sequence in the die.    
     
     
         19 . The method of  claim 18 , wherein the electrically conductive material to connect the first and second bond pads comprises a solder material.  
     
     
         20 . The method of  claim 18 , further comprising, after connecting the first and second bond pads, connecting a bonding wire to the conductive material.  
     
     
         21 . A method of testing circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by conducting a signal to a test mode bond pad to supply said signal to test mode function circuitry of the die, the die comprising the test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and within a single opening of a passivation layer on the die, each of said bond pads comprising an upper metal layer and a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and the test mode bond pad connected to said test mode function circuitry of the die, and the operational mode bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test sequence by disabling the connection of the test mode bond pad with said test mode function circuitry;    connecting the test mode bond pad to the operational mode bond pad with an electrically conductive material to form a single pad unit; and    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit, wherein applying a signal to the single pad unit conducts said signal to the operational mode function circuitry to initiate an operational sequence in the die.    
     
     
         22 . A method of testing circuitry of a die, comprising the steps of: 
 applying a signal to a first bond pad of the die to conduct said signal to test mode function circuitry of the die to initiate a test sequence on circuitry of the die; the die comprising the first bond pad and a second bond pad, said bond pads being electrically separate and within a single opening of a passivation layer on the die, each of the bond pads comprising a plurality of interconnected and stacked lower metal layers connected to an upper metal layer, with at least one of the lower metal layers of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad connected to the test mode function circuitry of the die, and the second bond pad connected to operational mode function circuitry of the die configured to initiate an operational mode in the die;    disabling the connection of the first bond pad with said test mode function circuitry to terminate the test sequence;    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit, wherein applying a signal to the single pad unit conducts said signal to the operational mode function circuitry to initiate an operational sequence in the die.    
     
     
         23 . A method of testing circuitry of a die, comprising the steps of: 
 initiating a test sequence on circuitry of the die by applying a signal to a first bond pad to conduct said signal to test mode function circuitry of the die, the die comprising the first bond pad and a second bond pad, said bond pads being electrically separate and situated within a single opening of a passivation layer on the die, each of the bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and the first bond pad but not the second bond pad connected to the test mode function circuitry of the die, and the second bond pad but not the first bond pad connected to an operational mode function circuitry of the die configured to initiate an operational mode in the die;    terminating the test sequence by applying a signal to the first bond pad to disable the connection of the first bond pad with said test mode function circuitry; and    connecting the first bond pad to the second bond pad with an electrically conductive material to form a single pad unit, wherein applying a signal to the single pad unit conducts said signal to the operational mode function circuitry to initiate an operational sequence in the die.    
     
     
         24 . A die, comprising: 
 a test mode function circuitry configured to initiate a test sequence on circuitry of the die;    an operational mode function circuitry configured to initiate an operational mode in the die; and    first and second bond pads, said bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of the bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and    the first bond pad connected to the test mode function circuitry of the die, and the second bond pad connected to the operational mode function circuitry of the die.    
     
     
         25 . A die, comprising: 
 a test mode function circuitry configured to initiate a test sequence on circuitry of the die;    an operational mode function circuitry configured to initiate an operational mode in the die; and    first and second bond pads, said bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and    the first bond pad but not the second bond pad connected to the test mode function circuitry of the die, and the second bond pad but not the first bond pad connected to the operational mode function circuitry of the die.    
     
     
         26 . A die, comprising: 
 a test mode function circuitry configured to initiate a test mode on circuitry of the die;    an operational mode function circuitry configured to initiate an operational mode on circuitry of the die; and    first and second bond pads, the bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of the bond pads comprising a plurality of interconnected and stacked lower metal layers connected to an upper metal layer, with at least one of the lower metal layers of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and    the first bond pad connected to the test mode function circuitry of the die, and the second bond pad connected to the operational mode function circuitry of the die.    
     
     
         27 . A die, comprising: 
 a test mode function circuitry configured to initiate a test sequence in the die;    an operational mode function circuitry configured to initiate an operational mode in the die; and    first and second bond pads, the bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of the bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of the bond pads extending underneath the upper metal layer of the other of the bond pads, and    the first bond pad connected to the test mode function circuitry of the die, and the second bond pad connected to the operational mode function circuitry of the die.    
     
     
         28 . A die, comprising: 
 a test mode function circuitry configured to initiate a test sequence in the die;    an operational mode function circuitry configured to initiate an operational mode in the die; and    a first bond pad and a second bond pad, said bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and    the first bond pad but not the second bond pad connected to the test mode function circuitry of the die, and the second bond pad but not the first bond pad connected to the operational mode function circuitry of the die.    wherein, when the connection of the first bond pad to the test mode function circuitry is disabled, and the first bond pad and the second bond pad are connected by a conductive material, said bond pads operate as a single unit to receive and conduct a signal only to the operational mode function circuitry of the die.    
     
     
         29 . A die, comprising: 
 a test mode function circuitry configured to initiate a test sequence in the die;    an operational mode function circuitry configured to initiate an operational mode in the die; and    a test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and    the test mode bond pad connected to the test mode function circuitry of the die, and the operational mode bond pad connected to the operational mode function circuitry of the die.    
     
     
         30 . A die, comprising: 
 a test mode function circuitry configured to initiate a test sequence in the die;    an operational mode function circuitry configured to initiate an operational mode in the die; and    a test mode bond pad and an operational mode bond pad, said bond pads being electrically separate and within a single opening of a passivation layer overlying the die, each of said bond pads comprising an upper metal layer connected to a lower metal layer, the lower metal layer of one of said bond pads extending underneath the upper metal layer of the other of said bond pads, and    the test mode bond pad but not the operational mode bond pad connected to the test mode function circuitry of the die, and the operational mode bond pad but not the test mode bond pad connected to the operational mode function circuitry of the die.    wherein, when the connection of the test mode bond pad to the test mode function circuitry is disabled, and the test mode bond pad and the operation mode bond pad are connected by a conductive material, said bond pads operate as a single unit to receive and conduct a signal only to the operational mode function circuitry of the die.