Array fabrication

Abstract

Methods, apparatus, and computer program, for use in fabricating a chemical array. The method may use an apparatus which includes a head system, a transport system, and a processor. The head system has multiple groups of drop dispensers which move in unison, each group having multiple dispensers. The transport system can move the head system with respect to a substrate with different dispensers of the groups following respective paths. The processor can dispense droplets from dispensers during operation of the transport system, in a pattern along a selected path for each group so as to form the array. The method includes identifying an error in one or more dispensers. When a dispenser of a first group is in error, then a second dispenser of each group is moved along the selected path for its group while dispensing droplets from at least the second dispenser of the first group in at least part of the pattern for the selected path of the first group.

1 - 13 . (canceled)  
     
     
         14 . An apparatus for fabricating a chemical array, comprising: 
 (a) a head system with multiple groups of drop dispensers which move in unison, each group having multiple drop dispensers;    (b) a transport system to move the head system with respect to a substrate with different dispensers of the groups following respective paths;    (c) a processor which: 
 dispenses droplets from dispensers during operation of the transport system, in a pattern along a selected path for each group so as to form the array; and  
 when an error indication is identified by the processor indicating an error in a first dispenser of a first group, then moves a second dispenser of each group along the selected path for its group while dispensing droplets from at least the second dispenser of the first group in at least part of the pattern for the selected path of the first group.  
   
     
     
         15 . An apparatus according to  claim 14  wherein the dispensers are pulse jets.  
     
     
         16 . An apparatus according to  claim 14  wherein the processor, when the error indication is identified, dispenses droplets from second dispensers of multiple groups in at least part of the pattern for the selected path of the same group.  
     
     
         17 . An apparatus according to  claim 16  wherein: 
 a series of dispensers within a group communicate with a corresponding common reservoir for that series; and    when the error indication is identified, the processor dispenses droplets from a non-error dispenser of the same series as the error dispenser.    
     
     
         18 . An apparatus according to  claim 16  wherein, when the error indication is identified, the processor dispenses droplets from at least one second dispenser of a group in the complete pattern for the selected path of the same group.  
     
     
         19 . An apparatus according to  claim 16  wherein, when the error indication is identified, the processor dispenses droplets from at least the second dispenser of the first group in the complete pattern for the selected path of the first group.  
     
     
         20 . A method according to  claim 16  wherein when another error indication is identified by the processor additionally indicating an error in a dispenser of a second dispenser of a second group, the processor alternately moves the first and second dispensers of each group along the selected path for that group while dispensing droplets from non-error dispensers of the first and second groups in different parts of the pattern for the selected path for the first group.  
     
     
         21 . An apparatus for fabricating a chemical array, comprising: 
 (a) a head system with multiple groups of drop dispensers which move in unison, each group having multiple rows and columns of dispensers;    (b) a transport system to move the head system with respect to a substrate with different rows following respective paths;    (c) a processor which: 
 dispenses droplets from dispensers during operation of the transport system, in a pattern along a selected path for each group so as to form the array;  
 when an error indication is identified by the processor indicating an error in dispensers of different columns within first and second rows of a first group, then:  
 (i) positions the head with a first row of each group aligned with the selected path for that group;  
 (ii) moves the head with respect to the substrate while dispensing droplets from non-error dispensers in the first row of the first group in accordance with a part of the pattern for the selected path for that group;  
 (iii) re-positions the head such that a second row of each group is aligned with the selected paths; and  
 (iv) moves the head with respect to the substrate while dispensing droplets from non-error dispensers in the second row of the first group in accordance with a part of the pattern for that group.  
   
     
     
         22 . An apparatus according to  claim 21  wherein the dispensers are pulse jets.  
     
     
         23 . An apparatus according to  claim 21  wherein in step (iv) droplets are dispensed from non-error dispensers in the second row of each of multiple groups in accordance with at least part of the pattern for that group.  
     
     
         24 . An apparatus according to  claim 21  wherein: 
 a series of dispensers in each of multiple columns of each of multiple groups, communicates with a corresponding common reservoir for that series; and    in step (iv) droplets are dispensed from a non-error dispenser of the same series as the error dispenser.    
     
     
         25 . An apparatus according to  claim 21  wherein in step (iv) droplets are dispensed from at least one second row of a group in the complete pattern for the selected path of the same group.  
     
     
         26 . An apparatus according to  claim 21  additionally comprising a sensor to monitor dispensers for an error and provide corresponding data to the processor.  
     
     
         27 . A computer program product for use with an apparatus for fabricating a chemical array having: 
 a head system with multiple groups of drop dispensers which move in unison, each group having multiple dispensers;    a transport system to move the head system with respect to a substrate with different dispensers of the groups following respective paths; and    a processor;    the computer program product comprising a computer readable storage medium having a computer program stored thereon which, when loaded into the processor, performs the steps of:    a) identifying for an error in one or more dispensers;    b) when a dispenser of a first group is in error, then moving a second dispenser of each group along a selected path for its group while dispensing droplets from at least the second dispenser of the first group in at least part of the pattern for the selected path of the first group.    
     
     
         28 . A computer program product according to  claim 27  wherein in step (b) droplets are dispensed from each second dispenser of multiple groups in at least part of the pattern for the selected path of the same group.  
     
     
         29 . A computer program product according to  claim 27  wherein when a dispenser of a second set of the first group is additionally identified as being in error, the program causes the first and second dispensers of each group to be alternately moved along the selected path for that group while droplets are dispensed from non-error dispensers of the first and second groups in different parts of the pattern for the selected path for the first group.