CROSS REFERENCE

This application is a U.S. National Phase under 35 U.S.C. § 371 of International Application No. PCT/JP2017/029667, filed on Aug. 18, 2017 which claims the benefit of Japanese Application No. 2016-166606, filed on Aug. 29, 2016, the entire contents of both are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a coating apparatus and a coating method, and more specifically to control of the coating amount in a coating apparatus that coats a target object with a liquid material using a coating needle.

BACKGROUND ART

With recent miniaturization of electronics, there has been a growing demand for stably applying a very small amount of liquid material, for example, in such applications as application of a conductive material in implementation of crystal resonators, application of a catalytic material to a MEMS (Micro Electro Mechanical Systems) gas sensor, and application of an adhesive to an LED (Light Emitting Diode).

Fine coating is typically performed by printing, inkjet, and dispenser. The technique using a coating needle has also drawn attention because of its capability of fine coating using liquid materials with a wide variety of viscosities.

A method of performing fine coating with a liquid material using a coating needle is disclosed, for example, in Japanese Patent Laying-Open No. 2007-268353 (PTL 1), which proposes a method using a coating unit.

Such a coating unit is aimed to correct defects in minute patterns and is capable of fine coating using liquid materials with a wide variety of viscosities. In the coating operation, a coating needle protrudes from a through hole at the bottom of a container holding a liquid material. The coating needle performs transfer coating (hereinafter simply referred to as “coating”) by bringing a coating liquid at the tip end thereof into contact with a coating target object.

CITATION LIST

Patent Literature

PTL 1: Japanese Patent Laying-Open No. 2007-268353

SUMMARY OF INVENTION

Technical Problem

In the coating unit as described in Japanese Patent Laying-Open No. 2007-268353 (PTL 1), the container for holding a liquid material may be replaceable in order to change the kind of liquid material used or to supply a liquid material depleted by coating.

In this case, for example, because of individual differences resulting from manufacturing errors of containers, such as the diameters of through holes at the bottom of containers, the coating amount may vary with containers even when the coating operation is performed under the same coating conditions.

With increasing miniaturization of electronics, it is necessary to reduce variation in the coating amount due to such differences of containers when an even smaller coating amount is required.

The present invention is made in order to solve such a problem and an object of the present invention is to reduce variation in the coating amount due to replacement of liquid material containers in a coating apparatus that applies a liquid material using a coating needle.

Solution to Problem

A coating apparatus according to the present invention applies a liquid material to a surface of a target object using a coating needle. The coating apparatus includes a coating unit, first and second driving devices, and a controller. The coating unit is configured to be replaceable and includes the coating needle and a container configured to hold the liquid material. The first driving device is configured to move the coating needle up and down. The second driving device is configured to move the coating unit up and down relative to the target object. The controller is configured to perform a coating operation of applying the liquid material to the target object by controlling the first and second driving devices. The controller is configured to adjust the coating amount of the liquid material by controlling the first and second driving devices in accordance with an operation parameter set corresponding to the coating unit attached.

Preferably, the container has a bottom having a hole. The controller is configured to apply the liquid material to a surface of the target object by moving the coating unit down using the second driving device while allowing the coating needle to protrude from the hole using the first driving device, and bringing the coating needle into contact with the target object.

Preferably, the operation parameter is a standby time in which a coating operation is on standby in a state in which the coating needle protrudes from the hole. When the coating amount is to be reduced, the standby time is extended. When the coating amount is to be increased, the standby time is shortened.

Preferably, the operation parameter is a contact time between the target object and the coating needle. When the coating amount is to be reduced, the contact time is shortened. When the coating amount is to be increased, the contact time is extended.

Preferably, the operation parameter is the push amount by which the coating unit further moves down from a state in which the target object and the coating needle are in contact with each other. When the coating amount is to be reduced, the push amount is reduced. When the coating amount is to be increased, the push amount is increased.

A coating method according to the present invention is a method of applying a liquid material to a surface of a target object using a coating needle in a coating apparatus. The coating apparatus includes a coating unit configured to be replaceable and first and second driving devices. The coating unit includes a container configured to hold a liquid material and the coating needle. The first driving device is configured to move the coating needle up and down. The second driving device is configured to move the coating unit up and down relative to the target object. The coating method includes: acquiring an operation parameter set corresponding to the coating unit attached; applying the liquid material to a surface of the target object by bringing the coating needle into contact with the target object using the first and second driving devices; measuring the coating amount of the liquid material applied; and adjusting the operation parameter based on the measured coating amount of the liquid material.

Advantageous Effects of Invention

According to the present invention, in a coating apparatus that applies a liquid material using a coating needle, an operation parameter for a driving device driven to perform a coating operation is adjusted for each liquid material container, thereby reducing variation in the coating amount due to replacement of liquid material containers.

