Flow metering for dispense monitoring and control

Patent metadata

Field	Value
Publication number	US-2016005668-A1
Application number	US-201514855487-A
Country	US
Kind code	A1
Filing date	Sep 16, 2015
Priority date	Nov 21, 2012
Publication date	Jan 7, 2016
Grant date	—

Abstract

Methods and systems of accurately dispensing a viscous fluid onto a substrate. In an embodiment, a method includes using an electronic flow meter device to produce electrical flow meter output signals and performing a responsive control function in a closed loop manner by adjusting at least one dispensing parameter to correct for a difference between an output data set and a reference data set. In another embodiment, a system includes a control operatively coupled to a gas flow meter device and to a weigh scale allowing for a density of an amount of viscous material to be determined. In another embodiment, a method includes using a control coupled to both a gas flow meter device and a weigh scale and performing a responsive control function in a closed loop manner by adjusting at least one dispensing parameter using gas flow meter output signals and weigh scale output signals.

First claim

What is claimed is:

1 . A method of controlling a non-contact jetting dispensing system to accurately dispense a viscous fluid onto a substrate, the method comprising:
directing the viscous fluid from a viscous fluid supply into a non-contact jetting dispenser having an inlet and an outlet; discharging the viscous fluid through the outlet of the non-contact jetting dispenser, the non-contact jetting dispenser being operable to start and stop the flow of the viscous fluid through the outlet onto the substrate; using an electronic flow meter device operatively coupled in a flow path between the viscous fluid supply and the outlet of the non-contact jetting dispenser to produce electrical flow meter output signals proportional to the flow rate of the viscous fluid flowing through the flow path, the electrical flow meter output signals forming an output data set; comparing the output data set to a reference data set stored in a control; and performing a responsive control function in a closed loop manner by adjusting at least one dispensing parameter to correct for a difference between the output data set and the reference data set.

2 . The method of claim 1 , wherein performing the responsive control function further comprises adjusting the flow rate of the viscous fluid flowing through and being dispensed through the outlet of the non-contact jetting dispenser.

3 . The method of claim 2 , wherein adjusting the flow rate further comprises adjusting the viscosity of the viscous fluid.

4 . The method of claim 1 , wherein performing the responsive control function further comprises adjusting the dispensing time.

5 . The method of claim 1 , wherein performing the responsive control function further comprises adjusting the frequency at which viscous fluid is dispensed through the outlet onto the substrate.

6 . The method of claim 1 , wherein the viscous fluid supply further comprises a pressurized supply using pressurized air flowing through a pneumatic input of the viscous fluid supply, wherein the electronic flow meter device further comprises being operatively coupled to the pneumatic input to produce electrical flow meter output signals proportional to the flow rate of the pressurized air flowing through the pneumatic input, and wherein adjusting at least one dispensing parameter further comprises adjusting the pressure of the pressurized supply.

7 . The method of claim 1 , wherein discharging the viscous fluid through the outlet and performing the responsive control function further comprise:
discharging the viscous fluid through the outlet during relative motion between the non-contact jetting dispenser and the substrate; and adjusting the speed of the relative motion between the non-contact jetting dispenser and the substrate.

8 . The method of claim 1 , wherein comparing the output data set to a reference data set and performing the responsive control function further comprise:
using the output data set to determine a speed of relative motion between the non-contact jetting dispenser and the substrate which results in a target amount of viscous fluid being discharged onto the substrate, wherein determining the speed of relative motion comprises:
determining the amount of viscous fluid in the form of a total number of dots required to substantially equal the target amount by determining an average per dot volume of the output data set;
determining a distance between each of the total number of dots required to distribute the dots; and
determining a rate at which the total number of dots is to be dispensed from the non-contact jetting dispenser; and
using the rate at which the total number of dots is to be dispensed and the distance between each of the dots in the total number of dots;
adjusting the speed of the relative motion between the non-contact jetting dispenser and the substrate to discharge the target amount of viscous fluid onto the substrate.

9 . The method of claim 1 , wherein comparing the output data set to a reference data set stored in the control further comprises integrating the output data set to determine a volume of the output data set.

10 . The method of claim 9 , wherein comparing the output data set to the reference data set and performing a responsive control function further comprise:
comparing the volume of the output data set to a reference volume of the reference data set; and performing a responsive control function in a closed loop manner by adjusting the at least one dispensing parameter to correct for the difference between the volume of the output data set and the reference volume of the reference data set.

11 . The method of claim 1 , wherein performing the responsive control function further comprises detecting an air bubble in the viscous fluid flowing through the non-contact jetting dispenser.

12 . A viscous fluid dispensing system for accurately dispensing a viscous fluid onto a substrate, the system comprising:
a viscous fluid dispenser including an inlet and an outlet; a viscous fluid supply adapted to hold the viscous fluid and coupled in fluid communication with the inlet of the viscous fluid dispenser to establish a flow path for the viscous fluid between the viscous fluid supply and the outlet of the viscous fluid dispenser; a gas flow meter device operatively coupled in the flow path to produce corresponding gas flow meter output signals corresponding to a first amount of the viscous fluid; a weigh scale configured to receive and weigh the first amount and to produce corresponding weigh scale output signals; and a control operatively coupled to the gas flow meter device and to the weigh scale, wherein the control determines a mass of the first amount using the weigh scale output signals received from the weigh scale, determines a volume of the first amount by integrating the gas flow meter output signals received from the gas flow meter device, and then determines a density of the first amount using the mass of the first amount and the volume of the first amount.

13 . The system of claim 12 , wherein the control compares the density of the first amount to a predetermined tolerance and warns a user if the density is outside of the predetermined tolerance.

14 . The system of claim 12 further comprising:
the gas flow meter device producing gas flow meter output signals proportional to a volume of a second amount of the viscous fluid flowing through the flow path and dispensed through the outlet,
wherein the control uses the density of the first amount and the volume of the second amount to determine a mass flow rate of the second amount.

15 . The system of claim 14 further comprising adjusting at least one dispensing parameter to adjust the mass flow rate of the second amount.

16 . The system of claim 15 , wherein the adjusting the at least one dispensing parameter further comprises adjusting fluid supply pressure of the viscous fluid supply.

17 . The system of claim 14 , wherein the adjusting the at least one dispensing parameter further comprises adjusting the frequency at which successive amounts of the viscous fluid are dispensed through the outlet.

18 . The system of claim 14 further comprising a temperature controller coupled to the control, wherein the adjusting of the at least one dispensing parameter further comprises using the temperature controller to adjust the temperature of the viscous fluid dispenser.

19 . The system of claim 14 , wherein the viscous fluid dispenser is a jetting dispenser configured to jet dots of visco

Assignees

• Nordson Corp

Inventors

• Donner Joseph E
• Gorman Michael
• Giusti Christopher L
• Lewis Alan R
• Quinones Horatio
• Ratledge Thomas L
• Suhinin Yuriy

Classifications

• H10W74/15

  on active surfaces of flip-chip devices, e.g. underfills · CPC title

• H10W74/012

  of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills · CPC title

• H10P74/238 Primary

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• B05C5/0225 Primary

  characterised by flow controlling means, e.g. valves, located proximate the outlet (B05C5/0258, B05C5/0275 take precedence; supply valves upstream the coating head B05C11/1036) · CPC title

• H01L21/563

  Electricity · mapped topic