Method and structure for die bonding using energy beam
Disclosed is a die-bonding method which provides a target substrate having a circuit structure with multiple electrical contacts and multiple semiconductor elements each semiconductor element having a pair of electrodes, arranges the multiple semiconductor elements on the target substrate with the pair of electrodes of each semiconductor element aligned with two corresponding electrical contacts of the target substrate, and applies at least one energy beam to join and electrically connect the at least one pair of electrodes of every at least one of the multiple semiconductor elements and the corresponding electrical contacts aligned therewith in a heating cycle by heat carried by the at least one energy beam in the heating cycle. The die-bonding method delivers scattering heated dots over the target substrate to avoid warpage of PCB and ensures high bonding strength between the semiconductor elements and the circuit structure of the target substrate.
1. A die-bonding method, comprising:
providing a target substrate, the target substrate comprising a supporting base and a circuit structure arranged on one side of the supporting base and having a pair of electrical contacts;
providing a carrier plate, multiple semiconductor elements, and a first bonding material, wherein the multiple semiconductor elements are arranged on the carrier plate and comprise a first semiconductor element, the first semiconductor element has a pair of electrodes aligned with and facing to the pair of electrical contacts, and the first bonding material is formed on the pair of electrodes;
providing an adhesive material arranged between the pair of electrodes and the pair of electrical contacts; and
providing an energy beam to pass through the carrier plate, heat the adhesive material in a dot distribution, and join the pair of electrodes and the pair of electrical contacts.
2. The method of claim 1 , wherein the target substrate comprises a PCB, a flexible PCB, a glass circuit board, or a backplane with thin-film transistor (TFT) circuits or pulse width modulation (PWM) driving circuits.
3. The method of claim 1 , wherein the supporting base comprises a glass substrate.
4. The method of claim 1 , wherein the energy beam heats the first bonding material in a heating cycle, and the heating cycle is in a range of 0.01 second to 1 second.
5. The method of claim 1 , wherein the energy beam is generated by a beam generator.
6. The method of claim 5 , wherein the beam generator is placed next to the multiple semiconductor elements.
7. The method of claim 5 , wherein the beam generator is placed next to the supporting base.
8. The method of claim 1 , wherein the first bonding material comprises a metal layer comprising tin or tin-silver.
9. The method of claim 1 , further comprising a step of providing a second bonding material on the pair of electrical contacts, wherein the second bonding material comprises flux or insulating adhesive.
10. The method of claim 1 , wherein the multiple semiconductor elements are spaced apart from each other by gaps on the carrier plate.
11. The method of claim 1 , wherein the energy beam is distributed in the dot-scattering heating pattern on the target substrate.
12. The method of claim 1 , wherein the energy beam is a laser beam of ultraviolet (UV) light, visible light, or infrared (IR) light.
13. The method of claim 1 , further comprising a step of generating the energy beam to heat two of the multiple semiconductor elements.
14. The method of claim 1 , further comprising a step of generating two energy beams to heat the first semiconductor element.
15. The method of claim 1 , further comprising a step of generating two energy beams with different energy level to respectively heat two of the multiple semiconductor elements.