Composite target manufacturing method

Abstract

The invention relates to the technical field of circuit board manufacturing, in particular to a composite target manufacturing method which comprises the steps that a composite target circuit pattern needing to be etched on the inner-layer circuit surface in a copper substrate is obtained, the inner-layer circuit surface comprises an upper-layer circuit surface and a lower-layer circuit surface, copper at the position corresponding to a hole site is etched off on the upper-layer circuit surface, and the lower-layer circuit surface is etched off on the lower-layer circuit surface; on the surface of the lower layer circuit, copper at the corresponding position of the composite target is etched, a plurality of inner layer boards to be laminated are laminated on the surface of the etched inner layer circuit after being laminated in sequence to form a multi-layer circuit board, and the position information of the composite target on the plurality of multi-layer circuit boards is obtained through a target drilling machine, the composite target on the multilayer circuit board comprises an alignment center and an alignment target point. Therefore, according to the composite target obtained through manufacturing, the position alignment of the drilling hole and the laser hole can be considered at the same time, the alignment degree of the line and the two different hole primitives is guaranteed to the maximum degree, and therefore the alignment precision of the graph is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board manufacturing, and in particular to a method for manufacturing a composite target. Background Art

[0002] As PCBs evolve toward higher-layer designs, alignment requirements become increasingly stringent, and manufacturing becomes increasingly challenging. This is because HDI multilayer circuit boards utilize specialized materials (such as PTFE and ceramic-based) on one side of their outer layers, and common materials (such as FR4) on the other. These two materials exhibit significant differences in physical and chemical properties, such as thermal expansion coefficient and hardness. These differences can lead to problems such as board deformation, poor signal quality, and CAF during processing. Therefore, improving alignment capabilities plays a key role in enhancing PCB manufacturing capabilities and strengthening a company's market competitiveness.

[0003] However, in existing PCB manufacturing processes, a single composite target 7 is typically used for pattern alignment to prevent pattern shift. This method can only ensure the alignment of the PCB circuit pattern with its single composite target 7, but cannot guarantee the alignment between the circuit pattern and other unreferenced elements, resulting in poor pattern alignment accuracy. Summary of the Invention

[0004] Based on this, it is necessary to provide a composite target manufacturing method to address the above technical problems in order to improve the alignment accuracy of the graphics.

[0005] In a first aspect, a method for manufacturing a composite target is provided, the method comprising: Obtaining a composite target circuit pattern to be etched on an inner circuit surface of a copper substrate, wherein the inner circuit surface includes an upper circuit surface and a lower circuit surface, the upper circuit surface is used to etch away copper at positions corresponding to the hole positions, and the lower circuit surface is used to etch away copper at positions corresponding to the composite target; Stacking a plurality of inner layer boards to be laminated in sequence and then laminating them on the etched inner layer circuit surface to form a multilayer circuit board; The position information of the composite targets on the plurality of multi-layer circuit boards is obtained by a target drilling machine, wherein the composite targets on the multi-layer circuit boards include an alignment center and an alignment target point.

[0006] Optionally, there are four composite targets on the multilayer circuit board, and the four composite targets are arranged in a rectangular shape at the four corners of the edge of the multilayer circuit board to provide alignment points for the production of outer layer circuit patterns on the multilayer circuit board.

[0007] Optionally, the alignment center and the alignment target are both circular through holes.

[0008] Optionally, the diameter of the alignment center is 2.0-3.5 mm, and the diameter of the alignment target is 0.15-0.3 mm.

[0009] Optionally, the alignment target point is concentrically arranged with the alignment center and surrounds it in a circular shape, and there are multiple alignment target points.

[0010] Optionally, the diameter of the ring formed by the center of the alignment target is 4.5-5.5 mm.

[0011] Optionally, the target drilling machine includes a mechanical drill and a laser machine, and obtaining the composite target position information on the plurality of multi-layer circuit boards by the target drilling machine includes: Using a mechanical positioning target hole formed by drilling a hole on the multilayer circuit board by a mechanical drill as an alignment center; Using laser positioning target holes drilled on the multilayer circuit board by a laser machine as alignment target points, wherein there are multiple alignment target points; The center coordinates of the mechanical positioning target hole and the center coordinates of the plurality of laser positioning target holes are averaged to determine composite target position information.

[0012] Optionally, after obtaining the composite target position information on the plurality of multi-layer circuit boards, the method further comprises: sequentially calculating the difference between the composite target position information on each of the multilayer circuit boards and the preset composite target position information; The differences are averaged to obtain the expansion and contraction coefficient of the multilayer circuit board.

[0013] Optionally, after obtaining the expansion and contraction coefficient of the multilayer circuit board, the method further includes: Determining whether a difference between the expansion and contraction coefficient of the multilayer circuit board and a preset expansion and contraction coefficient satisfies a preset difference threshold; If the preset difference threshold is met, it is determined that the multilayer circuit board meets the production requirements; If the preset difference threshold is not met, it is determined that the multilayer circuit board does not meet the manufacturing requirements, and the multilayer circuit board is manufactured according to the expansion and contraction coefficient.

[0014] In any one of the above-mentioned solutions, a composite target circuit pattern to be etched on the inner circuit surface of a copper substrate is obtained, wherein the inner circuit surface includes an upper circuit surface and a lower circuit surface, the upper circuit surface is to etch away the copper at the position corresponding to the hole position, and the lower circuit surface is to etch away the copper at the position corresponding to the composite target, and multiple inner layer boards to be pressed are sequentially superimposed and pressed on the etched inner circuit surface to form a multi-layer circuit board, and the position information of the composite targets on the multiple multi-layer circuit boards is obtained by a drilling target machine, wherein the composite targets on the multi-layer circuit boards include alignment centers and alignment target points. It can be seen that the composite target obtained by the present application can achieve the simultaneous alignment of the drilling holes and the laser holes, and maximize the alignment of the circuit and the two different hole graphic elements, thereby improving the alignment accuracy of the graphics. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 1 is a schematic flow chart of a composite target manufacturing method provided in one embodiment of the present invention; Figure 2 It is a schematic diagram of etching the upper circuit surface in a composite target manufacturing method provided in one embodiment of the present invention; Figure 3 It is a schematic diagram of etching the lower circuit surface in a composite target manufacturing method provided in one embodiment of the present invention; Figure 4 is a schematic diagram of a composite target circuit pattern in a composite target manufacturing method provided in one embodiment of the present invention; Figure 5 is a schematic diagram of a copper substrate shown in another embodiment of the present invention; Figure 6 is a cross-sectional view of a substrate of a composite target circuit pattern after etching, shown in another embodiment of the present invention; Figure 7 is a cross-sectional view of a substrate after lamination of multiple core layers shown in another embodiment of the present invention; Figure 8 is a cross-sectional view of a substrate after mechanical drilling and laser drilling shown in another embodiment of the present invention; Figure 9 Schematic diagram of the center coordinates of a composite target in a composite target manufacturing method provided in one embodiment of the present invention; Figure 10This is a schematic diagram of the position of a composite target provided in one embodiment of the present invention.

[0017] The reference numerals in the specification are as follows: 1. Copper substrate; 2. Composite target circuit pattern; 3. Laser positioning target hole (alignment target point); 4. Mechanical positioning target hole (alignment center); 5. Laser positioning target hole center coordinates; 6. Mechanical positioning target hole center coordinates; 7. Composite target. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0019] It should be understood that the embodiments set forth below represent the necessary information to enable those skilled in the art to implement the embodiments and to illustrate the best mode of implementing the embodiments. After reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and will recognize applications of these concepts not specifically mentioned herein. It should be understood that these concepts and applications fall within the scope of the present disclosure and the appended claims.

[0020] It should also be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of this disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0021] It should also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0022] It should also be understood that the terms "upper", "lower", "left", "right", "front", "back", "bottom", "middle", "center", "top", etc. may be used in this document to describe various elements, and the indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, so these elements should not be restricted by these terms.

[0023] These terms are only used to distinguish one element from another. For example, a first element can be referred to as an "upper" element, and similarly, a second element can be referred to as an "upper" element based on the relative orientation of these elements without departing from the scope of the present disclosure.

[0024] It is further understood that the terms “comprises,” “includes,” “includes,” and / or “comprising” when used herein specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0025] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0026] The first aspect of the present application provides a method for manufacturing a composite target, such as Figure 1 As shown, the composite target manufacturing method includes the following steps: S101: Obtain a composite target circuit pattern to be etched on an inner circuit surface in a copper substrate, wherein the inner circuit surface includes an upper circuit surface and a lower circuit surface, the upper circuit surface is for etching away copper at positions corresponding to the hole positions, and the lower circuit surface is for etching away copper at positions corresponding to the composite target.

[0027] In this embodiment, the copper substrate 1 is a substrate material with excellent electrical conductivity, commonly used in the production of multilayer printed circuit boards (PCBs). The copper substrate 1 has a thickness of 2 to 5 mm. A layer of photoresist is applied to the copper substrate. After exposure and development, the designed circuit pattern is transferred to the photoresist. Subsequently, an etching process removes the unnecessary copper layer, leaving the designed circuit pattern. After etching, the circuit pattern is clearly visible, allowing electronic components to be mounted and connected to form a multilayer PCB. The copper substrate 1 includes an upper surface and / or a lower surface. This means that drilling, copper plating, pattern etching, and lamination can be performed simultaneously on both the upper and lower surfaces of the copper substrate 1. In this embodiment, this process can be performed on both sides, resulting in a highly efficient production process for high-heat-dissipating copper substrates. Pattern etching is a process for manufacturing micro multilayer circuit boards. This application etches a pattern on a copper substrate 1 according to the pattern exposure, thereby ensuring that the copper substrate 1 does not have pattern dropouts. That is, the circuit pattern to be etched on the copper substrate 1 is input into the machine, and the copper substrate 1 is etched according to the input circuit pattern. The circuit pattern to be etched is a circuit pattern tested in advance and may include multiple circuit patterns. The embodiments of this application do not impose any restrictions on this.

[0028] Specifically, a suitable copper substrate 1 is selected as the substrate to ensure that it has good electrical conductivity and mechanical strength. According to the design requirements, a mask containing a composite target circuit pattern and hole position information is made. The mask is usually made of photoresist or other anti-etching materials, and has light-transmitting and light-opaque areas corresponding to the desired circuit pattern. The mask is tightly attached to the surface of the copper substrate 1 to ensure that the pattern on the mask is accurately aligned with the position on the copper substrate 1. The copper substrate 1 is exposed using a photolithography machine or exposure equipment to cause the photoresist to chemically react under light to form a resist layer corresponding to the mask pattern. The exposed copper substrate 1 is developed to remove the photoresist in the unexposed area, leaving the resist layer corresponding to the desired circuit pattern. The resist layer is cured to enhance its adhesion and corrosion resistance. Then, an etching solution (such as cupric chloride etching solution) is used to etch the copper substrate 1. The etching solution will undergo an oxidation-reduction reaction with the copper not protected by the resist layer, dissolving it. Figure 2 As shown in the figure, for the upper circuit surface, the etching solution will remove the copper at the corresponding position of the hole, such as Figure 3 As shown, for the lower circuit surface, the etching solution will remove the copper at the corresponding position of the composite target 7, as shown in FIG. Figure 4 As shown, the desired composite target circuit pattern 2 is formed. After etching is completed, the resist layer on the copper substrate 1 is removed using an appropriate solvent or chemical reagent to expose a clear circuit pattern. Finally, the etched copper substrate 1 is cleaned, dried, and subjected to subsequent treatments to ensure that its surface is clean and free of residue.

[0029] S102: stacking a plurality of inner layer boards to be laminated in sequence and laminating them on the etched inner layer circuit surface to form a multi-layer circuit board.

[0030] In this embodiment, after the etched inner layer circuit board is manufactured, the multiple inner layer circuit boards to be laminated need to be thoroughly cleaned to remove grease, oxides and other impurities on the surface, and then the multiple inner layer circuit boards to be laminated are subjected to browning treatment. Browning can increase the contact area between the copper foil and the resin, increase the bonding strength between the two, and prevent the hardener and copper from reacting under high temperature and high pressure to produce water and cause board explosion. The cleaned and treated inner layer circuit boards are stacked according to the designed stacking structure, which usually includes the prepared inner layer boards, prepregs (or prepregs), It is mainly composed of resin and glass fiber cloth) and the outer layer of copper foil is stacked together in sequence. During the lamination process, it is necessary to ensure the alignment accuracy between the layers to avoid misalignment problems in subsequent processing. Then, the stacked multiple inner layer boards to be laminated and processed are placed in a dedicated inner layer laminating machine. The laminating machine activates the resin in the prepreg by applying high temperature and high pressure, causing it to solidify and firmly bond the layers together. During the lamination process, parameters such as temperature, pressure, and time need to be strictly controlled to ensure sufficient curing of the resin and good bonding between the layers, thereby forming a multi-layer circuit board. During the lamination process, the board will expand and contract after undergoing processing such as high temperature and high pressure. Therefore, it is necessary to use the subsequent measurement steps to obtain the expansion and contraction coefficient of the board during the lamination process, so that the multi-layer circuit board can be produced according to the expansion and contraction coefficient.

[0031] In this embodiment, the electrical connection between the layers of the multilayer board is ensured to be correct through precise stacking arrangement and alignment system, thereby ensuring that the composite target position information can be obtained quickly and accurately in the subsequent process, thereby improving the alignment accuracy of the pattern. S103: Acquire position information of a plurality of composite targets on the multi-layer circuit boards by using a target drilling machine, wherein the composite targets on the multi-layer circuit boards include alignment centers and alignment target points.

[0032] In this embodiment, by placing a multilayer board into a drilling machine, the drilling machine illuminates the board. Because the composite targets 7 on each inner layer board are staggered and non-overlapping, the drilling machine can simultaneously acquire positional information for the composite targets 7 on multiple inner layer boards. The alignment center 4 is a specific area or point on the composite target 7 that serves as a reference point for alignment. During the manufacturing process of multilayer circuit boards, the alignment center is typically used to ensure precise alignment between layers. The alignment target points 3 supplement or assist the alignment center. These are typically located around or at specific locations on the composite target 7 to further verify and adjust alignment accuracy. During the manufacturing process, the alignment target points 3 help the machine or operator more accurately determine the position and orientation of the composite target 7 (and the entire multilayer circuit board).

[0033] In this embodiment, the position information of the composite targets 7 on the multiple multi-layer circuit boards is obtained by the drilling target machine, and the laser positioning target, the drilling positioning target, and the graphic exposure target can be integrated together, which is convenient for on-site personnel to better identify and improve personnel work efficiency, thereby solving the problem of blind spot mismatch, reducing scrap caused by incorrect alignment methods, and greatly optimizing the existing process capabilities.

[0034] In one embodiment, there are four composite targets on the multilayer circuit board. The four composite targets are arranged in a rectangular shape at the four corners of the edge of the multilayer circuit board to provide alignment points for the production of outer layer circuit patterns on the multilayer circuit board.

[0035] In this embodiment, composite targets 7 are set at the four corners of the edge of the multilayer circuit board. Figure 10 As shown, the through-holes and blind vias of a multilayer circuit board are accurately aligned, reducing their overall area, increasing board surface utilization, and improving the economic efficiency of multilayer circuit board production. Composite target 7 is often composed of a common combination of holes found on multilayer circuit boards. Composite target 7 can be used to accurately locate the desired outer layer circuit pattern on the board surface, aligning it with the designed holes on the multilayer circuit board. This allows for reliable interconnection between the inner and outer layers of the multilayer circuit board through the holes, improving the stability and reliability of the multilayer circuit board. When designing the composite target 7, the composite target is composed of a positioning center 4 and a positioning target point 3 surrounding the positioning center 4. As a result, the position of the outer layer pattern transfer on the multi-layer circuit board is determined by the relative positions of the positioning center 4 and the positioning target point 3, which greatly reduces the requirements for the individual positioning accuracy of the positioning center 4 and the positioning target point 3, lowers the positioning threshold, and improves the positioning accuracy during the production of the outer layer circuit pattern through the composite positioning of the positioning center 4 and the positioning target point 3. Usually, the composite target 7 is composed of through holes and blind holes, so that the dual positioning of the through holes and blind holes on the board surface is taken into account when producing the outer layer circuit pattern of the multi-layer circuit board. Therefore, by designing the alignment center and the alignment target point 3 to be through holes, the composite target 7 is less likely to be filled during multiple electroplating processes of the thick copper HDI multi-layer circuit board, thereby improving the applicability and practicality of the composite target 7. Even after multiple electroplating processes before the outer layer pattern is transferred, the composite target 7 can still maintain its effectiveness, providing precise alignment for the production of the outer layer circuit pattern, improving the reliability of the thick copper HDI multi-layer circuit board, and further improving the applicability and practicality of the composite target 7.

[0036] Specifically, the four composite targets 7 on the multilayer circuit board are arranged in a rectangular shape at the four corners of the multilayer circuit board. Compared with the cross distribution of the four composite targets 7 on the multilayer circuit board in the prior art, the four composite targets 7 on the multilayer circuit board in the present application are arranged in a rectangular shape, so that there are two groups of two composite targets 7 in the X direction or the Y direction. After the four composite targets 7 on the multilayer circuit board are recognized by the drill target machine, one expansion coefficient can be obtained by calculating the position information of the actual two composite targets 7 in one group in the X direction or the Y direction and the design position information of the composite target 7. In this way, two expansion coefficients in the X direction and the Y direction can be obtained according to the four composite targets 7 arranged in a rectangular shape, so that the expansion coefficient of the inner layer board is more accurate.

[0037] In an embodiment, the alignment center and the alignment target point are both circular through holes.

[0038] In the present embodiment, the circular through holes are relatively easy to realize in the manufacturing process, whether drilling or laser cutting, and can ensure high precision and consistency. By setting the shape of the alignment center 4 and the alignment target point 3 as circular through holes, the position information of the composite target 7 can be quickly and accurately determined subsequently, and the composite target 7 is less likely to be filled during the manufacturing process of the multilayer circuit board, thereby enhancing the alignment function of the composite target 7 considering through holes and blind holes, improving the applicability and practicality of the composite target 7, and eliminating the need to design multiple composite target 7 combinations on the multilayer circuit board, reducing the number of drill holes on the multilayer circuit board, and saving drilling time.

[0039] In an embodiment, the diameter of the alignment center is 2.0-3.5mm, and the diameter of the alignment target point is 0.15-0.3mm.

[0040] In an embodiment, the alignment target point is concentrically arranged with the alignment center and surrounds the alignment center in a circular ring shape, and the number of alignment target points is multiple.

[0041] In an embodiment, the ring diameter formed by the center of the alignment target point is 4.5-5.5mm.

[0042] In the embodiment, when the composite target 7 is generally called, the resolution of the composite target 7 when scanning and grabbing the composite target 7 is affected by the size of the aperture to be grabbed, the pattern resolution and the number ratio. In the technical solution, the number of the composite target 7 on the multilayer circuit board is 4, and the number of the alignment center 4 for providing the positioning point of the blind hole on the multilayer circuit board is also reduced to 4. Therefore, the size of the alignment center 4 is increased accordingly, and specifically, the alignment center 4 is 2.0-3.5 mm, so as to improve the resolution when the blind hole is aligned by grabbing the alignment center 4. Further, while ensuring that the designed composite target 7 can simultaneously realize the alignment of the through hole and the blind hole, and while ensuring that the overall area of the composite target 7 is reasonable and does not occupy a large area on the multilayer circuit board, the board surface utilization rate of the multilayer circuit board is improved. Therefore, while increasing the size of the alignment center 4, the size of the alignment target point 3 for providing the alignment of the through hole on the multilayer circuit board is reduced, and specifically, the diameter of the alignment target point 3 is 0.15-0.3 mm. Further, in order to improve the resolution when the through hole is aligned by grabbing the alignment target point 3, when the aperture size of the alignment target point 3 is small, the number of the alignment target point 3 is increased to be multiple, and preferably, the number is 8. That is, the center coordinates of the laser positioning target hole 3 are calculated by taking any four laser positioning target holes 3 around the mechanical positioning target hole 4 according to the obtained center coordinates of the mechanical positioning target hole 4. Then, the more accurate composite expansion value of the multilayer circuit board is calculated by comparing the average values of the pattern centers of the four corners of the multilayer circuit board with the standard values actually designed.

[0043] Meanwhile, the alignment target point 3 and the alignment center 4 are concentrically arranged and in the form of a circular ring. When the alignment target point 3 is grabbed, the circular ring center of the alignment target point 3 can be determined by grabbing the holes of four alignment target points 3, which improves the pattern resolution of the composite target 7 when the through hole is aligned by grabbing the alignment target point 3, improves the success rate and progress of target grabbing, and meanwhile, the circular ring center and the alignment center are concentrically arranged, which facilitates the fitting alignment of the hole centers of the alignment center 4 and the alignment target point 3 in the target grabbing composite target 7, and meanwhile, the blind hole and the through hole on the outer layer board are accurately aligned at the same time. Preferably, the ring diameter formed by the center of the alignment target point 3 is 4.5-5.5 mm, which ensures that the composite target 7 can simultaneously realize the alignment of the through hole and the blind hole of the multilayer circuit board, ensures that the overall area of the composite target 7 is small, reduces the area ratio of the composite target 7 on the edge of the multilayer circuit board, and improves the board surface utilization rate of the multilayer circuit board.

[0044] In an embodiment, the composite target position information on the plurality of multilayer circuit boards is obtained by a target drilling machine, and the composite target position information includes: The mechanical positioning target hole formed by drilling a hole on the multilayer circuit board by a mechanical drill is used as the alignment center. Using laser positioning target holes drilled on the multilayer circuit board by a laser machine as alignment target points, wherein the number of the alignment target points is multiple; The center coordinates of the mechanical positioning target hole and the center coordinates of the plurality of laser positioning target holes are averaged to determine composite target position information.

[0045] Specifically, the drilling target machine includes a mechanical drill and a laser machine, which will drill holes at predetermined positions of the multi-layer circuit board through the mechanical drill to form mechanical positioning target holes 4, which serve as the alignment center 4. The mechanical positioning target holes 4 usually have a larger diameter and clear edges to facilitate subsequent identification and positioning. The positions and number of the mechanical positioning target holes 4 are determined according to the design requirements of the multi-layer circuit board, and are usually located at key positions on the board surface, such as corners or center areas. A laser machine is used to drill holes in a multilayer circuit board to form laser positioning target holes 3, which serve as alignment target points 3. Multiple alignment target points 3 are located around a mechanical positioning target hole 4. The center of a circle formed by a plurality of adjacent laser positioning target holes 3 of the same diameter is co-located with the center of the mechanical positioning target hole 4, forming a composite target 7. These laser positioning target holes typically have a smaller diameter and higher precision to provide higher positioning accuracy. A machine vision system or image recognition algorithm is then used to identify the position and size of the mechanical positioning target holes 4 and the laser positioning target holes 3 on the multilayer circuit board, determining their precise positions on the multilayer circuit board. The center coordinates of the mechanical positioning target hole 6 and the center coordinates of the multiple laser positioning target holes 5 are then calculated and averaged to obtain the position information of the composite target 7 for subsequent alignment and processing. This combined use of the mechanical positioning target holes 4 and the laser positioning target holes 3 provides higher positioning accuracy.

[0046] It should be noted that during the production process of the composite target 7, the alignment target point 3 in the composite target 7 is drilled out by a laser drilling method, and the alignment center 4 is drilled out by a mechanical drilling method, which is used to accurately align the panel holes when the subsequent outer layer circuit graphics are produced. Furthermore, when producing the alignment target point 3, it is drilled with reference to the midpoint of the alignment center 4 of the entire board, so as to facilitate the simultaneous capture of the fitting alignment between the panel laser holes and graphics, the mechanical holes and graphics, and the laser holes and through holes in the composite target 7.

[0047] In this embodiment, the position information of the composite targets 7 on the multiple multi-layer circuit boards is obtained by the drilling target machine, and the laser positioning target, the drilling positioning target, and the graphic exposure target can be integrated together, which is convenient for on-site personnel to better identify and improve personnel work efficiency, thereby solving the problem of blind spot mismatch, reducing scrap caused by incorrect alignment methods, and greatly optimizing the existing process capabilities.

[0048] In one embodiment, after obtaining the composite target position information on the plurality of multi-layer circuit boards, the method includes: sequentially calculating the difference between the composite target position information on each of the multilayer circuit boards and the preset composite target position information; The differences are averaged to obtain the expansion and contraction coefficient of the multilayer circuit board.

[0049] Specifically, preset composite target 7 position information is obtained from design drawings, CAD files, or previously measured data. This information represents the position of the composite target 7 under ideal conditions (no expansion or contraction) for the multilayer circuit board. Multiple pieces of composite target 7 position information are then sequentially compared with the preset composite target 7 position information. This typically involves calculating the deviation or offset between the actual position and the preset position. Based on the comparison results, the difference between the composite target 7 position information on each multilayer circuit board and the preset composite target 7 position information is calculated. These differences are then averaged to obtain the expansion / contraction coefficient of the multilayer circuit board. This expansion / contraction coefficient can be determined by analyzing the distribution and magnitude of the deviations or offsets. For example, the overall expansion / contraction ratio, the expansion / contraction amount in each direction, or the unevenness of the expansion / contraction can be calculated. Through these steps, the expansion / contraction coefficient of the multilayer circuit board is calculated based on the composite target 7 position information on the multilayer circuit board, resulting in a more accurate expansion / contraction coefficient for the multilayer circuit board, thereby improving the alignment accuracy of the circuit patterns on the multilayer circuit board.

[0050] In one embodiment, after obtaining the expansion and contraction coefficient of the multilayer circuit board, the method includes: Determining whether a difference between the expansion and contraction coefficient of the multilayer circuit board and a preset expansion and contraction coefficient satisfies a preset difference threshold; If the preset difference threshold is met, it is determined that the multilayer circuit board meets the production requirements; If the preset difference threshold is not met, it is determined that the multilayer circuit board does not meet the manufacturing requirements, and the multilayer circuit board is manufactured according to the expansion and contraction coefficient.

[0051] Specifically, the system determines whether the difference between the multilayer circuit board's expansion coefficient and a preset expansion coefficient meets a preset difference threshold. If so, the multilayer circuit board is determined to meet manufacturing requirements. If not, the multilayer circuit board is determined to not meet manufacturing requirements and the multilayer circuit board is manufactured according to the expansion coefficient. These steps enable more accurate prediction of the dimensional changes of circuit boards under different environmental conditions (such as temperature and humidity changes), thereby optimizing designs and improving circuit board reliability. This provides more comprehensive data support for subsequent process adjustments and quality control, ultimately enhancing the product quality of the multilayer circuit boards.

[0052] In this embodiment, the two-side production is taken as an example. In combination with the above embodiments, a composite target production method is provided. Figure 5As shown, the copper substrate 1 is obtained, which is composed of an upper core layer and a lower core layer, and then the composite target 7 needs to be patterned on the copper of the core layer, that is, the copper corresponding to the hole position of the upper core layer is etched, and the copper corresponding to the composite target 7 of the lower core layer is etched, so that the pattern target is clearly visible when the laser hole is burned in the subsequent process, as shown in Figure 6 As shown, the composite target circuit pattern 2 in the copper substrate 1 that needs to be etched is obtained, as shown in Figure 7 As shown, after all the core layers are laminated together, a multi-layer circuit board is formed, as shown in Figure 8 As shown, the hole in the middle of the composite target 7 is made on the multi-layer circuit board by mechanical drilling and laser drilling, respectively, for automatic alignment of the subsequent process equipment. The position information of the composite target 7 on the multi-layer circuit board is obtained by the target drilling machine, that is, the center coordinates 5 of the composite target 7 are calculated according to the center coordinates 6 of the mechanical positioning target hole and any four laser positioning target holes around the mechanical positioning target hole, as shown in Figure 9 As shown, the center coordinates of the two are averaged to obtain the position information of the composite target 7 on the multi-layer circuit board. According to the position information of the composite target 7 on the multi-layer circuit board, the center average of the composite target 7 at the four corners of the multi-layer circuit board is compared with the standard value of the actual design to obtain more accurate composite expansion value of the multi-layer circuit board. It can be seen that the composite target 7 can simultaneously consider the position alignment of the drilling and the laser hole, and the alignment degree of the circuit and the two different hole patterns is maximized, thereby improving the alignment accuracy of the pattern.

[0053] It is worth noting that the composite target 7 prepared by the composite target manufacturing method provided by the embodiment of the application can make the pattern exposure more accurate, reduce the deviation between the laser hole and the pattern, the mechanical hole and the pattern, and the laser hole and the through hole, and improve the alignment accuracy of the pattern.

[0054] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for producing a composite target, characterized in that: include: Obtaining a composite target circuit pattern to be etched on an inner circuit surface of a copper substrate, wherein the inner circuit surface includes an upper circuit surface and a lower circuit surface, the upper circuit surface is used to etch away copper at positions corresponding to the hole positions, and the lower circuit surface is used to etch away copper at positions corresponding to the composite target; Stacking a plurality of inner layer boards to be laminated in sequence and then laminating them on the etched inner layer circuit surface to form a multilayer circuit board; The position information of the composite targets on the plurality of multi-layer circuit boards is obtained by a target drilling machine, wherein the composite targets on the multi-layer circuit boards include alignment centers and alignment target points.

2. The method for producing a composite target according to claim 1, wherein: There are four composite targets on the multilayer circuit board. The four composite targets are arranged in a rectangular shape at the four corners of the edge of the multilayer circuit board to provide alignment points for the production of outer layer circuit patterns on the multilayer circuit board.

3. The method for producing a composite target according to claim 1, wherein: The alignment center and the alignment target are both circular through holes.

4. The method for producing a composite target according to claim 1, wherein: The diameter of the alignment center is 2.0-3.5 mm, and the diameter of the alignment target is 0.15-0.3 mm.

5. The method for producing a composite target according to claim 1, wherein: The alignment target point is concentrically arranged with the alignment center and surrounds the alignment center in a circular shape, and there are multiple alignment target points.

6. The method for producing a composite target according to claim 1, wherein: The diameter of the ring formed by the center of the alignment target is 4.5-5.5 mm.

7. The method for producing a composite target according to claim 1, wherein: The target drilling machine includes a mechanical drill and a laser machine, and the method of obtaining the composite target position information on the plurality of multi-layer circuit boards by the target drilling machine includes: Using a mechanical positioning target hole formed by drilling a hole on the multilayer circuit board by a mechanical drill as an alignment center; Using laser positioning target holes drilled on the multilayer circuit board by a laser machine as alignment target points, wherein the number of the alignment target points is multiple; The center coordinates of the mechanical positioning target hole and the center coordinates of the plurality of laser positioning target holes are averaged to determine composite target position information.

8. The method for producing a composite target according to claim 1, wherein: After obtaining the composite target position information on the plurality of multilayer circuit boards, the method includes: sequentially calculating the difference between the composite target position information on each of the multilayer circuit boards and the preset composite target position information; The differences are averaged to obtain the expansion and contraction coefficient of the multilayer circuit board.

9. The method for producing a composite target according to claim 8, wherein: After obtaining the expansion and contraction coefficient of the multilayer circuit board, the method includes: Determining whether a difference between the expansion and contraction coefficient of the multilayer circuit board and a preset expansion and contraction coefficient satisfies a preset difference threshold; If the preset difference threshold is met, it is determined that the multilayer circuit board meets the production requirements; If the preset difference threshold is not met, it is determined that the multilayer circuit board does not meet the manufacturing requirements, and the multilayer circuit board is manufactured according to the expansion and contraction coefficient.

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