Method for making inkjet-printed encapsulated quantum dots, light conversion unit, and micro LED display panel

A light conversion unit, comprising:

• a transparent substrate;
• a light convertor carrying layer, being formed on a top surface of the transparent substrate, and being made of a metal material or a metal oxide material;
• a plurality of first through holes, being formed on the light convertor carrying layer, and being arranged to M/3 rows and M/3 columns, wherein each of the plurality of first through holes form a first accommodating groove in combination with the top surface of the transparent substrate;
• a plurality of second through holes, being formed on the light convertor carrying layer, and being arranged to M/3 rows and M/3 columns, wherein each of the plurality of second through holes form a second accommodating groove in combination with the top surface of the transparent substrate;
• a plurality of third through holes, being formed on the light convertor carrying layer, and being arranged to M/3 rows and M/3 columns, wherein each of the plurality of third through holes form a third accommodating groove in combination with the top surface of the transparent substrate;
• a first quantum dots (QDs) solution, comprising at least one red quantum dot (QD), a water solvent and a first solute having a cohesion force, wherein the first QDs solution is dropped into each of the first accommodating grooves by using an inkjet-printing nozzle, so as to form a first droplet in each of the first accommodating grooves;
• and
• a second QDs solution, comprising at least one green QD, the water solvent and a second solute having the cohesion force, wherein the second QDs solution is dropped into each of the second accommodating grooves by using the inkjet-printing nozzle, so as to form a second droplet in each of the second accommodating grooves;
• wherein in case of letting the top surface of the substrate be a hydrophobic surface so as to make the cohesion force of the first solute and the cohesion force of the second solute be both greater than a driving force for impelling outward-bound flow that is induced by a coffee ring effect, the first droplet and the second droplet being eventually converted to a first micro encapsulated QD structure and a second micro encapsulated QD structure after applying a drying process to the first droplet and the second droplet, thereby making each of the first accommodating grooves have the first micro encapsulated QD structure therein, and simultaneously making each of the second accommodating grooves have the second micro encapsulated QD structure therein;
• wherein M and N are both a positive integer.

A micro LED display panel, comprising:

• a substrate;
• M×N micro LED components, being disposed on the substrate;
• a transparent substrate, being disposed on the substrate and the M×N micro LED components;
• a light convertor carrying layer, being formed on a top surface of the transparent substrate, and being made of a metal material or a metal oxide material;
• a plurality of first through holes, being formed on the light convertor carrying layer, and being arranged to M/3 rows and M/3 columns, wherein each of the plurality of first through holes form a first accommodating groove in combination with the top surface of the transparent substrate;
• a plurality of second through holes, being formed on the light convertor carrying layer, and being arranged to M/3 rows and M/3 columns, wherein each of the plurality of second through holes form a second accommodating groove in combination with the top surface of the transparent substrate;
• a plurality of third through holes, being formed on the light convertor carrying layer, and being arranged to M/3 rows and M/3 columns, wherein each of the plurality of third through holes form a third accommodating groove in combination with the top surface of the transparent substrate;
• a first quantum dots (QDs) solution, comprising at least one red quantum dot (QD), a water solvent and a first solute having a cohesion force, wherein the first QDs solution is dropped into each of the first accommodating grooves by using an inkjet-printing nozzle, so as to form a first droplet in each of the first accommodating grooves;
• and
• a second QDs solution, comprising at least one green QD, the water solvent and a second solute having the cohesion force, wherein the second QDs solution is dropped into each of the second accommodating grooves by using the inkjet-printing nozzle, so as to form a second droplet in each of the second accommodating grooves;
• wherein in case of letting the top surface of the substrate be a hydrophobic surface so as to make the cohesion force of the first solute and the cohesion force of the second solute be both greater than a driving force for impelling outward-bound flow that is induced by a coffee ring effect, the first droplet and the second droplet being eventually converted to a first micro encapsulated QD structure and a second micro encapsulated QD structure after applying a drying process to the first droplet and the second droplet, thereby making each of the first accommodating grooves have the first micro encapsulated QD structure therein, and simultaneously making each of the second accommodating grooves have the second micro encapsulated QD structure therein;
• wherein M and N are both a positive integer.