Method of manufaturing a digital magneto-optical signal write/read head

Abstract

A method of manufacturing a digital magneto-optical signal write/read head ( 1 ) including a thin-film in-plane magnetic coil ( 3 ) disposed on an outwardly directed surface ( 5 A) of a coil substrate ( 7 ). Coil lead in and coil lead out sections ( 11,15 ) of the coil ( 3 ) are extended to an interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) and first and second spaced interconnecting conductors ( 21,23 ) are deposited on the side surface ( 9 ) of the coil substrate ( 7 ) in electrical connection with the lead in and lead out sections ( 11,15 ) of the magnetic coil ( 3 ) for contacting the external lead in and lead out lines ( 25,29 ). Alternatively first and second contacting conductors ( 29,31 ) may additionally be deposited on a top surface ( 5 B) of the coil substrate ( 7 ) in electrical connection with the first and second interconnecting conductors ( 21,23 ) on the side surface ( 9 A) of the coil substrate ( 7 ) for contacting the said external lead in and lead out lines ( 25,27 ).

1 . Method of manufacturing a magneto-optical write and/or read head ( 1 ) including a thin-film in-plane magnetic coil ( 3 ) disposed on an outwardly directed surface ( 5 A) of a coil substrate ( 7 ), the method comprising the steps of: 
 providing an electrically isolating coil substrate ( 7 ) having substantially parallel main surfaces ( 5 A,  5 B) comprising the outwardly directed surface ( 5 A) and an opposed top surface ( 5 B), interconnected by an adjoining side surface ( 9 ),    depositing a thin film magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) comprising a continuous electrical conductor pattern with a coil lead in section ( 11 ), a coil winding section ( 13 ) and a coil lead out section ( 15 ) and    providing means for contacting the thin film magnetic coil ( 3 ) by electrically connecting the coil lead in and lead out sections ( 13 , 15 ) to external lead in and lead out lines ( 25 , 27 ),    characterized in that the method comprises a plurality of further manufacturing steps including:    extending the coil lead in and coil lead out sections ( 11 , 15 ) of the magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) to an interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ), and    depositing a pattern of respective first and second spaced interconnecting conductors ( 21 , 23 ) on the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) in electrical connection with the lead in and lead out sections ( 11 , 15 ) respectively of the magnetic coil ( 3 ) for contacting the said external lead in and lead out lines ( 25 , 29 ) respectively by suitable contacting means such as bonding, welding or soldering,    such that a lead in conductor is formed comprising the first interconnecting conductor ( 21 ) and the lead in section ( 11 ) of the magnetic coil respectively and a lead out conductor is formed comprising the second interconnecting conductor ( 23 ) and the lead out section ( 15 , 19 ) of the magnetic coil, respectively.    
     
     
         2 . Method of manufacturing a digital magneto-optical write and/or read head ( 1 ) including a thin-film in-plane magnetic coil ( 3 ) disposed on an outwardly directed surface ( 5 A) of a coil substrate ( 7 ), the method comprising the steps of: 
 providing an electrically isolating substrate ( 7 ) having substantially parallel main surfaces ( 5 A,  5 B) comprising the outwardly directed surface ( 5 A) and an opposed top surface ( 5 B), interconnected by an adjoining side surface ( 9 ),    depositing a thin film magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) comprising a continuous electrical conductor pattern with a coil lead in section ( 11 ), a coil winding section ( 13 ) and a coil lead out section ( 15 ), and    providing means for contacting the thin film magnetic coil ( 3 ) by electrically connecting the coil lead in and lead out sections ( 11 , 15 ) to external lead in and lead out lines ( 25 , 27 ),    characterized in that the method comprises a plurality of further manufacturing steps including:    extending the coil lead in and coil lead out sections ( 11 , 15 ) of the magnetic coil ( 3 ) on the outwardly directed surface ( 9 A) of the coil substrate ( 7 ) to an interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ),    depositing a pattern of respective first and second spaced interconnecting conductors ( 21 , 23 ) on the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) in electrical connection with the lead in and lead out sections ( 11 , 15 ) of the magnetic coil ( 3 ) respectively and    depositing a pattern of respective spaced first and second contacting conductors ( 29 , 31 ) on a contacting part ( 5 C) of the top surface ( 5 B) of the coil substrate ( 7 ) in electrical connection with the first and second interconnecting conductors ( 21 , 23 ) respectively on the side surface ( 9 A) of the coil substrate ( 7 ) for contacting the said external lead in and lead out lines ( 25 , 27 ) respectively by suitable contacting means such as bonding, welding or soldering,    such that a lead in conductor is formed comprising the first contacting conductor ( 29 ), the first interconnecting conductor ( 21 ) and the lead in section ( 11 ) of the magnetic coil respectively and a lead out conductor is formed comprising the second contacting conductor ( 31 ), the second interconnecting conductor ( 23 ) and the lead out section ( 15 ) of the magnetic coil ( 3 ) respectively.    
     
     
         3 . Method according to  claim 1 , characterized in that the method comprises a plurality of further manufacturing steps including: 
 providing an auxiliary substrate ( 33 ) having a supporting surface ( 35 ) and an adjoining auxiliary side surface ( 37 ),    after depositing the thin film magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) but prior to the steps of depositing the interconnecting conductors ( 21 , 23 ) on the interconnection part ( 9 A) of the side surface of the coil substrate ( 35 ), detachably arranging the coil substrate ( 7 ) on the supporting surface ( 35 ) of the auxiliary substrate ( 33 ) in a position such that the thin film magnetic coil ( 3 ) is directed to the supporting surface ( 35 ) and the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) is flush with the auxiliary side surface ( 37 ) of the auxiliary substrate ( 33 ),    providing a mask ( 39 ) over at least a part of the interconnection part ( 9 A) of the side surface ( 9 ) such that the areas for disposing the interconnecting conductors ( 21 , 23 ) remain exposed areas,    depositing a layer of conducting material over at least a part of the mask ( 39 ) and over the said exposed areas,    removing the mask ( 39 ) and any conducting material deposited thereon so that the pattern of spaced interconnecting conductors ( 21 , 23 ) remains on the interconnecting part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ), and    detaching the coil substrate ( 7 ) from the auxiliary substrate ( 33 ).    
     
     
         4 . Method according to  claim 2 , characterized in that the method comprises a plurality of further manufacturing steps including: 
 providing an auxiliary substrate ( 33 ) having a flat supporting surface ( 35 ) and an adjoining auxiliary side surface ( 37 ),    after depositing the thin film magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) but prior to the steps of depositing the interconnecting conductors ( 21 , 23 ) on the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) and depositing the contacting conductors ( 29 , 31 ) on the contacting part ( 5 C) of the top surface ( 5 B) of the coil substrate ( 7 ), detachably arranging the coil substrate ( 7 ) on the supporting surface ( 35 ) of the auxiliary substrate ( 33 ) in a position such that the thin film magnetic coil ( 3 ) is directed to the supporting surface ( 35 ) and the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) is flush with the auxiliary side surface ( 37 ) of the auxiliary substrate ( 33 ),    providing a mask ( 39 ) over at least a part of the interconnection part ( 9 A) of the side surface ( 9 ) and a part of the top surface ( 5 B) of the coil substrate ( 7 ) such that the areas for disposing the interconnecting conductors ( 29 , 31 ) and contacting conductors ( 29 , 31 ) remain exposed areas,    depositing a layer of conducting material over at least a part of the mask ( 39 ) and over the said exposed areas,    removing the mask ( 39 ) and any conducting material deposited thereon so that the pattern of spaced interconnecting conductors ( 21 , 23 ) and contacting conductors ( 29 , 31 ) remains on the interconnecting part ( 9 A) of the side surface ( 9 ) and the contacting part ( 5 C) of the top surface ( 5 B) respectively of the coil substrate ( 7 ) and    detaching the coil substrate ( 7 ) from the auxiliary substrate ( 33 ).    
     
     
         5 . Method according to  claim 3  or  4 , characterized in that the coil substrate ( 7 ) is detachably arranged on the supporting surface ( 35 ) of the auxiliary substrate ( 33 ) by adhesive means disposed between the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) and the supporting surface ( 35 ) of the auxiliary substrate ( 33 ).  
     
     
         6 . Method according to  claim 3 ,  4  or  5 , characterized in that the method comprises a plurality of further manufacturing steps including: 
 providing a wafer substrate,    depositing a plurality of thin-film in-plane magnetic coils ( 3 ) on the wafer substrate using suitable stepper replication techniques to produce a plurality of individual thin-film in-plane magnetic coils ( 3 ) each disposed on a corresponding coil substrate ( 7 ) provided in the wafer substrate,    disposing an auxiliary substrate ( 33 ) over the wafer substrate,    in a first dicing step dicing the wafer substrate in a first direction into individual wafer substrate strips comprising rows of coil substrates ( 7 ) having thin-film in-plane magnetic coils ( 3 ) deposited thereon while leaving the auxiliary substrate intact, and    in a second dicing step dicing the auxiliary substrate and the said individual wafer substrate strips disposed thereover in a second direction different from the first direction into strip shaped auxiliary substrates ( 33 ) each supporting a plurality of diced individual wafer substrate parts comprising a coil substrate ( 7 ) and a thin-film in-plane magnetic coil ( 3 ) deposited thereon,    the coil lead in and lead out sections ( 11 , 15 ) of each individual magnetic coil ( 3 ) being formed such and the dicing steps being executed such that after the second dicing step a cross section of the lead in and lead out sections ( 11 , 15 ) is exposed at an edge of the interconnecting part ( 9 A) of a side surface ( 9 ) of the coil substrate ( 7 ).    
     
     
         7 . Method according to  claim 2  or  4 , characterized in that 
 the coil substrate ( 7 ) is transparent,    an optical lens part ( 41 ) of an optical pick up is provided on the top surface ( 5 B) of the coil substrate ( 7 ) in a position between the position of the lead in and lead out conductors ( 29 , 21 , 11 ; 31 , 23 , 15 ), such that any light focussed through the lens part ( 41 ) passes through the finished coil substrate ( 7 ) unobstructed by the lead in and lead out conductors ( 29 , 21 , 11 ; 31 , 23 , 15 ).    
     
     
         8 . Magneto-optical write and/or read head having a thin-film in-plane magnetic coil ( 3 ) disposed on an outwardly directed surface ( 5 A) of the head, comprising: 
 an electrically isolating coil substrate ( 7 ) having substantially parallel main surfaces ( 5 A,  5 B) comprising the outwardly directed surface ( 5 A) and an opposed top surface ( 5 B), interconnected by an adjoining side surface ( 9 ),    a thin film magnetic coil ( 3 ) deposited on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) comprising a continuous electrical conductor pattern with a coil lead in section ( 11 ), a coil winding section ( 13 ) and a coil lead out section ( 15 ), and    means for contacting the thin film magnetic coil ( 3 ) by electrically connecting the coil lead in and lead out sections ( 11 , 15 ) to external lead in and lead out lines ( 25 , 27 ),    characterized in that the head comprises:    extended coil lead in and coil lead out sections ( 11 , 15 ) of the magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) extending to an interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ), and    a pattern of respective first and second spaced interconnecting conductors ( 21 , 23 ) deposited on the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) in electrical connection with the lead in and lead out sections ( 11 , 15 ) respectively of the magnetic coil ( 3 ) for contacting the said external lead in and lead out lines ( 25 , 27 ) respectively by suitable contacting means such as bonding, welding or soldering,    such that a lead in conductor is formed comprising the first interconnecting conductor ( 21 ) and the lead in section ( 11 ) of the magnetic coil ( 3 ) respectively and a lead out conductor is formed comprising the second interconnecting conductor ( 23 ) and the lead out section ( 15 ) of the magnetic coil respectively.    
     
     
         9 . Magneto-optical write and/or read head having a thin-film in-plane magnetic coil ( 3 ) disposed on an outwardly directed surface ( 5 A) of the head, comprising: 
 an electrically isolating coil substrate ( 7 ) having substantially parallel main surfaces ( 5 A, 5 B) comprising the outwardly directed surface ( 5 A) and an opposed top surface ( 5 B), interconnected by an adjoining side surface ( 9 ),    a thin film magnetic coil ( 3 ) deposited on the outwardly directed surface ( 5 A) of the coil substrate ( 7 ) comprising a continuous electrical conductor pattern with a coil lead in section ( 11 ), a coil winding section ( 13 ) and a coil lead out section ( 15 ) and    means for contacting the thin film magnetic coil ( 3 ) by electrically connecting the coil lead in and lead out sections ( 11 , 15 ) to external lead in and lead out lines ( 25 , 27 ),    characterized in that the head comprises:    extended coil lead in and coil lead out sections ( 11 , 15 ) of the magnetic coil ( 3 ) on the outwardly directed surface ( 5 A) extending to an interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ),    a pattern of respective first and second spaced interconnecting conductors ( 21 , 23 ) deposited on the interconnection part ( 9 A) of the side surface ( 9 ) of the coil substrate ( 7 ) in electrical connection with the lead in and lead out sections ( 11 , 15 ) of the magnetic coil ( 3 ) respectively and    a pattern of respective spaced first and second contacting conductors ( 29 , 31 ) deposited on a contacting part of the top surface ( 5 B) of the coil substrate ( 7 ) in electrical connection with the first and second interconnecting conductors ( 21 , 23 ) respectively on the side surface ( 9 ) of the coil substrate ( 7 ) for contacting the said external lead in and lead out lines ( 25 , 27 ) respectively by suitable contacting means such as bonding, welding or soldering,    such that a lead in conductor is formed comprising the first contacting conductor ( 29 ), the first interconnecting conductor ( 21 ) and the lead in section ( 11 ) of the magnetic coil respectively and a lead out conductor is formed comprising the second contacting conductor ( 31 ), the second interconnecting conductor ( 23 ) and the lead out section ( 15 ) of the magnetic coil ( 3 ) respectively.    
     
     
         10 . Write/read head according to  claim 9 , characterized in that 
 the coil substrate ( 7 ) is transparent,    an optical lens part of an optical pick up is provided on the top surface ( 5 B) of the coil substrate ( 7 ) in a position between the lead in and lead out conductors ( 29 , 21 , 11 ; 31 , 23 , 15 ), such that any light focussed through the lens part passes through the coil substrate ( 7 ) unobstructed by the lead in and lead out conductors ( 29 , 21 , 11 ; 31 , 23 , 15 ).