Method for discharging droplets and droplet discharge apparatus

1. A method of discharging droplets comprising:

discharging a liquid material from a plurality of droplet discharge heads forming a discharge head assembly and causing the discharge head assembly and a substrate as a landing target for the liquid material to move relative to each other to thereby deposit the liquid material on the substrate;

feeding a to-be-treated substrate and removing a treated substrate to and from a droplet discharge apparatus provided with the discharge head assembly;

performing a weight measurement discharge from one of the droplet discharge heads included in the discharge head assembly substantially concurrently with the feeding and removing;

performing a dummy discharge from the rest of the droplet discharge heads included in the discharge head assembly concurrently with the performing of the weight measurement discharge from the one of the droplet discharge heads; and

measuring the weight of the liquid material discharged in the weight measurement discharge.

2. The method of discharging droplets according to claim 1 , further comprising

testing a discharge state of each of the droplet discharge heads substantially concurrently with the feeding and removing, the testing of the discharge state of each of the droplet discharge heads including

performing a test discharge from the droplet head, and

acquiring information on a state of the liquid material that has been discharged in the test discharge.

3. The method of discharging droplets according to claim 2 , wherein

the acquiring of the information on the state of the liquid material is performed at a different timing from the performing of the weight measurement discharge.

4. The method of discharging droplets according to claim 2 , wherein

the acquiring of the information on the state of the liquid material is performed substantially concurrently with the performing of the weight measurement discharge.

5. The method of discharging droplets according to claim 1 , further comprising

performing a confirmation test when a difference in a measured value of the weight of the liquid material measured in relation to a reference value has exceeded a prescribed value.

6. The method of discharging droplets according to claim 5 , wherein

the performing of the confirmation test is the performing of the weight measurement.

7. The method of discharging droplets according to claim 5 , wherein

the performing of the confirmation test is a testing of the discharge state of the droplet discharge heads.

8. The method of discharging droplets according to claim 1 , further comprising

correcting discharge conditions in the droplet discharge heads when a difference in a measured value of the weight of the liquid material in relation to a reference value has exceeded a first value and is equal to or less than a second value.

9. The method of discharging droplets according to claim 8 , further comprising

driving the droplet discharge heads by piezoelectric elements,

the correcting of the discharge conditions includes correcting one of a drive voltage value and a drive voltage waveform applied to each of the droplet discharge heads that exhibits that the difference has exceeded the first value and is equal to or less than the second value.

10. The method of discharging droplets according to claim 1 , wherein

the performing of the weight measurement discharge from the one of the droplet discharge heads is performed while a single cycle of the feeding and removing is performed.

11. The method of discharging droplets according to claim 10 , further comprising

sequentially performing a single cycle of the weight measurement discharge from each of the droplet discharge heads included in the discharge head assembly,

performing the measuring of the weight of the liquid material discharged by the droplet discharge heads included in the discharge head assembly, and

performing the feeding and removing for a prescribed number of times without concurrently performing the measuring of the weight of the liquid material while the measuring of the weight of the liquid material is paused.

12. The method of discharging droplets according to claim 1 , further comprising

issuing an instruction to replace a weight measurement receptacle that accommodates the liquid material discharged by the weight measurement discharge depending on whether the weight measurement discharge is being performed.

13. The method of discharging droplets according to claim 12 , further comprising

counting a total number of the weight measurement discharges, and

issuing an instruction to replace the weight measurement receptacle when the total number of the weight measurement discharges has exceeded a prescribed numerical value.

14. The method of discharging droplets according to claim 12 , further comprising

calculating a total weight of the liquid material measured, and

issuing an instruction to replace the weight measurement receptacle when the total weight has exceeded a prescribed numerical value.