A method of verifying that an exposure spot of a laser is affected by temperature rise

Abstract

The application discloses a method for verifying that exposure points of a laser are affected by temperature rise, comprising the following steps: arranging heat-sensitive paper on a focal plane shared by a plurality of lasers of a laser direct writing device, and the heat-sensitive paper being perpendicular to the main optical axes of the plurality of lasers; selecting an arbitrary laser as a test laser; when the laser direct writing device is in a non-running state, the test laser is exposed on the heat-sensitive paper for the first time at an optimal exposure power, and a first exposure point is obtained; after the laser direct writing device is warmed up, the test laser is exposed on the heat-sensitive paper for the second time at the optimal exposure power, and a second exposure point is obtained; according to the distance d between the second center of the second exposure point and the first center of the first exposure point, and the change size |r2-r1| of the second radius r2 of the second exposure point relative to the first radius r1 of the first exposure point, the influence size of the exposure point of the light beam emitted by the test laser after the temperature rise is determined. The method provides a reference for subsequent accurate exposure of an image.

Description

Technical Field

[0001] This invention belongs to the field of laser direct writing technology, and in particular relates to a method for verifying the effect of temperature rise on the exposure point of a laser. Background Technology

[0002] refer to Figure 1 The exposure component 30 of the laser direct writing device includes: an upper guide rail 31, a lower guide rail 32, a base 33, a control module 35, a left vertical guide rail 36, and a right vertical guide rail 37. The upper and lower ends of the base 33 are respectively mounted on the upper guide rail 31 and the lower guide rail 32. For example, nine lasers 39-1 to 39-9 are uniformly arranged along the center line of the long side of the base 33. The base 33 is connected to a first motor 34, which is connected to the control module 35. Under the control of the control module 35, the first motor 34 drives the base 33 to reciprocate horizontally on the upper guide rail 31 and the lower guide rail 32, so that each laser moves horizontally for exposure. Figure 2 The image bars in the image. Simultaneously, the control module 35 is also connected to a stepper motor 38, which is connected to the upper guide rail 31 and the lower guide rail 32 respectively. Under the control of the control module 35, the stepper motor 38 drives the upper guide rail 31 and the lower guide rail 32 as a whole to move downwards on the left vertical guide rail 36 and the right vertical guide rail 37, so that each laser is exposed simultaneously. Figure 2 After the corresponding row of images is displayed, the image moves downwards simultaneously to begin exposing the corresponding second row of images.

[0003] Because lasers are precision devices, the heat generated by the laser's light source and other components of the laser direct-writing equipment during the exposure process can cause changes in the position and size of the focused spot on the photosensitive coating, thus affecting the accuracy of image exposure. Summary of the Invention

[0004] This invention provides a method for verifying the effect of temperature rise on the exposure point of a laser. The purpose is to verify whether the position and size of the laser in a laser direct writing device have changed after the temperature rise relative to the exposure point before the temperature rise, so as to provide a reference for the subsequent accurate exposure of the image.

[0005] The solution of the present invention is as follows:

[0006] A method for verifying the effect of temperature rise on the exposure point of a laser includes:

[0007] Step 1: Place the thermal paper on the common focal plane of the lasers in the laser direct writing device.

[0008] Furthermore, the thermal paper is perpendicular to the principal optical axis of all the lasers;

[0009] Step 2: Select any one of the lasers as the test laser. When the laser direct writing equipment is not in operation, the test laser exposes the thermal paper with the optimal exposure power for the first time to obtain the first exposure point.

[0010] Step 3: After heating the laser direct writing device, the test laser is used to expose the thermal paper a second time at the optimal exposure power to obtain the second exposure point;

[0011] Step 4: Based on the distance d from the second center of the second exposure point to the first center of the first exposure point, and the change in the second radius r2 of the second exposure point relative to the first radius r1 of the first exposure point |r2-r1|, determine the degree to which the exposure point of the beam emitted by the test laser is affected by the temperature rise.

[0012] The physical position of the thermal paper did not change before and after the temperature rise of the laser direct writing device.

[0013] In some embodiments, the optimal exposure power is the exposure power obtained by the test laser on the thermal paper when the spot size is closest to the actual size, as measured by the test software.

[0014] In some embodiments, the optimal exposure power is 68.34 mA, and the actual size of the light spot is a radius of 65 micrometers.

[0015] In some embodiments, the test laser is exposed to the thermal paper for the first and second time at the optimal exposure power, which is obtained by the following method: the control module of the laser direct writing device controls all lasers to be lit up once and then turned off in sequence at the optimal exposure power, until the last laser is lit up once and then turned off, and then stops. The total time from the first laser to the last laser being lit up is T1 milliseconds.

[0016] When the test laser exposes the thermal paper twice, the first laser is the same laser.

[0017] In some embodiments, after the thermal paper is first exposed with the test laser and before the thermal paper is exposed for the second time, the method further includes: turning on the laser direct writing device and continuously lighting all lasers at maximum output power for T2 minutes.

[0018] In some embodiments, after the test laser first exposes the thermal paper but before all lasers are continuously lit, the thermal paper is further shielded by a baffle.

[0019] In some embodiments, in step 4, the first center and first radius of the first exposure point, as well as the second center and second radius of the second exposure point, are obtained through two-dimensional verification.

[0020] The technical effect of the present invention is that by using the same laser of the laser direct writing device to expose the same position of the fixed thermal paper twice, before and after the temperature rise of the laser direct writing device, the first exposure point and the second exposure point are obtained respectively. The image recognition module analyzes the circumferential contour image of the first exposure point and the circumferential contour image of the second exposure point, and further calculates the coordinates and first radius of the first center of the first exposure point, as well as the coordinates and second radius of the second center of the second exposure point. Based on the distance d from the second center of the second exposure point to the first center of the first exposure point, and the magnitude of the change in the second radius r2 of the second exposure point relative to the first radius r1 of the first exposure point |r2-r1|, the degree to which the exposure point of the laser beam emitted by the test laser on the thermal paper is affected after the temperature rise is determined: (1) The larger d is, the greater the change in the laser spot position before and after the temperature rise; the smaller d is, the smaller the change in the laser spot position before and after the temperature rise; (2) The larger |r2-r1| is, the greater the change in the laser spot radius before and after the temperature rise; the smaller |r2-r1| is, the smaller the change in the laser spot radius before and after the temperature rise. The verification results provide a reference for whether to use a laser for precise image exposure: if the exposure accuracy requirement of the image to be exposed is not high, and the changes in the position and radius of the focused spot of the laser beam are within an acceptable range, then the laser can be used for subsequent image exposure; if the exposure accuracy requirement of the image to be exposed is high, and the changes in the position and radius of the focused spot of the laser beam are large, failing to meet the image exposure accuracy requirements, then the laser cannot be used for subsequent image exposure. Attached Figure Description

[0021] Figure 1 A schematic diagram of the exposure component 30 of a laser direct writing device;

[0022] Figure 2 for Figure 1 A schematic diagram of an image to be exposed, consisting of N rows of image bars, exposed by several lasers.

[0023] Figure 3 This is a diagram illustrating the method steps of the present invention;

[0024] Figure 4 A schematic diagram for testing the focusing and exposure of laser 39-3 on thermal paper 41;

[0025] Figure 5This is a schematic diagram showing the shift in position and change in spot size of two exposure points obtained by two exposures of laser 39-3 on thermal paper 41. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention; the terms "first," "second," and "third" are only used to describe distinctions and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] refer to Figure 3 This invention discloses a method for verifying the effect of temperature rise on the position of a laser, comprising:

[0029] Step 1: Place the thermal paper on the common focal plane of the lasers in the laser direct writing device.

[0030] Furthermore, the thermal paper is perpendicular to the principal optical axis of each of the lasers;

[0031] Step 2: Select any one of the lasers as the test laser. When the laser direct writing equipment is not in operation, the test laser exposes the thermal paper with the optimal exposure power for the first time to obtain the first exposure point.

[0032] Step 3: After heating the laser direct writing device, the test laser is used to expose the thermal paper a second time at the optimal exposure power to obtain the second exposure point;

[0033] Step 4: Based on the distance d from the second center of the second exposure point to the first center of the first exposure point, and the change in the second radius r2 of the second exposure point relative to the first radius r1 of the first exposure point |r2-r1|, determine the degree to which the exposure point of the beam emitted by the test laser is affected by the temperature rise.

[0034] The physical position of the thermal paper did not change before and after the temperature rise of the laser direct writing device.

[0035] The following is a detailed description of steps 1 to 4.

[0036] refer to Figure 4 Several lasers (exemplarily nine lasers 39-1, 39-2, 39-3...39-9) are mounted on the base 33, and the laser beams emitted by these lasers converge on the focal plane 42. Thermal paper 41 is fixedly placed on the focal plane 42, meaning the thermal paper 41 is located on the common focal plane 42 of all the lasers. The principal optical axes of all the lasers are perpendicular to the focal plane 42. This is to ensure that the beam emitted by each laser has the smallest possible spot radius on the focal plane 42 and to reflect the actual size of the spot as closely as possible.

[0037] To verify the extent to which the exposure point of the laser in a laser direct-writing device is affected by temperature rise compared to before temperature rise, it is only necessary to select one laser from several for verification. (Reference) Figure 1 In this application, laser 39-3 is selected as the test laser for verification. It should be noted that the thermal paper 41 needs to be fixed throughout the verification process to ensure its position does not change. The temperature rise mentioned in this application refers to the increase in temperature of the laser and the laser direct writing equipment after the laser direct writing device is started and all lasers are continuously lit for a period of time.

[0038] After selecting laser 39-3 as the test laser, the entire laser direct-writing equipment was put into a non-operational state. The computer control module controlled all lasers to sequentially light up and then turn off at optimal power. The process stopped after all lasers completed one round of lighting and turning off. The total time taken for all lasers to sequentially light up and turn off once is defined as T1. During the first cycle of lighting up, test laser 39-3 exposed the thermal paper 41 to obtain the first exposure point. The camera module captured an image of the first exposure point. The image processing module identified the first exposure point and extracted its contour. Based on the contour, the coordinates O1 of the first center and the first radius r1 of the first exposure point were obtained. Figure 5The optimal power of the laser mentioned above refers to the exposure power measured by computer testing software when the spot size of the test laser 39-3 exposed on the thermal paper 41 is closest to the actual size. For example, in one embodiment, the radius of the spot closest to the actual size of the first exposure point obtained by the test laser 39-3 exposed on the thermal paper 41 is 65 micrometers, and the corresponding optimal exposure power is 68.34 mA.

[0039] After obtaining the first exposure point, the laser direct-writing equipment is powered on and all lasers are continuously lit at maximum output power for T2 minutes. In one embodiment, T2 is 5 minutes, meaning all lasers are continuously lit for 5 minutes. It should be noted that during the period when all lasers are continuously lit at maximum output power for T2 minutes, a baffle is needed to cover the thermal paper to prevent it from being burned by the continuously lit lasers. Preferably, a PS board is chosen as the baffle because PS boards have flame-retardant properties.

[0040] After all lasers have been continuously lit for T2 minutes, the laser direct writing device is turned off, all lasers are extinguished, and the baffle used to shield the thermal paper is removed. Then, the output power, exposure time, and exposure mode of all lasers are set exactly the same as during the first exposure: all lasers are sequentially lit at their optimal power once and then immediately turned off; all lasers are lit once in a cycle, and the total time taken for all lasers to be sequentially lit is still counted as T1. Next, the same test laser 39-4 is used to expose the thermal paper 41 to obtain a second exposure point. The camera module captures an image of the second exposure point, and the image processing module identifies the outline of the second exposure point, determining the coordinates of the second center O2 and the second radius r2 based on the outline. Setting the conditions for the two exposures of the thermal paper by the test laser to be exactly the same is to ensure that the objective conditions of the two tests are as similar as possible.

[0041] Finally, based on the distance d from the second center O2 of the second exposure point to the first center O1 of the first exposure point, and / or the change in the second radius r2 of the second exposure point relative to the first radius r1 of the first exposure point |r2-r1|, the degree to which the exposure point of the test laser is affected after the temperature rise is determined: (1) The larger d is, the greater the change in the laser spot position before and after the temperature rise; the smaller d is, the smaller the change in the laser spot position before and after the temperature rise; (2) The larger |r2-r1| is, the greater the change in the laser spot radius before and after the temperature rise; the smaller |r2-r1| is, the smaller the change in the laser spot radius before and after the temperature rise. It should be noted that the large change in spot radius and the large change in spot position mentioned in this application are conclusions drawn after comparison with a certain set threshold.

[0042] The above method can verify the impact of temperature rise on the position and size of the laser beam emitted by any laser in the laser direct writing device. This provides a reference for accurate image exposure using lasers: if the exposure accuracy requirement of the subsequent image is not high, and the position and radius changes of the focused laser beam are within an acceptable range, the laser can be used for subsequent image exposure; if the exposure accuracy requirement of the subsequent image is high, and the position and radius changes of the focused laser beam are large, affecting the image exposure accuracy, then the laser cannot be used for subsequent image exposure.

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for verifying the effect of temperature rise on the exposure point of a laser, characterized in that, include: Step 1: Place the thermal paper on the common focal plane of several lasers in the laser direct writing device, and the thermal paper is perpendicular to the principal optical axis of the several lasers; Step 2: Select any one of the lasers as the test laser. When the laser direct writing equipment is not in operation, the test laser exposes the thermal paper with the optimal exposure power for the first time to obtain the first exposure point. Step 3: After heating the laser direct writing device, the test laser is used to expose the thermal paper a second time at the optimal exposure power to obtain the second exposure point; Step 4: Based on the distance d from the second center of the second exposure point to the first center of the first exposure point, and the change in the second radius r2 of the second exposure point relative to the first radius r1 of the first exposure point |r2 - r1|, determine the degree to which the exposure point of the beam emitted by the test laser is affected by the temperature rise. The physical position of the thermal paper did not change before and after the temperature rise of the laser direct writing device.

2. The method for verifying the effect of temperature rise on the exposure point of a laser as described in claim 1, characterized in that, The optimal exposure power is the exposure power obtained by the test laser on the thermal paper when the spot size is closest to the actual size, as measured by the test software.

3. The method for verifying the effect of temperature rise on the exposure point of a laser as described in claim 1, characterized in that, The test laser was exposed to the thermal paper for the first and second times at the optimal exposure power, both times by the following method: the control module of the laser direct writing device controlled all lasers to be lit up once and then turned off sequentially at the optimal exposure power, until the last laser was lit up once and then turned off, and then the process stopped. The total time from the first laser to the last laser being lit was T1 milliseconds; wherein, when the test laser exposed the thermal paper twice, the first laser was the same laser.

4. The method for verifying the effect of temperature rise on the exposure point of a laser as described in claim 1, characterized in that, After the thermal paper is first exposed with the test laser and before the thermal paper is exposed for the second time, the process further includes: turning on the laser direct writing equipment and continuously lighting all lasers at maximum output power for T2 minutes.

5. The method for verifying the effect of temperature rise on the exposure point of a laser as described in claim 4, characterized in that, The process includes covering the thermal paper with a baffle after the test laser first exposes the thermal paper and before all lasers are continuously lit.

6. The method for verifying the effect of temperature rise on the exposure point of a laser as described in claim 1, characterized in that, In step 4, the first center and first radius of the first exposure point, as well as the second center and second radius of the second exposure point, are obtained through two-dimensional verification.

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