Quantitative detection method for interface bonding performance of surface plated layer

Abstract

The application discloses a kind of quantitative detection methods of surface plating layer interface bonding performance, vertical penetration and horizontal scratch are carried out to plating layer sample simultaneously using probe, according to probe normal displacement-time curve, determine the separation time of plating layer, according to probe lateral force-time curve and separation time, obtain the interface bonding force of plating layer, and then obtain the bonding strength of each layer plating layer.The application can carry out quantitative analysis and evaluation to surface plating layer bonding force and bonding strength, with strong application value and application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of surface detection and surface plating layer reliability evaluation, and particularly relates to a quantitative detection and analysis method for evaluating interface bonding performance of a surface plating layer. BACKGROUND

[0002] In surface engineering technology, the plating layer includes a plating layer, a coating layer, a paint film, etc. The coating layer may involve various functional coating layers and paint films such as insulating coating layers, invisible coating layers, heat insulation coating layers, corrosion-resistant coating layers, and wear-resistant coating layers. The plating layer is commonly used in electronic device products, involving surface plating layers, PCB pad plating layers, and metallization layers. Common plating layers include copper plating, nickel plating, gold plating, tin plating, etc., and also include Ni / Au, Ni / Pd / Au, etc. The PCB pad plating layer includes copper plating, copper-tin plating, SnPb plating, Cu plating Ni / Au, etc. The substrate metallization layer includes organic, ceramic, and composite substrate copper cladding. The performance and quality of the plating layer directly affect the realization of device performance and service reliability. However, in addition to basic performance such as electricity, heat, and corrosion resistance, the bonding strength is a key point in application, and shedding and wear will limit its function and service life. The interface bonding strength is the ability of the plating layer to resist separation, which is usually characterized by the force or energy required to peel off the plating layer per unit area from the substrate. However, current plating layer bonding performance (bonding force, bonding strength, etc.) still lacks effective in-situ quantitative characterization methods and testing methods. A large number of bonding reliability of the plating layer is evaluated by qualitative methods such as scratching and gridding; or indirectly evaluated by reliability tests such as loading thermal stress and mechanical stress to test whether the plating layer falls off or delaminates. Therefore, the current plating layer bonding force measurement is usually by qualitative detection method or semi-quantitative detection method. SUMMARY

[0003] The present application aims to overcome the above-mentioned defects, and provides a quantitative detection method for interface bonding performance of a surface plating layer, which solves the problem of difficult quantitative detection of the interface bonding performance of the current plating layer, has high feasibility, and effectively develops and expands the detection technology of the performance properties of the plating layer.

[0004] To achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0005] A quantitative detection method for interface bonding performance of a surface plating layer, comprising:

[0006] The substrate and n layers of plating layers on the surface of the substrate are taken as a plating layer sample, the thickness of each layer of the plating layer in the plating layer sample is measured, and n≥1;

[0007] The probe in the scratch system is used to simultaneously perform vertical pressing and horizontal scratching on the plating layer sample;

[0008] obtaining the probe normal displacement-time curve and the probe lateral force-time curve;

[0009] determining the separation time t of the plated layer according to the probe normal displacement-time curve m , 1≤m≤N, N is the total number of separation times;

[0010] obtaining the interfacial bonding force F of the plated layer according to the probe lateral force-time curve and t m ; lm ;

[0011] obtaining the bonding strength of each layer of plated layer according to F lm and the thickness of each layer of plated layer.

[0012] Further, it further comprises:

[0013] Before measuring the thickness of each layer of plated layer in the plated layer sample, polishing the surface of the plated layer sample, and the polishing removes the plated layer thickness≤20%-40% of the thickness of the outermost layer of plated layer.

[0014] Further, the method for simultaneously vertically pressing and horizontally scratching the plated layer sample by the probe in the scratch system is:

[0015] applying a linearly increasing normal load to the probe, while moving the probe at a constant speed in the horizontal direction;

[0016] The value range of the normal load is 10mN-5N, and the maximum depth of the probe vertically pressing the plated layer sample is greater than the total thickness of n layers of plated layer.

[0017] The value range of the constant speed of the probe moving in the horizontal direction is 1μm / s-10μm / s.

[0018] Further, a plurality of target regions are selected in the plated layer sample, the bonding strength of each layer of plated layer in the plurality of target regions is obtained, and the bonding strength and uniformity of each layer of plated layer in the whole plated layer sample are evaluated according to the bonding strength of each layer of plated layer in the plurality of target regions.

[0019] Further, the normal displacement resolution of the probe is ≤0.1nm, and the lateral force resolution of the probe is ≤1.0μN;

[0020] The horizontal movement range of the probe is ≥200mm×100mm, and the vertical movement range is ≥10mm;

[0021] The data acquisition feedback system in the scratch system collects the normal displacement and lateral force of the probe at a frequency of ≥10kHz;

[0022] The scratch system also includes a temperature control module, which is used to control the temperature of the coated sample and to achieve quantitative detection of the interfacial bonding performance of the coated layer under different temperature conditions.

[0023] Furthermore, the method for determining the separation time of the coating layer based on the probe normal displacement-time curve is as follows:

[0024] In the probe normal displacement-time curve, the intersection points of the tangents of adjacent curve segments where the slope changes abruptly are obtained sequentially in time order. The times corresponding to the intersection points are recorded as separation times t1, t2, ... t1. N , t m Let m be the m-th separation time.

[0025] Furthermore, based on the probe transverse force-time curve and t m The interfacial bonding force F of the coating layer is obtained. lm The method is as follows:

[0026] Based on the probe's transverse force-time curve, it will be compared with t m The corresponding probe lateral force serves as the interfacial bonding force F of the coating layer. lm .

[0027] Furthermore, according to F lm The method for obtaining the bonding strength of each coating layer based on the thickness of each coating layer is as follows:

[0028] Based on the thickness of each coating layer, determine the relationship with t. m The thickness of the corresponding plating layer is denoted as δ. m

[0029]

[0030] σ bm For t m The bonding strength of the corresponding coating layer.

[0031] Furthermore, the total separation time N is greater than or equal to the total number of coating layers n;

[0032] When multiple separation times correspond to the same coating layer, the bonding strength of the coating layer is the average of the bonding strengths obtained from the multiple separation times.

[0033] Furthermore, the coating layer can be a plating layer, a coating, or a paint film.

[0034] Compared with the prior art, the present invention has at least one of the following advantages:

[0035] (1) The application creatively proposes a quantitative detection method for the interface bonding performance of a surface plated layer, and the quantitative value of the bonding strength of each layer of the plated layer is obtained by analyzing the normal displacement and lateral force of a probe method according to the structural characteristics of the plated layer;

[0036] (2) The application limits the method of simultaneously performing vertical indentation and horizontal scratching on the plated layer sample, which is beneficial to improve the accuracy and comprehensiveness of the detection;

[0037] (3) The application can realize the bonding force (bonding strength) test of multiple interfaces at one time, and can provide technical means for differentiated analysis of heterogeneous interfaces;

[0038] (4) The method provided by the application is a quasi-non-destructive analysis, and the analysis method provides a way for the construction of technical indicators of interface bonding performance;

[0039] (5) The application can eliminate the influence of factors such as plated hardness and material, and can reduce detection errors by using multiple separation times, further improve the detection accuracy, and can be applied to the detection of various plated layer samples, has high flexibility and universality, and has wide application prospect in the field of quantitative detection technology and evaluation analysis technology of surface plated layer interface bonding performance. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a sectional structure diagram of a Ni / NiAu composite plated layer in the embodiment of the application;

[0041] Figure 2 is a surface analysis area diagram of a Ni / NiAu composite plated layer in the embodiment of the application;

[0042] Figure 3 is a surface morphology diagram of a Ni / NiAu composite plated layer after detection by the method of the application in the embodiment of the application;

[0043] Figure 4 is a method schematic diagram for obtaining the bonding force by the normal displacement-time curve and the lateral force-time curve in the embodiment of the application; wherein (a) and (b) are schematic diagrams for obtaining two separation times by the normal displacement-time curve, (c) and (d) are schematic diagrams for obtaining the bonding force according to the two separation times;

[0044] Figure 5 is a normal displacement-time curve of a Ni / NiAu composite plated layer in the embodiment of the application;

[0045] Figure 6 is a bonding force analysis diagram of each layer of a Ni / NiAu composite plated layer in the embodiment of the application;

[0046] Figure 7The binding strength of each layer of the Ni / NiAu composite plating layer in the embodiment of the present application;

[0047] Figure 8 The flow chart of the quantitative detection method for the interface bonding performance of the surface plating layer in the embodiment of the present application. DETAILED DESCRIPTION

[0048] The features and advantages of the present application will become more apparent from the detailed description in conjunction with the accompanying drawings.

[0049] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Although various aspects of embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale.

[0050] The present application provides a quantitative detection method for the interface bonding performance of a surface plating layer, which provides a new idea for the detection of the bonding force and the bonding strength of the surface plating layer, and has the advantages of clear detection principle, simplicity, feasibility, and the like, solves the problem of quantitative detection of the interface bonding performance of the plating layer, and provides an effective detection means for the bonding force and the bonding strength of the surface plating layer and an analysis and evaluation technology for the interface bonding reliability, and has strong application value and application prospect.

[0051] The quantitative detection method for the interface bonding performance of the surface plating layer of the present application obtains the "normal displacement-time" and "lateral force-time" information of the probe by vertically pressing and horizontally scratching the surface of the plating layer sample by using a scratch system, analyzes and processes the force, displacement, and time data of the probe in combination with the microstructure and thickness information of the plating layer, so as to obtain the bonding force and the bonding strength of the plating layer. The bonding force and the bonding strength of the plating layer can be the bonding force and the bonding strength of the plating layer and the base material, or the bonding force and the bonding strength between a certain plating layer and an adjacent plating layer.

[0052] Specifically, the quantitative detection method comprises the following steps:

[0053] Firstly, the surface of the plating layer sample is treated. Generally, the surface is polished to reduce the roughness of the sample surface and ensure the flatness. However, the polishing should not be excessive, which may completely destroy the plating layer. Optionally, the thickness of the plating layer removed by polishing is less than or equal to 20% to 40% of the thickness of the outermost plating layer.

[0054] Secondly, the cross section of the plating layer sample is checked. The structure of the plating layer is observed, and the thickness of the plating layer is measured. If the plating layer is a multi-layer structure, the thickness of each layer is measured, and the thickness of the i-th layer of the plating layer is denoted as δ i , 1≤i≤n, and n is the total number of layers of the plating layer.

[0055] Third step, using scratch system, preferably instrumented indentation system, to carry out non-contact imaging of surface morphology, and to carry out target area positioning of plated layer;

[0056] Fourth step, at t0, to carry out probe indentation, linearly applying vertical direction load. The optional load range of the indentation process is 10 mN-5 N, the indentation depth is set according to the plated layer thickness, and the indentation depth range is generally 1-50 μm; at the same time, the probe is set to move horizontally at a uniform speed, and the displacement rate is set to 1 μm / s-10 μm / s. The lateral force, normal displacement and time data are collected, and the probe "normal displacement-time" curve and "lateral force-time" curve are recorded;

[0057] Fifth step, replacing the test area 3-5 times, repeating the third step to the fourth step. The uniformity test of the sample is carried out.

[0058] Sixth step, based on the "normal displacement-time" and "lateral force-time" information obtained in the above steps, the analysis steps of the composite plated layer bonding performance are as follows:

[0059] 1) Obtain the separation time of the plated layer. For the "normal displacement-time" curve (D n (t)~t), at a certain time, the normal displacement rate suddenly changes, and the two curve segments with different slopes before and after the change are obtained, and the intersection point of the tangent lines of the two curve segments represents the separation time of the plated layer, and the corresponding indentation depth at this time is the thickness of the plated layer. The curve can be equally spaced into multiple line segments, and the corresponding slopes are obtained, and further slope outlier determination is carried out, when the slope outlier value appears, the deviation degree of the outlier value relative to the average value of the remaining slopes is calculated, if the deviation degree ≥20%, the left and right segments are treated as different curve segments, that is, the curve is equally spaced into segment short curves, if the second segment short curve appears outlier, the intersection point of the tangent lines of the first segment and the second segment short curves, and the intersection point of the tangent lines of the second segment and the third segment short curves are all taken as the separation time. When the plated layer is a multi-layer structure, the indentation depth increases, and multiple normal displacement rate mutation points and separation times will appear, and the mth separation time is recorded as t m , 1≤m≤N, N is the total number of separation times; in this step, due to the fact that the thickness of the plated layer cannot be completely uniform, the interface will also appear jagged bonding, and during the horizontal movement, the same plated layer can have multiple separation times;

[0060] 2) Obtain the bonding force of the plated layer. For the "lateral force-time" curve (F l (t)~t), the lateral force corresponding to the separation time t m represents the bonding force of the interface. The lateral force value F lm is read from the curve: Fl (t m When multiple separation times occur in the same coating layer, this step obtains the bonding force of the interface with the same number of separation times.

[0061] 3) Obtain the bonding strength of the coating. The normalized bonding strength of the interface is characterized by the coating thickness. The bonding strength is: In this step, it is necessary to first determine t based on the thickness of each coating layer. m The thickness of the coating layer is taken as δ, indicating which coating layer it belongs to. m When multiple separation times occur for the same coating layer, multiple bonding strengths will be obtained in this step. The average value of the multiple bonding strengths will be taken as the bonding strength of the coating layer.

[0062] Optionally, the scratching system involved in the above method should include: a probe loading system, a mobile positioning platform, a data acquisition and feedback system, and a temperature control module, which can be a conventional scratching system capable of implementing the above method.

[0063] Optionally, during the detection process, the probe's lateral load resolution is ≤1.0μN; the normal displacement resolution is ≤0.1nm; the horizontal platform of the scratch system has a movable range of not less than 200mm×100mm to achieve the acquisition of multiple target areas; the vertical movable range is not less than 10mm; and the data acquisition frequency of the data acquisition feedback system is ≥10kHz.

[0064] Optionally, the adhesion and bonding strength of the coating layer can be measured under different temperature conditions by adjusting the temperature module. For low-temperature testing, the temperature operating range is: room temperature to -120℃; for high-temperature testing, the temperature operating range is: room temperature to +800℃; heating rate: 5 to 20℃ / min; temperature resolution: ≤0.1℃; temperature control accuracy: 0.75%.

[0065] Optional, δ m The preferred method for determination is to perform the test according to the method disclosed in patent application 202011034523.X, or to perform microscopic measurement on a sectioned sample and use the average value as the coating thickness δ. m .

[0066] Optionally, the above method is applicable to the quantitative detection and evaluation of the interfacial bonding performance of the coating material in the whole specimen. The coating material includes, but is not limited to, plating, coating, and paint film, and the coating can be single-layer, double-layer, or multi-layer.

[0067] Examples

[0068] This embodiment will combine Figures 1 to 8 The technical solution of the present invention is described in detail below.

[0069] According to the method of the present application, the bonding performance of a composite plating layer sample with a plating layer structure of "electroplated Au layer / electroplated Ni layer / chemically plated Ni layer / resin substrate" (Ni / NiAu) is detected. As shown in Figure 8 , the following steps are implemented:

[0070] Step 1: sample surface treatment.

[0071] Step 2: sample cross-section inspection. The plating layer structure is observed, as shown in Figure 1 , the Ni / NiAu composite plating layer has a multi-layer structure, from the outside to the inside, in order: electroplated gold layer (the outermost surface layer, layer 1, represented by Au e ), electroplated nickel layer (layer 2, represented by Ni e ), chemically plated nickel layer (layer 3, represented by Ni c ), and resin substrate (the innermost layer, represented by Resin). The thickness of each layer is measured, as shown in Table 1.

[0072] Table 1: Results of thickness detection of each layer of the Ni / NiAu plating layer

[0073]

[0074]

[0075] Step 3: using an instrumented indentation test system, non-contact imaging of the surface topography is performed, and the target area of the Ni / NiAu plating layer is located, Figure 2 , the analysis area map;

[0076] Step 4: probe indentation is performed, and linear vertical load is applied. The normal force is linearly increased, with a maximum value of 1000 mN. The indentation depth is set according to the plating layer thickness. In this embodiment, the total thickness of the Ni / NiAu plating layer is 9.7±0.5 μm, so the indentation depth is set to 0-10 μm. At the same time, the probe is set to move horizontally at a constant speed, with a displacement rate of 8 μm / s. The sample topography after the test is shown in Figure 3 . The lateral force, normal displacement, and time data are collected, and the "normal displacement-time (D n (t)~t)" curve and the "lateral force-time (F l (t)~t)" curve are recorded;

[0077] Step 5: the test area is replaced 3-5 times, and steps 3-4 are repeated.

[0078] Step 6: based on the "normal displacement-time" and "lateral force-time" information obtained in the above steps, the analysis steps for the bonding performance of the composite plating layer are as follows:

[0079] 1) Obtain the separation time of the plated layer. For the "normal displacement-time (D n (t)~t)" curve, at a certain time, the normal displacement rate suddenly changes, and the intersection point of the two curve segments with different slopes before and after the change represents the separation time of the plated layer, and the corresponding indentation depth at this time is the thickness of the plated layer. When the plated layer is a multi-layer structure, the indentation depth increases, and multiple sudden changes in the normal displacement rate and separation times t m .

[0080] 2) Obtain the bonding force of the plated layer. For the "lateral force-time (F l (t)~t)" curve, the lateral force corresponding to the separation time t m represents the bonding force of the interface. The force value F lm =F l (t m ) is read from the curve, and a schematic diagram of obtaining the bonding force from the curve is shown in Figure 4 , wherein F lm and F lj are the bonding forces obtained from t m and t j , respectively.

[0081] 3) Obtain the bonding strength of the plated layer. The normalized bonding strength of the interface is represented by the thickness of the plated layer. The bonding strength is:

[0082] The normal displacement-time curve of the Ni / NiAu composite plated layer is shown in Figure 5 . The intersection points of the tangents of each curve segment of the curve are analyzed to obtain the separation times t1, t2…t6 of each layer of the composite plated layer. According to the thicknesses of each layer of the plated layer in Table 1, it can be seen that t1 and t3 are the separation times of the Au e layer, t2 and t4 are the separation times of the Ni e layer, t5 and t6 are the separation times of the Ni c layer, and in addition, Figure 5 the overall trend of the normal displacement increases, but there are local decreases, which may be related to the hardness difference of each layer, the undulating interface, or the interface inclination. The increasing or decreasing trend of the normal displacement does not affect the accuracy of the test of the present application. Further, by reading the lateral force, the bonding forces F l1 ~F l6 of each layer and the adjacent layer are obtained, as shown in Figure 6 F l1 ~F l6 are the ordinates corresponding to t1, t2…t6. Finally, the bonding strength σ b1 ~σ b6 of the composite plated layer is calculated, wherein σ b1 , σb2 Au e Layer bond strength, actually Au e -Ni e Bond strength, σ b3 , σ b4 Ni e Layer bond strength, actually Ni e -Ni c Bond strength, σ b5 , σ b6 Ni c Layer bond strength, actually Ni c -resin bond strength, such as Figure 7 .

[0083] The above detailed description and the example embodiments of the present application are not to be understood as limiting the present application. It is understood by those skilled in the art that various equivalents substitutions, modifications or improvements can be made to the technical solutions of the present application and the embodiments thereof without departing from the spirit and scope of the present application, and these all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims.

[0084] The contents not described in detail in the specification of the present application are the known technology to those skilled in the art.

Claims

1. A method for quantitatively detecting interface bonding performance of a surface plated layer, characterized by, The application relates to a method for evaluating the interface bonding performance of a multilayer plating layer. The method comprises the following steps: The thickness of each layer of the plating layer sample is measured; The probe is vertically pressed into and horizontally scratched on the plating layer sample at the same time, a linearly increasing normal load is applied to the probe, and the probe is uniformly moved in the horizontal direction at the same time; The separation time t of the plated layer is determined according to the probe method normal displacement-time curve m 1≤m≤N, N is the total number of separation times According to the probe lateral force-time curve and t m , the interface bonding force F lm of the plated layer is obtained According to F lm and the thickness of each plated layer, the bonding strength of each plated layer is obtained; The normal displacement-time curve of the probe and the lateral force-time curve of the probe are obtained; The probe is a probe in a scratch system; The data acquisition feedback system in the scratch system has a collection frequency of the normal displacement of the probe and the lateral force of the probe of greater than or equal to 10 kHz; In the probe normal displacement-time curve, according to time sequence, the tangent intersection points of the adjacent two curve sections with sudden change of slope are obtained in sequence, and the time corresponding to the tangent intersection points is recorded as separation time t1, t2, t N , t m is the mth separation time; The method for determining the separation time of the plating layer according to the normal displacement-time curve of the probe is as follows: The method for determining the adjacent two curves with a sudden change in the slope in the normal displacement-time curve of the probe is as follows:

2. The method for quantitatively detecting the interface bonding performance of a surface plated layer according to claim 1, characterized in that, The normal displacement-time curve of the probe is divided into more than or equal to five short curves, the slope of each short curve is obtained, and the outlying value of the slope of each short curve is determined; when the outlying value appears, the deviation degree of the outlying value is calculated; when the deviation degree is greater than or equal to 20%, the short curve corresponding to the deviation degree and the adjacent short curve are taken as the adjacent two curves with a sudden change in the slope. The application further relates to a method for evaluating the interface bonding performance of a multilayer plating layer.

3. The method for quantitatively detecting the interface bonding performance of a surface plated layer according to claim 1, characterized in that, Before the thickness of each layer of the plating layer sample is measured, the surface of the plating layer sample is polished, and the thickness of the plating layer removed by polishing is less than or equal to 20% to 40% of the thickness of the outermost plating layer. The method for vertically pressing and horizontally scratching the plating layer sample by using the probe is as follows: The value range of the normal load is 10 mN to 5 N, and the maximum depth of the vertical pressing of the probe on the plating layer sample is greater than the total thickness of the n layers of plating layers; 4. The method for quantitatively detecting interface bonding performance of a surface plated layer according to claim 1, characterized in that, The value range of the uniform moving speed of the probe in the horizontal direction is 1 mu m / s to 10 mu m / s. A plurality of target regions are selected in the plating layer sample, the bonding strength of each layer of the plating layer in the plurality of target regions is obtained, and the bonding strength and uniformity of each layer of the plating layer of the whole plating layer sample are evaluated according to the bonding strength of each layer of the plating layer in the plurality of target regions.

5. The method for quantitatively detecting the interface bonding performance of a surface plated layer according to claim 1, characterized in that, The plating layer is a plating layer, a coating layer or a paint film. The normal displacement resolution of the probe is less than or equal to 0.1 nm, the lateral force resolution of the probe is less than or equal to 1.0 mu N, the horizontal moving range of the probe is greater than or equal to 200 mm*100 mm, and the vertical moving range of the probe is greater than or equal to 10 mm.

6. The method for quantitatively detecting interface bonding performance of a surface plated layer according to claim 1, characterized in that, According to the probe lateral force-time curve and t m , the interface bonding force F lm of the plated layer is obtained. According to the probe lateral force-time curve, the t m The corresponding probe lateral force as the interface bonding force F lm .

7. The method for quantitatively detecting interface bonding performance of a surface plated layer according to claim 6, characterized in that, According to F lm and the thickness of each plated layer, the method for obtaining the bonding strength of each plated layer is: According to the thickness of each layer plating layer, judge and t m Corresponding plating layer, the thickness of the layer plating layer is recorded as δ m σ bm to t m corresponding plating layer.

8. The method for quantitatively detecting interface bonding performance of a surface plated layer according to claim 7, characterized in that, The scratch system further comprises a temperature control module, which is used for controlling the temperature of the plating layer sample and realizing quantitative detection of the interface bonding performance of the plating layer under different temperature environments. The total number N of separation times is greater than or equal to the total number n of plating layers. When a plurality of separation times correspond to the same plating layer, the bonding strength of the plating layer is the average value of the bonding strength obtained from the plurality of separation times.

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