CN112427812B

CN112427812B - Method for realizing separation of ultrathin workpieces through spacing ultrafine laser through holes

Info

Publication number: CN112427812B
Application number: CN202011002626.8A
Authority: CN
Inventors: 姜峰; 廖良洲; 于大全
Original assignee: Xiamen Yun Tian Semiconductor Technology Co ltd
Current assignee: Xiamen Yun Tian Semiconductor Technology Co ltd
Priority date: 2020-09-22
Filing date: 2020-09-22
Publication date: 2022-09-09
Anticipated expiration: 2040-09-22
Also published as: CN112427812A

Abstract

A method for realizing ultra-thin workpiece separation through spacing ultra-fine laser through holes comprises the following steps: 1) a laser is adopted to generate a plurality of laser beams, and a perforating beam with a preset focal depth is generated after optical shaping focusing; 2) injecting a punching beam into the ultrathin workpiece, arranging a plurality of focuses from a first surface of the ultrathin workpiece to a second surface along a first direction, and forming a laser through hole penetrating through the first surface and the second surface on the ultrathin workpiece; 3) controlling the ultrathin workpiece to move along a second direction relative to the punching beam, and then sequentially connecting the laser through holes to divide the ultrathin workpiece into a first workpiece and a second workpiece, wherein the distance between every two adjacent laser through holes is 0.1-5 um; 4) and applying external force to the ultrathin workpiece to separate the butt joint surfaces of the adjacent laser through holes, so that the first workpiece and the second workpiece are completely separated. The method has the advantages of low cost, difficult edge breakage, better product reliability, no wet etching and other processes, and more environmental protection in the whole processing process.

Description

Method for realizing separation of ultrathin workpieces through spacing ultrafine laser through holes

Technical Field

The invention relates to the field of glass plate cutting, in particular to a method for separating ultrathin workpieces through spacing ultrafine laser through holes.

Background

With the rapid development of electronic products, mobile-end devices are being developed toward thinner size, lighter weight, and lower manufacturing cost. At present, the thickness of a glass sheet on an electronic product is reduced to 0.3mm or even lower, and an ultrathin glass sheet is more sensitive to acting force and is more susceptible to brittle failure after being impacted, which undoubtedly increases the difficulty of cutting processing.

The existing glass cutting methods are roughly a mechanical cutting method and a common laser cutting method. The mechanical cutting method is to use a diamond cutter to scribe a line on the glass cutting path, and has many problems, such as edge chipping, microcracks, and edge chipping of the glass material are reduced, the strength of the cut edge is reduced, the generated deep cracks are not perpendicular to the surface of the glass, the strength and reliability of the glass are reduced, and the yield is low.

The laser cutting method adopts a laser beam generated by a laser with pulse width ranging from picoseconds to femtoseconds, and the laser beam is focused and then is incident into a glass workpiece to be cut; the laser beam and the glass workpiece relatively move according to a preset path, so that a cutting layer consisting of a plurality of micro-crack points along the path swept by the laser beam is formed in the glass workpiece by the focus, and the cutting layer is shown in fig. 13; and applying an external force to the glass workpiece to cause the glass workpiece to tear along the path. By adopting the method, the damage to the glass workpiece is large, and much dust is generated. In addition, edge breakage is easily generated at a position close to the cutting layer on the surface of the glass workpiece, as shown in fig. 14, so that the cut glass workpiece is easy to crack.

In still another method for processing a profile of a board-level material, referring to fig. 1 and 2, a laser beam 3 is focused and then is incident from a first surface to a second surface of the board-level material 1 to be cut, the focal point of the laser beam is in the direction perpendicular to the incident surface of the board-level material, a vertical cutting column 4 formed by a plurality of microcracks 41 is formed, and then the board-level material is separated along a required cutting route by wet etching. The method needs to combine laser cutting and wet etching, has high cost and more processing steps, needs to adopt corrosive liquid for wet etching, and is not environment-friendly enough.

Disclosure of Invention

The invention mainly aims to overcome the defects in the prior art, and provides a method for separating ultrathin workpieces through spacing ultrathin laser through holes, which is low in cost, less prone to edge breakage and more environment-friendly.

The invention adopts the following technical scheme:

a method for realizing separation of ultrathin workpieces through spacing type ultrafine laser through holes is characterized by comprising the following steps:

1) a laser is adopted to generate a plurality of laser beams, and a perforating beam with a preset focal depth is generated after optical shaping focusing;

2) injecting a punching beam into the ultrathin workpiece, arranging a plurality of focuses from a first surface of the ultrathin workpiece to a second surface along a first direction, and forming a laser through hole penetrating through the first surface and the second surface on the ultrathin workpiece, wherein the diameter of the laser through hole is 0.1-5 um;

3) controlling the ultrathin workpiece to move along a second direction relative to the punching beam, so that the plurality of laser through holes are sequentially connected to divide the ultrathin workpiece into a first workpiece and a second workpiece, and the distance between every two adjacent laser through holes is 0.1-5 mu m;

4) and applying external force to the ultrathin workpiece to separate the butt joint surfaces of the adjacent laser through holes, so that the first workpiece and the second workpiece are completely separated.

Preferably, the thickness of the ultrathin workpiece is 0.05 mm-0.15 mm.

Preferably, the single point energy of the perforating light beam is in the range of 40 muJ to 200 muJ.

Preferably, in the punching beam, the energy distribution is gradually reduced along a first direction, and the inner diameter of the laser through hole is gradually reduced along the first direction.

Preferably, the diameter of the light spot formed on the ultrathin workpiece by the focus is 0.5-5 microns.

Preferably, the pulse width of the laser is in the range of 10 femtoseconds to 100 picoseconds.

Preferably, the material of the ultrathin workpiece is non-quartz glass, lithium tantalate, lithium niobate or a transparent material in three families or five families.

Preferably, in the step 4), a film is firstly pasted on the first surface or the second surface of the ultrathin workpiece, and then a film expanding machine is used for expanding the film, so that the first workpiece and the second workpiece are completely separated.

As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following advantages:

1. according to the method, the laser beams are focused to generate the perforating beams with a plurality of focuses, the perforating beams are shot into the ultrathin workpiece to form the through laser through holes, the laser through holes are sequentially connected through relative movement, and finally, the butt joint surfaces of the adjacent laser through holes are separated through applying external force to realize cutting, so that a high-precision and flat cutting surface can be obtained, chipping is avoided, the processing quality can be effectively guaranteed, and the cutting efficiency and the product reliability are improved.

2. The method is suitable for cutting ultrathin workpieces, the pulse width range of a laser is 10 femtoseconds-100 picoseconds, the single-point energy range of a punching beam is 40 muJ-200 muJ, the diameter range of a light spot is 0.5 microns-5 microns, a through laser through hole is formed by processing with higher single-point energy, the laser through hole can be easily separated from a butt joint face through external force, processing steps are reduced, wet etching is avoided, the cost is reduced, and the method is more environment-friendly.

3. According to the method, the energy distribution of the punching beam is gradually reduced along the first direction, and the inner diameter of the corresponding laser through hole is gradually reduced along the first direction, so that the first workpiece and the second workpiece can be separated by applying smaller force in the subsequent steps.

4. According to the invention, the film is pasted on the ultrathin workpiece, and the film expanding machine is matched to expand the diameter of the film, so that the first workpiece and the second workpiece are completely separated, the damage can be reduced, and the ultrathin workpiece is protected.

Drawings

FIG. 1 is a schematic diagram of a conventional laser cutting method;

FIG. 2 is a schematic view of a vertical cutting column of a prior art method;

FIG. 3 is a schematic illustration of a cut of the method of the present invention;

FIG. 4 is an enlarged view of FIG. 3 at A;

FIG. 5 is a top view of an ultra-thin workpiece with laser vias;

FIG. 6 is an enlarged view of FIG. 5 at B;

FIG. 7 is a schematic diagram showing the separation of the abutting surfaces of a plurality of laser vias;

FIG. 8 is a view showing a cutting line in a Z-shape;

FIG. 9 is a view showing a cutting line in an S-shape;

FIG. 10 is a top view of a laser via of the present invention;

FIG. 11 is a first electron microscope image of an ultrathin workpiece cut by the method of the present invention;

FIG. 12 is a second electron microscope image of an ultrathin workpiece cut by the method of the present invention;

FIG. 13 is an electron microscope image of an inner cutting layer of a glass work piece according to a prior art method;

FIG. 14 is a side-blown electron micrograph of a prior art method;

wherein: 1. ultrathin workpiece, 2, first workpiece, 3, second workpiece, 4, first surface, 5, second surface, 6, laser through hole, 7, butt joint face.

The invention is described in further detail below with reference to the following figures and specific examples.

Detailed Description

The invention is further described below by means of specific embodiments.

A method for realizing separation of ultrathin workpieces through spacing ultrathin laser through holes is disclosed, referring to fig. 3-7, and materials of ultrathin workpieces 1 applied to cutting are non-quartz glass, lithium tantalate, lithium niobate or transparent materials in three five groups. The thickness of the ultrathin workpiece 1 is 0.05 mm-0.15 mm.

The method specifically comprises the following steps:

1) a laser is adopted to generate a plurality of laser beams, and after optical shaping focusing, a punching beam with a preset focal depth is generated.

The laser adopted by the invention can be a picosecond laser or a femtosecond laser. The picosecond laser is a laser with pulse width of picosecond, and the femtosecond laser is a laser with pulse width of femtosecond. During the processing, the picosecond laser or the femtosecond laser can obtain laser energy with high oscillation density during laser oscillation, and the debris accumulation phenomenon cannot be generated during the processing.

Wherein, the pulse width range of the laser is 10 femtoseconds to 100 picoseconds, and the wavelength of the laser beam is 355 nanometers to 1064 nanometers, preferably 700 nanometers to 800 nanometers. After focusing, the single-point energy range of the perforating beam is 40 muJ-200 muJ, and the focal depth can be larger than the thickness of the ultrathin workpiece. In practical application, the wavelength of the laser beam, the single-point energy of the perforating beam and the focal depth can be selected correspondingly according to different thicknesses of the ultrathin workpiece to be processed.

In the present invention, the plurality of focal points of the perforating beam are arranged in a first direction with an energy distribution that gradually decreases in the first direction, see fig. 4, i.e., the focal energy near the first surface is the largest and the focal energy near the second surface is smaller. The number of laser beams may be determined according to the thickness of the ultra-thin workpiece 1, and more laser beams may form more focal points. By adjusting the emission angle of each laser beam, the position, the pitch, and the like of the focal point can be changed.

2) And injecting a punching beam into the ultrathin workpiece 1, arranging a plurality of focuses from the first surface 4 to the second surface 5 of the ultrathin workpiece 1 along a first direction, and forming a laser through hole 6 penetrating through the first surface 4 and the second surface 5 on the ultrathin workpiece 1, wherein the diameter of the laser through hole 6 is 0.1-5 mu m.

In this step, the arrangement direction of the plurality of focal points is the same as the first direction, that is, the straight line in which the plurality of focal points are arranged is parallel to the first direction, and the first direction may be the thickness direction of the ultra-thin workpiece and may be perpendicular to the first surface 4 and the second surface 5.

Referring to fig. 4, when each focus is focused on the ultrathin workpiece 1, the diameter range of the formed light spot is 0.5-5 micrometers, a small hole is generated in the ultrathin workpiece, and a plurality of small holes can be sequentially communicated along a first direction to form a laser through hole 6 due to the fact that single-point energy is large. When the energy distribution of the perforating beam is gradually reduced along the first direction, the inner diameter of the laser via 6 is gradually reduced along the first direction, see the top view of the laser via of fig. 10.

3) And controlling the ultrathin workpiece 1 to move along a second direction relative to the punching beam, and then sequentially connecting the laser through holes 6 to divide the ultrathin workpiece 1 into a first workpiece 2 and a second workpiece 3, wherein the distance range between every two adjacent laser through holes 6 is 0.1-5 um.

In this step, the ultra-thin workpiece 1 may be controlled to move relative to the punching beam by the processing platform, or the punching beam may be controlled to move relative to the ultra-thin workpiece 1, the moving path may be a preset cutting path extending along the second direction, the cutting path may be a straight line or a curved line, for example, the curved line may be a Z-shape or an S-shape, see fig. 8 and 9, and the special-shaped cutting may be achieved. The second direction may be perpendicular to the first direction, and may be a length direction, a width direction, or other directions of the ultra-thin workpiece 1, without limitation.

Referring to fig. 6, by setting a suitable moving speed, the laser through holes 6 generated by each pulse are sequentially arranged along the second direction, and the adjacent laser through holes 6 have the abutting surfaces 7 therebetween. In this case, the first workpiece 2 and the second workpiece 3 are connected only by the abutment surface 7.

4) And applying external force to the ultrathin workpiece to separate the abutting surfaces 7 of the adjacent laser through holes 6, so that the first workpiece 2 and the second workpiece 3 are completely separated.

This step can be implemented by using a film expanding machine, but is not limited thereto, and other suitable equipment can be adopted. Specifically, a film is firstly pasted on one surface of the ultrathin workpiece 1, and preferably, the film is pasted on the first surface 4; and then a film expanding machine is used for uniformly expanding the diameter of the film. Because the ultrathin workpiece 1 is stuck on the film, the first workpiece 2 and the second workpiece 3 are separated along with the film after the film is expanded.

According to the method, a plurality of laser beams are focused to generate perforating beams with a plurality of focuses, the perforating beams are shot into the ultrathin workpiece 1 to form the through laser through holes 6, the laser through holes 6 are sequentially connected through relative movement, and finally, the butt joint surfaces 7 of the adjacent laser through holes 6 are separated to realize cutting through applying external force, referring to fig. 11 and fig. 12, a high-precision and flat cutting surface can be obtained, chipping is avoided, the processing quality can be effectively ensured, and the cutting efficiency is improved.

The above description is only an embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modifications made by using the design concept should fall within the scope of infringing the present invention.

Claims

1. A method for realizing ultra-thin workpiece separation through spacing ultra-thin laser through holes is characterized by comprising the following steps:

1) a laser is adopted to generate a plurality of laser beams, and a punching beam is generated after optical shaping focusing and has a preset focal depth, wherein the single-point energy range of the punching beam is 40 muJ-200 muJ;

2) injecting a punching beam into the ultrathin workpiece, arranging a plurality of focuses from the first surface of the ultrathin workpiece to the second surface along a first direction, processing the ultrathin workpiece to generate small holes, and sequentially communicating the small holes along the first direction to form laser through holes, so that the laser through holes penetrating through the first surface and the second surface are formed on the ultrathin workpiece, wherein the diameter range of the laser through holes is 0.1-5 mu m;

3) controlling the ultrathin workpiece to move along a second direction relative to the punching beam, wherein the moving route is a straight line or a curve, the plurality of laser through holes are sequentially connected to divide the ultrathin workpiece into a first workpiece and a second workpiece, and the distance range between every two adjacent laser through holes is 0.1-5 um;

2. The method of claim 1, wherein the ultra-thin workpiece has a thickness of 0.05 mm to 0.15 mm.

3. The method of claim 1, wherein the energy distribution of the perforating beam is gradually reduced along a first direction, and the inner diameter of the laser via is gradually reduced along the first direction.

4. The method of claim 1, wherein the spot formed on the ultra-thin workpiece by the focal point has a diameter ranging from 0.5 microns to 5 microns.

5. The method of claim 1, wherein the laser has a pulse width in the range of 10 femtoseconds to 100 picoseconds.

6. The method for separating ultrathin workpieces through the spacing ultrathin laser through holes as claimed in claim 1, wherein the ultrathin workpieces are made of non-quartz glass, lithium tantalate, lithium niobate or light-transmitting III-V materials.

7. The method for separating an ultra-thin workpiece through the pitch-type ultra-fine laser via hole as claimed in claim 1, wherein in the step 4), the first workpiece and the second workpiece are completely separated by sticking a film on the first surface or the second surface of the ultra-thin workpiece and then performing film expansion by using a film expander.