US 5,134,962 A · Spin coating apparatus

Abstract

The present invention relates to a spin coating apparatus for feeding a clean liquid at a fixed rate. In any of the feeding apparatus in the prior art, no constituent other than a filter has the function of eliminating foreign matter, and the operation of feeding a liquid under precise control is not attained. This results in the problem of the mixing of the foreign matter (and air bubbles) in the feed liquid, and the problem of nonuniformity in a feed speed as well as a feed amount. As expedients for solving these problems, the present invention provides the functions of automatically sensing and excluding factors for the appearances of the foreign matters, and devices for automatically and precisely controlling feed control elements such as a pump, thereby feeding the clean liquid in a constant amount and at a constant speed.

Claims23

Dependent claims

An apparatus for spin-coating a flat object with a viscous coating liquid, comprising:

(a) dispenser means having a diaphragm pump for sucking the coating liquid from a liquid source and for discharging and dropping the sucked liquid in a constant amount and at a constant speed from a discharge nozzle onto the flat object placed on a rotary stage;
(b) a dispenser central control device including a microcomputer or minicomputer for controlling said diaphragm pump;
and
(c) diaphragm displacement detection means for detecting at least one of a position and displacement speed of a diaphragm of said diaphragm pump in a noncontacting manner, and for delivering data of the at least one of the position and displacement speed to said central control device.

1 more element

An apparatus for spin-coating a flat object with a viscous coating liquid, comprising:

(a) dispenser means having a diaphragm pump for sucking the coating liquid from a liquid source and for discharging and dropping the sucked liquid in a constant amount and at a constant speed from a discharge nozzle onto the flat object placed on a rotary stage;
and
(b) a dispenser central control device including a microcomputer or minicomputer for controlling said diaphragm pump;
(c) diaphragm displacement detection means for detecting at least one of a position and displacement speed of a diaphragm of said diaphragm pump in a noncontacting manner, and for delivering data of the at least one of the position and displacement speed to said central control device;
(d) viscosity measurement means for measuring a viscosity of said coating liquid, and for delivering data of the viscosity to said central control device;
(e) foreign matter detection means for detecting foreign matter contained in said coating liquid within said dispenser means, and for delivering data of the foreign matter to said central control device;
(f) said diaphragm pump having a coating liquid suction valve or discharge valve provided independently of a diaphragm drive section, said diaphragm drive further includes a liquid pressure feed chamber and a pressure chamber;
(g) filter means interposed between said diaphragm pump and said suction or discharge valve, for removing foreign matter contained in said coating liquid;
(h) feed pressure detection means for detecting a pressure of said pressure feed chamber of said diaphragm pump;
wherein said central control device calculates an optimum feed pressure from the diaphragm displacement data and data of the feed pressure so as to control the feed pressure;
(i) valve or diaphragm damage detection means for detecting damage of a valve or diaphragm provided in said dispenser means, and for delivering data of the damage to said central control device;
and
(j) gas bubble trap means provided in said dispenser means, for trapping gas bubbles contained in said coating liquid.

10 more elements

Dependencies are inferred from the claim text.

Spin coating apparatus

Life of this patent

Spin coating apparatus

Life of this patent

Abstract

Claims23