Aluminum nitride non-contact laser online thickness measurement and thickness screening sorting machine

Aluminum nitride substrate non-contact laser online thickness measurement and thickness screening sorting machine

1、 Customer basic thickness measurement requirements:

1,Measurement objectAluminum nitride substrate(Heavy:100g）

Substrate size range: Square block,small114 mm*114 mm, Big124mm*124mm，

thickness range:small0.25 mm, Big1.5mm，

2,Classification standards:

qualified:
0.381 mm +/-0.03 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

0.381 mm +/-0.04 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

0.381 mm +/-0.05 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

0.5 mm +/-0.03 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

0.5 mm +/-0.04 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

0.5 mm +/-0.05 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

0.762 mm +/-0.05 mm;on-board9The difference between the maximum and minimum values of point thickness≤0.025mm

Products that exceed the above error range are considered non-conforming.And it requires the computer to retain the data.

Abstracting the specific standards of the above users into algorithms:

Let f (x, y) be the thickness function, in millimeters

XThe domain of definition is: 0.1≤x≤1.5

yThe domain of definition is: 0.01≤y≤0.05

Then: x-y≤f(x,y) ≤x+y;

MAX[f(x,y)]-MIN[f(x,y)] ≤0.025

And: [x-y]≤f(x,y) ≤x+y]AND {MAX[f(x,y)]-MIN[f(x,y)] ≤0.025}=true

3,Product thickness measurement requirements

Measure 9 points on each board and arrange them in three rows, as shown in the following figure:

2、 System architecture

In order to achieveSquare board：114 mm*114 mm and124 mmX124mm；thick：0.25 mm~1.5mmThe online dynamic non-contact high-precision laser thickness measurement and sorting function for qualified and unqualified thickness of the plate, we propose to use oneLTG-680Laser online thickness gaugeX-YTwo dimensional scanning step by step fixed-point measurement plate at various positions（9The thickness of the point (the scanning width of this model of laser online thickness gauge can reach:680mm；Thickness range:0.02 mm -6mmMeasurement accuracy:+/-0.002mm）At the same time, an automatic suction cup feeding system and automatic plate thickness will be addedSorting inspectionThe system constitutes an automated system for measuring the thickness of nitride aluminum plates and determining whether the thickness is qualified or notThe production line and system architecture diagram are shown in the following figure:

3、 System working principle

1,System Design

As shown in the above figure, the substrate to be tested is placed in the required position (the suction cup can be in place), and the feeding system is controlled by the upper computer.LTG-680The laser online thickness gauge is installed on a two-dimensional fixed-point scanning frame and can be used forX-YMobile positioning, jointly controlled by a microcontroller and an upper computer, completes the thickness measurement task of aluminum nitride plates. The thickness sorting mechanism is jointly controlled by a microcontroller and an upper computer to implement the sorting and judgment of qualified plates, ultra thick plates, and ultra-thin plates. The software interface diagram of the laser online thickness gauge is as follows:

The software interface for the upper computer is currently unavailable.

2,working principle

The system receives a start signal and starts working: first, it detects the set model of the test board, starts the corresponding positioning program according to the selected model, and then the positioning program sends control pulses (the number of pulses sent by different positioning programs is different) to guide the vacuum suction crane fixture to move above the test board, lift and transport the board to the automatic testing platform. The automatic testing platform starts the corresponding pulse movement program based on the computer set board size, controls the platform to lift the board and send it to the effective measurement range of the laser thickness gauge, scans and measures the thickness along three lines, and the computer system records the number of output pulse signals according to the settings of different sizes of boards, so as to calculate the position of the laser thickness gauge thickness measurement point on the board (the software only records the thickness value at the 9-point position, and the thickness values at other positions do not participate in whether it is qualified or not). At the point that needs to be tested, the thickness measurement data is stored and displayed on the computer. Afterwards, start the corresponding positioning program according to whether the tested board is qualified, guide the vacuum suction crane fixture to lift the board to the position, and complete one inspection cycle.

4、 Synchronization and position sensing issues in measurement

Aluminum nitride plate is a sheet that is transported one by one. Therefore, it is necessary to have a complete detection system to determine whether there is a plate under the feeding machine, whether the plate is transported in place, whether there is a measured plate under the laser online thickness gauge, and whether the measured plate is successfully selected for transportation. Therefore, a position detection device should also be designed. In addition, a set of control software should be designed to implement the coordination, interconnection, interlocking and other logic between the three executing mechanisms of feeding, thickness measurement, etc.

5、 Upper computer system

The upper computer system is a data processing system that obtains thickness data of various areas of aluminum nitride plates from laser thickness gauges and controls the sorting machine to complete the sorting function according to the rules. At the same time, it is also the control center of the entire system, which can control the collaborative work, interconnection communication, and interlocking logic between the feeding machine, thickness measuring machine, and machine, enabling the three action mechanisms to work together and complete the automatic thickness measurement and qualification of aluminum nitride plates.

• Software algorithm (thickness sorting)

Let f (x, y) be the thickness function, in millimeters

XThe domain of definition is: 0.1≤x≤1.5

yThe domain of definition is: 0.01≤y≤0.05

Then: x-y≤f(x,y) ≤x+y;

MAX[f(x,y)]-MIN[f(x,y)] ≤0.025

And: [x-y]≤f(x,y) ≤x+y]AND {MAX[f(x,y)]-MIN[f(x,y)] ≤0.025}=true