Optimization method and process method of laminated chip high-frequency inductor printing screen

Abstract

The application provides an optimization method and process method of laminated chip high-frequency inductance printing screen plate, and relates to the field of chip inductance. The optimization method comprises the following steps: S1, selecting multiple printing screen plates with different specifications; S2, calculating the screen opening rate αo of the printing screen plates with different specifications; S3, sequentially sorting the printing screen plates with different specifications according to the screen opening rate αo from large to small; S4, drawing a simulated J-shaped arc graph and a printing screen plate schematic diagram with corresponding specifications by using CAD drawing software, rotating the printing screen plate schematic diagram with the center point of the J-shaped arc graph, selecting multiple different screen tension angles θ between 0° and 45°, and respectively obtaining actual opening areas ΣW 2 and screen shielding areas Σd 2 ; calculating the arc graph internal slurry permeation screen opening rate Ao and the theoretical slurry permeation volume ΣV according to a formula, and sequentially sorting the different screen tension angles θ according to the opening areas ΣW 2 and the arc graph internal slurry permeation screen opening rate Ao from large to small.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chip inductors, in particular to a method and process for optimizing a printing screen of a laminated chip high-frequency inductor. BACKGROUND

[0002] Chip inductors are micro electronic components using surface mount technology (SMT). According to the manufacturing process, they can be divided into wound type, laminated type and thin film type. The laminated type is manufactured using multi-layer printing technology and laminating process, and has the advantages of small size and good magnetic shielding.

[0003] Currently, the design forms of the inner electrode coil structure of the laminated chip high-frequency inductor include U-shaped, O-shaped and J-shaped, and the screen specifications used for printing the inner electrode single coil of the high-frequency inductor include 400 mesh-18 μm and 500 mesh-18 μm, and the screen angle is 22.5° or 30°. As the line width of the inner electrode coil design becomes thinner and thinner, the requirement for the edge smoothness of the printed silver line is higher, and 500 mesh-16 μm and 640 mesh-15 μm screen parameters are selected for manufacturing. These screen parameters are mainly suitable for printing the U-shaped and O-shaped straight line segment patterns of the laminated chip high-frequency inductor.

[0004] Since the J-shaped inner electrode silver line design has a 50 μm wide arc pattern, if a 400 mesh-18 μm screen with a screen angle of 22.5° is selected for printing, the low mesh, thick wire diameter and thick screen knot will result in poor silver paste flow flatness and jagged edges. If a 500 mesh-16 μm screen with a screen angle of 22.5° is selected for printing, although the edge smoothness of the silver line is improved, the J-shaped inner electrode arc pattern still has the problem of uneven width and thickness. After the product is laminated, the silver layer with thick thickness is flattened, which leads to inconsistent line width and area in the coil, and cannot guarantee the inductance accuracy and yield of the product.

[0005] In summary, the prior art cannot select screen parameters suitable for printing the inner electrode coil of the laminated chip high-frequency J-shaped inductor, and cannot meet the requirements of uniform width and thickness of the J-shaped inner electrode coil arc pattern, good edge smoothness of the silver line, and product reliability and yield. SUMMARY

[0006] To solve the above problems, the purpose of the present application is to provide a method and process for optimizing a printing screen of a laminated chip high-frequency inductor, to solve the problem that it is difficult to select screen parameters suitable for printing the inner electrode coil of the laminated chip high-frequency J-shaped inductor, and to meet the requirements of uniform width and thickness of the J-shaped inner electrode coil arc pattern, good edge smoothness of the silver line, and product reliability and yield.

[0007] The technical scheme of the optimization method of the laminated chip high-frequency inductor printing screen plate of the present application is as follows:

[0008] The optimization method of the laminated chip high-frequency inductor printing screen plate comprises the following steps:

[0009] S1, a plurality of printing screen plates of different specifications are selected, and the specifications of the printing screen plates include mesh number n, wire diameter d and screen thickness h;

[0010] S2, the screen opening width W is obtained according to the mesh number n and the wire diameter d of the screen plate, and the screen opening rate αo of the screen plate of different specifications is calculated, and the screen opening rate αo = opening area / total screen area;

[0011] S3, the printing screen plates of different specifications are sequentially sorted from large to small according to the screen opening rate αo;

[0012] S4, a simulated J-shaped arc pattern and a corresponding printing screen plate schematic diagram are drawn by using CAD drawing software, the center point of the J-shaped arc pattern is rotated to the printing screen plate schematic diagram, a plurality of different screen tensioning angles θ are selected between 0° and 45°, and actual opening areas ΣW 2 and screen shielding areas Σd 2 are obtained respectively;

[0013] According to formula one: ΣV = ΣW 2 *(h+Eom), and formula two: Ao = ΣW 2 / (Σd 2 +ΣW 2 ), the theoretical permeation volume ΣV is positively correlated with the opening area ΣW 2 and the arc pattern inside the screen opening rate Ao; the screen opening rate Ao and the theoretical permeation volume ΣV are calculated according to the known photosensitive emulsion thickness Eom, and the different screen tensioning angles θ are sequentially sorted from large to small according to the opening area ΣW 2 and the arc pattern inside the screen opening rate Ao;

[0014] S5, the edge serration size of the printed cutting line is analyzed according to the different screen tensioning angles θ, and the screen knot shielding permeation area S of the screen edge corresponding to the different screen tensioning angles is calculated according to the wire diameter d and the screen tensioning angle θ by using a trigonometric function formula;

[0015] The smaller the screen knot shielding permeation area S of the screen edge is, the better the edge uniformity of the printed cutting line is;

[0016] S6, the printing screen plate of the best specification and the best screen tensioning angle is obtained according to the arc pattern inside the screen opening rate Ao and the screen knot shielding permeation area S of the screen edge.

[0017] Furthermore, in step S1, the printing screens of different specifications include a first printing screen, a second printing screen, a third printing screen, and a fourth printing screen; the specifications of the first printing screen are n = 400 mesh, d = 18 μm, and h = 25 μm; the specifications of the second printing screen are n = 500 mesh, d = 18 μm, and h = 25 μm; the specifications of the third printing screen are n = 500 mesh, d = 16 μm, and h = 20 μm; and the specifications of the fourth printing screen are n = 640 mesh, d = 15 μm, and h = 20 μm.

[0018] Furthermore, in step S4, the different netting angles θ include 22.5°, multiple netting angles that decrease in proportion to 22.5° as the base netting angle, and multiple netting angles that increase in proportion to 22.5° as the base netting angle.

[0019] Furthermore, in step S4, the different netting angles θ include 0°, 2.5°, 7.5°, 12.5°, 17.5°, 22.5°, 30°, 37.5° and 45°.

[0020] Furthermore, in step S4, according to the opening area ΣW 2 The mesh opening ratios Ao of the permeable mesh within the arc-shaped pattern, arranged from largest to smallest, are: θ1 = 7.5°, θ2 = 2.5°, θ3 = 12.5°, θ4 = 0°, θ5 = 17.5°, θ6 = 22.5°, θ7 = 30°, θ8 = 37.5°, and θ9 = 45°.

[0021] Furthermore, in step S4, printing screens with stretching angles θ1 = 7.5°, θ2 = 2.5°, θ3 = 12.5°, θ5 = 17.5°, and θ6 = 22.5° are selected, and the area S of the mesh knots blocking the ink penetration at the corresponding screen edges is calculated. It is found that the area S of the mesh knots blocking the ink penetration at the screen edges corresponding to stretching angles θ3 = 12.5°, θ5 = 17.5°, and θ6 = 22.5° is smaller than the area S of the mesh knots blocking the ink penetration at the screen edges corresponding to stretching angles θ1 = 7.5° and θ2 = 2.5°.

[0022] Furthermore, in step S5, the optimal specifications of the printing screen are n = 500 mesh, d = 16 μm, h = 20 μm, and the optimal screen stretching angle θ = 12.5°.

[0023] Furthermore, in step S4, the thickness Eom of the photosensitive emulsion is any size between 5 μm and 15 μm.

[0024] Furthermore, screen printing samples were made according to different specifications and stretching angles. Printing tests were conducted on different screen printing samples, and the printing effect of the arc graphics was observed through images to verify the printing screen with the best specifications and the best stretching angle.

[0025] The technical solution of the process method for the multilayer high-frequency inductive printing screen of the present invention is as follows:

[0026] The process method based on the above-mentioned multilayer wafer high-frequency inductive printing screen includes the following steps:

[0027] Step 1: Cut stainless steel wire mesh sheets with a stretching angle θ = 12.5°.

[0028] Take a piece of stainless steel wire mesh with specifications n=500 mesh and d=16μm, unfold it and lay it flat on the working surface, measure the stretching angle θ=12.5° and mark it, then cut out square stainless steel wire mesh sheets;

[0029] Step 2: Attach the stainless steel wire mesh to the subframe.

[0030] The four edges of the cut square stainless steel wire mesh are glued to the surface of the subframe polyester wire mesh. The subframe polyester wire mesh has tension. After the glue is firmly attached, the middle part of the polyester wire mesh is cut off.

[0031] Step 3: Apply the required tension to the top of the stainless steel wire mesh sheet bonded to the subframe.

[0032] Place the cast aluminum mesh frame of the required size in the middle part of the top mesh machine, and then place the sub-frame with the stainless steel wire mesh attached on the cast aluminum mesh frame. The top mesh machine drives the cast aluminum mesh frame to rise until it is fixed at the position of the sub-frame with the stainless steel wire mesh attached. The cast aluminum mesh frame contacts the stainless steel wire mesh and continues to rise until the stainless steel wire mesh reaches the required tension value. After stabilization, the stainless steel wire mesh is bonded to the cast aluminum mesh frame.

[0033] Step 4: Cut and separate the bonded stainless steel wire mesh and cast aluminum frame from the subframe, then place them stably to obtain the printing screen.

[0034] Step 5: After degreasing, coating, exposing, developing, retouching, inspecting, and measuring the printing screen, it can be used in the printing process of multilayer chip high-frequency inductors.

[0035] The optimization method and process of the multilayer high-frequency inductor printing screen of the present invention have the following advantages compared with the prior art: Based on the relationship between the mesh count, wire diameter, and aperture ratio of the printing screen, the required specifications of the printing screen can be preliminarily screened, which is beneficial to improving the fullness and uniformity of the line width and silver thickness of the printed pattern, and to improving the straightness of the silver lines on the printed inner electrode. Furthermore, according to the size of the edge serrations produced by different screen stretching angles θ in the printed cutting lines, the smaller the area S of the screen edge where the mesh knots obstruct the ink penetration, the better the uniformity of the printed cutting line edges. The final selected screen stretching angle must satisfy both the ink penetration mesh aperture ratio Ao and the requirements for uniform, straight, and full printed edges of straight lines. Using the above optimization method, the screen parameters suitable for printing the inner electrode coil of the multilayer high-frequency J-type inductor can be accurately selected, thereby meeting the requirements for uniform width and thickness of the arc pattern of the J-type inner electrode coil, good smoothness of the silver line edges, and product reliability and yield. Attached Figure Description

[0036] Figure 1 This is a planar schematic diagram of the printing screen in a specific embodiment of the optimization method for the multilayer high-frequency inductor printing screen of the present invention;

[0037] Figure 2 This is a cross-sectional schematic diagram of the printing screen in a specific embodiment of the optimization method for the multilayer high-frequency inductor printing screen of the present invention;

[0038] Figure 3 This is a cross-sectional schematic diagram of the silver paste penetration of the printing screen in a specific embodiment of the optimized method of the multilayer high-frequency inductive printing screen of the present invention;

[0039] Figure 4 This is a planar schematic diagram of the silver paste penetration of the printing screen in a specific embodiment of the optimized method of the multilayer high-frequency inductive printing screen of the present invention;

[0040] Figure 5 This is a schematic diagram of the screen edge knot blocking the ink penetration in a specific embodiment of the optimization method of the multilayer sheet high-frequency inductive printing screen of the present invention;

[0041] Figure 6 This is a printing test diagram of a screen printing sample in a specific embodiment of the optimization method for the multilayer high-frequency inductive printing screen of the present invention;

[0042] Figure 7 This is a comparison image of single-print / double-print of a screen printing sample in a specific embodiment of the optimization method for the multilayer high-frequency inductive printing screen of the present invention.

[0043] Figure 8 This is a screen verification diagram showing the optimal specifications and optimal stretching angle in a specific embodiment of the optimization method for the multilayer high-frequency inductive printing screen of the present invention.

[0044] Figure 9 This is a comparison chart showing the improvement of the electrode range within a printed J-type inductor product before and after improvement, in a specific embodiment of the optimization method for the multilayer chip high-frequency inductor printing screen of the present invention.

[0045] In the diagram: 1-printing screen, 2-photosensitive emulsion, n-mesh count, d-wire diameter, h-screen thickness, W-screen opening width, ΣV-theoretical paste penetration volume, Eom-photosensitive emulsion thickness. Detailed Implementation

[0046] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] This embodiment presents an optimization method for a multilayer chip high-frequency inductor printing screen, such as... Figures 1 to 9 As shown, the optimization method for multilayer chip high-frequency inductor printing screen includes the following steps:

[0048] S1. Select multiple printing screens 1 of different specifications. The specifications of the printing screen 1 include mesh count n, wire diameter d, and screen thickness h. Mesh count n is the number of mesh openings per inch, wire diameter d is the diameter of each wire, and screen thickness h is the thickness of the woven screen. Specifically, in step S1, the printing screens 1 of different specifications include a first printing screen, a second printing screen, a third printing screen, and a fourth printing screen; the specifications of the first printing screen are n = 400 mesh, d = 18μm, and h = 25μm; the specifications of the second printing screen are n = 500 mesh, d = 18μm, and h = 25μm; the specifications of the third printing screen are n = 500 mesh, d = 16μm, and h = 20μm; and the specifications of the fourth printing screen are n = 640 mesh, d = 15μm, and h = 20μm.

[0049] S2. Based on the mesh count n and wire diameter d of the screen, the opening width W of the screen is obtained. The opening ratio αo of different screen specifications is then calculated. The opening ratio αo = opening area / total screen area. For example... Figure 1 As shown, the opening of printing screen 1 is square. The opening area can be calculated based on the opening width W. Dividing the opening area by the total area of ​​the screen gives the screen opening ratio αo, as shown in Table 1 below:

[0050] Wire mesh number of mesh n Wire mesh wire diameter d Wire mesh opening W Wire mesh thickness h Opening ratio a0 400 mesh 18 μm 46 μm 25 μm 49％ 500 mesh 18 μm 33 μm 25 μm 42％ 500 mesh 16 μm 35 μm 20 μm 47％ 640 mesh 15 μm 25 μm 20 μm 39％

[0051] Table 1

[0052] S3. Sort the printing screens of different specifications in descending order of screen opening ratio αo. According to the comparison in Table 1, taking 400 mesh-18μm as a reference, for printing screens of 500 mesh-18μm specification, increasing the mesh number while keeping the wire diameter the same and decreasing the opening ratio only helps to improve the straightness of the printed inner electrode silver lines. Due to the smaller opening ratio, the amount of ink transmitted through the screen is relatively small, resulting in a smaller line width and silver thickness of the printed pattern, affecting the fullness and uniformity, and failing to meet the initial screening requirements.

[0053] A 500-mesh to 16μm printing screen, with its increased mesh count, reduced wire diameter, and relatively larger aperture ratio, is beneficial for improving the fullness and uniformity of the printed pattern's line width and silver thickness; it also helps improve the straightness of the silver lines on the printed internal electrodes, meeting the initial screening requirements.

[0054] A 640-mesh, 16μm printing screen, while exhibiting a smaller mesh count and lower wire diameter, resulted in less pattern diffusion during printing. However, it also had a lower aperture ratio, leading to less ink penetration and reduced line width and silver thickness, thus affecting the fullness and uniformity of the printed pattern; therefore, it did not meet the initial screening requirements. Analysis revealed that a 500-mesh, 16μm printing screen was more suitable for printing the desired J-shaped inner electrode arc pattern.

[0055] S4. Using CAD drawing software, draw a simulated J-shaped arc shape and a corresponding printing screen diagram. Rotate the printing screen diagram around the center point of the J-shaped arc shape, selecting multiple different screen stretching angles θ between 0° and 45° to obtain the actual opening area ΣW. 2 and the area covered by the mesh Σd 2 The different mesh stretching angles θ include 22.5°, multiple mesh stretching angles decreasing from 22.5° as the base angle, and multiple mesh stretching angles increasing from 22.5° as the base angle. In this embodiment, the different mesh stretching angles θ include 0°, 2.5°, 7.5°, 12.5°, 17.5°, 22.5°, 30°, 37.5°, and 45°, such as... Figure 4 As shown, the actual opening area ΣW is obtained respectively. 2 and the area covered by the mesh Σd 2 .

[0056] According to Formula 1: ΣV=ΣW 2 *(h+Eom), Formula 2: Ao=ΣW 2 / (Σd 2 +ΣW 2 From this, we can obtain the theoretical slurry penetration volume ΣV and the opening area ΣW. 2 The aperture ratio Ao of the permeable mesh within the arc-shaped pattern is positively correlated. Given the thickness Eom of the photosensitive emulsion, calculate the aperture ratio Ao and the theoretical permeable volume ΣV within the arc-shaped pattern, and then calculate based on the opening area ΣW.2 The mesh opening ratio Ao of the permeable mesh inside the arc shape is sorted in descending order for different mesh stretching angles θ.

[0057] like Figure 3 As shown, taking a printing screen with specifications n=500 mesh, d=16μm, h=20μm as an example, the photosensitive emulsion thickness Eom=15μm. In the figure, photosensitive emulsion 2 is coated and cured on the printing screen 1, and the height of photosensitive emulsion 2 beyond the surface of the printing screen 1 is the photosensitive emulsion thickness Eom. The volume of silver paste printed onto the film, i.e., the theoretical through-paste volume ΣV, can be obtained. According to the above formula, the opening area ΣW 2 The larger the aperture ratio Ao, the larger the photosensitive emulsion mesh opening ratio within the arc pattern, and the greater the theoretical photosensitive emulsion volume ΣV during printing; conversely, it decreases. In other embodiments, to meet different practical needs, the photosensitive emulsion thickness Eom can also be any other size between 5μm and 15μm.

[0058] In step S4, according to the opening area ΣW 2 The mesh tensioning angles, ordered from largest to smallest by the mesh opening ratio Ao within the arc-shaped pattern, are θ1 = 7.5°, θ2 = 2.5°, θ3 = 12.5°, θ4 = 0°, θ5 = 17.5°, θ6 = 22.5°, θ7 = 30°, θ8 = 37.5°, and θ9 = 45°. To maximize the mesh opening area and thus the maximum permeable volume within the arc-shaped pattern, the mesh tensioning angle is θ1 = 7.5°, with θ2 = 2.5° and θ3 = 12.5° being the next best choices.

[0059] S5. Analyze the serration size of the printed cutting lines at different screen stretching angles θ. Using trigonometric formulas, calculate the area of ​​screen edge obstruction and ink penetration corresponding to different screen stretching angles based on the wire diameter d and the screen stretching angle θ.

[0060] The smaller the area S of the screen edge where the mesh knots obstruct the ink penetration, the better the uniformity of the printed cutting lines. Since the J-shaped inner electrode arc pattern to be printed also includes the printed cutting lines around its edges, and the lines need to be printed evenly, straightly, and fully, the screen stretching angle differs between the cutting lines and the arc pattern. The chosen stretching angle must satisfy both the ink penetration rate Ao and the requirement for uniform, straight, and full edges of the straight lines. To meet these two requirements, printing screens with stretching angles θ1 = 7.5°, θ2 = 2.5°, θ3 = 12.5°, θ5 = 17.5°, and θ6 = 22.5° are selected, and the area S of the ink penetration obstruction at the corresponding screen edge is calculated. For example... Figure 5As shown, the area S of ink penetration obstructed by the mesh knots at the edge of the screen with stretching angles θ3 = 12.5°, θ5 = 17.5°, and θ6 = 22.5° is smaller than that at stretching angles θ1 = 7.5° and θ2 = 2.5°. This indicates that printing screens made with stretching angles θ3 = 12.5°, θ5 = 17.5°, and θ6 = 22.5° produce printing cut lines with relatively better uniformity, straightness, and fullness.

[0061] S6. Based on the aperture ratio Ao of the ink penetration mesh within the arc shape and the area S of ink penetration obstruction by the mesh knots at the edge of the screen, the optimal specifications and optimal screen stretching angle of the printing screen are obtained. In step S5, considering that the screen stretching angle θ3 = 12.5° has a larger aperture ratio Ao of ink penetration mesh within the arc shape compared to θ5 = 17.5° and θ6 = 22.5°, and based on the requirement that the arc shape on the same screen needs a large ink penetration area and that the printed edges of the cutting lines be as uniform, straight, and full as possible, the optimal specifications of the printing screen are n = 500 mesh, d = 16μm, h = 20μm, and the optimal screen stretching angle θ = 12.5°.

[0062] Screen samples were made according to different specifications and stretching angles. Printing tests were conducted on different screen samples, and the printing effect of the arc graphics was observed through images to verify the printing screen with the best specifications and the best stretching angle.

[0063] Different screen printing samples were prepared using screens with mesh sizes of 500 mesh -16μm -12.5°, 500 mesh -16μm -22.5°, 640 mesh -15μm -22.5°, and 400 mesh -18μm -22.5°. Printing tests were conducted, and the uniformity of the inner electrode linewidth and silver thickness in the double-printed J-shaped inner electrode arc pattern were compared. Figure 6 As shown, the 500 mesh - 16 μm - 12.5° screen printing sample has a silver thickness range of 1.68 μm, and the silver lines of the inner electrode are full and have good uniformity; the 500 mesh - 16 μm - 12.5° screen printing sample has slightly less fullness and uniformity of the silver lines of the inner electrode; the 640 mesh - 15 μm - 22.5° screen printing sample has moderate fullness and uniformity of the silver lines of the inner electrode; and the 400 mesh - 18 μm - 22.5° screen printing sample has poor fullness and uniformity of the silver lines of the inner electrode.

[0064] like Figure 7As shown in the single / double printing effect diagrams of the silver wires for the internal electrodes printed on the two types of films, it can be seen that in single printing, the printing effect and smoothness of the four different printing screens are good, but the printed silver thickness does not reach the requirement of 17μm±2μm. In double printing, the upper two sets of printing screens have better double printing effect and smoothness; the lower two sets of printing screens have poorer double printing effect and smoothness. Further, the optimal screen specifications and optimal screen stretching angle were verified through calculations of theoretical screen production parameters, such as... Figure 8 As shown, the actual double-layer silver thickness is 18.51μm, which meets the silver thickness requirement. Considering factors such as the calculated theoretical ink penetration, the actual printed silver thickness, line width uniformity, and consistent printing effect of the J-type inductor internal electrode, the screen printing parameters for the printed multilayer high-frequency J-type inductor internal electrode coil are determined to be 500 mesh - 16μm - 12.5°.

[0065] The uniformity of coil linewidth and silver thickness for J-type inductor products is compared in Table 2 below:

[0066]

[0067] Table 2

[0068] After the improvement, the internal electrode difference of the printed J-type inductor product is significantly improved compared to the original internal electrode difference. Figure 9 This confirms that the line width and silver thickness have good uniformity and consistency.

[0069] The product testing hit rate is shown in Table 3 below:

[0070] Adjustment design product specification model Test and compile batch number Average test and compile hit rate 10-22 nH 7 94.03％ 3.0-9.1 nH (S / J) general precision requirement 8 93.67％ 3.0-9.1 nH high precision (G / H) requirement 3 88.39％

[0071] Table 3

[0072] This embodiment provides a process method for a multilayer wafer-type high-frequency inductor printing screen. This process method is based on the optimized method of the above-mentioned multilayer wafer-type high-frequency inductor printing screen and includes the following steps:

[0073] Step 1: Cut stainless steel wire mesh sheets with a stretching angle θ = 12.5°.

[0074] Take a piece of stainless steel wire mesh with specifications n=500 mesh and d=16μm, unfold it and lay it flat on the working surface, measure the stretching angle θ=12.5° and mark it, then cut out square stainless steel wire mesh sheets;

[0075] Step 2: Attach the stainless steel wire mesh to the subframe.

[0076] The four edges of the cut square stainless steel wire mesh are glued to the surface of the subframe polyester wire mesh. The subframe polyester wire mesh has tension. After the glue is firmly attached, the middle part of the polyester wire mesh is cut off.

[0077] Step 3: Apply the required tension to the top of the stainless steel wire mesh sheet bonded to the subframe.

[0078] Place the cast aluminum mesh frame of the required size in the middle part of the top mesh machine, and then place the sub-frame with the stainless steel wire mesh attached on the cast aluminum mesh frame. The top mesh machine drives the cast aluminum mesh frame to rise until it is fixed at the position of the sub-frame with the stainless steel wire mesh attached. The cast aluminum mesh frame contacts the stainless steel wire mesh and continues to rise until the stainless steel wire mesh reaches the required tension value. After stabilization, the stainless steel wire mesh is bonded to the cast aluminum mesh frame.

[0079] Step 4: Cut and separate the bonded stainless steel wire mesh and cast aluminum frame from the subframe, then place them stably to obtain the printing screen.

[0080] Step 5: After degreasing, coating, exposing, developing, retouching, inspecting, and measuring the printing screen, it can be used in the printing process of multilayer chip high-frequency inductors.

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. An optimization method for a multilayer high-frequency inductive printing screen, characterized in that, Includes the following steps: S1. Select multiple printing screens of different specifications. The specifications of the printing screens include mesh count n, wire diameter d, and screen thickness h. S2. Based on the mesh count n and wire diameter d of the screen, the opening width W of the screen is obtained, and the opening ratio αo of the screen for different specifications is calculated. The opening ratio αo = opening area / total area of ​​the screen. S3. Arrange the printing screens of different specifications in descending order of their screen opening ratio αo; S4. Using CAD drawing software, draw a simulated J-shaped arc shape and a corresponding printing screen diagram. Rotate the printing screen diagram around the center point of the J-shaped arc shape, selecting multiple different screen stretching angles θ between 0° and 45° to obtain the actual opening area ΣW. 2 and the area covered by the mesh Σd 2 ; According to Formula 1: ΣV=ΣW 2 *(h+Eom), Formula 2: Ao=ΣW 2 / (Σd 2 +ΣW 2 From this, we can obtain the theoretical slurry penetration volume ΣV and the opening area ΣW. 2 The aperture ratio Ao of the permeable mesh within the arc-shaped pattern is positively correlated. Given the thickness Eom of the photosensitive emulsion, calculate the aperture ratio Ao and the theoretical permeable volume ΣV within the arc-shaped pattern, and then calculate based on the opening area ΣW. 2 The mesh opening ratios Ao of the slurry permeable mesh within the arc-shaped pattern are sorted from largest to smallest for different mesh stretching angles θ. S5. Analyze the serration size of the printed cutting lines at different screen stretching angles θ. Using trigonometric formulas, calculate the area of ​​screen edge obstruction and ink penetration corresponding to different screen stretching angles based on the wire diameter d and the screen stretching angle θ. ; The smaller the area S of the mesh knots at the edge of the screen that blocks the ink from penetrating, the better the uniformity of the printed cutting line edges. S6. Based on the aperture ratio Ao of the ink penetration mesh within the arc shape and the area S of ink penetration obstruction by the mesh knots at the edge of the screen, the printing screen with the optimal specifications and the optimal stretching angle is obtained.

2. The optimization method for the multilayer high-frequency inductive printing screen according to claim 1, characterized in that, step In S1, printing screens of different specifications include a first printing screen, a second printing screen, a third printing screen, and a fourth printing screen; the specifications of the first printing screen are n=400 mesh, d=18μm, and h=25μm; the specifications of the second printing screen are n=500 mesh, d=18μm, and h=25μm; the specifications of the third printing screen are n=500 mesh, d=16μm, and h=20μm; and the specifications of the fourth printing screen are n=640 mesh, d=15μm, and h=20μm.

3. The optimization method for the multilayer high-frequency inductive printing screen according to claim 1, characterized in that, In step S4, the different netting angles θ include 22.5°, multiple netting angles that decrease in proportion to 22.5°, and multiple netting angles that increase in proportion to 22.5°.

4. The optimization method for the multilayer high-frequency inductive printing screen according to claim 1, characterized in that, In step S4, the different netting angles θ include 0°, 2.5°, 7.5°, 12.5°, 17.5°, 22.5°, 30°, 37.5° and 45°.

5. The optimization method for the multilayer chip high-frequency inductive printing screen according to claim 4, characterized in that, In step S4, according to the opening area ΣW 2 The mesh opening ratios Ao of the slurry permeable mesh inside the arc shape, arranged from largest to smallest, are θ1=7.5°, θ2=2.5°, θ3=12.5°, θ4=0°, θ5=17.5°, θ6=22.5°, θ7=30°, θ8=37.5°, and θ9=45°.

6. The optimization method for the multilayer chip high-frequency inductive printing screen according to claim 5, characterized in that, In step S4, printing screens with stretching angles θ1=7.5°, θ2=2.5°, θ3=12.5°, θ5=17.5°, and θ6=22.5° are selected. The area S of the mesh knots blocking the ink penetration at the corresponding screen edges is calculated. It is found that the area S of the mesh knots blocking the ink penetration at the screen edges corresponding to stretching angles θ3=12.5°, θ5=17.5°, and θ6=22.5° is smaller than the area S of the mesh knots blocking the ink penetration at the screen edges corresponding to stretching angles θ1=7.5° and θ2=2.5°.

7. The optimization method for the multilayer high-frequency inductive printing screen according to claim 1, characterized in that, In step S5, the optimal specifications of the printing screen are n=500 mesh, d=16μm, h=20μm, and the optimal screen stretching angle θ=12.5°.

8. The optimization method for the multilayer high-frequency inductive printing screen according to claim 1, characterized in that, In step S4, the thickness Eom of the photosensitive emulsion is any size between 5 μm and 15 μm.

9. The optimization method for the multilayer high-frequency inductive printing screen according to claim 1, characterized in that, Screen samples were made according to different specifications and stretching angles. Printing tests were conducted on different screen samples, and the printing effect of the arc graphics was observed through images to verify the printing screen with the best specifications and the best stretching angle.

10. A process method for optimizing the multilayer high-frequency inductive printing screen according to claim 7, characterized in that, Includes the following steps: Step 1: Cut stainless steel wire mesh sheets with a stretching angle θ = 12.5°. Take a piece of stainless steel wire mesh with specifications n=500 mesh and d=16μm, unfold it and lay it flat on the working surface, measure the stretching angle θ=12.5° and mark it, then cut out square stainless steel wire mesh sheets. Step 2: Attach the stainless steel wire mesh to the subframe. The four edges of the cut square stainless steel wire mesh are glued to the surface of the subframe polyester wire mesh. The subframe polyester wire mesh has tension. After the glue is firmly attached, the middle part of the polyester wire mesh is cut off. Step 3: Apply the required tension to the top of the stainless steel wire mesh sheet bonded to the subframe. Place the cast aluminum mesh frame of the required size in the middle part of the top mesh machine, and then place the sub-frame with the stainless steel wire mesh attached on the cast aluminum mesh frame. The top mesh machine drives the cast aluminum mesh frame to rise until it is fixed at the position of the sub-frame with the stainless steel wire mesh attached. The cast aluminum mesh frame contacts the stainless steel wire mesh and continues to rise until the stainless steel wire mesh reaches the required tension value. After stabilization, the stainless steel wire mesh is bonded to the cast aluminum mesh frame. Step 4: Cut and separate the bonded stainless steel wire mesh and cast aluminum frame from the subframe, then place them stably to obtain the printing screen. Step 5: After degreasing, coating, exposing, developing, retouching, inspecting, and measuring the printing screen, it can be used in the printing process of multilayer chip high-frequency inductors.

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