A COB board production method and COB board

Abstract

The present invention discloses a COB board production method and COB board, the method comprising: obtaining a first substrate, a second substrate, and a prepreg; performing a first laser depth control process on the second copper layer and the second surface of the first substrate to obtain a first substrate having a first groove; performing a pressing process to obtain a first plate; performing a drilling and copper deposition process on the first plate to obtain a second plate; performing an electroplating copper layer process on the second plate to obtain a third plate; performing a circuit process on the first copper layer and the fourth copper layer of the third plate to obtain a fourth plate; performing an electroplating and second laser depth control process on the fourth plate to obtain at least one COB board; and performing laser gong on the first surface of the COB board to obtain a second groove. By precisely performing laser depth control and laser gong on the first substrate, the high-precision COB board production requirements can be met, and the method can be widely applied to the field of COB board packaging technology.

Description

Technical Field

[0001] The present invention relates to the technical field of COB board processing, and in particular to a COB board production method and a COB board. Background Art

[0002] The COB (Chip On Board) board is a key component of chip packaging, used to carry the chip and provide electrical connections between the chip and external circuits.

[0003] The current production process of COB boards is difficult to meet the high-precision COB board production needs. Summary of the Invention

[0004] In view of this, an object of the embodiments of the present invention is to provide a COB board production method and a COB board, which can meet the high-precision COB board production requirements.

[0005] In a first aspect, an embodiment of the present invention provides a COB board production method, comprising:

[0006] Obtain a first substrate, a second substrate, and a prepreg, wherein the first substrate has a first copper layer provided on its first surface and a second copper layer provided on its second surface, and the second substrate has a third copper layer provided on its first surface and a fourth copper layer provided on its second surface;

[0007] Performing a first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having a first groove, wherein the depth of the first groove ranges from 70 micrometers to 170 micrometers;

[0008] The first substrate having the first groove, the prepreg, and the second substrate are sequentially arranged and pressed together to obtain a first plate, wherein the second copper layer is pressed together with the first surface of the prepreg, and the third copper layer is pressed together with the second surface of the prepreg;

[0009] Performing a drilling and copper deposition process on the first plate to obtain a second plate;

[0010] Performing copper electroplating on the second plate to obtain a third plate;

[0011] performing circuit processing on the first copper layer and the fourth copper layer of the third plate to obtain a fourth plate;

[0012] Performing electroplating and second laser depth control processing on the fourth plate to obtain at least one COB plate, wherein one COB plate corresponds to one first groove;

[0013] After laser grooving the first surface of the COB board, a second groove is obtained. The second groove is connected to the first groove to form a third groove. The third groove is used to place the chip. The depth of the third groove ranges from 190 microns to 210 microns.

[0014] In some optional embodiments, performing a first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having the first groove includes:

[0015] Obtaining positioning Mark points on the first substrate;

[0016] Determine at least one COB area according to the positioning Mark point, where the COB area belongs to the COB board;

[0017] Acquire first thickness information of the first substrate and second thickness information of the second copper layer;

[0018] determining a first depth of the first groove according to the first thickness information and the second thickness information;

[0019] Acquiring first area information of the first groove;

[0020] determining a first laser divergence and a first laser energy according to the first depth and the first area information;

[0021] The first groove is obtained by laser etching the COB area using a laser with a first laser divergence and a first laser energy.

[0022] In some optional embodiments, before performing the first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having the first groove, the method further includes:

[0023] A plurality of first mark points are evenly arranged at the first end of the first substrate, and a plurality of second mark points are evenly arranged at the second end of the first substrate, wherein the first mark points and the second mark points correspond to each other in the first direction, and the COB area is located between the first mark points and the second mark points, and the first mark points and the second mark points both represent the positioning mark points;

[0024] Drilling two first positioning holes at the first end of the first substrate, wherein the plurality of first mark points are located between the two first positioning holes;

[0025] Two second positioning holes are drilled at the second end of the first substrate, a plurality of second Mark points are located between the two second positioning holes, and the first positioning hole and the second positioning hole are staggered in the first direction.

[0026] In some optional embodiments, the step of drilling and copper plating the first plate to obtain the second plate includes:

[0027] Drilling the first plate to obtain a plurality of first through holes, wherein the first through holes are located on a first side surface of the third groove;

[0028] Performing copper plating on the first through hole to obtain a second through hole, wherein the second through hole is used to electrically connect the first copper layer and the fourth copper layer;

[0029] The first plate having the second through hole is configured as the second plate.

[0030] In some optional embodiments, the step of performing copper electroplating on the second plate to obtain the third plate comprises:

[0031] Performing a first copper electroplating on the second through hole on the second plate to obtain a third through hole, wherein the third through hole has a preset copper thickness;

[0032] After plugging the third through hole with resin, a fourth through hole is obtained;

[0033] Performing a second copper electroplating on the first copper layer located at the edge of the fourth through hole to obtain a first thick copper layer, and performing a second copper electroplating on the fourth copper layer located at the edge of the fourth through hole to obtain a fourth thick copper layer;

[0034] The second plate having the first thick copper layer and the fourth thick copper layer is configured as the third plate.

[0035] In some optional embodiments, the step of performing circuit processing on the first copper layer and the fourth copper layer of the third plate to obtain the fourth plate includes:

[0036] performing a first exposure, a first development, and a first etching on the first copper layer to obtain a first circuit, wherein the first circuit is used to electrically connect pins of the chip after wire bonding, and the first circuit is composed of the first thick copper layer;

[0037] performing a second exposure, a second development, and a second etching on the fourth copper layer to obtain a second circuit, wherein the second circuit is used to be electrically connected to an external circuit, the second circuit being composed of the fourth thick copper layer, and the first circuit and the second circuit being electrically connected through the fourth through hole;

[0038] The third plate having the first circuit and the second circuit is configured as the fourth plate.

[0039] In some optional embodiments, the step of performing electroplating and second laser depth control processing on the fourth plate to obtain at least one COB plate includes:

[0040] Electroplating the first circuit with nickel-palladium-gold to obtain a first nickel-palladium-gold circuit;

[0041] Performing secondary nickel-palladium-gold electroplating on the second circuit to obtain a second nickel-palladium-gold circuit, wherein the primary nickel-palladium-gold electroplating and the secondary nickel-palladium-gold electroplating represent the electroplated gold;

[0042] According to the first nickel-palladium-gold circuit and the second nickel-palladium-gold circuit, a first V-cut line is obtained after a second laser depth control treatment is performed on the first surface of the first substrate, and a second V-cut line is obtained after a second laser depth control treatment is performed on the second surface of the second substrate. The enclosed area of ​​multiple first V-cut lines is the first surface of the COB board, and the enclosed area of ​​multiple second V-cut lines is the second surface of the COB board.

[0043] In some optional embodiments, the laser reaming of the first surface of the COB board to obtain a second groove, the second groove being connected to the first groove to form a third groove, includes:

[0044] determining a second depth of the second groove according to the first depth, the first thickness information, and the second thickness information;

[0045] configuring the second area information of the second groove as the first area information, so that the second groove and the first groove overlap with each other in the thickness direction of the first substrate;

[0046] determining a second laser divergence and a second laser energy according to the second depth and the second area information;

[0047] The second groove is obtained by laser rouging the first surface of the COB board with a laser of a second laser divergence and a second laser energy.

[0048] In some optional embodiments, before sequentially arranging the first substrate having the first groove, the prepreg, and the second substrate and laminating them to obtain the first plate, the method further includes:

[0049] Performing circuit processing on the second copper layer to obtain a connecting circuit, wherein the connecting circuit is used to assist the electroplating;

[0050] The third copper layer is subjected to circuit processing to obtain a positioning circuit, and the positioning circuit is used for pressing and positioning.

[0051] In a second aspect, an embodiment of the present invention provides a COB board, which is manufactured by the above-mentioned COB board production method.

[0052] The implementation of the embodiment of the present invention includes the following beneficial effects: The embodiment of the present invention provides a COB board production method, including: obtaining a first substrate, a second substrate and a prepreg, wherein the first surface of the first substrate is provided with a first copper layer, and the second surface is provided with a second copper layer, and the first surface of the second substrate is provided with a third copper layer, and the second surface is provided with a fourth copper layer; performing a first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having a first groove, and the depth of the first groove ranges from 70 microns to 170 microns; arranging the first substrate having the first groove, the prepreg and the second substrate in sequence, and performing a pressing process to obtain a first plate material, wherein the second copper layer and the first surface are provided with a third copper layer, and the fourth copper layer is provided; The first surface of the prepreg is pressed together, and the third copper layer is pressed together with the second surface of the prepreg; the first plate is subjected to a copper plating process to obtain a second plate; the second plate is subjected to a copper electroplating process to obtain a third plate; the first copper layer and the fourth copper layer of the third plate are subjected to circuit processing to obtain a fourth plate; the fourth plate is subjected to electro-gold and second laser depth control processes to obtain at least one COB board, and one COB board corresponds to one first groove; the first surface of the COB board is subjected to laser erosion to obtain a second groove, and the second groove is connected to the first groove to form a third groove, and the third groove is used to place the chip, and the depth of the third groove ranges from 190 microns to 210 microns. By precisely performing laser depth control and laser erosion on the first substrate, the third groove for placing the chip is accurately etched, and the required COB board is obtained after drilling and copper plating, electro-plating the copper layer, and electro-gold treatment, which can meet the high-precision COB board production requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a flow chart of the steps of a COB board production method provided by an embodiment of the present invention;

[0054] Figure 2 is a schematic structural diagram of a first groove provided by an embodiment of the present invention;

[0055] Figure 3 This is a schematic structural diagram of a finished plate provided by an embodiment of the present invention;

[0056] Figure 4 is a schematic diagram of lamination provided by an embodiment of the present invention;

[0057] Figure 5 is a schematic diagram of drilling a first through hole provided by an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of the structure of the COB board provided by an embodiment of the present invention;

[0059] Figure 7 is a schematic diagram of a third groove provided in an embodiment of the present invention;

[0060] Figure 8 Schematic diagram of performing circuit processing on the second copper layer and the third copper layer according to an embodiment of the present invention;

[0061] Figure 9 Schematic diagram of drilling split holes according to an embodiment of the present invention.

[0062] Reference numerals: first positioning hole 100, second positioning hole 110, second positioning hole 120, first mark point 130, COB board 140, COB board first surface 141, first nickel-palladium-gold circuit 142, third groove 143, first groove 1431, COB board second surface 144, second nickel-palladium-gold circuit 145, segmentation hole 150, V-cut line along the first direction 160, V-cut line along the second direction 170;

[0063] First copper layer 210, first substrate 211, second copper layer 212, first through hole 213, prepreg 220, third copper layer 230, second substrate 231, fourth copper layer 232; DETAILED DESCRIPTION

[0064] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0065] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0066] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0067] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0068] An embodiment of the present invention provides a COB board production method and a COB board, wherein the COB board production method includes: obtaining a first substrate, a second substrate and a prepreg, wherein the first surface of the first substrate is provided with a first copper layer, and the second surface is provided with a second copper layer, and the first surface of the second substrate is provided with a third copper layer, and the second surface is provided with a fourth copper layer; performing a first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having a first groove, wherein the depth of the first groove ranges from 70 microns to 170 microns; arranging the first substrate having the first groove, the prepreg and the second substrate in sequence, and performing a pressing process to obtain a first plate material, wherein the second copper layer and the first surface are provided with a third copper layer, and the fourth copper layer is provided ... The first surface of the prepreg is pressed together, and the third copper layer is pressed together with the second surface of the prepreg; the first plate is subjected to a copper plating process to obtain a second plate; the second plate is subjected to a copper electroplating process to obtain a third plate; the first copper layer and the fourth copper layer of the third plate are subjected to circuit processing to obtain a fourth plate; the fourth plate is subjected to electro-gold and second laser depth control processes to obtain at least one COB board, and one COB board corresponds to one first groove; the first surface of the COB board is subjected to laser erosion to obtain a second groove, and the second groove is connected to the first groove to form a third groove, and the third groove is used to place the chip, and the depth of the third groove ranges from 190 microns to 210 microns. By precisely performing laser depth control and laser erosion on the first substrate, the third groove for placing the chip is accurately etched, and the required COB board is obtained after drilling and copper plating, electro-plating the copper layer, and electro-gold treatment, which can meet the high-precision COB board production requirements.

[0069] The following further describes the COB board production method according to an embodiment of the present invention.

[0070] Reference Figure 1 , Figure 1 This is a flow chart of a COB board production method provided in an embodiment of the present invention. The COB board production method includes but is not limited to the following steps:

[0071] S100, obtaining a first substrate 211, a second substrate 231 and a prepreg 220, wherein the first surface of the first substrate 211 is provided with a first copper layer 210 and the second surface is provided with a second copper layer 212, and the first surface of the second substrate 231 is provided with a third copper layer 230 and the second surface is provided with a fourth copper layer 232.

[0072] Specifically, the first surface of the first substrate 211 is provided with a first copper layer 210, and the second surface is provided with a second copper layer 212. Copper layers play a key conductive role in circuit boards and can transmit current and signals. The first copper layer 210 and the second copper layer 212 can be deposited on the corresponding surfaces of the first substrate 211 through processes such as electroplating and sputtering. The first surface of the second substrate 231 is provided with a third copper layer 230, and the second surface is provided with a fourth copper layer 232. Similar to the first substrate 211, these copper layers are also used to achieve the electrical connection function of the circuit. Parameters such as the material, size, and characteristics of the copper layer of the second substrate 231 will be selected and customized according to the design requirements of the final product. The first substrate 211 and the second substrate 231 of the present application use BT (Bismaleimide Triazine, bismaleimide triazine resin) board materials, which are not specifically limited. For example, for some circuits that need to withstand large currents, the thickness of the copper layer will be increased to reduce resistance. The first substrate 211 of the present application is obtained by cutting, and the thickness of the first substrate 211 is 175 microns to 225 microns. The second substrate 231 is obtained by cutting, and the thickness of the second substrate 231 is 125 microns to 175 microns.

[0073] The semi-cured sheet 220, also known as prepreg, is usually made of reinforcing materials such as glass fiber cloth impregnated with thermosetting resins such as epoxy resin. In the subsequent manufacturing process, the semi-cured sheet 220 plays a dual role of bonding and insulation. It can firmly bond the first substrate 211 and the second substrate 231 together, while providing good insulation performance to prevent problems such as short circuits between different layers; the semi-cured sheet 220 is also obtained after cutting, and the thickness of the semi-cured sheet 220 is 60 microns to 70 microns. After obtaining these materials, they are used for a series of subsequent processing, such as laser processing, pressing, drilling and copper plating of the substrate, and gradually manufacturing the COB board 140 that meets specific functional requirements.

[0074] S200 , performing a first laser depth control process on the second copper layer 212 and the second surface of the first substrate 211 to obtain the first substrate 211 having a first groove 1431 , wherein the depth of the first groove 1431 ranges from 70 μm to 170 μm.

[0075] Specifically, laser depth control processing uses a high-energy-density laser beam to irradiate the surface of a material, causing the material to absorb the laser energy and undergo physical changes such as melting and vaporization, thereby removing part of the material and forming a groove on the surface of the material. In this process, by precisely controlling the laser energy, pulse width, scanning speed and other parameters, the groove depth can be precisely controlled. Figure 2When processing the second copper layer 212 and the second surface of the first substrate 211, the laser needs to act on the second copper layer 212 first to remove part of it, and then continue to act on the second surface of the first substrate 211 to form a groove of a certain depth on the substrate.

[0076] Processing process and key points: First, accurately place the first substrate 211 on the workbench of the laser processing equipment, ensuring that the second copper layer 212 and the second surface are in the appropriate processing position. Then, according to the design requirements, set the various laser parameters, such as the laser wavelength, power, and frequency. Generally speaking, different materials have different absorption efficiencies for lasers of different wavelengths, so it is necessary to select an appropriate laser wavelength to improve processing efficiency and quality. During the processing process, the laser beam scans the second copper layer 212 and the second surface along a predetermined path. As the laser continues to act, the material is gradually removed, and the first groove 1431 is gradually formed. During the processing process, the groove depth is monitored in real time or measured regularly to ensure that the depth of the first groove 1431 is within the range of 70 microns to 170 microns. If the depth is found to not meet the requirements, the laser parameters can be adjusted promptly to correct it.

[0077] The significance of the depth range for the first groove 1431: The depth range of 70 to 170 microns for the first groove 1431 was determined based on a comprehensive consideration of various factors. On the one hand, this depth range ensures that the first groove 1431 has sufficient space to meet subsequent process requirements. Furthermore, the first groove does not penetrate the first surface of the first substrate 211, preventing subsequent process chemicals from entering through the first groove and corroding the internal circuitry. On the other hand, the depth range also takes into account the mechanical strength and stability of the first substrate 211. If the groove is too deep, the overall strength of the first substrate 211 will be weakened, affecting product reliability. On the other hand, if the groove is too shallow, the subsequent laser gong process on the first surface of the first substrate 211 will require higher laser energy and a higher gong plate depth, thus affecting the quality and precision of the third groove 143. Therefore, through extensive experimentation and practical verification, this appropriate depth range was determined to ensure the optimal balance between product performance and quality.

[0078] In some optional embodiments, the first substrate 211 having a first groove 1431 is obtained after the first laser depth control processing is performed on the second copper layer 212 and the second surface of the first substrate 211, including: obtaining a positioning mark point on the first substrate 211; determining at least one COB area based on the positioning mark point, and the COB area belongs to the COB board 140; obtaining first thickness information of the first substrate 211 and second thickness information of the second copper layer 212; determining a first depth of the first groove 1431 based on the first thickness information and the second thickness information; obtaining first area information of the first groove 1431; determining a first laser divergence and a first laser energy based on the first depth and the first area information; and obtaining the first groove 1431 after laser etching the COB area with a laser of the first laser divergence and the first laser energy.

[0079] Specifically, positioning marks are pre-placed markers with specific shapes, positions, and identifiers on the first substrate 211. High-precision optical recognition equipment or sensors can quickly and accurately detect the location of these positioning marks. For example, on an automated production line, a camera scans the first substrate 211 and identifies the coordinates of the positioning marks, thereby determining the substrate's specific position and posture on the workbench.

[0080] After obtaining the positioning mark points, at least one COB area is calculated and determined based on these positioning mark points according to the pre-set design rules and algorithms. The COB area refers to the specific area on the first substrate 211 that will eventually be used to make the COB board 140. The position and shape of these areas are determined according to the functional requirements and design layout of the product. For example, based on the size of the chip, the pin layout, and the connection relationship with other circuit components, multiple COB areas are divided on the first substrate 211, and each area will be independently made into a COB board 140.

[0081] The first depth of first groove 1431 is determined using a specific calculation formula or algorithm based on the first thickness of first substrate 211 and the second thickness of second copper layer 212, in conjunction with product design and functional requirements. The area of ​​first groove 1431 is equal to or greater than the area of ​​the chip to be placed, ensuring the chip can be placed within the groove. Furthermore, first groove 1431 does not penetrate the first surface of first substrate 211 and maintains a predetermined thickness. This prevents impurities or chemicals from entering first groove 1431 from the first surface of first substrate 211 during subsequent processing, contaminating or etching second copper layer 212 and thus affecting the quality of the final COB board 140. The area of ​​first groove 1431 refers to the planar area occupied by first groove 1431 on first substrate 211. The side length of first groove 1431 is determined based on the chip to be placed, thereby obtaining the corresponding area information. Based on this specific area information, first groove 1431 is etched within the COB area.

[0082] The first laser divergence and the first laser energy are key parameters that affect the laser etching effect. Based on the first depth and first area information of the first groove 1431, combined with the principles of laser etching and empirical formulas, the appropriate first laser divergence and first laser energy are determined through calculation and optimization. When the depth of the first groove 1431 is deeper, higher laser energy is required; when the area of ​​the first groove 1431 is larger, the laser divergence needs to be adjusted to ensure the uniformity and accuracy of the etching. By precisely controlling the first divergence and first energy of the laser, a high-precision first groove 1431 is etched on the first surface of the first substrate 211, thereby improving the production quality of the COB board 140.

[0083] After determining the first laser divergence and the first laser energy, the laser equipment is adjusted to the corresponding parameter settings. Then, the laser is used to perform a laser etching operation on the previously determined COB area. During the etching process, the laser beam acts on the second copper layer 212 and the second surface of the first substrate 211 according to a predetermined path and scanning method. Through the thermal and photochemical effects of the laser, the material undergoes changes such as melting and vaporization, thereby removing part of the material and gradually forming the first groove 1431. During the etching process, the progress and quality of the etching also need to be monitored and controlled in real time to ensure that the depth, shape and size of the first groove 1431 meet the design requirements.

[0084] In some optional embodiments, before the first copper layer 212 and the second surface of the first substrate 211 are subjected to the first laser depth control processing to obtain the first substrate 211 having the first groove 1431, it also includes: a plurality of first Mark points 130 are evenly set at the first end of the first substrate 211, and a plurality of second Mark points are evenly set at the second end of the first substrate 211, the first Mark point 130 and the second Mark point correspond to each other in the first direction, the COB area is located between the first Mark point 130 and the second Mark point, and the first Mark point 130 and the second Mark point both represent the positioning Mark point; two first positioning holes 100 are obtained by drilling at the first end of the first substrate 211, and a plurality of the first Mark points 130 are located between the two first positioning holes 100; two second positioning holes 110 are obtained by drilling at the second end of the first substrate 211, and a plurality of the second Mark points are located between the two second positioning holes 110, and the first positioning hole 100 and the second positioning hole 110 are staggered in the first direction.

[0085] Specifically, refer to Figure 3 , a plurality of first Mark points 130 are evenly arranged at the first end of the first substrate 211, and a plurality of second Mark points are evenly arranged at the second end of the first substrate 211, and these first Mark points 130 and second Mark points correspond to each other in the first direction (the width direction of the substrate). In the subsequent processing process, by identifying these Mark points, the position, direction, size and other information of the substrate can be accurately determined. The COB area is set between the first Mark point 130 and the second Mark point. These Mark points provide a boundary reference for the positioning of the COB area, which helps to accurately divide the position and range of the COB area; specifically, in the middle of the first Mark point 130 and the second Mark point, the square area with the diameter of the first Mark point 130 or the second Mark point as the side length is the COB area. When performing operations such as laser etching, the equipment can determine the specific position of the COB area by detecting the Mark point, thereby ensuring the accuracy of etching and the accuracy of subsequent V-cut line etching.

[0086] Two first positioning holes 100 are drilled at the first end of the first substrate 211, and a plurality of first Mark points 130 are located between the two first positioning holes 100. The function of the two first positioning holes 100 is to further improve the positioning accuracy of the first end. The first positioning holes 100 formed by drilling can cooperate with the positioning device on the processing equipment to achieve precise fixation and positioning of the first end of the substrate. For example, when the first substrate 211 is placed on the workbench of the laser processing equipment, the positioning pins on the equipment can be inserted into the first positioning holes 100 to ensure that the substrate will not be displaced during the processing process, thereby ensuring the accuracy of operations such as the first laser depth control processing. Moreover, through the two first positioning holes 100, the specific number of first Mark points 130 and the position of each first Mark point 130 can also be accurately calculated, so that the corresponding first Mark point 130 can be set between the two first positioning holes 100.

[0087] Similar to the first end, two second positioning holes 110 are drilled at the second end of the first substrate 211, with multiple second mark points located between the two second positioning holes 110. Specifically, a second positioning hole 120 is located directly between the two first positioning holes 100, and another second positioning hole 120 is located directly between the two second positioning holes 110. This second positioning hole 120 provides better positioning and securement of the substrate. However, the first positioning holes 100 and the second positioning holes 110 are offset in the first direction. This offset arrangement increases the stability and uniqueness of the substrate during positioning, preventing machining errors caused by incorrect substrate orientation. For example, if the first positioning holes 100 and the second positioning holes 110 are aligned in the first direction, the substrate may be placed incorrectly, potentially preventing accurate recognition by the device. This offset arrangement effectively prevents this. Furthermore, the second positioning holes 110, together with the first positioning holes 100, provide stable positioning for the substrate, ensuring that it maintains its correct position and orientation during various machining operations on the first substrate 211. Furthermore, the number of specific second mark points and the position of each second mark point can be accurately calculated through the two second positioning holes 110, thereby setting the corresponding second mark point between the two second positioning holes 110. The above operations before the first laser depth control process provide a reliable positioning foundation for the subsequent precise processing of the first groove 1431 and the production of the COB board 140, helping to improve production efficiency and product quality and reduce the scrap rate caused by inaccurate positioning.

[0088] S300, the first substrate 211 having the first groove 1431, the prepreg 220 and the second substrate 231 are arranged in sequence and pressed together to obtain a first plate, wherein the second copper layer 212 is pressed together with the first surface of the prepreg 220, and the third copper layer 230 is pressed together with the second surface of the prepreg 220.

[0089] Specifically, before lamination, it is necessary to ensure that the first substrate 211 with the first groove 1431, the prepreg 220, and the second substrate 231 are all in place and meet quality requirements. The second copper layer 212 of the first substrate 211 with the first groove 1431 will contact the prepreg 220; the third copper layer 230 of the second substrate 231 will also contact the other side of the prepreg 220. According to design requirements, these three materials are arranged in sequence, so that the second copper layer 212 of the first substrate 211 is closely aligned with the first surface of the prepreg 220, and the third copper layer 230 of the second substrate 231 is closely aligned with the second surface of the prepreg 220. During the arrangement process, the position and alignment of each material must be strictly controlled to ensure the connection accuracy between the layers after lamination.

[0090] Reference Figure 4 , the arranged materials are placed in a laminating device, such as a hot press. The hot press causes the prepreg 220 to undergo a curing reaction by applying a certain amount of pressure and temperature. During the heating process, the resin in the prepreg 220 gradually softens and flows, filling the small gap between the first substrate 211 and the second substrate 231, and enhancing the bonding force between the layers. At the same time, under the action of pressure, the second copper layer 212 of the first substrate 211 and the first surface of the prepreg 220, and the third copper layer 230 of the second substrate 231 and the second surface of the prepreg 220 can be in closer contact, forming a strong connection. Parameters such as temperature, pressure, and time during the laminating process need to be precisely controlled according to the characteristics of the prepreg 220 and the design requirements of the product. Generally speaking, the temperature will gradually rise to the curing temperature of the resin, the pressure will be maintained at a suitable value to ensure sufficient fit between the layers, and the time will be determined according to the progress of the curing reaction to ensure that the prepreg 220 is completely cured. Through the laminating process, the first plate obtained has good structural strength and electrical properties. After curing, the prepreg 220 firmly bonds the first and second substrates 211 and 231 together, forming a single unit. This improves the mechanical stability of the panels, enabling them to withstand certain external forces without deformation or delamination. Furthermore, the tight connection between the layers ensures reliable electrical performance, allowing the copper layers on the first and second substrates 211 and 231 to effectively transmit current and signals, providing a stable foundation for subsequent circuit fabrication and chip assembly. The thickness of the first panel ranges from 315 to 415 microns.

[0091] S400: Performing a drilling and copper deposition process on the first plate to obtain a second plate.

[0092] Specifically, refer to Figure 5 , drilling operations are performed on the first plate, thereby creating through or partially through holes on the first plate to achieve electrical connections between different layers. When drilling, a special drilling machine or CNC drilling machine is used to determine the position, size and number of holes according to design requirements. For example, in cases where signals need to be transmitted between different layers, through holes are drilled at the corresponding positions; in cases where only adjacent layers need to be connected, blind holes or buried holes are drilled. During the drilling process, the depth and aperture of the holes must be precisely controlled to meet the requirements of subsequent electrical connections. Specifically, this application drills holes in the first side area of ​​the first groove 1431 in the COB area, so that the final COB board 140 can be electrically connected between different layers. The specific number and type of holes are set according to demand and are not limited here.

[0093] After drilling is complete, contaminants such as drill cuttings and resin may remain on the hole walls, affecting the quality and reliability of subsequent copper deposition. Therefore, desmear treatment is necessary, typically using chemical solutions such as strongly alkaline or oxidizing solutions to remove these contaminants. For example, using potassium permanganate solution for desmearing can oxidize and remove organic contaminants from the hole walls, leaving them clean and rough, allowing for better adhesion of the copper layer during subsequent copper deposition. After desmearing, copper deposition is performed. Copper deposition forms a thin layer of copper on the hole walls through chemical deposition, serving as a foundation for subsequent copper electroplating. During this process, copper ions in the electroless plating solution undergo a reduction reaction on the hole wall surface, depositing copper atoms. After drilling and copper deposition, a copper layer is deposited on the hole walls of the first substrate, forming the second substrate. This second substrate provides the electrical connection foundation between the different layers, creating excellent conditions for subsequent copper electroplating. The copper layer in these holes connects the different copper layers, forming a complete electrical pathway, enabling smooth signal and current transmission between the different layers, further improving the electrical performance of the circuit board and enabling the realization of complex circuit functions.

[0094] In some optional embodiments, the second plate is obtained after drilling and copper plating treatment on the first plate, including: drilling the first plate to obtain a plurality of first through holes 213, the first through holes 213 being located on the first side of the third groove 143; the first through holes 213 are subjected to copper plating treatment to obtain second through holes, the second through holes being used to electrically connect the first copper layer 210 and the fourth copper layer 232; and the first plate having the second through holes is configured as the second plate.

[0095] Specifically, refer to Figure 5Drilling holes in the first plate is performed to achieve electrical connections between different layers, specifically to electrically connect the first copper layer 210 and the fourth copper layer 232. The first through-hole 213 is positioned on the first side of the third recess 143, allowing subsequent electrical connections to conveniently serve the chip located within the third recess 143, thereby facilitating electrical connections between the chip and external devices. Copper plating is a chemical process that deposits a layer of copper on the walls of the first through-hole 213. First, the first through-hole 213 is pretreated with a chemical solution to remove impurities such as drill cuttings and oil stains, leaving the walls clean and with a certain roughness to facilitate copper deposition. Then, the first through-hole 213 is immersed in a chemical plating solution containing copper ions. Through a chemical reaction, the copper ions are reduced to copper atoms and deposited on the walls. In the copper plating process, the plating solution contains components such as copper salts, reducing agents, chelating agents, and stabilizers. Under appropriate temperature and pH conditions, the copper ions undergo an autocatalytic reaction on the surface of the walls, gradually forming a uniform copper layer. The second through-hole obtained after the copper plating process forms a copper layer on the basis of the first through-hole 213. This copper layer can effectively achieve electrical connection between the first copper layer 210 and the fourth copper layer 232. When the first through-hole 213 is transformed into the second through-hole after the copper plating process, the first board has a significant improvement in electrical connection performance. At this time, it is configured as the second board. The second board will serve as the basis for subsequent process steps, preparing for further electroplating copper layer processing, circuit processing, and other operations, making it closer to the final COB board 140.

[0096] S500: Electroplating the second plate with a copper layer to obtain a third plate.

[0097] Specifically, copper electroplating utilizes electrolysis to increase the thickness of the copper layer on the surface of the second plate and the inner wall of the second through-hole. The basic principle is to use the second plate as the cathode, copper as the anode, and a solution containing copper ions as the electroplating solution. Under the action of a DC electric field, the copper ions receive electrons at the cathode (i.e., the second plate) and are reduced to copper atoms, thereby depositing a thicker copper layer on the surface of the second plate and the inner wall of the second through-hole. After the copper electroplating process, the copper layer on the surface of the second plate and the inner wall of the second through-hole increases in thickness, forming a third plate. This third plate exhibits improved electrical and mechanical properties.

[0098] In some optional embodiments, the copper plating treatment on the second plate to obtain a third plate includes: performing a first copper plating treatment on the second through hole on the second plate to obtain a third through hole, the third through hole having a preset copper thickness; performing resin plugging on the third through hole to obtain a fourth through hole; performing a second copper plating treatment on the first copper layer 210 located on the edge of the fourth through hole to obtain a first thick copper layer, and performing a second copper plating treatment on the fourth copper layer 232 located on the edge of the fourth through hole to obtain a fourth thick copper layer; configuring the second plate having the first thick copper layer and the fourth thick copper layer as the third plate.

[0099] Specifically, the first copper electroplating operation is performed on the second through-hole on the second plate, mainly to ensure that the copper layer in the second through-hole reaches a preset hole copper thickness. The copper electroplating process follows the principle of electrolysis, with the second plate as the cathode, the pure copper plate as the anode, and the electroplating solution containing copper ions as the electrolyte. Under the action of the DC electric field, the copper ions will migrate to the hole wall of the second through-hole and obtain electrons on its surface to be reduced to copper atoms, thereby gradually depositing on the hole wall. By precisely controlling factors such as the electroplating time, current density, composition and temperature of the electroplating solution, it is ensured that the copper layer in the second through-hole reaches the preset hole copper thickness, thereby forming a third through-hole. The preset hole copper thickness is determined according to the performance requirements of the final product, and the thickness will vary in different application scenarios. For example, for circuits that need to carry large currents, a thicker hole copper thickness is required to ensure the stability and reliability of the electrical connection and avoid overheating or melting of the copper layer due to excessive current.

[0100] Resin plugging involves filling the third through-hole with a special resin to completely fill the hole. This provides a smooth surface for subsequent processing, preventing short circuits or other electrical issues within the hole during subsequent processing. It also enhances the mechanical strength and stability of the board.

[0101] First, select a suitable resin with good fluidity, suitable hardness after curing, and good insulation properties. Fill the third through-hole with the resin by injection or printing, then perform a curing process to solidify the resin within the third through-hole, forming a solid filling structure and creating the fourth through-hole. During this process, ensure that the resin is evenly filled and completely cured to avoid voids or underfill, which could affect subsequent processing and use.

[0102] The first copper layer 210 located near the fourth through-hole is subjected to a second copper electroplating process to obtain a first thick copper layer, and the fourth copper layer 232 located near the fourth through-hole is subjected to a second copper electroplating process to obtain a fourth thick copper layer. This is to increase the thickness of the copper layer in the COB area to meet circuit requirements. Similar to the first copper electroplating process, factors such as current density and plating time must also be controlled during the electroplating process. By increasing the thickness of the first copper layer 210 and the fourth copper layer 232, their current carrying capacity and mechanical strength are improved, providing better conditions for subsequent circuit wiring and chip mounting operations.

[0103] After completing the above steps, the second through-hole on the second plate undergoes a series of treatments to become a fourth through-hole filled with resin. Furthermore, the thickness of the first copper layer 210 and the fourth copper layer 232 in the corresponding areas is increased, forming a first thick copper layer and a fourth thick copper layer. The second plate is now configured as the third plate, further optimizing its electrical and mechanical properties, providing a better foundation for subsequent circuit processing, electroplating, and other operations.

[0104] S600 , performing circuit processing on the first copper layer 210 and the fourth copper layer 232 of the third plate to obtain a fourth plate.

[0105] Specifically, the main purpose of the circuit processing is to form precise conductive circuits on the first copper layer 210 and the fourth copper layer 232 of the third plate to realize the various functions of the circuit. Specifically, the circuit of the first copper layer 210 is used to connect the pins of the chip, the circuit of the fourth copper layer 232 is electrically connected to the circuit of the first copper layer 210 through the fourth through hole, and the circuit of the fourth copper layer 232 is electrically connected to the external device. After the circuit processing, precise conductive circuits are formed on the first copper layer 210 and the fourth copper layer 232 of the third plate, thereby converting the third plate into the fourth plate. The circuits on the first copper layer 210 and the fourth copper layer 232 of the fourth plate will provide a basis for subsequent operations such as electroplating and chip mounting, making it closer to the final COB board 140 product. These circuits will form a complete circuit system together with the circuits and components of other layers in subsequent operations to realize various complex electronic functions.

[0106] In some optional embodiments, the fourth plate is obtained after circuit processing of the first copper layer 210 and the fourth copper layer 232 of the third plate, including: performing a first exposure, a first development and a first etching on the first copper layer 210 to obtain a first circuit, the first circuit being used to electrically connect the pins of the chip after bonding, and the first circuit being composed of the first thick copper layer; performing a second exposure, a second development and a second etching on the fourth copper layer 232 to obtain a second circuit, the second circuit being used to electrically connect to an external circuit, the second circuit being composed of the fourth thick copper layer, and the first circuit and the second circuit being electrically connected through the fourth through hole; and configuring the third plate having the first circuit and the second circuit as the fourth plate.

[0107] Specifically, a photoresist is coated on the first copper layer 210. Then, using a photomask corresponding to the first circuit design, a first exposure operation is performed on the photoresist-coated first copper layer 210 by irradiation. The exposed first copper layer 210 is placed in a developer. Depending on the properties of the photoresist, the photoresist after the first exposure may become soluble or insoluble in the developer. The first development process dissolves the photoresist in the area where the first circuit is to be formed, while the photoresist in other areas remains, thereby forming a photoresist pattern on the first copper layer 210 that matches the shape of the first circuit. The first copper layer 210, which has undergone the first development process, is placed in an etching solution. The etching solution chemically reacts with the copper layer not protected by the photoresist, removing it. The areas of the first thick copper layer protected by the photoresist remain unaffected by the etching solution, thereby forming the first circuit. This first circuit, consisting of the first thick copper layer, is primarily used in subsequent wire bonding operations to establish electrical connections with the chip's pins, ensuring efficient signal and current transmission between the chip and the circuit board.

[0108] Similar to the processing of the first copper layer 210, a photoresist is first coated on the fourth copper layer 232, and then a second exposure is performed using a corresponding photoresist mask. The fourth copper layer 232, which has undergone the second exposure, is placed in a developer for a second development operation. This causes the photoresist to dissolve or insolubilize depending on its chemical properties after exposure, forming a photoresist pattern that conforms to the shape of the second circuit, protecting the area of ​​the fourth copper layer 232 where the second circuit is to be formed. The fourth copper layer 232 is then placed in an etching solution for a second etching operation. The etching solution etches away the copper layer not protected by the photoresist, leaving the thicker fourth copper layer area forming the second circuit. The second circuit is primarily used for electrical connection to external circuits, providing a signal and current transmission channel between the entire COB board 140 and the external system. Simultaneously, the first and second circuits are electrically connected via the fourth through-hole, ensuring electrical connectivity between the chip and the external circuit, enabling the electrical functionality of the entire COB board 140. After the first and second circuits are formed on the first copper layer 210 and the fourth copper layer 232, the third plate is configured as the fourth plate. The line width of the first line and the second line is 145 microns to 150 microns, and the line spacing is 115 microns to 125 microns.

[0109] S700 , performing electroplating and second laser depth control processing on the fourth plate to obtain at least one COB plate 140 , where one COB plate 140 corresponds to one first groove 1431 .

[0110] Specifically, the electroplating gold treatment primarily deposits a layer of gold on the first and second circuits of the fourth plate. Gold has excellent electrical conductivity, oxidation resistance, and corrosion resistance. In COB board 140, electroplating gold improves the connection reliability and long-term stability between the chip and the circuit board, while also reducing contact resistance and improving signal transmission quality.

[0111] After completing the electroplating process, refer to Figure 3 , a second laser depth control process is performed on the fourth plate, thereby etching corresponding V-cut lines on the first substrate 211 and the second substrate 231, dividing at least one COB area into corresponding COB boards 140 to meet the final structure and functional requirements of the COB board 140, and one COB board 140 corresponds to one first groove 1431.

[0112] In some optional embodiments, at least one COB board 140 is obtained after the fourth plate is subjected to electroplating and second laser depth control processing, including: a first nickel-palladium-gold electroplating is performed on the first circuit to obtain a first nickel-palladium-gold circuit 142; a second nickel-palladium-gold electroplating is performed on the second circuit to obtain a second nickel-palladium-gold circuit 145, the first nickel-palladium-gold electroplating and the second nickel-palladium-gold electroplating represent the electroplating; according to the first nickel-palladium-gold circuit 142 and the second nickel-palladium-gold circuit 145, a first V-cut line is obtained after a second laser depth control processing is performed on the first surface of the first substrate 211, and a second V-cut line is obtained after a second laser depth control processing is performed on the second surface of the second substrate 231, the enclosed area of ​​multiple first V-cut lines is the first surface 141 of the COB board, and the enclosed area of ​​multiple second V-cut lines is the second surface 144 of the COB board.

[0113] Specifically, refer to Figure 6 , the first circuit on the fourth plate is used as the cathode, the electroplating solution containing nickel, palladium and gold ions is used as the electrolyte, and the nickel plate, palladium plate and gold plate are used as anodes (or soluble anodes), and electroplating is carried out under certain current density and temperature conditions. First, the nickel layer is plated. Nickel is used as the bottom layer to enhance the bonding strength with the first circuit and provide a good foundation for the subsequent palladium and gold deposition. Then the palladium layer is plated. The palladium layer is on top of the nickel layer to further enhance the corrosion resistance and improve the surface properties. Finally, the gold layer is plated. The gold layer is the outermost layer to provide good conductivity and oxidation resistance for the first circuit. By precisely controlling parameters such as the electroplating time, current density and composition of the electrolyte, the thickness and quality of the nickel, palladium and gold layers can be controlled, and finally the first nickel palladium gold circuit 142 is obtained.

[0114] Similar to the primary nickel-palladium-gold electroplating, the second circuit is electroplated with nickel-palladium-gold to obtain a second nickel-palladium-gold circuit 145. This process also uses the second circuit as the cathode, sequentially depositing nickel, palladium, and gold through a similar electroplating process to form a composite metal layer with excellent performance, meeting the high requirements for reliability, corrosion resistance, and conductivity when the second circuit is connected to an external circuit.

[0115] After the electroplating is completed, the electrical performance test of the first nickel-palladium-gold circuit 142 and the second nickel-palladium-gold circuit 145 is performed to ensure that the electrical connection between the first nickel-palladium-gold circuit 142 and the second nickel-palladium-gold circuit 145 is normal.

[0116] Reference Figure 3, based on the first nickel-palladium-gold circuit 142, a second laser depth control process is performed on the first surface of the first substrate 211, the purpose of which is to form a first V-cut line on the surface. The V-cut line is a special cutting mark line used for subsequent cutting, separation or division of the COB board 140. Utilizing the high energy density characteristics of the laser, the laser beam is focused on the first surface of the first substrate 211. According to the layout of the first nickel-palladium-gold circuit 142 and the design requirements of the COB board 140, the laser energy, scanning speed, pulse frequency and other parameters are precisely controlled to cause the laser to produce local melting, vaporization or chemical decomposition on the surface of the material, forming a first V-cut line with a certain depth and width.

[0117] The formation of these first V-cut lines helps to determine the boundary of the first surface 141 of the COB board. The area surrounded by multiple first V-cut lines is the first surface 141 of the COB board, which provides a clear mark and basis for subsequent cutting and separation operations.

[0118] Similarly, a second laser depth control process is performed on the second surface of the second substrate 231 based on the second nickel-palladium-gold circuit 145 to form a second V-cut line. The formation principle of the second V-cut line is similar to that of the first V-cut line. Through precise laser parameter control, the desired cutting mark is produced on the second surface of the second substrate 231. The enclosed area defines the second surface of the COB board 140. The first and second V-cut lines together provide precise boundaries for the demarcation of the COB board 140 and the formation of the final product, ensuring that the COB board 140 can be accurately separated from the fourth sheet material during the subsequent cutting process, while ensuring that the surface of the COB board 140 meets the design requirements. The thickness of the COB board is 300 to 500 microns, the board curvature is less than or equal to 0.75%, the length of the COB board is 1150 to 1250 microns, and the width of the COB board is 1050 to 1150 microns.

[0119] Specifically, the first V-cut line and the second V-cut line both include a V-cut line 160 along the first direction and a V-cut line 170 along the second direction. The V-cut line 160 along the first direction is tangent to the side of the first Mark point 130 in the first direction, and is tangent to the side of the second Mark point in the first direction; the two V-cut lines 170 along the second direction are symmetrical about the center line of the first substrate 211, and the enclosed area formed by the two V-cut lines 170 along the second direction and multiple V-cut lines 160 along the first direction is the COB area. After subsequent processing, the COB area becomes the corresponding COB board 140.

[0120] S800, laser rhombus is performed on the first surface of the COB board 140 to obtain a second groove, which is connected to the first groove 1431 to form a third groove 143, and the third groove 143 is used to place the chip. The depth of the third groove 143 ranges from 190 microns to 210 microns.

[0121] Specifically, refer to Figure 7 Laser gong is a technology that uses laser beams for processing. By irradiating the first surface of the COB board 140 with a high-energy-density laser, the material undergoes physical or chemical changes, thereby achieving the removal and processing of the material. The purpose of laser gong processing on the first surface of the COB board 140 is to form a second groove; this second groove is connected to the first groove 1431 previously obtained on the first substrate 211 through the first laser depth control treatment, and together constitutes the third groove 143. The formation of the second groove is to further improve the space for chip placement to meet the chip size and heat dissipation requirements. When the chip is placed in the third groove 143, it can ensure better electrical connection, mechanical fixation and heat dissipation between the chip and the COB board 140.

[0122] The third groove 143 is formed by connecting the first groove 1431 and the second groove. Its depth range is set to 190 to 210 microns. This depth range takes into account factors such as chip thickness, packaging process, and heat dissipation requirements. The first groove 1431 and the second groove have the same area. If the third groove 143 is too shallow, it cannot accommodate the chip or the chip may be too close to the surface of the COB board 140, affecting heat dissipation and electrical connection. If the depth is too deep, the chip may be positioned too deep, which is not conducive to subsequent packaging and electrical connection operations. During the laser processing process, the depth of the first groove 1431 and the second groove is controlled to ensure that the third groove 143 formed by the connection is within the range of 190 to 210 microns. This ensures that the third groove 143 provides a suitable placement space for the chip, which is beneficial for chip installation and ensures the overall performance of the COB board 140. As can be seen, the third groove penetrates the first substrate 211, so the thickness of the first substrate 211 is 190 to 210 microns.

[0123] In some optional embodiments, the laser raftering of the first surface of the COB board 140 to obtain a second groove, the second groove being connected to the first groove 1431 and forming a third groove 143, includes: determining the second depth of the second groove according to the first depth, the first thickness information and the second thickness information; configuring the second area information of the second groove as the first area information so that the second groove and the first groove 1431 overlap with each other in the thickness direction of the first substrate 211; determining the second laser divergence and the second laser energy according to the second depth and the second area information; and obtaining the second groove by laser raftering the first surface of the COB board 140 with lasers of the second laser divergence and the second laser energy.

[0124] Specifically, the first depth is the depth information of the first groove 1431 obtained when the second copper layer 212 and the second surface of the first substrate 211 were previously subjected to the first laser depth control process. The first thickness information represents the thickness of the first substrate 211, and the second thickness information represents the thickness of the second copper layer 212. In order to connect the second groove with the first groove 1431 and form the third groove 143, it is necessary to calculate the second depth of the second groove based on this information. The calculation process involves meeting the requirements of the depth range of the third groove 143 (190 microns to 210 microns). This ensures that after the second groove and the first groove 1431 are connected, the third groove 143 formed as a whole meets the depth requirements for chip placement.

[0125] The second area information of the second groove is configured as the first area information to ensure that the second groove and the first groove 1431 overlap each other in the thickness direction of the first substrate 211. This is done to ensure that the first groove 1431 and the second groove are perfectly connected to avoid misalignment or mismatching, thereby providing a continuous and suitable placement space for the chip. When the area of ​​the second groove matches the area of ​​the first groove 1431, the electrical connection and mechanical stability between the chip and the COB board 140 can be guaranteed during subsequent chip installation and other operations, because they have a consistent contact area in the horizontal direction, which helps to evenly distribute the pressure on the chip and ensure the reliability of the electrical connection.

[0126] The second laser divergence and the second laser energy are key parameters for the operation of the laser gong plate. According to the second depth and the second area information, combined with the physical principles and empirical formulas of laser processing, the appropriate second laser divergence and second laser energy can be determined. Generally speaking, for a larger second area, a larger laser divergence is required to ensure the uniformity of processing; and for a deeper second depth, a higher laser energy is required to ensure that the material can be effectively removed. At the same time, the material properties of the COB board 140 also need to be considered. Different materials absorb and react to the laser differently, so these parameters need to be fine-tuned according to the specific material of the COB board 140. For example, for a harder substrate material, a higher laser energy and a more concentrated laser beam (smaller laser divergence) may be required to achieve the required processing depth and accuracy.

[0127] The laser equipment parameters are set to the calculated second laser divergence and second laser energy. The laser beam is then focused on the first surface of the COB board 140 for laser rouging. During the machining process, the laser beam acts on the first surface of the COB board 140 according to a predetermined scanning path and pattern, processing the corresponding area based on the set second area information. By precisely controlling the energy and divergence of the laser beam, material is gradually removed from the first surface, forming the second groove. During the machining process, the depth and shape of the final second groove are continuously monitored to ensure that the depth and area of ​​the second groove meet the requirements and that, when connected to the first groove 1431, they can form a third groove 143 within the depth range, providing optimal conditions for chip placement. Using the first depth, first thickness information, and second thickness information, the laser routing parameters are rationally determined. The second groove is then formed on the first surface of the COB board 140 through laser machining, ultimately creating a third groove 143 that meets the design requirements for chip placement.

[0128] In some optional embodiments, before sequentially arranging the first substrate 211 having the first groove 1431 , the prepreg 220 , and the second substrate 231 and laminating them to obtain the first plate, the method further includes:

[0129] Performing circuit processing on the second copper layer 212 to obtain a connecting circuit, wherein the connecting circuit is used to assist the electroplating;

[0130] The third copper layer 230 is subjected to circuit processing to obtain a positioning circuit, and the positioning circuit is used for press-fit positioning.

[0131] Specifically, refer to Figure 8The second copper layer 212 is processed to form connecting lines to achieve auxiliary functions such as electrical conductivity during the subsequent manufacturing process, particularly assisting in the electroplating operation. The connecting lines have a line width of 45 to 50 microns and a line spacing of 90 to 110 microns. The connecting lines will assist in the subsequent electroplating process, specifically assisting in the smooth electroplating of the first and second lines (because electroplating requires conductivity, and therefore requires the help of the connecting lines).

[0132] The third copper layer 230 is processed to obtain a positioning circuit, mainly for providing accurate positioning information in the lamination process, wherein the line width of the positioning circuit is 40 microns to 60 microns and the line spacing is 80 microns to 120 microns. The positioning circuit formed on the third copper layer 230 can be some specific marks or patterns, which can match the structure or marks of other layers during lamination, ensuring the accurate alignment between the layers in the lamination process. For example, when the prepreg 220, the first substrate 211 and the second substrate 231 are arranged in sequence, the positioning circuit on the third copper layer 230 can be coordinated with certain features on the prepreg 220 or other marks on the first substrate 211, helping operators or automated equipment to accurately align each layer, avoiding position offset in the lamination process, and ensuring the accuracy of lamination. By positioning the circuit, the position of the prepreg 220 can be accurately fixed on the third copper layer 230 of the second substrate 231, thereby ensuring the stability and consistency of the entire lamination structure and improving the quality of the first plate material.

[0133] In some optional embodiments, after obtaining a plurality of COB boards 140, a plurality of splitting holes 150 are formed on the four sides of each COB board 140, thereby securing the four corners of the COB board 140 to the fourth board, thereby facilitating separation of the COB board 140 from the fourth board. Specifically, the splitting holes 150 are aligned with the side edges of the COB board 140, so that only the corners of the COB board 140 are secured to the fourth board.

[0134] In some optional embodiments, FQC (Final Quality Control) is also performed on the COB boards to ensure that the COB boards meet quality requirements. COB boards that meet the requirements are packaged and stored or shipped.

[0135] The implementation of the embodiment of the present invention includes the following beneficial effects: The embodiment of the present invention provides a COB board production method, including: obtaining a first substrate 211, a second substrate 231 and a semi-cured sheet 220, wherein the first surface of the first substrate 211 is provided with a first copper layer 210, and the second surface is provided with a second copper layer 212, and the first surface of the second substrate 231 is provided with a third copper layer 230, and the second surface is provided with a fourth copper layer 232; performing a first laser depth control process on the second copper layer 212 and the second surface of the first substrate 211 to obtain the first substrate 211 having a first groove 1431, and the depth of the first groove 1431 ranges from 70 microns to 170 microns; arranging the first substrate 211 having the first groove 1431, the semi-cured sheet 220 and the second substrate 231 in sequence, and performing a pressing process to obtain a first plate material, wherein the The second copper layer 212 is pressed onto the first surface of the semi-cured sheet 220, and the third copper layer 230 is pressed onto the second surface of the semi-cured sheet 220; the first sheet is subjected to drilling and copper plating treatment to obtain the second sheet; the second sheet is subjected to copper electroplating treatment to obtain the third sheet; the first copper layer 210 and the fourth copper layer 232 of the third sheet are subjected to circuit processing to obtain the fourth sheet; the fourth sheet is subjected to electro-gold and second laser depth control treatment to obtain at least one COB board 140, and one COB board 140 corresponds to one first groove 1431; the first surface of the COB board 140 is subjected to laser gong to obtain a second groove, the second groove is connected to the first groove 1431 and forms a third groove 143, the third groove 143 is used to place the chip, and the depth of the third groove 143 ranges from 190 microns to 210 microns. By precisely controlling the depth of the first substrate 211 with laser and performing laser erosion, the third groove 143 for placing the chip is precisely etched, and the required COB board 140 is obtained after copper drilling, copper electroplating and gold electroplating, which can meet the high-precision COB board production requirements.

[0136] In a second aspect, an embodiment of the present invention further provides a COB board, which is manufactured by the above-mentioned COB board production method.

[0137] It can be seen that the contents of the above method embodiments are all applicable to this COB board embodiment. The functions specifically implemented by this COB board embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0138] On the other hand, an embodiment of the present invention further proposes an electronic device, comprising: a memory for storing program instructions; a processor for calling the program instructions stored in the memory, and executing the above-mentioned COB board production method according to the obtained program instructions. Wherein, the processor can be implemented in the form of a general central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, for executing relevant programs to implement the technical solutions provided in the embodiments of the present application; the memory can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device or a random access memory (RAM). The memory can store an operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory, and the COB board production method of the embodiment of the present application is called by the processor; the memory and the processor can be connected by a bus, etc.

[0139] On the other hand, an embodiment of the present invention further provides a storage medium, which is a computer-readable storage medium, and the storage medium stores a computer program, which implements the above-mentioned COB board production method when executed by the processor. The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory includes a memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and may be located in one place, or may be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0140] In some optional embodiments, the functions / operations mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the functions / operations involved, the two boxes shown in succession may actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiments presented and described in the flow chart of the present application are provided in an exemplary manner for the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operations and logic flows presented herein. Optional embodiments are contemplated in which the order of the various operations is changed and the sub-operations described as a part of a larger operation are performed independently.

[0141] In addition, although the present application is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present application. More specifically, given the properties, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the module will be understood within the routine skills of an engineer. Therefore, a person skilled in the art can implement the present application as set forth in the claims using ordinary techniques without undue experimentation. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present application, which is determined by the full scope of the appended claims and their equivalents.

[0142] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0143] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

[0144] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A COB board production method, characterized in that: include: Obtain a first substrate, a second substrate, and a prepreg, wherein the first substrate has a first copper layer provided on its first surface and a second copper layer provided on its second surface, and the second substrate has a third copper layer provided on its first surface and a fourth copper layer provided on its second surface; Performing a first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having a first groove, wherein the depth of the first groove ranges from 70 micrometers to 170 micrometers; The first substrate having the first groove, the prepreg, and the second substrate are sequentially arranged and pressed together to obtain a first plate, wherein the second copper layer is pressed together with the first surface of the prepreg, and the third copper layer is pressed together with the second surface of the prepreg; Performing a drilling and copper deposition process on the first plate to obtain a second plate; Performing copper electroplating on the second plate to obtain a third plate; performing circuit processing on the first copper layer and the fourth copper layer of the third plate to obtain a fourth plate; Performing electroplating and second laser depth control processing on the fourth plate to obtain at least one COB plate, wherein one COB plate corresponds to one first groove; After laser grooving the first surface of the COB board, a second groove is obtained. The second groove is connected to the first groove to form a third groove. The third groove is used to place the chip. The depth of the third groove ranges from 190 microns to 210 microns.

2. The method according to claim 1, characterized in that The first substrate having a first groove is obtained by performing a first laser depth control process on the second copper layer and the second surface of the first substrate, comprising: Obtaining positioning Mark points on the first substrate; Determine at least one COB area according to the positioning Mark point, where the COB area belongs to the COB board; Acquire first thickness information of the first substrate and second thickness information of the second copper layer; determining a first depth of the first groove according to the first thickness information and the second thickness information; Acquiring first area information of the first groove; determining a first laser divergence and a first laser energy according to the first depth and the first area information; The first groove is obtained by laser etching the COB area using a laser with a first laser divergence and a first laser energy.

3. The method according to claim 2, characterized in that Before performing the first laser depth control process on the second copper layer and the second surface of the first substrate to obtain the first substrate having the first groove, the method further includes: A plurality of first mark points are evenly arranged at the first end of the first substrate, and a plurality of second mark points are evenly arranged at the second end of the first substrate, wherein the first mark points and the second mark points correspond to each other in the first direction, and the COB area is located between the first mark points and the second mark points, and the first mark points and the second mark points both represent the positioning mark points; Drilling two first positioning holes at the first end of the first substrate, wherein the plurality of first mark points are located between the two first positioning holes; Two second positioning holes are drilled at the second end of the first substrate, a plurality of second Mark points are located between the two second positioning holes, and the first positioning hole and the second positioning hole are staggered in the first direction.

4. The method according to claim 1, wherein The method of obtaining a second plate by performing a drilling and copper deposition process on the first plate comprises: Drilling the first plate to obtain a plurality of first through holes, wherein the first through holes are located on a first side surface of the third groove; Performing copper plating on the first through hole to obtain a second through hole, wherein the second through hole is used to electrically connect the first copper layer and the fourth copper layer; The first plate having the second through hole is configured as the second plate.

5. The method according to claim 4, characterized in that The method of obtaining a third plate by electroplating the second plate with a copper layer comprises: Performing a first copper electroplating on the second through hole on the second plate to obtain a third through hole, wherein the third through hole has a preset copper thickness; After plugging the third through hole with resin, a fourth through hole is obtained; Performing a second copper electroplating on the first copper layer located at the edge of the fourth through hole to obtain a first thick copper layer, and performing a second copper electroplating on the fourth copper layer located at the edge of the fourth through hole to obtain a fourth thick copper layer; The second plate having the first thick copper layer and the fourth thick copper layer is configured as the third plate.

6. The method according to claim 5, characterized in that The fourth plate is obtained by performing circuit processing on the first copper layer and the fourth copper layer of the third plate, comprising: performing a first exposure, a first development, and a first etching on the first copper layer to obtain a first circuit, wherein the first circuit is used to electrically connect pins of the chip after wire bonding, and the first circuit is composed of the first thick copper layer; performing a second exposure, a second development, and a second etching on the fourth copper layer to obtain a second circuit, wherein the second circuit is used to be electrically connected to an external circuit, the second circuit being composed of the fourth thick copper layer, and the first circuit and the second circuit being electrically connected through the fourth through hole; The third plate having the first circuit and the second circuit is configured as the fourth plate.

7. The method according to claim 6, characterized in that The step of performing electroplating and second laser depth control processing on the fourth plate to obtain at least one COB plate comprises: Electroplating the first circuit with nickel-palladium-gold to obtain a first nickel-palladium-gold circuit; Performing secondary nickel-palladium-gold electroplating on the second circuit to obtain a second nickel-palladium-gold circuit, wherein the primary nickel-palladium-gold electroplating and the secondary nickel-palladium-gold electroplating represent the electroplated gold; According to the first nickel-palladium-gold circuit and the second nickel-palladium-gold circuit, a first V-cut line is obtained after a second laser depth control treatment is performed on the first surface of the first substrate, and a second V-cut line is obtained after a second laser depth control treatment is performed on the second surface of the second substrate. The enclosed area of ​​multiple first V-cut lines is the first surface of the COB board, and the enclosed area of ​​multiple second V-cut lines is the second surface of the COB board.

8. The method according to claim 2, characterized in that The second groove is obtained by laser riveting the first surface of the COB board, and the second groove is connected with the first groove to form a third groove, including: determining a second depth of the second groove according to the first depth, the first thickness information, and the second thickness information; configuring the second area information of the second groove as the first area information, so that the second groove and the first groove overlap with each other in the thickness direction of the first substrate; determining a second laser divergence and a second laser energy according to the second depth and the second area information; The second groove is obtained by laser rouging the first surface of the COB board with a laser of a second laser divergence and a second laser energy.

9. The method according to claim 1, characterized in that Before sequentially arranging the first substrate having the first groove, the prepreg, and the second substrate and performing a lamination process to obtain the first plate, the method further includes: Performing circuit processing on the second copper layer to obtain a connecting circuit, wherein the connecting circuit is used to assist the electroplating; The third copper layer is subjected to circuit processing to obtain a positioning circuit, and the positioning circuit is used for pressing and positioning.

10. A COB board, characterized in that: The COB board is produced by the COB board production method according to any one of claims 1 to 9.

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