Method for improving surface binding force of aluminum substrate by adopting atomic layer deposition process

Abstract

The invention discloses a method for improving the surface binding force of an aluminum substrate through an atomic layer deposition process, the aluminum substrate comprises a metal layer, an insulating layer and a circuit layer, the metal layer is made of aluminum alloy, the insulating layer is deposited on the metal layer through the atomic layer deposition process, the insulating layer is made of aluminum oxide, and the circuit layer is made of copper. The aluminum film and the aluminum oxide film are deposited on the metal layer through the atomic layer deposition method, damage to the surface of the metal layer during pretreatment is repaired through the aluminum film, meanwhile, the binding force of the surface of the aluminum substrate can be further improved, and the deposited aluminum oxide film serves as an insulating layer, so that the isolation effect of a traditional aluminum substrate insulating layer is achieved; and meanwhile, the surface bonding force among multiple layers is enhanced in an atomic layer deposition mode, and a key effect is achieved on pressing of a copper layer.

Description

Technical Field

[0001] The invention belongs to the field of aluminum substrate manufacturing, and in particular relates to a method for improving the surface bonding force of an aluminum substrate by adopting an atomic layer deposition process. Background Art

[0002] Atomic layer deposition is a method of forming a deposited film by alternately passing gaseous precursor pulses into a reactor and chemically adsorbing and reacting on a deposition substrate. When the precursors reach the surface of the deposition substrate, they will chemically adsorb on its surface and undergo a surface reaction. The atomic layer deposition reactor needs to be cleaned with an inert gas between precursor pulses. It can be seen that whether the deposition reaction precursor substance can chemically adsorb on the surface of the deposited material is the key to achieving atomic layer deposition. Any gaseous substance can be physically adsorbed on the surface of the material, but to achieve chemical adsorption on the surface of the material, it must have a certain activation energy. Therefore, whether atomic layer deposition can be achieved depends on the selection of appropriate reaction precursor substances.

[0003] The surface reaction of atomic layer deposition is self-limiting. This self-limiting feature is the basis of atomic layer deposition technology. The required thin film can be formed by repeating this self-limiting reaction.

[0004] However, the current aluminum substrates generally have the problem of insufficient surface bonding between multiple layers, which brings safety risks to practical applications. Summary of the invention

[0005] In view of the above background, an object of the present invention is to provide a method for improving the surface bonding force of an aluminum substrate by using an atomic layer deposition process, so as to solve the problems in the prior art.

[0006] The specific scheme of the present invention is as follows:

[0007] A method for improving the surface bonding force of an aluminum substrate by using an atomic layer deposition process. The aluminum substrate comprises a metal layer, an insulating layer and a circuit layer. The metal layer is an aluminum alloy. The insulating layer is deposited on the metal layer by an atomic layer deposition process. The insulating layer is aluminum oxide and the circuit layer is copper.

[0008] Further,

[0009] The method comprises the following steps:

[0010] 1) Pre-treating the bottom plate for the metal layer, the pre-treating comprising cleaning the bottom plate and adjusting the flatness of the bottom plate and detecting the flatness;

[0011] 2) reducing damage to the surface of the base plate during pretreatment, and depositing an aluminum film with a thickness of σ1 on the metal layer of the aluminum substrate using the atomic layer deposition process;

[0012] 3) generating an insulating layer, and depositing an aluminum oxide film with a thickness of σ2 on the formed aluminum film using the atomic layer deposition process;

[0013] 4) Then press the copper foil onto the aluminum oxide film.

[0014] Further,

[0015] The thickness σ2 of the aluminum oxide film is greater than the thickness σ1 of the aluminum film, preferably 30σ1≥σ2≥20σ1.

[0016] Further,

[0017] In the step 1), the flatness of the bottom plate is firstly tested, and if the flatness meets the requirement, the bottom plate is cleaned; if the flatness does not meet the requirement, the flatness of the bottom plate is adjusted, and then the bottom plate is cleaned;

[0018] The steps of the flatness detection are first to design a detection sensor and calibrate multiple sensors, select four PSD sensors, and perform absolute calibration on the PSD sensors; in order to increase the detection range of the PSD sensor, the four PSD sensors are evenly distributed on a ring, the ring is driven to rotate, and the ring moves linearly along the bottom plate surface at the same time, the motion trajectory of the four PSD sensors on the ring is a cycloid, and the trajectories of the four PSD sensors all have intersections, and the trajectory of one of the cycloids is selected as the standard curve, and the four PSD sensors are relatively calibrated through the measurement data at the intersection, so that the measurement data at the intersection are the same, and at the same time, the calibration values ​​of other points on the cycloid trajectory are calculated according to the adjustment ratio or difference at the intersection; in order to make the relative calibration accurate, the radius r of the ring is set to be adjustable, that is, the relative positions of the four PSD sensors are adjustable, assuming that the moving distance for one measurement is l; in order to make each cycloid have an intersection with other cycloids, so that relative calibration can be performed, and the number of measurements is reduced as much as possible (that is, the measurement range is increased during each walk), so it is necessary to meet the following requirements:

[0019]

[0020] Right now

[0021]

[0022] When the radius r of the ring satisfies formula (2), the calibration accuracy can be improved and the detection range of each linear movement is increased.

[0023] Further,

[0024] The flatness detection step also includes flatness calculation. Since the cycloid trajectory of each PSD sensor is a curve, the intersection points on the cycloid of the same PSD sensor are not on the same straight line. Three intersection points within a cycloid cycle are selected. The plane equation formed by the three intersection points is ax+by+cz=1. A reference point is selected on the bottom plate. The coordinates of the three intersection points can be expressed as (x1, y1, z1), (x2, y2, z2), and (x3, y3, z3). According to the parallelogram formed by the above three intersection points, a virtual intersection point (x1, y1, z1) on the fourth vertex is generated. virtually ,y virtually ,z virtually ), choose any other intersection point (x s ,y s ,z s ), calculate the distance between the virtual intersection and other intersections According to the direction of the parallelogram formed by the three intersection points, the virtual intersection point is projected outward with a radius of d, and the intersection points (x s ,y s ,z s )The minimum distance is d t The projection point (x t ,y t ,z t ), traverse all other intersections in the same way, assuming that the total number of other intersections is n, then calculate the minimum distance d associated with all other intersections t,i , so the variance of the minimum distance can be expressed as,

[0025] where d t,i is the minimum distance associated with the i-th other intersection point, represents the average value of λ minimum distances, when σ t When σ is less than the set threshold, it is considered that the flatness meets the requirements; if σ t If the value is greater than the set threshold, the obtained deviation is large (it can be sorted by value, and When the difference is greater than Δκ, it is considered that the deviation is large) the positions of other intersection points are monitored in the subsequent leveling steps;

[0026] Move the ring to the starting position so that the ring rotates in the opposite direction to the previous one, detect the previous path again, and repeat the above detection steps;

[0027] Get the judgment index of the first flatness calculation. Different movement trajectories of the PSD sensor will produce multiple judgment indexes. According to the number of unqualified points n in a round-trip measurement pe Get the judgment index Npt is the total number of intersection points in a return, is the base index (settable),

[0028] Multiple judgment indexes Can be recorded as

[0029] Further,

[0030] The step of flatness detection also includes performing a second flatness calculation, starting from the starting point of the ring, selecting a cycloid track in the same area after four intersections, the cycloid track does not contain intersections, using the standard curve selected during relative calibration as the reference curve, and the points on the reference curve as reference points, calculating the dynamic degree of approach to the reference curve η', η", η"', and the dynamic degree of moving away from the other three cycloid tracks in each cycle. If the dynamic degree of approach and the dynamic degree of moving away in multiple cycles are both within the set threshold range, the second flatness calculation considers that the flatness is qualified; otherwise, the cycloid is unqualified, and a judgment index for the second flatness calculation is obtained. Different movement trajectories of the PSD sensor will produce multiple judgment indexes. According to the number of unqualified cycloids in a round-trip measurement, n le Get the judgment index N lt is the total number of cycloids in a return, is the base index (settable),

[0031] Multiple judgment indexes Can be recorded as

[0032] Further,

[0033] The flatness adjustment in step 1) is to flatten the bottom plate by means of pressure flattening, and the number of times k that the bottom plate needs to be flattened is calculated according to the results of the first flatness calculation and the second flatness calculation.

[0034]

[0035] Among them, k0 is the basic leveling pass, for The value of the i-th for The minimum value, for The maximum value; is the jth value, for The minimum value, for The maximum value.

[0036] Further,

[0037] In the step 1), the bottom plate is cleaned by using a laser cleaning head, the bottom plate is placed on a platform, and the smoke generated by the cleaning is removed by a purifier during the cleaning process. After the cleaning is completed, the adhesion of the bottom plate is tested, and the cleaning is repeated until the adhesion meets the set requirements.

[0038] Further,

[0039] In the step 2), the precursors are selected to be trimethylaluminum and hydrogen, nitrogen is used as a carrier gas, and the temperature of the reaction chamber is maintained at T;

[0040] The atomic layer deposition process steps are:

[0041] Driven by nitrogen, trimethylaluminum enters the reaction chamber and undergoes adsorption reaction on the surface of the bottom plate. 11 0.2s;

[0042] Use nitrogen to purge to remove excess gas and reaction products from the reaction chamber. The purge time is t 12 is 2s, and the flow rate Q1 is 0.03slm;

[0043] Driven by nitrogen, hydrogen enters the reaction chamber with a flow rate Q2 of 0.1slm and reacts with the deposited layer for a time t 13 0.2s, to generate aluminum film;

[0044] Use nitrogen to purge and remove excess gas and reaction by-products from the reaction chamber. The cleaning time is t 14 is 5s, and the flow rate Q1 is 0.03slm;

[0045] The above steps are repeated to finally produce an aluminum film with a thickness of σ1.

[0046] Further,

[0047] In step 3), the precursors are selected to be trimethylaluminum and water, nitrogen is used as a carrier gas, and the temperature of the reaction chamber is maintained at T;

[0048] The atomic layer deposition process steps are:

[0049] Driven by nitrogen, trimethylaluminum enters the reaction chamber and undergoes adsorption reaction on the surface of the aluminum film. 21 0.2s;

[0050] Use nitrogen to purge to remove excess gas and reaction products from the reaction chamber. The purge time is t 22 is 2s, and the flow rate Q1 is 0.03slm;

[0051] Water enters the reaction chamber driven by nitrogen, with a flow rate Q2 of 0.1slm, and reacts with the deposited layer for a time t 23 0.2s, aluminum oxide is generated;

[0052] Use nitrogen to purge and remove excess gas and reaction by-products from the reaction chamber. The cleaning time is t 24 is 5s, and the flow rate Q1 is 0.03slm;

[0053] The above steps are repeated to finally produce an aluminum oxide film with a thickness of σ2.

[0054] The beneficial effects of the present invention are:

[0055] 1. The present invention uses atomic layer deposition to deposit aluminum film and aluminum oxide film on the metal layer. The aluminum film repairs the damage on the surface of the metal layer during pretreatment, and can also further improve the bonding strength of the surface of the aluminum substrate. The aluminum oxide film is deposited as an insulating layer, which not only plays the isolation role of the traditional aluminum substrate insulating layer, but also enhances the surface bonding strength between the multiple layers through atomic layer deposition, which plays a key role in pressing the copper layer.

[0056] 2. The thickness σ2 of the aluminum oxide film of the present invention is greater than the thickness σ1 of the aluminum film, preferably 30σ1≥σ2≥20σ1, which can ensure the effect of the aluminum oxide film.

[0057] 3. The present invention adopts a ring-shaped PSD sensor, which rotates and moves at the same time for measurement, and achieves accurate measurement data through calibration, providing relatively accurate data for subsequent cleaning, and further improving the surface bonding force.

[0058] Specific real-time method

[0059] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0060] The invention discloses a method for improving the surface bonding force of an aluminum substrate by using an atomic layer deposition process. Compared with a traditional method for manufacturing an aluminum substrate, the invention can improve the surface bonding force of the aluminum substrate.

[0061] In the present invention, the aluminum substrate comprises a metal layer, an insulating layer and a circuit layer. The metal layer is an aluminum alloy. The insulating layer is deposited on the metal layer by an atomic layer deposition process. The insulating layer is aluminum oxide and the circuit layer is copper.

[0062] The method of the present invention comprises the following four steps:

[0063] Step 1: pre-treating the bottom plate used for the metal layer, wherein the pre-treating includes cleaning the bottom plate and adjusting the flatness of the bottom plate and detecting the flatness.

[0064] First, the flatness of the bottom plate is tested. If the flatness meets the requirements, the bottom plate is cleaned. If the flatness does not meet the requirements, the flatness of the bottom plate is adjusted and then the bottom plate is cleaned.

[0065] The steps of the flatness detection are first to design the detection sensor and calibrate multiple sensors. Four PSD sensors are selected and absolutely calibrated. Absolute calibration is to calibrate the data of the PSD sensor with a standard sensor of known accuracy.

[0066] In order to increase the detection range of the PSD sensor, four PSD sensors are evenly distributed on a circular ring. The circular ring is driven to rotate and move in a straight line along the surface of the bottom plate. The motion trajectory of the four PSD sensors on the circular ring is a cycloid. The trajectories of the four PSD sensors all have intersections. The trajectory of one of the cycloids is selected as the standard curve. The four PSD sensors are relatively calibrated through the measurement data at the intersection so that the measurement data at the intersection are the same. At the same time, the calibration values ​​of other points on the cycloid trajectory are calculated according to the adjustment ratio or difference at the intersection.

[0067] Relative calibration is similar to absolute calibration, except that the choice of standard sensor is different. In relative calibration, one of the PSD sensors is selected as the standard sensor. The other calibration methods are similar to absolute calibration.

[0068] Absolute calibration and relative calibration can improve the measurement accuracy of the PSD sensor, and at the same time can reduce the difference between multiple PSD sensors and reduce the error caused by measurement.

[0069] In order to make the relative calibration accurate, the radius r of the ring is set to be adjustable, that is, the relative positions of the four PSD sensors are adjustable. Assume that the moving distance for one measurement is l; in order to make each cycloid have an intersection with other cycloids, so that relative calibration can be performed, and the number of measurements is reduced as much as possible (that is, the measurement range is increased during each walk), it is necessary to meet the following conditions:

[0070]

[0071] Right now

[0072]

[0073] When the radius r of the ring satisfies formula (2), the calibration accuracy can be improved and the detection range of each linear movement is increased.

[0074] The flatness detection step also includes flatness calculation. Since the cycloid trajectory of each PSD sensor is a curve, the intersection points on the cycloid of the same PSD sensor are not on the same straight line. Three intersection points within a cycloid cycle are selected. The plane equation formed by the three intersection points is ax+by+cz=1. A reference point is selected on the bottom plate. The coordinates of the three intersection points can be expressed as (x1, y1, z1), (x2, y2, z2), and (x3, y3, z3). According to the parallelogram formed by the above three intersection points, a virtual intersection point (x1, y1, z1) on the fourth vertex is generated. virtually ,y virtually ,z virtually ), choose any other intersection point (x s ,y s ,z s ), calculate the distance between the virtual intersection and other intersections According to the direction of the parallelogram formed by the three intersection points, the virtual intersection point is projected outward with a radius of d, and the intersection points (x s ,y s ,z s )The minimum distance is d t The projection point (x t ,y t ,z t ), traverse all other intersections in the same way, assuming that the total number of other intersections is n, then calculate the minimum distance d associated with all other intersections t,i , so the variance of the minimum distance can be expressed as,

[0075] where d t,i is the minimum distance associated with the i-th other intersection point, represents the average value of λ minimum distances, when σ t When σ is less than the set threshold, it is considered that the flatness meets the requirements; if σ t If the value is greater than the set threshold, the obtained deviation is large (it can be sorted by value, and When the difference is greater than Δκ, it is considered that the deviation is large) and the positions of other intersection points are monitored in the subsequent leveling steps.

[0076] Move the ring to its starting position so that its rotation direction is opposite to that of the previous one, detect the previous path again, and repeat the above detection steps.

[0077] Get the judgment index of the first flatness calculation. Different movement trajectories of the PSD sensor will produce multiple judgment indexes. According to the number of unqualified points n in a round-trip measurement pe Get the judgment index Npt is the total number of intersection points in a return, As the basic index (settable), multiple judgment indexes Can be recorded as

[0078] The step of flatness detection also includes performing a second flatness calculation, starting from the starting point of the ring, selecting a cycloid track in the same area after four intersections, the cycloid track does not contain intersections, using the standard curve selected during relative calibration as the reference curve, and the points on the reference curve as reference points, calculating the dynamic degree of approach to the reference curve η', η", η"', and the dynamic degree of moving away from the other three cycloid tracks in each cycle. If the dynamic degree of approach and the dynamic degree of moving away in multiple cycles are both within the set threshold range, the second flatness calculation considers that the flatness is qualified; otherwise, the cycloid is unqualified, and a judgment index for the second flatness calculation is obtained. Different movement trajectories of the PSD sensor will produce multiple judgment indexes. According to the number of unqualified cycloids in a round-trip measurement, n le Get the judgment index N lt is the total number of cycloids in a return, As the basic index (settable), multiple judgment indexes Can be recorded as

[0079] The adjustment of the flatness in the step is to flatten the bottom plate by means of pressure flattening, and the number of times k that the bottom plate needs to be flattened is calculated according to the results of the first flatness calculation and the second flatness calculation.

[0080]

[0081] Among them, k0 is the basic leveling pass, for The value of the i-th for The minimum value, for The maximum value; is the jth value, for The minimum value, for The maximum value.

[0082] In the step, the bottom plate is cleaned by using a laser cleaning head, the bottom plate is placed on a platform, the smoke and dust generated by the cleaning is removed by a purifier during the cleaning process, the adhesion of the bottom plate is tested after cleaning, and the cleaning is repeated until the adhesion reaches the set requirements.

[0083] Step 2: To reduce the damage to the surface of the base plate during pretreatment, an aluminum film with a thickness of σ1 is deposited on the metal layer of the aluminum substrate using the atomic layer deposition process.

[0084] The precursors are selected as trimethylaluminum and hydrogen, nitrogen is used as the carrier gas, and the temperature of the reaction chamber is maintained at T.

[0085] The atomic layer deposition process steps are:

[0086] Driven by nitrogen, trimethylaluminum enters the reaction chamber and undergoes adsorption reaction on the surface of the bottom plate. 11 0.2s;

[0087] Use nitrogen to purge to remove excess gas and reaction products from the reaction chamber. The purge time is t 12 is 2s, and the flow rate Q1 is 0.03slm;

[0088] Driven by nitrogen, hydrogen enters the reaction chamber with a flow rate Q2 of 0.1slm and reacts with the deposited layer for a time t 13 0.2s, to generate aluminum film;

[0089] Use nitrogen to purge and remove excess gas and reaction by-products from the reaction chamber. The cleaning time is t 14 is 5s, and the flow rate Q1 is 0.03slm;

[0090] The above steps are repeated to finally produce an aluminum film with a thickness of σ1.

[0091] Step three, generate an insulating layer, and deposit an aluminum oxide film with a thickness of σ2 on the formed aluminum film using the atomic layer deposition process; the thickness σ2 of the aluminum oxide film is greater than the thickness σ1 of the aluminum film, preferably 30σ1≥σ2≥20σ1.

[0092] The precursors are selected as trimethylaluminum and water, nitrogen is used as the carrier gas, and the temperature of the reaction chamber is maintained at T;

[0093] The atomic layer deposition process steps are:

[0094] Driven by nitrogen, trimethylaluminum enters the reaction chamber and undergoes adsorption reaction on the surface of the aluminum film. 21 0.2s;

[0095] Use nitrogen to purge to remove excess gas and reaction products from the reaction chamber. The purge time is t22 is 2s, and the flow rate Q1 is 0.03slm;

[0096] Water enters the reaction chamber driven by nitrogen, with a flow rate Q2 of 0.1slm, and reacts with the deposited layer for a time t 23 0.2s, aluminum oxide is generated;

[0097] Use nitrogen to purge and remove excess gas and reaction by-products from the reaction chamber. The cleaning time is t 24 is 5s, and the flow rate Q1 is 0.03slm;

[0098] The above steps are repeated to finally produce an aluminum oxide film with a thickness of σ2.

[0099] Step 4: Press the copper foil onto the aluminum oxide film.

[0100] The beneficial effects of the present invention are:

[0101] 1. The present invention uses atomic layer deposition to deposit aluminum film and aluminum oxide film on the metal layer. The aluminum film repairs the damage on the surface of the metal layer during pretreatment, and can also further improve the bonding strength of the surface of the aluminum substrate. The aluminum oxide film is deposited as an insulating layer, which not only plays the isolation role of the traditional aluminum substrate insulating layer, but also enhances the surface bonding strength between the multiple layers through atomic layer deposition, which plays a key role in pressing the copper layer.

[0102] 2. The thickness σ2 of the aluminum oxide film of the present invention is greater than the thickness σ1 of the aluminum film, preferably 30σ1≥σ2≥20σ1, which can ensure the effect of the aluminum oxide film.

[0103] 3. The present invention adopts a ring-shaped PSD sensor, which rotates and moves at the same time for measurement, and achieves accurate measurement data through calibration, providing relatively accurate data for subsequent cleaning, and further improving the surface bonding force.

[0104] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. 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 improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process, characterized in that: The aluminum substrate comprises a metal layer, an insulating layer and a circuit layer, the metal layer is an aluminum alloy, the insulating layer is deposited on the metal layer by an atomic layer deposition process, the insulating layer is aluminum oxide, and the circuit layer is copper.

2. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 1, characterized in that: The method comprises the following steps: 1) Pre-treating the bottom plate for the metal layer, the pre-treating comprising cleaning the bottom plate and adjusting the flatness of the bottom plate and detecting the flatness; 2) reducing damage to the surface of the base plate during pretreatment, and depositing an aluminum film with a thickness of σ1 on the metal layer of the aluminum substrate using the atomic layer deposition process; 3) generating an insulating layer, and depositing an aluminum oxide film with a thickness of σ2 on the formed aluminum film using the atomic layer deposition process; 4) Then press the copper foil onto the aluminum oxide film.

3. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 2, characterized in that: The thickness σ2 of the aluminum oxide film is greater than the thickness σ1 of the aluminum film, preferably 30σ1≥σ2≥20σ1.

4. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 3, characterized in that: In the step 1), the flatness of the bottom plate is firstly detected. If the flatness meets the requirement, the bottom plate is cleaned. If the flatness does not meet the requirement, the flatness of the bottom plate is adjusted, and then the bottom plate is cleaned; The steps of the flatness detection are first to design a detection sensor and calibrate multiple sensors, select four PSD sensors, and perform absolute calibration on the PSD sensors; in order to increase the detection range of the PSD sensor, the four PSD sensors are evenly distributed on a ring, the ring is driven to rotate, and the ring moves linearly along the bottom plate surface at the same time, the motion trajectory of the four PSD sensors on the ring is a cycloid, and the trajectories of the four PSD sensors all have intersections, and the trajectory of one of the cycloids is selected as the standard curve, and the four PSD sensors are relatively calibrated through the measurement data at the intersection, so that the measurement data at the intersection are the same, and at the same time, the calibration values ​​of other points on the cycloid trajectory are calculated according to the adjustment ratio or difference at the intersection; in order to make the relative calibration accurate, the radius r of the ring is set to be adjustable, that is, the relative positions of the four PSD sensors are adjustable, assuming that the moving distance for one measurement is l; in order to make each cycloid have an intersection with other cycloids, so that relative calibration can be performed, and the number of measurements is reduced as much as possible (that is, the measurement range is increased during each walk), so it is necessary to meet the following requirements: Right now When the radius r of the ring satisfies formula (2), the calibration accuracy can be improved and the detection range of each linear movement is increased.

5. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 4, characterized in that: The flatness detection step also includes flatness calculation. Since the cycloid trajectory of each PSD sensor is a curve, the intersection points on the cycloid of the same PSD sensor are not on the same straight line. Three intersection points within a cycloid cycle are selected. The plane equation formed by the three intersection points is ax+by+cz=1. A reference point is selected on the bottom plate. The coordinates of the three intersection points can be expressed as (x1, y1, z1), (x2, y2, z2), and (x3, y3, z3). According to the parallelogram formed by the above three intersection points, a virtual intersection point (x1, y1, z1) on the fourth vertex is generated. virtually ,y virtually ,z virtually ), choose any other intersection point (x s ,y s ,z s ), calculate the distance between the virtual intersection and other intersections According to the direction of the parallelogram formed by the three intersection points, the virtual intersection point is projected outward with a radius of d, and the intersection points (x s ,y s ,z s )The minimum distance is d t The projection point (x t ,y t ,z t ), traverse all other intersections in the same way, assuming that the total number of other intersections is n, then calculate the minimum distance d associated with all other intersections t,i , so the variance of the minimum distance can be expressed as, where d t,i is the minimum distance associated with the i-th other intersection point, represents the average value of λ minimum distances, when σ t When σ is less than the set threshold, it is considered that the flatness meets the requirements; if σ t If the value is greater than the set threshold, the obtained deviation is large (it can be sorted by value, and When the difference is greater than Δκ, it is considered that the deviation is large) the positions of other intersection points are monitored in the subsequent leveling steps; Move the ring to the starting position so that the ring rotates in the opposite direction to the previous one, detect the previous path again, and repeat the above detection steps; Get the judgment index of the first flatness calculation. Different movement trajectories of the PSD sensor will produce multiple judgment indexes. According to the number of unqualified points n in a round-trip measurement pe Get the judgment index N pt is the total number of intersection points in a return, is the base index (settable), Multiple judgment indexes Can be recorded as 6. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 5, characterized in that: The step of flatness detection also includes performing a second flatness calculation, starting from the starting point of the ring, selecting a cycloid track in the same area after four intersections, the cycloid track does not contain intersections, using the standard curve selected during relative calibration as the reference curve, and the points on the reference curve as reference points, calculating the dynamic degree of approach to the reference curve η', η", η"', and the dynamic degree of moving away from the other three cycloid tracks in each cycle. If the dynamic degree of approach and the dynamic degree of moving away in multiple cycles are both within the set threshold range, the second flatness calculation considers that the flatness is qualified; otherwise, the cycloid is unqualified, and a judgment index for the second flatness calculation is obtained. Different movement trajectories of the PSD sensor will produce multiple judgment indexes. According to the number of unqualified cycloids in a round-trip measurement, n le Get the judgment index N lt is the total number of cycloids in a return, is the base index (settable), Multiple judgment indexes Can be recorded as 7. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 6, characterized in that: The flatness adjustment in step 1) is to flatten the bottom plate by means of pressure flattening, and the number of times k that the bottom plate needs to be flattened is calculated according to the results of the first flatness calculation and the second flatness calculation. Among them, k0 is the basic leveling pass, for The value of the i-th for The minimum value, for The maximum value; is the jth value, for The minimum value, for The maximum value.

8. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 7, characterized in that: In the step 1), the bottom plate is cleaned by using a laser cleaning head, the bottom plate is placed on a platform, and the smoke generated by the cleaning is removed by a purifier during the cleaning process. After the cleaning is completed, the adhesion of the bottom plate is tested, and the cleaning is repeated until the adhesion meets the set requirements.

9. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 8, characterized in that: In the step 2), the precursors are selected to be trimethylaluminum and hydrogen, nitrogen is used as a carrier gas, and the temperature of the reaction chamber is maintained at T; The atomic layer deposition process steps are: Driven by nitrogen, trimethylaluminum enters the reaction chamber and undergoes adsorption reaction on the surface of the bottom plate. 11 0.2s; Use nitrogen to purge to remove excess gas and reaction products from the reaction chamber. The purge time is t 12 is 2s, and the flow rate Q1 is 0.03slm; Driven by nitrogen, hydrogen enters the reaction chamber with a flow rate Q2 of 0.1slm and reacts with the deposited layer for a time t 13 0.2s, to generate aluminum film; Use nitrogen to purge and remove excess gas and reaction by-products from the reaction chamber. The cleaning time is t 14 is 5s, and the flow rate Q1 is 0.03slm; The above steps are repeated to finally produce an aluminum film with a thickness of σ1.

10. The method for improving the surface bonding strength of an aluminum substrate using an atomic layer deposition process according to claim 9, characterized in that: In step 3), the precursors are selected to be trimethylaluminum and water, nitrogen is used as a carrier gas, and the temperature of the reaction chamber is maintained at T; The atomic layer deposition process steps are: Driven by nitrogen, trimethylaluminum enters the reaction chamber and undergoes adsorption reaction on the surface of the aluminum film. 21 0.2s; Use nitrogen to purge to remove excess gas and reaction products from the reaction chamber. The purge time is t 22 is 2s, and the flow rate Q1 is 0.03slm; Water enters the reaction chamber driven by nitrogen, with a flow rate Q2 of 0.1slm, and reacts with the deposited layer for a time t 23 0.2s, aluminum oxide is generated; Use nitrogen to purge and remove excess gas and reaction by-products from the reaction chamber. The cleaning time is t 24 is 5s, and the flow rate Q1 is 0.03slm; The above steps are repeated to finally produce an aluminum oxide film with a thickness of σ2.

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