CN217096141U

CN217096141U - Laser optical system

Info

Publication number: CN217096141U
Application number: CN202221595248.3U
Authority: CN
Inventors: 肖向荣
Original assignee: Wuhan Songsheng Photoelectric Technology Co ltd
Current assignee: Wuhan Songsheng Photoelectric Technology Co ltd
Priority date: 2022-06-24
Filing date: 2022-06-24
Publication date: 2022-08-02
Anticipated expiration: 2032-06-24

Abstract

The utility model relates to a laser optical system, which aims to solve the technical problem that the adoption of a rectangular light spot to weld a miniLED chip can cause dark damage to the central part of the chip in the prior art; the laser device comprises a laser emitting unit, a beam splitting unit and a light path modulation component, wherein original laser emitted by the laser emitting unit passes through the beam splitting unit and then outputs two beams of emergent laser, and each emergent laser passes through the light path modulation component and then is output to a sample to form a laser spot; the laser welding device can realize that two laser spots just correspond to two ends of a long edge of a miniLED chip to be welded, laser irradiation is not carried out in the middle area of the chip, and the possibility of dark injury in the middle of the chip is remarkably reduced.

Description

Laser optical system

Technical Field

The utility model relates to the field of optical technology, concretely relates to laser optical system.

Background

The Mini LED is defined as: the LED device with the chip size between 50 and 200 mu m is a unit which consists of a Mini LED pixel array and a driving circuit and has the pixel center distance of 0.3-1.5 mm. With the large-scale introduction of miniLED products, more and more miniLED repair problems also synchronously appear. The miniLED is actually too small, the die bonding effect is difficult to improve (unless the speed is greatly reduced) due to the precision of the traditional die bonding equipment, and on the other hand, the defects in the production process are aggravated by the traditional reflow furnace mode.

At present, the yield of miniLED is difficult to control within 100 PPM, that is to say, the number of bad LEDs is about 4-5 for RGB miniLED display screen with palm as large as this.

The repair process is split, including: melting the welding points of the chip, removing the chip, cleaning the welding pad, re-welding the tin paste, fixing the crystal to a new chip and welding the chip. The most important tool in this process is the laser, which is used to remove the bad die and to bond the new die.

With the miniLED's getting smaller and smaller in size, especially to micro size, the rework device also faces more challenges, mainly expressed as: the light spot of the common laser is generally circular, and the energy is in Gaussian distribution. The LED chip is generally rectangular, and the LED chip is welded by using the traditional laser, which means that the energy of the laser is directly exposed on the PCB at the short side of the LED, so that the PCB is burned; the gaussian distributed laser energy also means that the temperature of the center position of the LED chip is relatively high, which is very easy to cause dark damage (especially red LED chip) to the LED chip, resulting in increased leakage current of the LED chip and light decay or even lamp death of the LED chip.

SUMMERY OF THE UTILITY MODEL

Based on the above, the utility model provides a laser optical system to adopt rectangle facula welding miniLED chip can cause the technical problem of hindering secretly to chip central part among the solution prior art.

The utility model provides an above-mentioned technical problem's technical scheme as follows:

a laser optical system comprises a laser emitting unit, a beam splitting unit and a light path modulation component, wherein original laser emitted by the laser emitting unit passes through the beam splitting unit and then outputs two beams of emergent laser, and each emergent laser passes through the light path modulation component and then is output to a sample to form a laser spot.

Compared with the prior art, the technical scheme of the application has the following beneficial technical effects:

the application provides a laser optical system, adopt the beam splitting unit to split the beam of laser emission unit into two bundles of emergent laser, export simultaneously through the light path modulation subassembly on the sample and form the laser spot, two laser spots of direct formation on the sample promptly, the realization is set for the interval of two laser spots, both can realize that two laser spots just in time correspond the both ends of treating the long limit of welded miniLED chip, do not have laser irradiation in chip middle part region, show the possibility that reduces the chip middle part and appear the dark wound.

On the basis of the technical scheme, the utility model discloses can also do following improvement.

Further, the device also comprises a distance adjusting unit, wherein the distance adjusting unit is connected with the beam splitting unit and is used for adjusting the distance between the laser light spots on the sample.

Furthermore, the light path modulation component comprises a collimating optical lens group, a reflecting mirror, a first spectroscope and a multiband focusing lens group which are sequentially arranged along a light path, wherein the collimating optical lens group is used for collimating the emergent laser into parallel light, the parallel light is transmitted to the first spectroscope after being reflected by the reflecting mirror, and the multiband focusing lens group is arranged on the reflecting side of the first spectroscope and is used for focusing and outputting the parallel light reflected by the first spectroscope to the sample.

Furthermore, the beam splitting unit, the collimating optical lens group and the reflecting mirror are arranged along a first straight line, the first beam splitter and the multiband focusing lens group are arranged along a second straight line, the first straight line and the second straight line are distributed in parallel at intervals, and the reflecting mirror and the first beam splitter are arranged in parallel at intervals.

Furthermore, the laser optical system further comprises an imaging unit, wherein the imaging unit is arranged on the second straight line and is positioned on one side of the multiband focusing mirror group away from the sample.

Furthermore, the laser optical system further comprises a temperature measuring unit and a second spectroscope, wherein the second spectroscope is arranged on the transmission side of the first spectroscope, the reflection side of the second spectroscope is arranged corresponding to the temperature measuring unit, and the transmission side of the second spectroscope is arranged corresponding to the imaging unit.

Further, the distance adjusting unit comprises a focal length adjusting mechanism, the beam splitting unit comprises a binary diffractive optical element, and the focal length adjusting mechanism is used for adjusting the focal length of the binary diffractive optical element.

Drawings

Fig. 1 is a schematic structural diagram of a laser optical system according to an embodiment of the present invention;

FIG. 2 is a schematic side view of the structure of FIG. 1;

FIG. 3 is a schematic diagram of the optical path of the laser optical system during use;

FIG. 4 is a schematic diagram showing the relationship between the DOE distance between the optical fibers and the laser spot distance;

fig. 5 is a schematic diagram of different laser spot pitches.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that spatial relationship terms, such as "under … …," "under … …," "under … …," "over … …," "over," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "below … …" and "below … …" can encompass both an orientation of up and down. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations) and the spatial descriptors used herein interpreted accordingly.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. The "connection" in the following embodiments is understood as "electrical connection", "communication connection", or the like if the connected circuits, modules, units, or the like have electrical signals or data transmission therebetween.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

As shown in fig. 1 to 3, the present embodiment provides a laser optical system including a laser emitting unit 1, a beam splitting unit 2, and an optical path modulating assembly 3.

The original laser emitted by the laser emitting unit 1 passes through the beam splitting unit 2 and then outputs two beams of emergent laser, and each emergent laser passes through the light path modulation component 3 and then is output to a sample to form a laser spot.

This laser optical system, adopt beam splitting unit 2 to split into two bundles of outgoing laser with the original laser that laser emission unit 1 transmitted, export simultaneously behind light path modulation subassembly 3 and form the laser facula on sample 4, two laser facula of direct formation on sample 4 promptly, the realization is set for the interval of two laser facula, both can realize that two laser facula just in time correspond the both ends of treating the long limit of welded miniLED chip, do not have laser irradiation in chip middle part region, show the possibility that reduces chip middle part and appear the dark wound.

In some preferred embodiments of the present application, the laser optical system further includes a distance adjusting unit 4, and the distance adjusting unit 4 is connected to the beam splitting unit 2 and is used for adjusting the pitch of the laser spots on the sample 10 (preferably a miniLED chip in this embodiment).

Specifically, the distance adjusting unit 4 includes a focal length adjusting mechanism, the beam splitting unit 2 includes a binary diffractive optical element, more specifically, a binary diffractive beam splitter, which is also called DOE, and it can have a defined diffraction pattern (regular or irregular dot matrix) as required, so that a single incident laser beam is split into multiple emergent beams, which is equivalent to understand that a part of the incident beam is diffracted, so that a position originally of one laser spot is low in light intensity of a partial region to form a dark portion, and a position of the partial region is high to form a bright portion.

The focal length adjusting mechanism 4 is used for adjusting the focal length of the binary diffractive optical element, wherein the adjusting mechanisms that can be used for adjusting the focal length are all the focal length adjusting mechanisms 4 described in the present application, in the prior art, there are many structures and elements used for adjusting the focal length of the optical element, and in this embodiment, it is preferable to adjust the distance between the binary diffractive beam splitter and the optical fiber to adjust the focal length of the binary diffractive optical element, and further adjust the distance between the laser spots to match the sizes of miniLED chips of different specifications, for example, in some embodiments, when the DOE is 15mm away from the optical fiber, the distance between the laser spots is 0.1 mm; when the DOE is 36mm away from the optical fiber, the distance between laser spots is 0.25 mm; when the DOE is 57mm from the fiber, the laser spot pitch is 0.4mm, as shown in fig. 4 and 5, different laser spot pitches correspond to different DOE-to-fiber distances.

The optical path modulation component 3 includes a collimating optical lens group 31, a reflecting mirror 32, a first beam splitter 33 and a multiband focusing lens group 34, which are sequentially arranged along an optical path, where the collimating optical lens group 31 is configured to collimate the emergent laser light into parallel light, in this embodiment, the collimating optical lens group 31 includes a first collimating lens 311, a second collimating lens 312 and a third collimating lens 313, which are coaxially arranged, and are fixedly installed inside a housing of the collimating unit 1, and an emergent surface of the first collimating lens 311 is a concave surface for converging incident circular laser light; the second collimating lens 312 has a concave incident surface and a convex output surface, and is used to convert the laser light converged by the first collimating lens 311 into approximately parallel laser light, and the third collimating lens 313 is a fine tuning lens, and is used to fine tune the approximately parallel laser light, so as to achieve better collimation effect and form parallel light.

The parallel light is reflected by the reflecting mirror 32 and then transmitted to the first beam splitter 33, and the multiband focusing mirror group 34 is disposed on the reflecting side of the first beam splitter 33 and is used for focusing and outputting the parallel light reflected by the first beam splitter 33 to the sample.

The multiband focusing mirror group 34 can focus the laser beams with multiple wavebands, and focuses the parallel light reflected by the first beam splitter 33 to a proper spot size, thereby completing the welding of the miniLED chip.

In order to facilitate the arrangement of the first beam splitter 33 and the reflector 32, the binary diffractive optical element, the collimating optical lens group 31 and the reflector 32 are disposed along a first straight line, i.e., a left barrel, the first beam splitter 33 and the multiband focusing optical lens group 31 are disposed along a second straight line, i.e., a right barrel, the first straight line and the second straight line are distributed in parallel at intervals, and the reflector 32 and the first beam splitter 33 are disposed in parallel at intervals.

Preferably, in this embodiment, the laser optical system further includes an imaging unit 5, where the imaging unit 5 is disposed on the second straight line and is located on a side of the multiband focusing mirror group 34 away from the sample; the imaging unit 5 is used for sampling the reflected light at the welding point and imaging the reflected light of the welding point, so that the welding condition is monitored on a background display, and the welding abnormity is discovered in time, and the loss is stopped in time, and the imaging unit 5 can adopt a CCD camera provided with an optical imaging lens.

In this embodiment, the laser optical system further includes a temperature measuring unit 6 and a second beam splitter 7, the second beam splitter 7 is disposed on the transmission side of the first beam splitter 33, the reflection side of the second beam splitter 7 is disposed corresponding to the temperature measuring unit 6, and the transmission side of the second beam splitter 7 is disposed corresponding to the imaging unit 5.

And part of the laser reflected by the welding point is transmitted from the second spectroscope 7 and enters the imaging unit for imaging, the other part of the laser is reflected by the second spectroscope 7 and enters the temperature measuring unit 6 for measuring the temperature, and the temperature measuring unit can adjust the laser power according to the obtained real-time temperature of the welding point, so that the temperature of the welding point is ensured to be constant, and the welding quality is ensured. The specific control of the laser power according to the temperature value obtained by sampling is not a protection point required by the application, and is not repeated here.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser optical system is characterized by comprising a laser emitting unit, a beam splitting unit and a light path modulation component, wherein original laser emitted by the laser emitting unit passes through the beam splitting unit and then outputs two beams of emergent laser, and each emergent laser passes through the light path modulation component and then is output to a sample to form a laser spot.

2. The laser optical system according to claim 1, further comprising a distance adjusting unit connected to the beam splitting unit for adjusting a pitch of the laser spot on the sample.

3. The laser optical system according to claim 2, wherein the optical path modulation assembly includes a collimating optical lens group, a reflecting mirror, a first beam splitter and a multiband focusing lens group, which are sequentially disposed along the optical path, the collimating optical lens group is configured to collimate the emergent laser light into parallel light, the parallel light is transmitted to the first beam splitter after being reflected by the reflecting mirror, and the multiband focusing lens group is disposed on a reflecting side of the first beam splitter and is configured to focus and output the parallel light reflected by the first beam splitter to the sample.

4. The laser optical system of claim 3, wherein the beam splitting unit, the collimating optic and the mirror are disposed along a first line, the first beam splitter and the multiband focusing optic are disposed along a second line, the first line and the second line are spaced apart in parallel, and the mirror and the first beam splitter are spaced apart in parallel.

5. The laser optical system of claim 4, further comprising an imaging unit disposed on the second straight line and on a side of the multi-band focusing mirror group away from the sample.

6. The laser optical system according to claim 5, further comprising a temperature measuring unit and a second beam splitter, wherein the second beam splitter is disposed on a transmission side of the first beam splitter, a reflection side of the second beam splitter is disposed corresponding to the temperature measuring unit, and a transmission side of the second beam splitter is disposed corresponding to the imaging unit.

7. The laser optical system according to claim 2, wherein the distance adjusting unit includes a focal length adjusting mechanism, and the beam splitting unit includes a binary diffractive optical element, and the focal length adjusting mechanism is configured to adjust a focal length of the binary diffractive optical element.