Process for dispensing semiconductor die-bond adhesive using a printhead having a microjet array and the product produced by the process

Method of die bonding microchips to a substrate utilizing an array of individually controllable microjets arranged to deposit a desired pattern of microdrops of adhesive;

• comprising the steps of:
• providing a printhead having an array of adjacent individually electrically operated microjets, each microjet having a dispensing tip for adhesive and a channel leading from the dispensing tip in fluid communication with a supply reservoir of die bonding adhesive;
• providing a programmable controller adapted to selectively send electrical signals to any one or more of the microjets sufficient to fire selected ones of the microjets in a controlled sequence and thereby dispense microdrops from the dispensing tips of the fired microjets in the same controlled sequence;
• mounting the dispensing tips of the printhead a dispensing distance from a controlled path of a die bonding machine capable of controllably moving successive substrates along the controlled path and sending substrate position information to the programmable controller, said position information indicating at least an initial depositing position, a series of intermediate depositing positions and a final depositing position for each successive substrate;
• moving successive substrates along the controlled path;
• firing the microjets in said controlled sequence in response to said position information as successive substrates reach the initial depositing position and ceasing said firing when each successive substrate reaches the final depositing position;
• whereby a desired pattern of microdrops of adhesive is laid down on successive substrates moving along said controlled path.

Method of die bonding microchips to a substrate utilizing a dual array of individually controllable microjets arranged to deposit a desired pattern comprising a first desired pattern of microdrops of curable epoxy adhesive and a second adjacent desired pattern of curable epoxy adhesive similar to said first pattern, comprising the steps of:

• providing a dual array of individually electrically operated microjets comprising a first array and a second array, each of said arrays having a supply reservoir for one component of a two part epoxy die bonding adhesive, each microjet in the respective arrays having a dispensing tip for adhesive and a channel leading from the dispensing tip in fluid communications with the supply reservoir;
• providing a programmable controller adapted to selectively send electrical signals to any one or more of the microjets in said first array and said second array, said signals being firing signals sufficient in strength to fire selected ones of the microjets of each array in a controlled sequence and thereby dispense microdrops from the dispensing tips of the fired microjets in the same controlled sequence to produce a desired pattern comprising a first desired pattern from the first array and a second desired pattern from the second array;
• mounting the dispensing tips of the first and second arrays adjacently, a dispensing distance from successive substrates on a surface of a medium capable of creating relative movement along a controlled path between successive substrates and said first and second arrays;
• sensing the substrate position relative to the first and second arrays and sending substrate position information to the programmable controller, said position information including at least an initial depositing position, a series of intermediate depositing positions, and a final depositing position for each successive substrate;
• creating relative movement along the controlled path between the successive substrates and the first and second arrays;
• firing said microjets of the first array and the second array in said controlled sequence in response to said position information as successive substrates reach the initial depositing position and until said successive substrates reach the final dispensing position and ceasing firing said microjets until the next successive substrate reaches the initial depositing position;
• whereby a desired pattern comprising a first desired pattern of microdrops of one component from the first array is deposited on successive substrates and a second desired pattern of microdrops of one component from the second array is deposited on successive substrates, wherein the first and second patterns are offset so that microdrops of each component are deposited adjacently;
• mixing the two components of the epoxy after deposition by pressing a microchip against the components on at least one of the successive substrates whereby the microchip is epoxy bonded to the substrate.

The method of die bonding flip chips having a pattern of solder bumps on a bonding surface to a substrate utilizing an array of individually controllable electrically operated microjets arranged to deposit a desired pattern of microdrops of curable adhesive between the solder bumps, comprising the steps of:

• providing a printhead having an array of adjacent individually electrically operated microjets, each microjet having a dispensing tip for adhesive and a channel leading from the dispensing tip in fluid communication with a supply reservoir of curable die bonding adhesive;
• providing a programmable controller adapted to selectively send electrical signals to any one or more of the microjets sufficient to fire selected ones of the microjets in a controlled sequence and thereby dispense microdrops from the dispensing tips of the fired microjets in the same controlled sequence;
• mounting the dispensing tips of the printhead a dispensing distance from successive flip chips on a surface of a medium capable of creating relative movement along a controlled path between successive flip chips and said printhead;
• sensing the flip chip position relative to the printhead and sending flip chip position information to the programmable controller, said position information including at least an initial depositing position, a series of intermediate depositing positions, and a final depositing position for each successive flip chip;
• creating relative movement along the controlled path between the successive flip chips and the printhead;
• depositing a first desired pattern of microdrops of curable die bonding adhesive between the solder bumps on successive flip chips by firing selected ones of said microjets in said controlled sequence in response to said position information as successive flip chips reach the initial depositing position and ceasing said firing when each successive flip chip reaches the final depositing position;
• thereby preparing said flip chips for placement of the bonding surface against a substrate to make a bonded structure.