Manufacturing method of high-precision circuit board
By setting alignment holes and slots on the substrate, embedding high-precision alignment pieces, and utilizing inner layer segmentation exposure and target positioning, electrical processing is performed layer by layer, solving the problem of low alignment accuracy of circuit boards, realizing the production of high-precision circuit boards, reducing the cumulative error of multi-layer circuit boards, and improving the yield rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-03-27
AI Technical Summary
Existing circuit board alignment systems have low alignment accuracy, which cannot meet the manufacturing requirements of high-precision circuit boards. In particular, during the lamination process of multilayer boards, insufficient alignment accuracy between layers leads to electrical problems such as signal interference, short circuits, or open circuits.
Alignment holes and slots are set on the substrate, high-precision alignment pieces are embedded, and inter-board electrical processing is performed layer by layer through inner layer segmentation exposure and target point positioning. CCD camera is used to identify the target point position, and blind holes are formed by laser to make electrical connections. The circuit boards are stacked layer by layer to achieve high-precision alignment.
It significantly reduces the cumulative error of multilayer circuit boards, improves alignment accuracy, meets the requirements for small pads and large blind vias, and improves the yield of multilayer circuit boards.
Smart Images
Figure CN121751518A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of packaging circuit board technology, and particularly relates to a method for manufacturing a high-precision circuit board. Background Technology
[0002] In the production process of PCB (Printed Circuit Board), especially in the lamination process of multilayer boards, the alignment accuracy between layers is crucial. The circuit patterns of each layer need to be accurately aligned to ensure the normal function of the entire circuit board. If the alignment is inaccurate, it may lead to electrical problems such as signal interference, short circuits or open circuits, affecting the quality of the final product.
[0003] Embedded circuit board solutions have become a viable option for high-performance printed circuit boards (PCBs). Embedding components allows for lower power consumption, higher performance, and lower costs. Currently, industries such as smartphones, AI servers, new energy vehicles, and the medical field have stringent requirements for reliability and density. In the COWOS, SIP, COWOP, and SLP fields, the embedding of passive and active components and bare dies into the PCB requires precise alignment of device electrodes, inner layer pads, blind vias, and outer layer pads in three-dimensional space, with error tolerance decreasing to tens of micrometers or even single-micrometer levels. Furthermore, the increasing demand for ultra-fine pitch in high-end HDI circuits places even higher demands on the alignment accuracy of inner and outer layers for micro-blind vias, micro-through vias, and micro-pitch traces. Deviations in any layer can affect signal integrity and reliable soldering.
[0004] Currently, to meet integration requirements, some bare chips have small pads, but to meet input and output current requirements, the blind vias are relatively large. After removing the blind vias, the remaining deviation after removing the pads is only a few tens of micrometers. However, the alignment accuracy of current circuit board direct packaging systems is only at the hundred-micrometer level, which is far from meeting the needs of high-performance packaging circuit boards. The deviation of tens of micrometers between the front and back exposure patterns in the inner layer exposure process alone, plus the cumulative errors from single-sided pattern deviation in inner layer exposure, X-ray drilling deviation, laser deviation, etc., far exceeds the requirement of tens of micrometers. In the fabrication of multilayer circuit boards, the target point position is subject to expansion and contraction, requiring real-time adjustments to ensure the positional accuracy of the blind vias. Therefore, a new alignment method is needed for the fabrication of high-precision circuit boards. Summary of the Invention
[0005] The purpose of this invention is to provide a method for manufacturing high-precision circuit boards, in order to solve the problem that the existing circuit board alignment system has low alignment accuracy and cannot meet the requirements for manufacturing high-precision circuit boards.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows:
[0007] A method for manufacturing a high-precision circuit board includes the following steps:
[0008] Several alignment holes are made on the substrate, and an alignment groove penetrating the substrate is made inside each alignment hole. The front alignment piece and the back alignment piece of the substrate are respectively embedded at both ends of the alignment groove. The substrate alignment target point is set at the relative position of the front alignment piece and the back alignment piece of the substrate.
[0009] The alignment process of the substrate is performed based on the alignment target points. The alignment process includes: forming several patterned areas on the substrate based on the alignment target points, exposing the first alignment target points at the corners of the patterned areas, performing inter-board electrical processing on each patterned area based on the first alignment target points, and covering the front and back sides of the substrate after the inter-board electrical processing is completed with an insulating layer and laminating them to form the first circuit board.
[0010] The first alignment target on the first layer circuit board is exposed from under the insulating layer by opening a window. Based on the exposed first alignment target, a corresponding first edge target is made on the edge of the first layer circuit board. Based on the exposed first alignment target, blind holes for electrical connection between adjacent circuit boards or devices are opened.
[0011] Several layers of boards to be processed are stacked sequentially on both sides of the first layer of the circuit board. Each stacking is based on the target point on the edge of the previous layer, repeating the above alignment processing steps until the number of circuit board layers reaches the preset value and the multi-layer circuit board is completed.
[0012] The method for fabricating the edge target points on each layer of the circuit board is as follows: Based on the position of the Nth alignment target point, locate the Nth edge target point, laser-drill a groove at the location, and partially fill the groove through electroplating to form an easily identifiable concave-convex structure, i.e., the Nth edge target point, where N is a positive integer and N≥2.
[0013] The method for creating blind vias for electrical connections between adjacent circuit boards or devices based on the exposed Nth alignment target point is as follows: the exposed Nth alignment target point is identified by a CCD camera, the position of the electrical connection point within the graphic area is determined based on the position of the Nth alignment target point, the electrical connection point is exposed from under the insulating layer by laser, and electroplating is performed at the laser hole to form a blind via for electrical connection between boards, where N is a positive integer and N≥2.
[0014] The Nth alignment target point on the Nth layer circuit board is determined based on the (N-1)th board edge target point. Electrical processing of the Nth layer board to be processed is achieved based on the position of the Nth alignment target point, thus realizing the electrical connection between the Nth layer circuit board and the (N-1)th layer board to be processed. N is a positive integer and N≥2.
[0015] The alignment groove is an "I"-shaped through hole. The front alignment piece and the back alignment piece of the substrate are high-precision transparent alignment pieces. The front alignment piece and the back alignment piece of the substrate are respectively fixed to the upper and lower grooves of the "I"-shaped through hole with solid adhesive.
[0016] The substrate alignment target is a circular target, and the substrate alignment target on the front and back of the substrate is the same size and vertically aligned.
[0017] The inter-board electrical processing includes: grooving and shaping the substrate or the board to be processed, component placement, inter-board wiring connection and potting, pressing and baking, and grinding.
[0018] The Nth alignment target and the Nth plate edge target can be circular, square, annular, or plum blossom shaped.
[0019] The insulating layer is made of FR4, BT, or ABF.
[0020] The multilayer circuit board is also encapsulated with functional or protective devices on both sides.
[0021] Beneficial effects: The high-precision circuit board manufacturing method of the present invention uses inner layer segmentation exposure to locate and manufacture target points, providing alignment accuracy, avoiding the additional errors caused by traditional mechanical drilling methods, and significantly reducing multi-layer cumulative errors; the shape and size of the target points are not limited, and the dynamic expansion and contraction of the target point position is achieved by setting target points layer by layer, effectively reducing alignment errors; the manufacturing method of the present invention can perform high-precision alignment of device electrodes, blind holes, and circuit board pads of each layer, meeting the requirements of small pads and large blind holes for device lead-out, effectively improving the yield of multi-layer circuit boards. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the exposure state of the inner layer of the substrate according to the present invention;
[0023] Figure 2 This is a schematic diagram of the alignment groove and alignment piece of the present invention;
[0024] Figure 3 This is a schematic diagram of the first alignment target point and the first plate edge target point of the present invention;
[0025] Figure 4 This is a schematic diagram of the structure of a multilayer circuit board produced by the high-precision circuit board manufacturing method of the present invention.
[0026] In the figure, 1-alignment hole; 2-alignment piece; 3-substrate alignment target point; 4-first alignment target point; 5-first board edge target point. Detailed Implementation
[0027] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.
[0028] Example 1
[0029] refer to Figures 1 to 3 As shown, a method for manufacturing a high-precision circuit board includes the following steps:
[0030] Step S1: A number of alignment holes are made on the substrate, and an alignment groove penetrating the substrate is made inside each alignment hole. A front alignment piece and a back alignment piece are respectively embedded at both ends of the alignment groove. Alignment target points are set on the relative positions of the front alignment piece and the back alignment piece.
[0031] Step S2: The substrate is exposed for inner layer segmentation based on the substrate alignment target point to form several patterned areas on the substrate, and the first alignment target point is exposed at the corner of the patterned area. Based on the first alignment target point, the board electrical processing is performed on each patterned area. An insulating layer is added to the front and back of the substrate after the board electrical processing is completed and then laminated to form the first circuit board.
[0032] Step S3: Expose the first alignment target on the first layer circuit board from the insulating layer by opening a window. Based on the exposed first alignment target, make a number of first board edge targets on the board edge of the first layer circuit board. Based on the exposed first alignment target, open blind holes for electrical connection between adjacent circuit boards or devices.
[0033] Step S4: Add a second layer of the board to be processed to both sides of the first layer circuit board. Perform inner layer segmentation and exposure on the second layer of the board based on the target point on the edge of the first board. Repeat steps S2 and S3 above to complete the electrical processing of the second layer of the board and the electrical connection with the first layer circuit board, and make the second layer circuit board. Add functional devices or protection devices to both sides of the second layer circuit board to complete the packaging of the double-layer high-precision circuit board.
[0034] Example 2
[0035] refer to Figures 1 to 4 As shown, the high-precision circuit board manufacturing method in Example 1 can be used for the manufacturing of multilayer circuit boards. The specific method includes:
[0036] Step S1: Drill holes at several preset points on the substrate to make alignment holes, and make alignment grooves through the substrate inside each alignment hole. Embed the front alignment piece and the back alignment piece of the substrate at both ends of the alignment groove respectively. Set the substrate alignment target point at the relative position of the front alignment piece and the back alignment piece of the substrate.
[0037] In this embodiment, the alignment hole is located at the corner of the substrate, and the alignment groove is an "I"-shaped through hole. The transparent and high-precision front alignment sheet and back alignment sheet of the substrate are fixed to the upper and lower grooves of the "I"-shaped hole by solid adhesive. A circular alignment target point is set at the center of the front alignment sheet and the back alignment sheet of the substrate, that is, the substrate alignment target point. The substrate alignment target points on the front and back sides of the substrate are the same size and vertically aligned. The substrate alignment target point can ensure that the exposure pattern deviation of the front and back patterns is <5μm, while the traditional mechanical hole can only achieve <20μm.
[0038] Step S2: The substrate is exposed for inner layer segmentation based on the substrate alignment target point to form several patterned areas on the substrate, and the first alignment target point is exposed at the corner of the patterned area. Based on the first alignment target point, the board electrical processing is performed on each patterned area. An insulating layer is added to the front and back of the substrate after the board electrical processing is completed and then laminated to form the first circuit board.
[0039] In this embodiment, the alignment exposure of the first alignment target point is performed using a high-precision alignment film. After exposure, the deviation between the first alignment target point on the front and back sides of the substrate is less than 5μm, and the error comes only from the exposure accuracy of the exposure equipment itself.
[0040] Inter-board electrical processing includes: slot forming, component placement, inter-board circuit connection and potting, pressing and baking, and grinding. The first alignment target point etched by the inner layer is captured by a CCD camera to perform slot processing on the image area to ensure the relative position accuracy between the slot and the first alignment target point. The alignment and placement are performed in the slot to ensure the accuracy is within 5μm.
[0041] The shape of the first target point can be a circle, a square, a plum blossom shape, or a special shape, and its size is not limited.
[0042] The insulating layer is made of FR4, BT, or ABF.
[0043] Step S3: Expose the first alignment target on the first layer circuit board from the insulating layer by opening a window. Based on the exposed first alignment target, make a number of first board edge targets on the board edge of the first layer circuit board. Based on the exposed first alignment target, open blind holes corresponding to the inter-board electrical connections in the graphic area.
[0044] After lamination, the insulating layer covers the first alignment target and the electrical connection points in the pattern area. The insulating layer above the first alignment target is removed by laser or etching to form a window area, exposing the first alignment target in the window area. The CCD camera identifies the exposed first alignment target and determines the position of the electrical connection points in the pattern area based on the position of the first alignment target. The electrical connection points are exposed from under the insulating layer by laser, and electroplating is performed at the laser hole to form blind holes for inter-board electrical connections.
[0045] The method for creating several first board edge targets on the edge of the first layer circuit board based on the first alignment target is as follows: several target points corresponding to the first alignment target are laser-etched on the edge of the board. These can be circular targets or plum blossom targets. By controlling the electroplating parameters, the laser-etched target points are electroplated and filled, but not completely filled, to form a concave-convex structure, i.e., the first board edge target points. This facilitates recognition by the CCD camera and ensures the alignment accuracy of the pads and blind holes on the outer layer circuit board.
[0046] Step S4: Stack several layers of boards to be processed on both sides of the first layer circuit board in sequence. Each stacking is based on the target point on the edge of the previous layer, repeating the alignment processing steps of steps S2 and S3 until the number of circuit board layers reaches the preset value to complete the production of multi-layer circuit boards. Add functional devices or protection devices on both sides of the multi-layer circuit boards to complete the packaging of high-precision circuit boards.
[0047] The Nth alignment target point on the Nth layer circuit board is determined based on the (N-1)th board edge target point. Electrical processing of the Nth layer board to be processed is achieved based on the position of the Nth alignment target point, thus realizing the electrical connection between the Nth layer circuit board and the (N-1)th layer board to be processed. N is a positive integer and N≥2.
[0048] The positions of the target points on the edges of adjacent layers are staggered in the vertical direction to avoid misidentification of the target points by the CCD camera.
[0049] In summary, the high-precision circuit board manufacturing method of the present invention uses inner layer segmentation exposure to locate and manufacture target points, providing alignment accuracy, avoiding the additional errors caused by traditional mechanical drilling methods, and significantly reducing multi-layer cumulative errors; the shape and size of the target points are not limited, and the dynamic expansion and contraction of the target point position is achieved by setting target points layer by layer, effectively reducing alignment errors; the manufacturing method of the present invention can perform high-precision alignment of device electrodes, blind holes, and circuit board pads of each layer, meeting the requirements of small pads and large blind holes for device lead-out, effectively improving the yield of multi-layer circuit boards.
[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for manufacturing a high-precision circuit board, characterized in that, Includes the following steps: Several alignment holes are made on the substrate, and an alignment groove penetrating the substrate is made inside each alignment hole. The front alignment piece and the back alignment piece of the substrate are respectively embedded at both ends of the alignment groove. The substrate alignment target point is set at the relative position of the front alignment piece and the back alignment piece of the substrate. The alignment process of the substrate is performed based on the alignment target points. The alignment process includes: forming several patterned areas on the substrate based on the alignment target points, exposing the first alignment target points at the corners of the patterned areas, performing inter-board electrical processing on each patterned area based on the first alignment target points, and covering the front and back sides of the substrate after the inter-board electrical processing is completed with an insulating layer and laminating them to form the first circuit board. The first alignment target on the first layer circuit board is exposed from under the insulating layer by opening a window. Based on the exposed first alignment target, a corresponding first edge target is made on the edge of the first layer circuit board. Based on the exposed first alignment target, blind holes for electrical connection between adjacent circuit boards or devices are opened. Several layers of boards to be processed are stacked sequentially on both sides of the first layer of the circuit board. Each stacking is based on the target point on the edge of the previous layer, repeating the above alignment processing steps until the number of circuit board layers reaches the preset value and the multi-layer circuit board is completed.
2. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The method for fabricating the edge target points on each layer of the circuit board is as follows: Based on the position of the Nth alignment target point, locate the Nth edge target point, laser-drill a groove at the location, and partially fill the groove through electroplating to form an easily identifiable concave-convex structure, i.e., the Nth edge target point, where N is a positive integer and N≥2.
3. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The method for creating blind vias for electrical connections between adjacent circuit boards or devices based on the exposed Nth alignment target point is as follows: the exposed Nth alignment target point is identified by a CCD camera, the position of the electrical connection point within the graphic area is determined based on the position of the Nth alignment target point, the electrical connection point is exposed from under the insulating layer by laser, and electroplating is performed at the laser hole to form a blind via for electrical connection between boards, where N is a positive integer and N≥2.
4. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The Nth alignment target point on the Nth layer circuit board is determined based on the (N-1)th board edge target point. Electrical processing of the Nth layer board to be processed is achieved based on the position of the Nth alignment target point, thus realizing the electrical connection between the Nth layer circuit board and the (N-1)th layer board to be processed. N is a positive integer and N≥2.
5. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The alignment groove is an "I"-shaped through hole. The front alignment piece and the back alignment piece of the substrate are high-precision transparent alignment pieces. The front alignment piece and the back alignment piece of the substrate are respectively fixed to the upper and lower grooves of the "I"-shaped through hole with solid adhesive.
6. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The substrate alignment target is a circular target, and the substrate alignment target on the front and back of the substrate is the same size and vertically aligned.
7. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The inter-board electrical processing includes: grooving and shaping the substrate or the board to be processed, component placement, inter-board wiring connection and potting, pressing and baking, and grinding.
8. The method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The Nth alignment target and the Nth plate edge target can be circular, square, annular, or plum blossom shaped.
9. A method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The insulating layer is made of FR4, BT, or ABF.
10. A method for manufacturing a high-precision circuit board according to claim 1, characterized in that, The multilayer circuit board is also encapsulated with functional or protective devices on both sides.