Jetting Apparatus and Method of Improving the Performance of a Jetting Apparatus

Abstract

The present invention is generally related to a jetting device for jetting droplets of viscous medium onto a substrate, said jetting device comprising an ejector element for performing the jetting process and a jetting outlet through which said droplets are jetted. In particular, the invention is related to a method, a measuring device, a jetting device, and a viscous medium container for use in such a jetting device for measuring or monitoring a level or volume of viscous medium during a jetting process and / or measuring electrical properties of the viscous medium to determine characteristics of the medium.

Description

TECHNICAL FIELD[0001]The present application refers to systems for applying viscous mediums onto substrates using jet printing within the field of electronics production. More specifically, the invention relates to a method of improving the performance of a jetting device, and a device for jetting droplets of viscous medium onto a substrate.BACKGROUND[0002]Systems, devices and methods for jetting droplets of viscous medium, e.g. solder paste or glue, onto a sub-strate, e.g. an electronic circuit board, are known in the art. See for instance patent publications U.S. Pat. No. 6,450,416 B1, US 2002 / 0043570 A1, US 2002 / 0047052 A1, US 2002 / 0014602 A1, US 2002 / 0015780 A1, US 2004 / 0118935 A1, US 2004 / 0217193 A1, US 2004 / 0262824 A1, US 2005 / 0092774 A1, US 2005 / 0167519 A1, WO 2005 / 048678, which are incorporated herein by reference.[0003]In the MY500 Jet Printer provided by Mydata automation AB, a system for jetting viscous medium comprises a jet printing machine, a solder paste container for...

AI Technical Summary

Benefits of technology

[0008]Thus, an object of the present invention is to provide an improved jetting method and device.

[0009]Another object of the present invention is to improve the performance of a device for jetting droplets of viscous medium onto a substrate.

[0010]A further object of the present invention is to provide improved and more reliable methods and devices for measuring and / or monitoring the solder paste consumption during a jet printing process.

[0017]Hence, the present invention is based on the idea of utilizing electromagnetical signals and / or fields applied in the viscous medium container, e.g. a solder paste tube, measuring a response of the viscous medium to the applied signals and / or fields, and determining the present level, volume, or filling degree of the viscous medium in the container using this response. Thereby, it is possible to continuously monitor and measure the volume or level of viscous medium held by the container during a jet printing process. This can be used to keep a user updated of the current level of viscous medium and the remaining volume of viscous medium and, thus, the jet printing process be improved, for example, in that interruption of the process can be predicted and / or adapted to the product production flow.

[0024]Also, the provision of conduction paths or points within the viscous medium container, provides the possibility to determine the permittivity, the loss factor or dielectric constant of the viscous medium through impedance measurements and other characteristics of the viscous medium, for example, with respect to quality, remaining shelf-life, etc, can be monitored. For instance, the viscous medium could have a limited useful life, i.e. that the quality of the viscous medium deteriorates over time due to, inter alia, oxidation of the solder particles in solder paste. Furthermore, by conducting impedance measurements over a predetermined frequency range it is possible to obtain a “fingerprint” of the viscous medium which may be used to identify a certain type of viscous medium, for example, a solder paste having a certain quality or produced by a certain manufacturer. It is thereby also possible to, for example, verify that a solder paste container actually contains the indicated solder paste.

Problems solved by technology

Such interruptions may be caused by shortage of solder paste.

However, this is impaired with problems.

For example, the accuracy is low due to counting errors caused by difficulties of estimating the quantity of solder paste in the droplets or due to the fact that information regarding the quantity of solder paste contained in the solder paste tube may be erroneous.

This method is associated with drawbacks, for example, that the operator of the jetting device is not provided with any information regarding the solder paste quantity during a jet printing process until the solder paste is about to ran out.

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