Apparatus and method for sampling ultra-pure chemical

• US 5,237,878 A
• Filed: 11/24/1992
• Issued: 08/24/1993
• Est. Priority Date: 07/02/1991
• Status: Expired due to Fees

• Current Assignee: Sematech, Inc.
• Original Assignee: Sematech, Inc.
• Inventors: Hackenberg, Diana L.
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US07/982,107
• Time in Patent Office: 273 Days
• Field of Search: 73/864.73, 73/863.81-863.85, 73/864.34, 73/864.35, 73/863.33, 73/
• US Class Current: 73/861.34
• CPC Class Codes: G01N 1/14 Suction devices, e.g. pumps; Ejector devices
• CPC Class Codes: G01N 1/16 with provision for intake at several levels G01N1/2035 G01N1/12, G01N1/14 take precedence
• CPC Class Codes: G01N 2001/1427 Positive displacement, piston, peristaltic
• CPC Class Codes: G01N 2001/2071 Removable sample bottle

Abstract

An ultra-pure chemical sampling apparatus has an elongated sampling tube which is lowered into the liquid to obtain samples of the chemical. The sampling tube extends the depth of the liquid and holes arranged along the tube provides for a representative sample to be obtained at different depths. The sampling tube is coupled to a collection bottle by a tubing of which a section of flexible tubing is coupled to a peristaltic pump to pump the liquid up the sampling tube, through the tubing and into the collection bottle. A cap is used to seal the sampling tube and a secondary containment receptacle is used to enclose the bottle in order to inhibit the escape of chemical fumes which could harm the environment or the person obtaining the sample.

Claims

1. A hand-carried portable apparatus for obtaining a sample from an enclosed container having a liquid chemical utilized for semiconductor manufacturing contained therein comprising;

a cap adapted for fitting over an opening of said container in order to prevent leakage of fumes of said chemical from said container;

a collection container for collecting said sample of said liquid;

an elongated sampling tube having a plurality of holes disposed along its length wherein a distal section of said sampling tube has holes of relatively larger openings as compared to holes located at other portions of said sampling tube and wherein a proximal section adjacent to a proximal end of said sampling tube has holes of relatively smaller openings as compared to holes located at other portions of said sampling tube, such that when said sampling tube is inserted into said liquid and its proximal and coupled to and through said cap, a pumping action initiated at said proximal end provides for drawing of said liquid from various depths of said enclosed container and wherein said pumping action causes relatively more suction to draw said liquid at said proximal end than at said distal end, but is compensated by smaller openings at said proximal end in order to obtain a representative sample quantity of said liquid from various levels of said enclosed container;

a tubing having one end coupled to said proximal end of said sampling tube and its other end coupled to said collection container.

2. The apparatus of claim 1 wherein said sampling tube, tubing and collection container are constructed from a non-metallic, non-corrosive material.

3. The apparatus of claim 1 wherein said sampling tube, tubing and collection container are constructed from a fluoro-containing material.

4. The apparatus of claim 1 wherein said collection container includes a transparent secondary container for retaining fumes emanating from said collection container and spillage from said collection container while obtaining said sample.

5. A hand-carried, portable apparatus for obtaining a homogenous sample from an enclosed container having an ultra-pure chemical in liquid form and which is utilized for semiconductor manufacturing contained therein, while inhibiting the escape of chemical fumes into the ambient comprising;

a cap adapted for fitting over an opening of said container in order to prevent leakage of fumes of said chemical from said container while said sample is being obtained, said cap having a central opening for drawing said liquid out from said container;

a fitting disposed in said central opening of said cap;

a collection container for collecting said sample of said liquid;

an elongated sampling tube having a plurality of holes disposed along its length wherein holes disposed farther from the end coupled to said cap have relatively larger diameter openings as compared to holes located at other portions of said sampling tube and holes disposed proximal to said cap have relatively smaller diameter openings as compared to holes located at other portions of said sampling tube, such that when said sampling tube is inserted into said liquid and a peristaltic pumping action is initiated, causing more suction at said end coupled to said cap than at other portions of said sampling tube, said plurality of holes having different diameter openings at various depths compensate for drawing of said liquid from various depths of said container in order to obtain a homogenous sample quantity of said liquid from said container, said sampling tube coupled to said first fitting;

a non-metallic tubing having one end coupled to said sampling tube and its other end coupled to said collection container;

a peristaltic pump coupled to said tubing for providing peristaltic pumping action to draw said liquid into said sampling tube, through said tube and into said collection container.

6. The apparatus of claim 5 wherein said collection container includes a transparent secondary container for retaining fumes emanating from said collection container and spillage from said collection while obtaining said sample.

7. The apparatus of claim 6 wherein said sampling tube, tubing and collection container are constructed from a fluoro-containing material, and has a section of said tubing coupled to said peristaltic pump constructed from a polycarbonate material.

8. A method for obtaining a sample from an enclosed container having a liquid chemical utilized for semiconductor manufacturing contained therein while inhibiting the escape of chemical fumes into the ambient, comprising the steps of:

attaching an elongated sampling tube, having a plurality of holes disposed along its length, through a cap for sealing an opening of said container, wherein holes of said sampling tube disposed farther from the end coupled to said cap have relatively larger diameter openings as compared to holes located at other portions of said sampling tube and holes disposed proximal to said cap have relatively smaller diameter openings as compared to holes located at other portions of said sampling tube;

attaching one end of a tubing to said cap end of said sampling tube and its other end to a collection bottle;

inserting said sampling tube into said opening of said container and sealing said opening by tightening said cap;

coupling a flexible section of said tubing to a peristaltic pump for pumping said liquid into said sampling tube, through said tubing and into said collection bottle, wherein said pumping causes relatively more suction to draw said liquid though holes disposed proximal to said cap, but said plurality of holes having different diameter openings at various depths compensate for drawing of said liquid in order to obtain a representative sample quantity of said liquid to be drawn from various depths of said container;

pumping to obtain said representative sample quantity from said container.

9. The method of claim 8 further comprising the step of placing said collection bottle in a sealed secondary container prior to drawing said sample.