A method and device for micro hole processing

Abstract

The present application discloses a method and equipment for micro-hole processing, wherein a device to be processed is placed in an etching liquid, wherein the device to be processed has a modified line extending from a first surface to a second surface and arranged corresponding to the position of the micro-hole; the etching liquid on at least one side of the first surface and the second surface of the device to be processed is pressurized until the modified line of the device to be processed expands to form a through hole; the first pressure of the etching liquid on the first surface side of the device to be processed is made greater than the second pressure of the etching liquid on the second surface side, and the etching liquid is driven to flow from the first surface side to the second surface side through the through hole of the device to be processed, thereby accelerating the corrosion speed of the inner wall of the through hole; the present invention can improve the problems of poor taper and low aspect ratio of holes in laser drilling, thereby processing thicker through holes and reducing the "hourglass hole" effect; different hole types can also be obtained by changing the processing conditions to meet the processing requirements of different products.

Description

Technical Field

[0001] The present application relates to the technical field of laser micro-hole processing, and more specifically, to a method and equipment for laser micro-hole processing. Background Art

[0002] The laser drilling technology currently used generally uses a high-power density laser beam to irradiate the processed material, so that the material is quickly heated to the vaporization temperature and evaporates to form holes. Compared with traditional mechanical drilling, it has the advantages of high precision, strong versatility and high efficiency. However, due to the high energy and high focus characteristics of laser, laser drilling has problems such as large actual aperture, broken edges, and rough side walls. In addition, when a large number of through holes are produced at a single point, the cost will be very high.

[0003] Laser modification processing combined with chemical etching technology solves the above-mentioned problems of conventional laser drilling, but there are still problems in terms of aperture taper and aspect ratio. It is difficult to process holes with small taper and high aspect ratio. Summary of the invention

[0004] In view of at least one defect or improvement need of the prior art, the present invention provides a method and equipment for micro-hole processing, which is intended to improve the problems of poor taper and low aspect ratio of holes in laser drilling.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for micro-hole processing is provided, which is used to etch a device to be processed having a modified line to form a through hole, and the steps are as follows:

[0006] S1: placing a device to be processed in an etching solution, wherein the device to be processed has a modified line extending from a first surface to a second surface and arranged corresponding to a position of a microhole;

[0007] S2 pressurizes the etching liquid on at least one of the first surface and the second surface of the device to be processed until the modified line of the device to be processed expands to form a through hole;

[0008] S3 makes the first pressure of the etching liquid on the first surface side of the device to be processed greater than the second pressure of the etching liquid on the second surface side, driving the etching liquid to flow from the first surface side to the second surface side through the through hole of the device to be processed.

[0009] Preferably, the above-mentioned micro-hole processing method further includes S4 changing the pressure difference between the first pressure and the second pressure so that the second pressure is greater than the first pressure, driving the etching liquid to flow along the through hole from the second surface side of the device to be processed to the first surface side;

[0010] And optional S5, repeating S3 and S4, so that the etching liquid flows along the through hole alternately from the first surface side to the second surface side of the device to be processed and from the second surface side to the first surface side.

[0011] Preferably, in the above-mentioned micro-hole processing method, in step S2, the first surface side and the second surface side of the device to be processed are pressurized simultaneously, and the first pressure of the corrosive liquid on the first surface side is equal to the second pressure of the corrosive liquid on the second surface side.

[0012] Preferably, in the above-mentioned micro-hole processing method, in step S2, the first pressure of the etching liquid on the first surface side is made greater than the second pressure of the etching liquid on the second surface side; or

[0013] The second pressure of the etching liquid on the second surface side is made greater than the first pressure of the etching liquid on the first surface side.

[0014] Preferably, in the above-mentioned micro-hole processing method, the pressure applied to the corrosive liquid in S2 is 2-50 bar, and the time is 5-600 minutes;

[0015] The first pressure in S3 is 2-30 bar, the second pressure is 1 bar, and the time is 1-60 minutes;

[0016] In S4, the first pressure is 1 bar, the second pressure is 2-30 bar, and the time is 1-60 minutes;

[0017] In S5, the number of alternations is 1-100 times.

[0018] Preferably, in the above-mentioned micro-hole processing method, the pressure applied to the corrosive liquid in step S2 is 2-10 bar, and the time is 10-60 minutes;

[0019] The first pressure in S3 is 2-10 bar, the second pressure is 1 bar, and the time is 5-30 minutes;

[0020] In S4, the first pressure is 1 bar, the second pressure is 2-10 bar, and the time is 5-30 minutes; in S5, the number of alternations is 1-10 times.

[0021] Preferably, in the above-mentioned micro-hole processing method, the modified line of the device to be processed is irradiated from the first surface of the device to be processed by a laser beam, which generates induced absorption in the device to be processed and generates a modified line extending from the first surface to the second surface.

[0022] Preferably, in the above-mentioned micro-hole processing method, the modified line of the device to be processed is irradiated from the first surface of the device to be processed by a Bessel laser beam to form a linear focused spot of a certain length, generate induced absorption in the device to be processed, and generate a modified line extending from the first surface to the second surface; or,

[0023] Laser filamentation processing is adopted, whereby laser is irradiated from the first surface of the device to be processed, plasma is excited on the surface layer of the first surface, a linear focused light spot of a certain length is formed and propagates forward, induced absorption is generated in the device to be processed, and a modified line extending from the first surface to the second surface is generated; or,

[0024] A laser beam is used to irradiate the first surface of the device to be processed, and the focus of the beam is moved toward the second surface to generate a modified line extending from the first surface to the second surface.

[0025] Preferably, in the above-mentioned micro-hole processing method, the etching liquid is arranged in a closed container, two closed and independent etching chambers are formed on both sides of the device to be processed, and the pressure of the etching liquid in each etching chamber is controlled separately.

[0026] Preferably, in the above-mentioned micro-hole processing method, the etching liquid is an alkaline etching liquid or an acidic etching liquid.

[0027] Preferably, in the above-mentioned micro-hole processing method, the alkaline etching solution is a mixture of any one or more of potassium hydroxide, sodium hydroxide, and tetramethylammonium hydroxide; or, the alkaline etching solution is a solution or a mixture containing alkali metal ions and hydroxide ions;

[0028] The acidic etching liquid is a mixture of any one or more of hydrofluoric acid, hydrochloric acid and sulfuric acid; or, the acidic etching liquid is a mixture of a fluorine-containing alkaline solution and a hydrogen ion solution.

[0029] Preferably, in the above-mentioned micro-hole processing method, the device to be processed is glass, quartz or crystal.

[0030] Preferably, in the above-mentioned micro-hole processing method, the thickness of the device to be processed is 10 μm-5 mm, and the diameter of the through hole is 2 μm-1 mm.

[0031] According to another aspect of the present invention, there is also provided a micro-hole processing device for etching a device to be processed having a modified line to form a through hole, which comprises:

[0032] Closed container for storing corrosive liquid;

[0033] The device to be processed is arranged in the closed container, and the closed container is divided into at least two independent and closed etching chambers, and the first surface and the second surface of the device to be processed face the first etching chamber and the second etching chamber respectively and contact the etching liquid in the first etching chamber and the second etching chamber respectively;

[0034] The pressurizing device pressurizes the independent first corrosion chamber and / or the second corrosion chamber respectively.

[0035] Preferably, in the above-mentioned micro-hole processing equipment, the pressurizing device applies the same or different pressures to the independent corrosion chambers.

[0036] Preferably, in the above-mentioned micro-hole processing equipment, the pressurizing device pressurizes the independent corrosion chamber to increase the pressure inside the corrosion chamber, so that the corrosion liquid corrodes along the modified line until a through hole is formed.

[0037] Preferably, in the above-mentioned micro-hole processing equipment, the pressurizing device pressurizes the interior of at least one corrosion cavity, and makes the pressures of the corrosion cavities corresponding to the first surface and the second surface different, thereby generating a pressure difference, so that the corrosion liquid flows from the corrosion cavity on one side into the corrosion cavity on the other side through the through hole on the device to be processed.

[0038] Preferably, in the above-mentioned micro-hole processing equipment, the pressurizing device is a liquid booster pump or a gas-liquid booster pump, which pressurizes the corrosion cavity through an air pipe.

[0039] Preferably, the above-mentioned micro-hole processing equipment also includes: an adapter frame for clamping the device to be processed, and its shape matches the inner wall profile of the closed container; the adapter frame is inserted into the closed container to form an independent and closed corrosion cavity on both sides of the first surface and the second surface of the device to be processed.

[0040] Preferably, in the above-mentioned micro-hole processing equipment, a sealing ring is provided on the edge of the adapter frame.

[0041] Preferably, in the above-mentioned micro-hole processing equipment, a grid-shaped fixed bracket is provided in the middle of the adapter frame, and the grid positions on the fixed bracket correspond to the positions of the micro-holes to be processed on the device to be processed.

[0042] Preferably, the above-mentioned micro-hole processing equipment further comprises: a conduit, both ends of which extend into independent corrosion chambers respectively, and the corrosion liquids in the two corrosion chambers reflux through the conduit.

[0043] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0044] (1) The method and equipment for micro-hole processing provided by the present invention place the device to be processed with the modified line in a closed container filled with a corrosive liquid, and control the liquid intensity of the corrosive liquid on both sides of the device to be processed so that the modified line expands to form a micro-hole, which is beneficial to improve the taper of the hole, reduce the "hourglass hole" effect, and improve production efficiency.

[0045] (2) The micro-hole processing method and equipment provided by the present invention can obtain a variety of different hole shapes by controlling the pressure and opening time in the etching chamber on both sides of the processing surface of the device to be processed, thereby meeting the processing requirements of different products. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the composition of the micro-hole processing equipment provided in this embodiment;

[0048] Figure 2 Schematic diagram of the change of micropore taper with time at different stages of the corrosion process;

[0049] Figure 3 This is a front view of the processed device after etching is completed;

[0050] Figure 4 is a cross-sectional view of a processing device corresponding to Comparative Example 1;

[0051] Figure 5 is a cross-sectional view of a processing device corresponding to Example 1;

[0052] Figure 6 It is a cross-sectional view of the processing device corresponding to Example 2. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0054] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0055] The present invention provides a method and device for micro-hole processing, aiming to improve the problems of poor taper and low aspect ratio of micro-hole processing in the prior art, and also improve the efficiency of micro-hole processing, which is particularly suitable for glass micro-hole processing (TGV), thereby improving the filling and transfer effect when using the adapter plate with the micro-hole as a carrier, and its applicability as other applications. In addition, the method and device for micro-hole processing provided by the present invention can also obtain different hole shapes such as trumpet holes, straight holes, hourglass-shaped holes or asymmetric micro-holes as needed.

[0056] On the one hand, the present application provides a method for micro-hole processing, which is mainly used to perform micro-hole processing on devices such as glass, and to form straight holes, trumpet holes or hourglass-shaped holes as needed, and can improve the efficiency of micro-hole processing and improve the problems of poor taper and low aspect ratio of holes in micro-hole processing in the prior art.

[0057] The device to be processed of the present invention has a first surface and a second surface which are substantially parallel to each other, and the processed device has one or more micro-holes extending from the first surface to the second surface.

[0058] The micro-hole processing method of the present invention first forms a modified line on the device to be processed, and the modified line is a modified line (laser damage mark) extending from the first surface to the second surface and arranged corresponding to the position of the micro-hole. Then the device to be processed is placed in an etching liquid, and the first surface and the second surface of the device to be processed correspond to the etching liquid with a first pressure and a second pressure, respectively. The modified line is amplified by etching to form a through hole. Optionally, the pressure difference between the first pressure and the second pressure is then controlled to make the etching liquid flow from one side of the device to be processed to the other side through the through hole, accelerate the corrosion, and expand the through hole. And by controlling the pressure difference between the first pressure and the second pressure, the flow direction of the etching liquid in the through hole is changed. According to needs, a straight hole, a trumpet hole, an hourglass-shaped hole or an asymmetric micro-hole is formed.

[0059] Specifically, it includes the following steps:

[0060] S1: placing a device to be processed in a corrosive solution, wherein the device to be processed has a modified line (laser damage mark) extending from a first surface to a second surface and arranged corresponding to the position of the microhole;

[0061] S2 pressurizes the etching liquid on at least one of the first surface and the second surface of the device to be processed until the modified line on the device to be processed expands to form a through hole;

[0062] S3 makes the first pressure of the etching liquid on the first surface side of the device to be processed greater than the second pressure of the etching liquid on the second surface side, driving the etching liquid to flow from the first surface side to the second surface side along the device to be processed through the through hole;

[0063] S4 further includes: changing the first pressure and the second pressure so that the second pressure is greater than the first pressure, driving the etching liquid to flow along the through hole from the second surface side of the device to be processed to the first surface side;

[0064] S5: Further, S3 and S4 are repeated to make the etching liquid flow along the through hole alternately from the first surface side to the second surface side of the device to be processed and from the second surface side to the first surface side.

[0065] Furthermore, the modified line of the device to be processed can be formed by the following method:

[0066] A laser beam is used to irradiate the first surface of the device to be processed, so as to generate induced absorption in the device to be processed and generate a modified line extending from the first surface to the second surface.

[0067] Specifically, as a non-limiting embodiment, the modified line of the device to be processed is formed by one of the following methods.

[0068] Preferably, a Bessel laser beam is used to irradiate from the first surface to form a linear focused spot of a certain length, which induces absorption in the device to be processed and generates a modified line (laser damage mark) extending from the first surface to the second surface.

[0069] Preferably, the modified line of the device to be processed is processed by laser filamentation. The laser is irradiated from the first surface of the device to be processed, and plasma is excited on the surface of the first irradiated surface, inducing the self-focusing effect of the light beam and the divergent clamping balanced therewith, forming a linear focused light spot of a certain length that propagates forward, generating induced absorption in the device to be processed, and generating a modified line extending from the first surface to the second surface.

[0070] Alternatively, the modified line of the device to be processed is formed by irradiating the first surface of the device to be processed with a laser beam and moving the focus of the beam toward the second surface to generate a modified line extending from the first surface to the second surface.

[0071] When there are multiple modified lines, the laser beam is used to irradiate them one by one to complete the processing of all the modified lines.

[0072] It is preferred to use a picosecond or femtosecond laser as the laser source to increase the peak power.

[0073] S2 to S5 can be carried out in a closed container filled with etching liquid. The device to be processed is placed in the closed container to form two closed and independent etching chambers on both sides of the device to be processed. The first etching chamber corresponds to the first surface, and the second etching chamber corresponds to the second surface. The pressures of the two etching chambers can be adjusted separately.

[0074] Through the above scheme, the present application controls the hole shape of the through hole by adjusting the pressure in the etching chamber on both sides of the device to be processed and the pressurization time, so as to obtain a straight hole, a trumpet hole, an hourglass-shaped hole or an asymmetric micro-hole.

[0075] In the first specific embodiment, the hourglass hole, straight hole or asymmetric micro-hole can be obtained by performing the following processing steps:

[0076] In S2, the first etching chamber and the second etching chamber are pressurized respectively to ensure that the pressures in the two etching chambers are the same, so that the etching liquid etches the modified line from the first surface and the second surface along the modified line direction, expanding the modified line until a through hole is formed;

[0077] In this step, by pressurizing the etching liquid to produce a higher pressure, the longitudinal corrosion rate of the hole (i.e., the corrosion rate along the length of the modified line) will be accelerated, so that the laser damage marks can complete the hole penetration at a smaller aperture, thereby obtaining a through hole with a higher aspect ratio.

[0078] In S3, pressure is applied to the interior of at least one of the etching chambers to generate a pressure difference between the first etching chamber and the second etching chamber. Driven by the pressure difference, the etching liquid flows from the etching chamber with high pressure to the other etching chamber through the through hole, thereby accelerating the etching speed of the inner wall of the through hole.

[0079] In S4, the pressure difference between the two etching chambers is changed to make the etching liquid flow in the reverse direction, that is, the flow direction of the etching liquid in the through hole is opposite to that in S3.

[0080] In S5, S3 and S4 may be repeated to change the flow direction of the etching liquid in the through hole according to the set frequency, thereby improving the uniformity of the etching inside the through hole.

[0081] Generally speaking, if only S2 and S3 are executed, that is, after the modified line is expanded into a through hole, the etching liquid is only allowed to flow unidirectionally inside the through hole, an asymmetric micropore between an hourglass hole and a trumpet hole can be obtained; if S2, S3, S4 and S5 are executed, that is, after the modified line is expanded into a through hole, the etching liquid is allowed to flow alternately in bidirectional directions inside the through hole, an hourglass hole or a straight hole can be obtained.

[0082] Further preferably, the pressure applied to the corrosive liquid in S2 is 2-50 bar, and the time is 5-600 minutes;

[0083] The first pressure in S3 is 2-30 bar, the second pressure is 1 bar, and the time is 1-60 minutes;

[0084] In S4, the first pressure is 1 bar, the second pressure is 2-30 bar, and the time is 1-60 minutes;

[0085] In S5, the number of alternations is 1-100 times.

[0086] Further preferably, the first pressure and the second pressure in step S2 are both 2-10 bar, and the time is 10-60 minutes;

[0087] In step S3, the first pressure is 2-10 bar, the second pressure is 1 bar, and the time is 5-30 minutes;

[0088] In step S4, the first pressure is 1 bar, the second pressure is 2-10 bar, and the time is 5-30 minutes;

[0089] In step S5, the number of cycles is 1-10 times.

[0090] In the second specific embodiment, the following processing steps are performed to obtain a trumpet hole or an asymmetric micro-hole:

[0091] In S2, the etching liquid on at least one side of the first surface and the second surface of the device to be processed is pressurized so that the first pressure of the etching liquid on the first surface side is greater than the second pressure of the etching liquid on the second surface side, until the modified line of the device to be processed expands to form a through hole;

[0092] Specifically, for example, only the etching liquid on the first surface side of the device to be processed may be pressurized, or the etching liquid on both the first surface and the second surface may be pressurized at the same time, but the first pressure of the etching liquid on the first surface side is controlled to be greater than the second pressure of the etching liquid on the second surface side;

[0093] In S3, after the through hole is formed, the first pressure of the etching liquid on the first surface side of the device to be processed is maintained to be greater than the second pressure of the etching liquid on the second surface side, and the etching liquid is driven to flow from the first surface side to the second surface side through the through hole of the device to be processed;

[0094] By executing the above processing steps, a horn hole can be obtained; it should be noted that the through hole formed in S2 already has the shape of a horn hole, and continuing to execute S3 for a period of time is conducive to improving the taper inside the horn hole.

[0095] In this embodiment, the first pressure in step S2 is 2-10 bar, and the corresponding second pressure needs to be less than the first pressure, for example, 1 bar, and the time is 10-60 minutes;

[0096] The first pressure in step S3 is 2-10 bar, and the corresponding second pressure needs to be smaller than the first pressure, for example, 1 bar, and the time is 5-60 minutes.

[0097] If in the aforementioned step S2, the second pressure of the etching liquid on the second surface side is controlled to be greater than the first pressure of the etching liquid on the first surface side, until the modified line of the device to be processed expands to form a through hole; and then in S3, the first pressure of the etching liquid on the first surface side of the device to be processed is greater than the second pressure of the etching liquid on the second surface side, and the etching liquid is driven to flow from the first surface side to the second surface side through the through hole of the device to be processed, then an asymmetric micropore between the hourglass hole and the trumpet hole can be obtained.

[0098] In this embodiment, the second pressure in step S2 is 2-10 bar, and the corresponding first pressure needs to be less than the first pressure, for example, 1 bar, and the time is 10-60 minutes;

[0099] The first pressure in step S3 is 2-10 bar, and the corresponding second pressure needs to be smaller than the first pressure, for example, 1 bar, and the time is 5-60 minutes.

[0100] After the two processing methods provided in this embodiment are executed to obtain the trumpet hole or the asymmetric micro-hole, if the bidirectional alternating etching steps in S4 and S5 provided in the first embodiment are continued to be executed, the asymmetric micro-hole can be finally obtained.

[0101] Specifically, the type of etching liquid is selected according to the material of the device to be processed, and is generally divided into two types: alkaline etching liquid and acidic etching liquid. The alkaline etching liquid is any etching material based on hydroxide such as potassium hydroxide, sodium hydroxide or tetramethylammonium hydroxide, and the acidic etching liquid is hydrofluoric acid, hydrochloric acid, sulfuric acid or a mixture thereof.

[0102] On the other hand, the present application also provides a micro-hole processing device.

[0103] Figure 1 This is a schematic diagram of the composition structure of the micro-hole processing equipment provided in this embodiment, see Figure 1 The micro-hole processing equipment includes: a closed container for storing etching liquid; a device to be processed is placed in the closed container, and the closed container is divided into at least two independent and closed etching chambers; a pressurizing device is used to pressurize each independent and closed etching chamber respectively; the first surface and the second surface of the device to be processed are respectively facing the two independent etching chambers and are in contact with the etching liquid in the chambers.

[0104] Among them, the closed container is used to store the corrosive liquid; the type of corrosive liquid can be selected according to the material of the device to be processed, and is generally divided into two types: alkaline corrosive liquid and acidic corrosive liquid. The alkaline corrosive liquid is any corrosive material based on hydroxide such as potassium hydroxide, sodium hydroxide or tetramethylammonium hydroxide, or the alkaline corrosive liquid is a solution or mixed liquid including alkali metal ions and hydroxide ions; the acidic corrosive liquid is such as hydrofluoric acid, hydrochloric acid, sulfuric acid or a mixture thereof; or the acidic corrosive liquid can be two solutions that can generate acids such as hydrofluoric acid after mixing, such as a mixed solution of a fluorine-containing alkaline solution and a hydrogen ion-containing solution. Those skilled in the art can select similar acidic or alkaline corrosive liquids as needed, which will not be repeated here.

[0105] The device to be processed has a modified line (laser damage mark) extending from the first surface to the second surface and arranged corresponding to the position of the microhole.

[0106] As an implementation method, see Figure 1 A device to be processed is placed vertically in a closed container, and the closed container is divided into two independent and sealed first and second etching chambers on the left and right. The liquids and gases in the two etching chambers cannot be exchanged with each other. The first surface and the second surface of the device to be processed face the first and second etching chambers respectively and contact the etching liquids in the first and second etching chambers respectively.

[0107] If there are multiple devices to be processed, the first surface and the second surface of each device to be processed form an independent and sealed etching cavity. Of course, for example, when multiple identical devices to be processed are stacked in the vertical direction in a closed container, the multiple vertically placed devices to be processed can share two left and right etching cavities. Alternatively, when N devices to be processed are arranged side by side in a closed container, the interior of the closed container is divided into N+1 etching cavities, and the opposite sides of two adjacent devices to be processed share one etching cavity.

[0108] The pressurizing device is used to apply pressure to the inside of the corrosion chamber, so that the corrosion liquid in the corrosion chamber becomes a pressurized corrosion liquid. Specifically, the pressurizing device can apply pressure to each corrosion chamber separately.

[0109] In a specific embodiment, the pressurizing device is a liquid booster pump or a gas-liquid booster pump, which together with the closed container forms a liquid separation pressurizing corrosion device;

[0110] The pressurizing device is connected to each corrosion cavity in the closed container through an air pipe, and each air pipe is provided with a valve; the corrosion liquid in the closed container is not filled up, and the air pipe is inserted into the remaining space at the top of each corrosion cavity to introduce gas, such as the commonly used inert gas nitrogen, into the corrosion cavity; the pressurizing device controls the pressure applied to the corrosion cavity and the pressure application time through the valve provided on each air pipe.

[0111] The micro-hole processing equipment of the present invention is described in detail below by taking the processing of hourglass holes and straight holes as examples.

[0112] At the initial stage of etching, corresponding to the aforementioned step S2, the pressurizing device applies pressure to the interior of each etching cavity respectively to increase the pressure inside the etching cavity and keep the pressure in each etching cavity the same, so that the etching liquid etches along the laser damage marks from both sides of the first surface and the second surface until a through hole is expanded.

[0113] By pressurizing the etching solution to generate a higher pressure, the etching rate of the hole along the laser damage path will be accelerated, so that the damage mark can be penetrated at a smaller aperture, thereby obtaining a through hole with a higher aspect ratio.

[0114] Then, corresponding to step S3, pressure is applied to the interior of at least one of the etching cavities, and the pressures of the etching cavities corresponding to the first surface and the second surface are made inconsistent, thereby generating a pressure difference. Thus, under the pressure difference, the etching liquid will flow from the etching cavity on one side (the first etching cavity) to the etching cavity on the other side (the second etching cavity) through the through hole on the device to be processed. The etching liquid with a stronger impact force flowing through the through hole can accelerate the corrosion of the inner wall of the through hole, so that the corrosion rate of the hole wall is much greater than the corrosion rate of the hole mouth.

[0115] By the above method, corresponding to step S4 and / or S5, the pressure in the etching chamber on both sides of the device to be processed and the pressurization time are adjusted, so that the hole shape of the through hole formed by the damage trace can be controlled to obtain a straight hole or an hourglass hole.

[0116] Please continue reading Figure 1 As an implementable method, when a hole is not formed in the initial stage of etching, corresponding to step S2, the valves F1 and F2 on the two air pipes are opened to ventilate the two etching chambers respectively, so that the pressure in the etching chamber increases and the pressure in the two etching chambers is kept consistent. As the pressure in the etching chamber increases, a higher pressure is generated in the etching liquid, so that the laser damage mark can be formed at a smaller aperture, thereby obtaining a hole with a higher aspect ratio.

[0117] After the through hole is formed, the valve F2 of the right corrosion chamber (the second corrosion chamber) is closed, and only the left corrosion chamber (the first corrosion chamber) is ventilated and pressurized, so that a certain pressure difference is generated between the left and right corrosion chambers. Under this pressure difference, the corrosion liquid will flow from the left corrosion chamber into the right corrosion chamber through the through hole on the device to be processed. The corrosion liquid with strong impact force flows through the through hole, which can accelerate the corrosion of the inner wall of the through hole, making the corrosion rate of the hole wall much greater than the corrosion rate of the hole mouth, thereby improving the taper of the hole.

[0118] Figure 2 This is a schematic diagram of the change of hole taper over time at different stages of the corrosion process. Figure 2 It can be seen that after the through hole is formed by etching, the taper of the hole is gradually improved with the increase of etching time. Figure 3 This is the front view of the product after etching. It can be seen that by adopting the above processing method, the apertures formed are uniform and evenly distributed.

[0119] Of course, the pressurizing device described in the present application is not limited to the above-mentioned gas pressurizing method, and any equipment that can apply pressure to the inside of the corrosion chamber is within the protection scope of the present application.

[0120] In a preferred embodiment, the pressurizing device applies pressure to the etching cavities on both sides of the processing surface of the device to be processed in turn, or changes the flow direction of the etching liquid in the through hole by adjusting the pressure inside two adjacent etching cavities to improve the uniformity of the etching inside the through hole.

[0121] Specifically, the valves F1 and F2 corresponding to the two etching chambers can be opened and closed alternately, that is, the two etching chambers can be pressurized alternately, so that the flow direction of the etching liquid in the through hole of the sample to be processed is converted according to a certain period. The corresponding steps S4 and / or S5 can make the hole type corrosion more uniform.

[0122] In a preferred embodiment, the etching chambers on both sides of the device to be processed are connected by a conduit, and both ends of the conduit extend into the etching liquid in the etching chambers on both sides of the device to be processed respectively, so that the etching liquid in two adjacent etching chambers can flow back through the conduit.

[0123] In this scheme, by controlling the pressure and opening time in the two etching chambers, different hole shapes can be obtained, such as straight holes, hourglass holes, trumpet holes, etc. When the pressure is increased in the two etching chambers in turn, it is easier to obtain straight holes. When only one etching chamber is pressurized, a trumpet hole can be obtained.

[0124] In a preferred embodiment, the device to be processed with the modified line can be clamped and fixed by an adapter frame and then inserted into a closed container. The shape of the adapter frame matches the inner wall profile of the closed container. In this way, after the adapter frame holding the device to be processed is inserted into the closed container, an independent and closed corrosion cavity can be formed on both sides of the processing surface of the device to be processed. Preferably, a sealing ring is provided on the edge of the adapter frame to improve the sealing effect and the airtightness of the corrosion cavity, so that liquids and gases cannot be exchanged with each other. Further preferably, a slot matching the adapter frame is opened on the inner wall of the closed container, and the adapter frame holding the device to be processed is inserted into the slot, which can further improve the airtightness of the corrosion cavity.

[0125] In a specific embodiment, a U-shaped adapter frame with a sealing ring on the edge is used. Preferably, a grid-shaped fixed bracket is set in the middle of the adapter frame to enhance the compressive strength of the device to be processed. Preferably, the grid of the grid-shaped bracket is set corresponding to the hole to be processed of the device to be processed. Two adapter frames are put together face to face, the sample to be processed is clamped in the middle, and then the entire adapter frame is inserted into a closed container with a slot, and the closed container is divided into at least two independent corrosion chambers.

[0126] The micro-hole processing method and equipment provided in this solution can be applied to materials with high hardness and transparent to lasers, such as glass, quartz or crystal. Generally, the processing thickness of the material is 10μm-5mm, and the micro-hole diameter after processing is 2μm-1mm; further, it is more suitable for processing the material with a thickness of 10μm-3mm, and the micro-hole diameter after processing is 3μm-500μm. The following is an example of a through hole to be processed, which is ordinary borosilicate glass with a thickness of 0.5mm and a diameter of 50μm.

[0127] 1. Devices to be processed with modified lines

[0128] An infrared picosecond or infrared femtosecond laser beam is converted into a Bessel beam and irradiated from the first surface of the glass to form a linear focused light spot of a certain length, which induces absorption in the glass and generates a modified line (laser damage mark) extending from the first surface to the second surface.

[0129] 2. Corrosion processing of the device to be processed

[0130] S1: Place the aforementioned glass into a closed container containing HF etching solution.

[0131] Specifically, the glass is first fixed in the rubber transfer frame, and then the transfer frame is vertically inserted into the closed container to form a closed first corrosion cavity and a second corrosion cavity on both sides of the glass.

[0132] S2 opens the pressure valves F1 and F2 of the first corrosion chamber and the second corrosion chamber, and ventilates and pressurizes at least one of the first corrosion chamber and the second corrosion chamber, with a pressure of 2-10 bar, and controls the pressure inside the two chambers for 10-60 minutes.

[0133] It should be noted that the pressurization during the actual operation is also related to the size of the glass sample and the volume of the closed container, and is not limited to the 2-10 bar provided in this embodiment; the pressurization time depends on the thickness of the glass sample and the pressure. The greater the pressure and the smaller the thickness of the glass sample, the faster the hole is opened and the shorter the time.

[0134] S3 closes the pressure valve F2 of the second corrosion chamber and continues the corrosion for 5-60 minutes, and the corrosion liquid flows from the first corrosion chamber to the second corrosion chamber.

[0135] S4 is switched, the pressure valve F2 of the second corrosion chamber is opened, and the pressure valve F1 of the first corrosion chamber is closed, the duration is 5-60 minutes, and the corrosion liquid flows from the second corrosion chamber to the first corrosion chamber.

[0136] S5 repeatedly switches the pressure valves F1 and F2 to obtain a glass device with micropores.

[0137] Table 1 shows the through-hole conditions obtained under different processing conditions, wherein pressure control was performed in both Example 1 and Example 2, while pressure control was not performed in Comparative Example 1. Specific parameters and results are shown in Table 1.

[0138] Table 1 Processing parameters and corresponding processing effects

[0139]

[0140] Figure 4 , Figure 5 , Figure 6They are cross-sectional views of the processed products corresponding to comparative example 1, example 1, and example 2, respectively. Among them, the taper is calculated according to the minimum aperture / maximum aperture of the hole type*100%. Combined with the accompanying drawings, first, comparing example 1 and example 2, there is a difference in the pressure applied to the corrosion chamber in step S2, and the other conditions are the same; it can be found that under the same conditions, applying a greater pressure to the corrosion chamber is conducive to obtaining a straight hole. If no pressure is applied to the two corrosion chambers, relying on the natural corrosion effect of the corrosion liquid under normal pressure, not only the processing time is prolonged, but only an hourglass hole can be obtained. By comparing example 3 and example 4, it can be found that if the same pressure conditions are adopted before and after the through hole is formed, a trumpet hole can be obtained, and if the opposite pressure conditions are adopted, an asymmetric micropore between the hourglass hole and the trumpet hole can be obtained. The attached Figure 5 , 6 With attached Figure 4 By comparison, it can be seen that when the glass product is processed by this solution, the final through hole not only has a small taper, but also a smaller aperture and a higher depth-to-width ratio.

[0141] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for micro-hole processing, for corroding a device to be processed with a modified line to form a through hole, characterized in that: The steps are: S1: placing a device to be processed in an etching solution, wherein the device to be processed has a modified line extending from a first surface to a second surface and arranged corresponding to a position of a microhole; S2 pressurizes the etching liquid on at least one of the first surface and the second surface of the device to be processed until the modified line of the device to be processed expands to form a through hole; S3 makes the first pressure of the etching liquid on the first surface side of the device to be processed greater than the second pressure of the etching liquid on the second surface side, driving the etching liquid to flow from the first surface side to the second surface side through the through hole of the device to be processed; S4 changes the pressure difference between the first pressure and the second pressure, making the second pressure greater than the first pressure, driving the etching liquid to flow from the second surface side to the first surface side of the device to be processed along the through hole; S5, repeat S3 and S4, so that the etching liquid flows along the through hole alternately from the first surface side of the device to be processed to the second surface side and from the second surface side to the first surface side, and the hole shape of the through hole is controlled by adjusting the pressure in the etching chamber on both sides of the device to be processed and the pressurization time to obtain a straight hole, a trumpet hole, an hourglass-shaped hole, or an asymmetric microhole between the hourglass-shaped hole and the trumpet hole.

2. The micro-hole processing method according to claim 1, characterized in that: In S2, the first surface side and the second surface side of the device to be processed are pressurized simultaneously, and the first pressure of the etching liquid on the first surface side is equal to the second pressure of the etching liquid on the second surface side.

3. The micro-hole processing method according to claim 1, characterized in that: In S2, the first pressure of the etching liquid on the first surface side is made greater than the second pressure of the etching liquid on the second surface side; or The second pressure of the etching liquid on the second surface side is made greater than the first pressure of the etching liquid on the first surface side.

4. The micro-hole processing method according to claim 1, characterized in that: The pressure applied to the corrosive liquid in S2 is 2-50 bar, and the time is 5-600 minutes; The first pressure in S3 is 2-30 bar, the second pressure is 1 bar, and the time is 1-60 minutes; In S4, the first pressure is 1 bar, the second pressure is 2-30 bar, and the time is 1-60 minutes; In S5, the number of alternations is 1-100 times.

5. The micro-hole processing method according to claim 1, characterized in that: The pressure applied to the corrosive liquid in S2 is 2-10 bar, and the time is 10-60 minutes; The first pressure in S3 is 2-10 bar, the second pressure is 1 bar, and the time is 5-30 minutes; The first pressure in S4 is 1 bar, the second pressure is 2-10 bar, and the time is 5-30 minutes; In S5, the number of alternations is 1-10 times.

6. The micro-hole machining method according to claim 1, characterized in that: The modified line of the device to be processed is irradiated from the first surface of the device to be processed by a laser beam, which generates induced absorption in the device to be processed and generates a modified line extending from the first surface to the second surface.

7. The micro-hole machining method according to claim 6, characterized in that: The modified line of the device to be processed is irradiated from the first surface of the device to be processed by a Bessel laser beam to form a linear focused light spot of a certain length, generate induced absorption in the device to be processed, and generate a modified line extending from the first surface to the second surface; or, The modified line of the device to be processed is processed by laser filamentation. The laser is irradiated from the first surface of the device to be processed, and plasma is excited on the surface layer of the first surface to form a linear focused light spot of a certain length that propagates forward, and induced absorption is generated in the device to be processed to generate a modified line extending from the first surface to the second surface; or, The modified line of the device to be processed is irradiated from the first surface of the device to be processed by a laser beam, and the focus of the beam is moved to the second surface to generate a modified line extending from the first surface to the second surface.

8. The micro-hole machining method according to claim 1, characterized in that: The etching liquid is arranged in a closed container, two closed and independent etching chambers are formed on both sides of the device to be processed, and the pressure of the etching liquid in each etching chamber is controlled respectively.

9. The micro-hole machining method according to claim 1, characterized in that: The corrosive liquid is an alkaline corrosive liquid or an acidic corrosive liquid.

10. The micro-hole machining method according to claim 9, characterized in that: The alkaline etching solution is potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide or a mixture thereof; or, the alkaline etching solution is a solution or a mixture containing alkali metal ions and hydroxide ions; The acidic corrosive liquid is hydrofluoric acid, hydrochloric acid, sulfuric acid or a mixture thereof; Alternatively, the acidic corrosive solution is a mixture of a fluorine-containing alkaline solution and a hydrogen ion solution.

11. The micro-hole machining method according to claim 1, characterized in that: The device to be processed is glass, quartz or crystal.

12. The micro-hole machining method according to claim 1, characterized in that: The device to be processed has a thickness of 10 μm-5 mm and a through hole diameter of 2 μm-1 mm.

13. A micro-hole processing device for implementing the micro-hole processing method according to any one of claims 1 to 12, used for etching a device to be processed with a modified line to form a through hole, characterized in that: include: Closed container for storing corrosive liquid; The device to be processed is placed in the closed container, and the closed container is divided into at least two independent and closed etching chambers, and the first surface and the second surface of the device to be processed face the first etching chamber and the second etching chamber respectively and are in contact with the etching liquid in the first etching chamber and the second etching chamber respectively; The pressurizing device pressurizes the independent first etching chamber and / or the second etching chamber respectively until the modified line of the device to be processed expands to form a through hole; makes the first pressure of the etching liquid on the first surface side of the device to be processed greater than the second pressure of the etching liquid on the second surface side, and drives the etching liquid to flow from the first surface side to the second surface side through the through hole of the device to be processed; changes the pressure difference between the first pressure and the second pressure, makes the second pressure greater than the first pressure, drives the etching liquid to flow from the second surface side to the first surface side of the device to be processed along the through hole, repeats the above steps, makes the etching liquid flow from the first surface side to the second surface side of the device to be processed and from the second surface side to the first surface side along the through hole alternately, and controls the hole shape of the through hole by adjusting the pressure in the etching chambers on both sides of the device to be processed and the pressurizing time, so as to obtain a straight hole, a trumpet hole, an hourglass-shaped hole, or an asymmetric micro-hole between the hourglass-shaped hole and the trumpet hole.

14. The micro-hole processing equipment according to claim 13, characterized in that: The pressurizing device is a liquid booster pump or a gas-liquid booster pump, which pressurizes the corrosion cavity through an air pipe.

15. The micro-hole processing equipment according to claim 13, characterized in that: Also includes: Transfer A frame, used to hold the device to be processed, whose shape matches the inner wall section of the closed container; The adapter frame is inserted into the closed container to form an independent and closed etching cavity on both sides of the first surface and the second surface of the device to be processed.

16. The micro-hole processing equipment according to claim 15, characterized in that: A sealing ring is arranged on the edge of the adapter frame.

17. The micro-hole processing equipment according to claim 15 or 16, characterized in that: A grid-shaped fixing bracket is arranged in the middle of the adapter frame, and the grid positions on the fixing bracket correspond to the positions of the micro-holes to be processed on the device to be processed.

18. The micro-hole processing equipment according to claim 13, characterized in that: Also includes: The two ends of the conduit extend into the independent corrosion chambers respectively, and the corrosion liquids in the two corrosion chambers flow back through the conduit.

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