Surface flatness measuring device and surface flatness measuring method

Patent metadata

Field	Value
Publication number	US-10837764-B2
Application number	US-201816323783-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Nov 22, 2018
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A surface flatness measuring device and a surface flatness measuring method are disclosed. By non-contacting laser measurement, measurement precision can reach 0.001 mm so the measurement precision is high. A repetitive measurement error thereof can be controlled to be within 3 um so the measurement error is tiny, which prevent issues of low measurement precision and great measurement errors due to manual measurement in prior art. At the same time, the present invention measurement data can be automatically recorded and saved, measurement for a large batch of boards under measurement can be implemented, which prevents the issues of the conventional measurement data requiring manual recording and lacking capability of uploading the measurement data.

First claim

What is claimed is:

1. A surface flatness measuring device, wherein the surface flatness measuring device comprises:
a measuring platform, configured to be placed with a board under measurement, a surface of the board under measurement marked with a plurality of points under measurement, wherein a number of the points under measurement is eight, first four of the points under measurement are distributed on the surface of the board under measurement near a periphery region, and last four of the points under measurement are distributed on the surface of the board under measurement near a central region;
at least one laser head, configured to emit laser beams to one of the points under measurement and receive reflected light;
a computer, configured to control the at least one laser head to move to different ones of the points under measurement and control the at least one laser head to emit laser beams to obtain height measurement values of all of the points under measurement, and the computer, further according to the points under measurement corresponding to first three of the obtained height measurement values, determining a datum plane, calculating out distance values each of which is between the datum plane and one of the points under measurement corresponding to remaining five of the height measurement values, and obtaining a maximum of the distance values to serve as a surface flatness measurement value of the board under measurement; and
the computer further configured to record and save the surface flatness measurement value.

2. The surface flatness measuring device as claimed in claim 1 , wherein the surface flatness measuring device further comprises a plurality of the laser heads, the laser heads correspond to the points under measurement, and all of the laser heads are configured to emit laser beams to corresponding ones of the points under measurement and receive reflected light.

3. A surface flatness measuring device, wherein the surface flatness measuring device comprises:
a measuring platform, configured to be placed with a board under measurement, and a surface of the board under measurement marked with a plurality of points under measurement;
at least one laser head, configured to emit laser beams to one of the points under measurement and receive reflected light;
a computer, configured to control the at least one laser head to move to different ones of the points under measurement and control the at least one laser head to emit laser beams to obtain height measurement values of all of the points under measurement, and the computer, further according to the points under measurement corresponding to three of the obtained height measurement values, determining a datum plane, calculating out distance values each of which is between the datum plane and one of the points under measurement corresponding to remains of the height measurement values, and obtaining a maximum of the distance values to serve as a surface flatness measurement value of the board under measurement;
wherein a number of the points under measurement is eight, first four of the points under measurement are distributed on the surface of the board under measurement near a periphery region, and last four of the points under measurement are distributed on the surface of the board under measurement near a center region.

4. The surface flatness measuring device as claimed in claim 3 , wherein the surface flatness measuring device further comprises a plurality of laser heads, the laser heads correspond to the points under measurement, and all of the laser heads are configured to emit laser beams to corresponding ones of the points under measurement and receive reflected light.

5. The surface flatness measuring device as claimed in claim 3 , wherein the computer, further according to the points under measurement corresponding to first three of the obtained height measurement values, determines a datum plane, calculates out distance values each of which is between the datum plane and one of the points under measurement corresponding to remaining five of the height measurement values, and obtains a maximum of the distance values to serve as the surface flatness measurement value.

6. The surface flatness measuring device as claimed in claim 3 , wherein the computer is further configured to record and save the surface flatness measurement value.

7. A surface flatness measuring method, wherein the surface flatness measuring method comprises:
Step (1), placing a board under measurement on a measuring platform, wherein a surface off the board under measurement is marked with a plurality of points under measurement;
Step (2), by a computer, controlling a laser head to move to different ones of the points under measurement and controlling the laser head to emit laser beams to obtain height measurement values of all of the points under measurement;
Step (3), by the computer, according to the points under measurement corresponding to three of the obtained height measurement values, determining a datum plane, calculating out distance values each of which is between the datum plane and one of the points under measurement corresponding to remains of the height measurement values; and
Step (4), by the computer, obtaining a maximum of the distance values to serve as a surface flatness measurement value of the board under measurement;
wherein a number of the points under measurement is eight, first four of the points under measurement are distributed on the surface of the board under measurement near a periphery region, and last four of the points under measurement are distributed on the surface of the board under measurement near a central region; the Step (3) further comprises by the computer, according to the points under measurement corresponding to first three of the obtained height measurement values, determining a datum plane, calculating out distance values each of which is between the datum plane and one of the points under measurement corresponding to remaining five of the height measurement values, and obtaining a maximum of the distance values to serve as the surface flatness measurement value.

8. The surface flatness measuring method as claimed in claim 7 , wherein Step (2) further comprises:
by the computer, controlling a plurality of the laser heads to emit laser beams to the points under measurement to obtain the height measurement values of all of the points under measurement.

9. The surface flatness measuring method as claimed in claim 7 , wherein Step (2) further comprises by the computer, obtaining optical path differences from the laser head to the points under measurement, and calculating out the height measurement values of the points under measurement.

10. The surface flatness measuring method as claimed in claim 7 , wherein the surface flatness measuring method further comprises:
Step (5), recording and saving the surface flatness measurement value by the computer.

Assignees

• Wuhan China Star Optoelectronics Technology Co Ltd

Inventors

• Zhang Jinpeng

Classifications

• G02F1/1309

  Repairing; Testing · CPC title

• G01B11/306 Primary

  for measuring evenness · CPC title

• G01B11/30 Primary

  for measuring roughness or irregularity of surfaces · CPC title

• G01B11/026

  by measuring distance between sensor and object (G01B11/0608 takes precedence) · CPC title

• G01B11/2408 Primary

  for measuring roundness · CPC title