阅读说明：本技术 一种具有高表面结合力的基材及其制备方法 (Base material with high surface binding force and preparation method thereof ) 是由 王恒亮 于 2021-06-25 设计创作，主要内容包括：本发明提供了一种具有高表面结合力的基材及其制备方法,所述制备方法使用脉冲激光,在基材上测试单脉冲与材料反应后的微坑直径和深度。通过改变功率或者加工次数,可得出单脉冲能量及加工次数与微坑大小和深度的关系曲线,在实际应用中,可依据该关系曲线和所需微坑大小,能快速设置一定的加工路径和扫描速度进行加工,从而在表面形成含有规则排列且无交叠微小凹坑的高结合力的基材。本发明所述方法能够显著提高基材表面的粗糙度、结合力、以及变表面张力(亲疏水性)。所述制备方法特别适合疏水基材,经激光加工后,其亲水性显著提高,因此可加快它们在水性溶液沉积速度,能够增加润湿性,加快材料沉积速度。(The invention provides a substrate with high surface bonding force and a preparation method thereof. In practical application, a certain processing path and scanning speed can be quickly set for processing according to the relation curve and the required size of the micro pits, so that a high-bonding-force base material containing regularly-arranged non-overlapping micro pits is formed on the surface. The method can obviously improve the roughness, the bonding force and the variable surface tension (hydrophilic and hydrophobic) of the surface of the base material. The preparation method is particularly suitable for hydrophobic base materials, and after laser processing, the hydrophilicity of the hydrophobic base materials is obviously improved, so that the deposition speed of the hydrophobic base materials in aqueous solution can be increased, the wettability can be increased, and the material deposition speed can be increased.)

1. A substrate having a high surface bonding force, characterized in that: the surface of the base material (1) is provided with a matrix array formed by a plurality of micro pits (2), and the range of the distance d between two adjacent micro pits (2) is as follows: d is more than 0 and less than 1mm, and the range of the diameter-depth ratio beta of the micro-pits (2) is more than 0.1 and less than beta and less than 1000.

2. A method for preparing a substrate having high surface bonding force according to claim 1, wherein: the method comprises the following steps:

1) laser selection: scanning the surface of a substrate (1) in the form of a single pulse laser beam by using different types of pulse lasers to form micro pits (2) on the surface, measuring the diameter and the depth of the formed micro pits (2), and selecting the type of the pulse laser capable of reacting with the surface of the substrate;

2) determining the relation: after the laser is determined, the diameter size and the depth of the micro-pits (2) under different energy and processing times can be obtained by changing the energy and the processing times of the single pulse laser beam so as to determine a relation curve;

3) parameter selection: selecting parameters in the relation curve according to the size, the thickness and the acceptable deformation range of the application base material;

4) preparing a matrix array: according to the diameter d of the micro pit (2)₁The laser scanning path pitch and scanning speed/frequency are set to be larger than the diameter, i.e., the laser scanning path pitch d is the scanning speed/frequency, d ranges from: d₁＜d＜d_max，d_maxThe distance is the distance when the binding force is just lower than a specified value; and the substrate (1) with the matrix array micro-pits (2) obtained after scanning is the substrate with high surface bonding force.

3. The method for preparing a substrate having high surface bonding force according to claim 2, wherein: the single pulse laser beam parameter ranges are as follows: wavelength: 266nm-10700 nm; pulse width: 10fs-1000 mus; pulse repetition rate: 1KHz-100 MHz; average power: 1W-10000W.

4. The method for preparing a substrate having high surface bonding force according to claim 2, wherein: in performing steps 1) and 2), depending on the type of pulsed laser used, the processing path spacing and scanning speed/frequency are set to be sufficiently large to ensure that the laser reacts with the substrate surface in a single pulse or burst and that the substrate surface forms non-overlapping, independent micropits.

Technical Field

The invention relates to the technical field of surface processing, in particular to a base material with high surface bonding force and a preparation method thereof.

Background

In industrial manufacturing, the application of compounding one material on top of another is very widespread, and the properties of the composite thus formed are highly dependent on the bonding force between the two materials, and therefore, the bonding force is an important parameter of the materials industrially.

Mechanical or chemical methods are currently the most common methods for improving the bonding force, and they are used to roughen the surface of the workpiece by mechanical abrasion or chemical corrosion to obtain a micro-rough structure on the surface of the workpiece. The coarsening treatment can increase the contact area between the two materials and simultaneously increase the peeling strength between the two materials, thereby improving the bonding force. However, these methods have several drawbacks.

The mechanical method adopts a common treatment mode of sand blasting or sand paper grinding, has the advantages of simple process and low cost, but has requirements on the hardness of a base material, high destructiveness, large microcosmic concave-convex fluctuation and limited improvement on the binding force. Therefore, the method is mainly used for spraying, dipping or electroplating of metal substrates and is not suitable for film materials. The chemical principle is that strong acid, strong base or strong oxidant is used to etch partial molecular particles on the surface of the base material to make the surface of the base material become uneven. The method has the advantages that the microscopic surface is fine and smooth, the binding force is obviously increased, but the method needs to use chemical products which are not environment-friendly, has different chemical reaction mechanisms of different substrates, needs to prepare a plurality of chemical reagents, and is difficult to find a proper coarsening formula especially for materials with particularly good chemical resistance. In addition to mechanical and chemical roughening, other roughening methods exist for specific applications, but their process flow is complicated.

Patent CN106696245A discloses a method for roughening the surface of a composite material by cementing: the method comprises the steps of firstly paving a composite material on a mould with a clean surface, then selecting a piece of demolding cloth with a proper type, and paving the piece of demolding cloth on the surface of the mould paved with the composite material, so as to ensure that the piece of demolding cloth is tightly attached to a cementing agent on the surface of the composite material and is soaked by the cementing agent. After the composite material is solidified and formed, the demolding cloth is torn off to form a certain rough surface.

In patent US9,924,601B2, the applicant LPKF Laser & Electronics AG discloses a method of increasing the surface roughness of plastic parts. The method uses laser to manufacture microstructures on an injection mold, and when a workpiece is molded, the microstructures are embedded into the surface of the conductive pattern area of the plastic workpiece, so that the surface area of the conductive pattern area is increased, and the bonding force between the area and a conductive layer added through chemical plating is increased. The method has the defects that the precision of the laser is not matched with that of the die, and the microstructure is easy to damage, so that the using times of the die are reduced.

Patent CN101285208B discloses a method for increasing the surface roughness of the positive electrode material of a lithium ion secondary battery. The method adopts an electrochemical method to form holes on the surface of the aluminum foil, namely, a carrier attached with the aluminum foil and a corrosion-resistant material are immersed into an electrolytic bath filled with electrolyte, the aluminum foil is connected with a positive electrode, the corrosion-resistant material is connected with a negative electrode, electrolytic reaction is carried out after electrification, the surface of the aluminum foil is partially oxidized and decomposed to generate micropores, so that the surface roughness of the aluminum foil is increased, and the surface is changed from hydrophobic to hydrophilic.

As described above, the roughening method can be roughly classified into a physical method, a chemical method, and an electrochemical method. The physical method has large destructiveness, is not suitable for thin film materials, has rough appearance state after coarsening and small increase of binding force. The chemical method pollutes the environment, and each coarsening formula has small application range. The electrochemical method needs the conduction of a matrix and has complex process. Therefore, there is a need to develop a method and a material with controllable surface roughness, environmental protection, and capability of effectively enhancing the bonding force between materials.

Disclosure of Invention

In view of the above, the present invention is directed to a substrate with high surface bonding force and a method for preparing the same, which is suitable for improving the surface bonding force of substrates of various materials, and the shape and size of micro pits and the depth of the micro pits are controllable, so that the surface roughening degree can be conveniently controlled, and the process is environment-friendly and pollution-free.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a substrate with high surface bonding force is provided, a matrix array composed of a plurality of micro pits is arranged on the surface of the substrate, and the range of the distance d between two adjacent micro pits is as follows: d is more than 0 and less than 1mm, and the range of the diameter-depth ratio beta of the micro-pits is more than 0.1 and less than beta and less than 1000.

The invention also provides a preparation method of the substrate with high surface bonding force, which comprises the following steps:

1) laser selection: scanning the surface of the base material in the form of a single pulse laser beam by using different types of pulse lasers to form micro pits on the surface, measuring the diameter and the depth of the formed micro pits, and selecting the type of the pulse laser capable of reacting with the surface of the base material;

generally, the reaction mechanism between the laser type and the substrate surface is very different, and the pulsed laser is used because a single pulse or pulse train can process a single micro-pit independently, which is faster and more efficient than the continuous laser.

When the reaction effect of the selected laser and the surface of the substrate is tested, a simple graph can be selected, and the path interval and the scanning speed which are large enough are set, so that the edge interval of the micro-pits can be ensured to be large enough, and the diameter of the micro-pits can be measured conveniently.

2) Determining the relation: after the laser is determined, the diameter and the depth of the micro-pits under different energy and processing times can be obtained by changing the energy and the processing times of the single pulse laser beam so as to determine a relation curve;

when the same laser is used for processing with different energy, the size and the depth of the micro-pits are different. For most materials, the greater the energy density, the larger the diameter of the micropits, and the deeper the micropits. Likewise, increasing the number of processes can also increase the depth and diameter of the micropits.

However, for some materials, the craters cannot be too deep, which would affect other properties; and the laser processing times are too many, which also affects the processing efficiency. Therefore, the determination of the relation curve has a guiding significance for practical application.

Therefore, the micro-pit morphology under various energies and processing times needs to be tested, and a relation curve is made, so that the micro-pit morphology can have a certain range of operation parameters under the limitation of an application scene.

3) Parameter selection: a set of parameters is selected from the relationship curves according to the size, thickness and acceptable deformation range of the substrate for a particular application. The parameter can meet the requirement of the depth of the micro pit under fewer processing times, the performance of the micro pit is not influenced, and the processing efficiency is also ensured.

4) Preparing a matrix array: according to the diameter d of the micro-pit corresponding to the selected single pulse laser beam₁Setting the excitation greater than the diameterThe light scan path pitch and scan speed/frequency, i.e., the laser scan path pitch d ═ scan speed/frequency, and the range of d is: d₁＜d＜d_max，d_maxThe distance is the distance when the binding force is just lower than a specified value; the substrate with the matrix array micro-pits obtained after scanning is the substrate with high surface bonding force.

The lower limit of the distance d is the diameter d of the micro-pits under a fixed parameter₁If the distance is reduced, the pit wall disappears, the micro pits no longer exist, the anchor points do not have support, and the binding force is deteriorated. Conversely, increasing the pitch decreases the anchor points per unit area, and the bonding force becomes weaker until it becomes smaller than a prescribed value. Setting the distance d when the bonding force is just lower than the specified value_maxThen the operating range for the laser scan path spacing d, scan speed/frequency, is: d₁＜d＜d_max。

And testing the roughness or hydrophilicity and hydrophobicity of the surface of the base material, compounding other materials on the surface of the base material, and testing the binding force of the obtained composite material.

If the composite material has stress after being finished, the stress is released. And finally, testing the binding force according to the standard.

Further, the single pulse laser beam parameter ranges are: wavelength: 266nm-10700 nm; pulse width: 10fs-1000 mus; pulse repetition rate: 1KHz-100 MHz; average power: 1W-10000W.

Further, in the steps 1) and 2), the processing path pitch and the scanning speed/frequency are set to be sufficiently large according to the type of the selected pulsed laser, and specifically, the processing path pitch and the scanning speed/frequency can be set to be 50 μm or more, so that the laser can react with the surface of the substrate in the form of a single pulse or a pulse train to form independent micro pits without overlapping on the surface of the substrate.

Compared with the prior art, the base material with high surface bonding force and the preparation method thereof have the following advantages:

(1) the method provided by the invention uses the laser single pulse to process the surface of the base material, is convenient to control the shape, size and depth of the micro-pits, and is particularly suitable for materials which cannot be processed by the current physical method, chemical method or electrochemical method.

(2) The method provided by the invention defines the surface state after laser processing for improving the binding force, and provides the operating range d of the laser scanning path distance d (d is the scanning speed/frequency) by combining the pit theory₁＜d＜d_maxThe concept of (2) enables the operation to be more data-based and increases the practicability.

(3) The method provided by the invention has the advantages of adjustable pit size and depth, simple and clear adjustment process, adjustable corresponding surface roughness, wide application range and environmental protection. Meanwhile, the method can also change the surface tension of the material, thereby changing the hydrophilicity and hydrophobicity of the material.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of a substrate with high surface bonding force according to an embodiment of the present invention.

FIG. 2 is a graph of the variation of the diameter of the micro-pits for the LCP material of example one at different power percentages and processing times.

FIG. 3 is a graph of variation in dimple depth for LCP materials of the first example at different power percentages and processing times.

Fig. 4 is a plot of variation in dimple diameter and dimple depth for FR4 material at different power percentages in example one.

Description of reference numerals:

1-a substrate; 2-micro pits.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

The first embodiment is as follows:

the material selected in this embodiment is LCP thin film insulation material, the film thickness is 100 μm, copper plating is needed on the surface, and sand blasting may deform or damage the material. LCP has good chemical resistance and difficult chemical coarsening.

A method for preparing a substrate having a high surface bonding force, the method comprising the steps of:

1) laser selection: scanning the surface of a substrate (1) in the form of a single pulse laser beam by using different types of pulse lasers, forming micro pits (2) on the surface, measuring the diameter size and the depth of the micro pits (2) formed on the substrate, and selecting the type of the pulse laser capable of reacting with the surface of the substrate;

the laser processing test is preferably performed in this example using a DirectLaser 550U uv nanosecond laser machine manufactured by deum technologies development ltd.

The pattern size was 5mm by 5mm, the laser path pitch was set to 50 μm, the frequency was 50kHz, the scanning speed was 2500mm/s, the size of the micropore diameter at 100% power was 28.3 μm, and the depth was 10.3 μm.

2) And (3) making a relation curve: after the laser is determined, the diameter and the depth of the micro-pits (2) under different energy and processing times are measured by changing the energy and the processing times of the single pulse laser beam, and a relation curve is made;

TABLE 1 micropit diameter/. mu.m at different power percentages and processing times

TABLE 2 micropit depth/. mu.m at different power percentages and processing times

3) Parameter selection

Taking the example that the micro-pits specified by a customer cannot be deeper than 3 μm, under the condition of selecting lower power and ensuring that the processing frequency does not influence the processing efficiency, the power is selected to be 17 percent, and the micro-pits are processed once.

4) Preparing a matrix array: according to d₁＝17.3μm，d_maxThe laser scan path pitch and scan speed/frequency were set to 20 μm, 29.2 μm.

Furthermore, a bonding force test was performed on a pattern having a size of 10cm by 10cm, a laser processing path pitch of 20 μm, a frequency of 100kHz, and a scan plating speed of 2000 mm/s.

5) And testing the roughness or hydrophilicity and hydrophobicity of the surface of the base material, adding other materials to the surface of the base material, and testing the binding force.

The surface of the material before laser processing is hydrophobic, and the roughness Rz is less than 1 μm.

The surface of the material after laser processing is hydrophilic, and the roughness Rz3.3 mu m.

And (3) performing material increase on the laser-processed surface, wherein the material increase process comprises oil removal, presoaking, activation, dispergation, chemical copper deposition and copper electroplating, and the copper plating thickness is tested to be 30.2 mu m after the copper electroplating.

The result of the hundred grid test is 5B.

The peel force test result was 0.54 kgf/cm.

Example two:

the material selected in the embodiment is FR4 insulating material, the thickness is 0.5mm, and copper deposition and copper plating are needed on the surface. The material is coarsened by plasma treatment or a traditional glue removing mode such as potassium permanganate, and the like, and the problem of foaming can occur during copper deposition. The treatment conditions are enhanced, or the two treatment modes are combined, the copper deposition does not bubble, but the copper plating is directly layered.

1) Laser selection: scanning the surface of a substrate (1) in the form of a single pulse laser beam by using different types of pulse lasers, forming micro pits (2) on the surface, measuring the diameter size and the depth of the micro pits (2) formed on the substrate, and selecting the type of the pulse laser capable of reacting with the surface of the substrate;

the laser processing test is preferably performed in this example using a DirectLaser 550U uv nanosecond laser machine manufactured by deum technologies development ltd.

The pattern used 5mm by 5mm dice, the laser path spacing was set at 50 μm, the frequency was 50kHz, the scanning speed was 2500mm/s, the pore size was 30.7 μm at 100% power, and the depth was 18 μm.

2) And (3) making a relation curve: after the laser is determined, measuring the diameter and the depth of the micro-pits (2) under different energy and processing times by changing the energy of the single pulse laser beam and changing the processing times, and making a relation curve;

the depth of the micro-pits after FR4 laser processing is deeper, and the increase of times can make the micro-pits deeper, which is not beneficial to the stability of the material. So this case only changes the power percentage and does not take any more tests to increase the number of machining operations.

TABLE 3 dimple diameter and dimple depth/μm at different power percentages

Percentage of power/%)	8％	11％	17％	27％	51％	100％
							Micro-pit diameter/mum	11.9	12.8	15.5	18.8	27.9	30.7
Depth of micro-pit/μm	1.67	2.17	4.89	7.9	10.9	18

3) And (4) selecting parameters.

When the power is higher than 17%, the periphery is blackened, the requirement can be met under the condition of ensuring lower power, and under the condition that the machining frequency does not influence the machining efficiency, the power is selected to be 17%, and the machining is carried out once.

4) Preparing a matrix array: according to the diameter d of the micro-pit (2) corresponding to the selected single pulse laser beam₁15.5 μm, tested by test d_maxThe laser scan path pitch and scan speed/frequency were set to 20 μm, 31 μm.

And (3) making a bonding force test pattern with the size of 10cm by 10cm, wherein the laser processing path interval is 20 micrometers, the frequency is 50kHz, and the scanning plating speed is 1000 mm/s.

5) And testing the roughness or hydrophilicity and hydrophobicity of the surface of the base material, adding other materials to the surface of the base material, and testing the binding force.

The surface of the material before laser processing is hydrophobic, and the roughness Rz is less than 1 μm.

The surface of the material after laser processing is hydrophilic, and the roughness Rz5.3 mu m.

And (3) performing material increase on the laser-processed surface, wherein the material increase process comprises oil removal, presoaking, activation, glue removal, chemical copper deposition and copper electroplating, and the copper plating thickness is tested to be 29.6 mu m after the copper electroplating.

The result of the hundred grid test is 5B.

The peel force test result was 0.98 kgf/cm.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.