Circuit boards and their manufacturing methods, packaging modules

Abstract

A circuit board and its manufacturing method and packaging module are disclosed. The circuit board includes: a main substrate having two main surfaces opposite each other in a first direction and an edge region connecting the two main surfaces; the main substrate includes a protrusion and a groove defined by the protrusion in the edge region; the groove is recessed from a first side surface of the protrusion toward a central region of the main substrate in a second direction parallel to the main surfaces of the main substrate; and an edge connection structure covering the first side surface and at least one second side surface of the protrusion and electrically connected to one or more circuit layers of the main substrate, wherein the first side surface is the outermost side surface of the protrusion in the second direction, and the second side surface is the side surface of the protrusion defining the groove.

Description

Technical Field

[0001] This disclosure relates to a circuit board, its manufacturing method, and a packaging module. Background Technology

[0002] Printed circuit boards (PCBs), serving as the supporting carriers and electrical connection hubs for electronic components, are widely used in various electronic products. To achieve external connections on a PCB, soldering structures can be installed along its edges. The structural design of these edge soldering structures significantly impacts the connection reliability of the circuit board, and consequently, the reliability of the electronic products containing that circuit board. How to achieve PCB connection structures with high connection reliability is an important research topic in this field. Summary of the Invention

[0003] A circuit board is provided according to at least one embodiment of the present disclosure, comprising: a main substrate having two main surfaces opposite each other in a first direction and an edge region connecting the two main surfaces, the main substrate including a protrusion and a groove defined by the protrusion in the edge region, the groove being recessed from a first side surface of the protrusion toward a central region of the main substrate in a second direction parallel to the main surfaces of the main substrate; and an edge connection structure covering the first side surface and at least one second side surface of the protrusion and electrically connected to one or more circuit layers of the main substrate, the first side surface being the outermost side surface of the protrusion in the second direction, and the second side surface being the side surface of the protrusion defining the groove.

[0004] In a circuit board provided according to at least one embodiment of the present disclosure, the board edge connection structure further covers at least one of a first surface and a second surface of the protrusion that are opposite each other in the first direction.

[0005] In a circuit board provided according to at least one embodiment of the present disclosure, the one or more circuit layers include circuit layers exposed on one or more of the two main surfaces of the main substrate and the side surfaces of the board edge region, and the exposed portions of the circuit layers are connected to the board edge connection structure.

[0006] In a circuit board provided according to at least one embodiment of the present disclosure, the board edge connection structure includes a plurality of spaced pads, and the gap area between adjacent pads is located at the bottom of the groove or exposes a portion of the first side surface of the protrusion.

[0007] In a circuit board provided according to at least one embodiment of the present disclosure, the protrusion includes a plurality of protruding sub-parts arranged in a third direction parallel to the main surface of the main substrate and perpendicular to the second direction, and the board edge connection structure includes a plurality of first pads arranged at intervals in the third direction and respectively covering the plurality of protruding sub-parts.

[0008] In a circuit board provided according to at least one embodiment of the present disclosure, the plurality of first pads are isolated from each other by an insulating isolation groove, the insulating isolation groove being located in the groove and including at least a pad opening between adjacent first pads.

[0009] In a circuit board provided according to at least one embodiment of the present disclosure, the groove includes a main groove and an additional groove located between adjacent protrusions among the plurality of protrusions. The additional groove is located on one side of the main groove near the central region of the main substrate in the second direction. The main groove and the additional groove are spatially connected to each other and space adjacent protrusions apart. The plurality of first pads respectively cover the surfaces of the plurality of protrusions that define the main groove, and adjacent first pads are isolated from each other by an insulating isolation groove. The insulating isolation groove includes a pad opening between adjacent first pads and the additional groove, and the pad opening and the additional groove are spatially connected to each other.

[0010] In a circuit board provided according to at least one embodiment of the present disclosure, the main groove is recessed in the second direction from the first side surface of the protrusion toward the central region of the main substrate and is defined by the second side surface of the adjacent protruding sub-part; the additional groove is further recessed in the second direction from the bottom of the main groove toward the central region and is defined by the third side surface of the adjacent protruding sub-part.

[0011] In a circuit board provided according to at least one embodiment of the present disclosure, the third side surface of the adjacent protruding sub-parts is exposed by the board edge connection structure.

[0012] In a circuit board provided according to at least one embodiment of the present disclosure, the width of the main body recess in the third direction is greater than the width of the insulating isolation groove in the third direction.

[0013] In a circuit board provided according to at least one embodiment of the present disclosure, the main groove has a first depth in the second direction, the additional groove has a second depth in the second direction, and the overall depth of the groove in the second direction is the sum of the first depth and the second depth; the first depth is greater than the second depth.

[0014] In a circuit board provided according to at least one embodiment of the present disclosure, the width of the main body groove gradually decreases as the main body groove moves away from the first side surface of the protrusion in the second direction.

[0015] In a circuit board provided according to at least one embodiment of the present disclosure, the width of the insulating isolation groove gradually decreases as the insulating isolation groove moves away from the main body groove in the second direction.

[0016] In a circuit board provided according to at least one embodiment of the present disclosure, the width of the insulating isolation groove in the third direction is 25% to 100% of the depth of the groove in the second direction.

[0017] In a circuit board provided according to at least one embodiment of the present disclosure, one or more of the plurality of first pads each include a plurality of sub-pads, the plurality of sub-pads covering the same protruding sub-part and arranged at intervals from each other in the first direction, and the gap area between adjacent sub-pads exposes a portion of the first side surface of the protruding sub-part.

[0018] In a circuit board provided according to at least one embodiment of the present disclosure, the board edge connection structure includes at least one of signal transmission pads and power transmission pads.

[0019] At least one embodiment of this disclosure provides a packaging module, including: a circuit board as described in any of the preceding claims, wherein the circuit board serves as a first circuit board of the packaging module; and a second circuit board, which is soldered to the edge connection structure of the first circuit board via a solder layer, and is electrically connected to the one or more line layers of the first circuit board via the edge connection structure.

[0020] In a packaging module provided according to at least one embodiment of the present disclosure, at least a portion of the solder layer is located on the side of the protrusion of the first circuit board away from the central region of the first circuit board, and is located between the board edge connection structure and the second circuit board.

[0021] In a packaging module provided according to at least one embodiment of the present disclosure, the corner portion of the board edge connection structure of the first circuit board is covered by the solder layer, and the corner portion of the board edge connection structure covers the junction area of ​​the first side surface and the second side surface of the protrusion of the main substrate.

[0022] In a packaging module provided according to at least one embodiment of the present disclosure, a portion of the solder layer is located within the groove, and the thickness of the portion of the solder layer in the second direction is less than the depth of the groove in the second direction.

[0023] In the packaging module provided according to at least one embodiment of the present disclosure, the board edge connection structure of the first circuit board includes a plurality of first pads, and the second circuit board includes a plurality of second pads. The plurality of first pads are respectively disposed corresponding to the plurality of second pads and soldered to each other. In the correspondingly disposed first pads and second pads, the surface dimension of the second pad facing the first pad is larger than the surface dimension of the first pad facing the second pad.

[0024] At least one embodiment of this disclosure provides a method for manufacturing a circuit board, comprising: providing a main substrate having two main surfaces opposite each other in a first direction and an edge region connecting the two main surfaces; forming a protrusion and a groove defined by the protrusion in the edge region of the main substrate; the groove being recessed from a first side surface of the protrusion toward a central region of the main substrate in a second direction parallel to the main surfaces of the main substrate; and forming an edge connection structure in the edge region to cover the first side surface of the protrusion and at least one second side surface, the first side surface being the outermost side surface of the protrusion in the second direction on the main substrate, and the second side surface being the side surface of the protrusion defining the groove.

[0025] According to at least one embodiment of the present disclosure, a method for manufacturing a circuit board includes forming the protrusion, the groove, and the edge connection structure by: forming an initial groove with a half-hole structure in the edge region of a main substrate using a half-hole forming process, and forming an initial protrusion; performing an edge electroplating process to form a conductive material layer in the edge region of the main substrate, the conductive material layer covering the initial protrusion and the initial groove; and performing a removal process to remove at least a portion of the conductive material layer covering the bottom of the initial groove, and forming an insulating isolation groove that divides the conductive material layer into a plurality of spaced-apart first pads; wherein the initial groove forms at least a portion of the groove, the initial protrusion forms at least a portion of the protrusion, and the plurality of first pads together constitute the edge connection structure.

[0026] In a method for manufacturing a circuit board according to at least one embodiment of the present disclosure, the removal process further removes the portion of the main substrate exposed by the bottom of the initial groove and forms an additional groove in the main substrate, wherein the initial groove serves as the main groove and together with the additional groove constitutes the groove, and the initial protrusion and the portion of the main substrate defining the additional groove together constitute the protrusion.

[0027] The method for manufacturing a circuit board according to at least one embodiment of the present disclosure further includes: performing an additional removal process to remove a portion of a first pad and to divide the first pad into a plurality of sub-pads spaced apart in the first direction. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0029] Figure 1 A schematic perspective view of a circuit board according to some embodiments of the present disclosure is shown.

[0030] Figure 2 A schematic top view of a circuit board according to some embodiments of the present disclosure is shown.

[0031] Figure 3A A schematic plan view of a circuit board according to some embodiments of the present disclosure is shown; Figure 3B Show Figure 3A A schematic enlarged view of a portion of the edge area of ​​the circuit board shown.

[0032] Figure 4A A schematic plan view of a circuit board according to other embodiments of the present disclosure is shown; Figure 4B Show Figure 4A A schematic enlarged view of a portion of the edge area of ​​the circuit board shown.

[0033] Figure 5A A side view of a circuit board according to some embodiments of the present disclosure is shown; Figure 5B A side view of a circuit board according to other embodiments of the present disclosure is shown.

[0034] Figure 6A A schematic top view of a packaged module according to some embodiments of the present disclosure is shown; Figure 6B A schematic partial enlarged view of a package module according to some embodiments of the present disclosure is shown.

[0035] Figures 7A to 10B A schematic diagram of the structure of each step in a method for manufacturing a circuit board according to some embodiments of the present disclosure is shown.

[0036] Figure 10C Schematic plan views of the circuit boards formed after the removal process are shown in some other embodiments. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0038] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0039] Circuit boards are widely used in semiconductor packaging technology, such as in electronic products, specifically in power supply products. As power supply devices and other electronic products develop towards miniaturization, precision, and high power density, higher requirements are placed on product size and other aspects. PCB half-hole technology, due to its high space utilization, has gradually gained widespread application.

[0040] In some examples, a PCB half-hole process can be used to form a half-hole on the edge of the circuit board, followed by copper plating within the half-hole recess for inter-board connection between the PCB and other circuit boards. Generally, the copper plating layer is formed within the half-hole recess and also has a recess. This type of half-hole can be called a copper-plated half-hole. However, when using this type of copper-plated half-hole for inter-board connection, because the copper-plated half-hole has a recess, there is a gap between it and the pads of the other circuit board. Therefore, during circuit board soldering, problems such as cold solder joints and insufficient mechanical strength at the connection are prone to occur, thus affecting the reliability of the connection.

[0041] To address this, this disclosure provides a circuit board that improves the connection reliability of the circuit board. For example, the circuit board of this disclosure includes a main substrate and an edge connection structure. The main substrate has two main surfaces opposite each other in a first direction and an edge region connecting the two main surfaces. The main substrate includes a protrusion and a groove defined by the protrusion in the edge region. The groove is recessed from a first side surface of the protrusion toward the center region of the main substrate in a second direction parallel to the main surfaces of the main substrate. The edge connection structure covers the first side surface of the protrusion and at least one second side surface and is electrically connected to one or more circuit layers of the main substrate. The first side surface is the outermost side surface of the protrusion in the second direction on the main substrate, and the second side surface is the side surface of the protrusion that defines the groove.

[0042] In the circuit board of this disclosure embodiment, the board edge connection structure covers a first side surface and at least one second side surface of the protrusion, such that both the portion of the board edge connection structure covering the first side surface of the protrusion and the portion covering the second side surface of the protrusion can serve as connection surfaces for electrical connections (e.g., soldering) between the circuit board and other components. The board edge connection structure provides a relatively large connection area, thereby improving the connection reliability of the circuit board and providing a reliable connection channel between the circuit board and external components, such as providing a highly reliable power transmission and / or signal transmission channel. In some embodiments, the larger connection area can also improve the high current carrying capacity and heat dissipation efficiency of the board edge connection structure.

[0043] In some embodiments, the board edge connection structure further covers at least one of the first and second surfaces of the protrusion that are opposite each other in the first direction, thereby further increasing the surface area of ​​the board edge connection structure that can be used for connection and further improving the connection reliability of the circuit board.

[0044] Figure 1 A schematic perspective view of a circuit board according to some embodiments of the present disclosure is shown. Figure 2 A schematic top view of a circuit board according to some embodiments of the present disclosure is shown; Figure 3A A schematic plan view of a circuit board according to some embodiments of the present disclosure is shown, for example, along... Figure 1 The plan view intercepted by line II.

[0045] refer to Figure 1 , Figure 2 and Figure 3AIn some embodiments, the circuit board 120 includes a main substrate 100 and an edge connection structure 105. The main substrate 100 has two main surfaces opposite each other in a first direction D1, such as a first main surface 100a and a second main surface 100b. The main substrate 100 has an edge region SR on its side, which connects the first main surface 100a and the second main surface 100b. The edge region SR includes the side edge of the main substrate 100 and a region near the side edge. In some embodiments, the circuit board 120 is a circuit board that can be side-soldered, and may include, for example, the edge connection structure 105 disposed in the edge region SR. The edge connection structure 105 can serve as an external connection port of the circuit board 120 for electrically connecting the circuit board 120 to other components (e.g., other circuit boards).

[0046] In some embodiments, the main substrate 100 includes a protrusion 101 and a recess 102 defined by the protrusion 101 in the edge region SR. For example, the recess 102 is recessed from the first side surface S1 of the protrusion 101 toward the central region of the main substrate 100 in a second direction D2 parallel to the main surface of the main substrate 100. For example, the recess 102 may also be referred to as a lateral recess. The central region of the main substrate 100 refers to the region away from its side edge. In some embodiments, the recess 102 penetrates the main substrate 100 in the first direction D1, that is, extends from the first main surface 100a of the main substrate 100 to the second main surface 100b.

[0047] In some embodiments, the plate edge connection structure 105 covers multiple surfaces of the protrusion 101. For example, as Figure 1 and Figure 3A As shown, the board edge connection structure 105 covers the first side surface S1 and at least one second side surface S2 of the protrusion 101, and is electrically connected to one or more circuit layers 103 of the main substrate 100. The first side surface S1 is the side surface of the protrusion 101 located on the outermost side of the main substrate 100 in the second direction D2, and the second side surface S2 is the side surface of the defining groove 102 of the protrusion 101.

[0048] refer to Figure 1 and Figure 2 In some embodiments, the plate edge connection structure 105 may further cover at least one of the first surface TS and the second surface BS opposite to each other in the first direction D1 of the protrusion 101. It should be understood that in Figure 1 Since the protrusion 101 is covered by the plate edge connection structure 105 and is not visible, the protrusion 101 and its corresponding surface are indicated by dashed lines.

[0049] In some embodiments, the protrusion 101 includes a plurality of protruding sub-parts 101a, which may be arranged along a third direction D3 that is parallel to the main surface of the main substrate 100 and substantially perpendicular to the second direction D2. For example, the protruding sub-parts 101a and the groove 102 may be arranged alternately in the third direction D3.

[0050] For example, each protruding sub-part 101a includes a first side surface S1, one or more second side surfaces S2, and a first surface TS and a second surface BS opposite each other in the first direction D1. In some embodiments, such as Figure 1 and Figure 3A As shown, for the protruding sub-part 101a in the edge region SR that is far from the opposite edge of the main substrate 100 in the third direction D3, the edge connection structure 105 can cover five surfaces of the protruding sub-part 101, the five surfaces including the first side surface S1, two second side surfaces S2, the first surface TS and the second surface BS of the protruding sub-part 101a.

[0051] In some embodiments, such as Figure 3A As shown, for the protruding sub-part 101a near the edge of the main substrate 100 in the board edge region SR, the first side surface S1 and the second side surface S2 of the protruding sub-part 101a are covered by the board edge connection structure 105, while the other side surface S2' of the protruding sub-part 101a opposite to the second side surface S2 is located at the edge of the circuit board and may not be covered by the board edge connection structure 105. The opposing surfaces of the protruding sub-part 101a in the first direction may also be covered by the board edge connection structure 105. In some other embodiments, the side surface S2' of the protruding sub-part 101a may also be covered by the board edge connection structure 105, which is not a limitation of this disclosure.

[0052] It should be understood that, for the sake of simplicity in the diagram, Figure 2 and Figure 3A The dimensions and number of protrusions and grooves located in the plate edge area, as well as the corresponding plate edge connection structure, are specified. Figure 1 The structures shown are not completely identical. This disclosure does not limit the specific dimensions, shapes, and quantities of the protruding parts and grooves, and the plate edge connection structure can be set accordingly based on the setting of the protruding parts and grooves.

[0053] In some embodiments, the edge connection structure is electrically connected to one or more circuit layers of the main substrate, and the one or more circuit layers include circuit layers exposed on one or more of the two main surfaces of the main substrate and the side surfaces of the edge region, and the exposed portions of the circuit layers are connected to the edge connection structure. The edge connection structure is electrically connected to one or more circuit layers of the main structure, thereby serving as an external connection port of the main substrate, such as a power transmission port, signal transmission port, etc.

[0054] refer to Figure 1 , Figure 2 and Figure 3A In some embodiments, one or more circuit layers of the main substrate 100 electrically connected to the edge connection structure 105 include one or more of the following: a circuit layer (not shown) exposed on a first main surface 100a of the main substrate 100, a circuit layer (not shown) exposed on a second main surface 100b of the main substrate 100, and a circuit layer 103 exposed on the side surface of the edge region SR. The edge connection structure 105 is connected to the exposed portion of the corresponding circuit layer.

[0055] For example, the main substrate 100 includes a core layer 10 and a first stacked layer 20 and a second stacked layer 30 located on opposite sides of the core layer 10 in a first direction D1. The first stacked layer 20 and the second stacked layer 30 may include a plurality of alternately stacked insulating layers and circuit layers.

[0056] For example, the top circuit layer in the first stacked layer 20 that is furthest from the core layer 10 can be exposed at the first main surface 100a of the main substrate 100, and the surface of the top circuit layer on the side furthest from the core layer 10 and its side surface can be covered by the board edge connection structure 105, thereby contacting and electrically connecting with the board edge connection structure 105.

[0057] For example, the bottom circuit layer in the second stacked layer 30 that is furthest from the core layer 10 can be exposed at the second main surface 100b of the main substrate 100, and the surface of the bottom circuit layer on the side furthest from the core layer 10 and its side surface can be covered by the board edge connection structure 105, thereby contacting and electrically connecting with the board edge connection structure 105.

[0058] In some embodiments, the circuit layer located in the middle region of the first stacked layer 20 or the second stacked layer 30 in the first direction D1 (i.e., the non-end circuit layer away from the main surface of the main substrate) is, for example... Figure 3A One or more conductive lines DL in the circuit layer 103 shown may extend to the edge region SR and be exposed on the side surface of the main substrate 100, thereby contacting and electrically connecting with the edge connection structure 105. It should be understood that the specific positions, extension directions, and dimensions of the conductive lines in the circuit layer shown in the figure are merely illustrative examples, and this disclosure is not limited thereto.

[0059] In some embodiments, the board edge connection structure includes a plurality of spaced-apart pads, and the gap between adjacent pads is located at the bottom of a recess or on a portion of a first side surface exposing a protrusion. The board edge connection structure includes a plurality of spaced-apart pads, thereby enabling functional partitioning. For example, the plurality of pads in the board edge connection structure may include pads for power transmission and pads for signal transmission, etc. In this document, "pad" generally refers to a contact pad used for electrical connection, and does not limit the method of electrical connection with other components to soldering. For example, pads and other components can be electrically connected in any suitable manner. A pad may also be referred to as a connection terminal.

[0060] In some embodiments, the protrusions of the main substrate include a plurality of protruding sub-parts arranged in a third direction parallel to the main surface of the main substrate and perpendicular to the second direction. The board edge connection structure includes a plurality of first pads arranged at intervals in the third direction and respectively covering the plurality of protruding sub-parts. The plurality of first pads respectively cover the plurality of protruding sub-parts, thereby making each first pad have a large connection area and high connection reliability.

[0061] Continue to refer to Figures 1 to 3A For example, the board edge connection structure 105 includes a plurality of first pads 105a spaced apart on a third direction D3. The plurality of first pads 105a respectively cover a plurality of protruding sub-parts 101a. For example, the plurality of first pads 105a may be configured one-to-one with the plurality of protruding sub-parts 101a, each first pad 105a covering a first side surface S1 and at least one second side surface S2 of the corresponding protruding sub-part 101a, and may also cover a first surface TS and / or a second surface BS of the protruding sub-part 101a. In some embodiments, the first pad 105a covering a single protruding sub-part 101a may be a continuous single pad. However, this disclosure is not limited thereto. In alternative embodiments, the first pad 105a covering a single protruding sub-part 101a may also include a plurality of spaced-apart sub-pads.

[0062] In some embodiments, a plurality of first pads are isolated from each other by insulating isolation grooves located in recesses in the main substrate and including at least pad openings between adjacent first pads. By providing insulating isolation grooves to isolate the plurality of first pads in the board edge connection structure from each other, the insulation performance between adjacent pads can be ensured, functional partitioning can be achieved, and each pad can reliably perform its corresponding transmission function.

[0063] In some embodiments, the recess of the body substrate includes a main recess and an additional recess located between adjacent protrusions among a plurality of protrusions. The additional recess is located in a second direction on one side of the main recess near the central region of the body substrate. The main recess and the additional recess are spatially connected to each other and space adjacent protrusions apart. A plurality of first pads respectively cover the surfaces of the plurality of protrusions defining the main recess, and adjacent first pads are isolated from each other by an insulating isolation trench. The insulating isolation trench includes a pad opening between adjacent first pads and an additional recess, and the pad opening and the additional recess are spatially connected to each other. The insulating isolation trench includes a pad opening and also includes an additional recess of the body substrate, thereby improving the insulation performance of the insulating isolation trench and further ensuring isolation between adjacent first pads.

[0064] For example, the main groove is recessed in the second direction from the first side surface of the protrusion toward the central region of the main substrate and is defined by the second side surface of the adjacent protruding sub-part; the additional groove is further recessed in the second direction from the bottom of the main groove toward the central region of the main substrate and is defined by the third side surface of the adjacent protruding sub-part. For example, the third side surface of the adjacent protruding sub-part is exposed by the plate edge connection structure.

[0065] Figure 3B Show Figure 3A The diagram shows a partial enlarged view of the plate edge area and the plate edge connection structure. It should be understood that, for the sake of brevity, the diagram is intended to be simplified. Figure 3B The line layer is not shown.

[0066] refer to Figure 3A and Figure 3B For example, a plurality of first pads 105a are isolated from each other by an insulating isolation groove 100 located in a recess 102 and including at least a pad opening 105b between adjacent first pads 105a.

[0067] In some embodiments, the groove 102 in the edge region SR of the main substrate 100 includes a main groove 102a and an additional groove 102b; the additional groove 102b is located on the side of the main groove 102a near the center region of the main substrate 100 in the second direction D2, and is spatially connected to the main groove 102a. For example, adjacent protruding sub-parts 101a can be spaced apart from each other by the main groove 102a and the additional groove 102b.

[0068] For example, the main groove 102a may be generally a semi-hole structure; the auxiliary groove 102b is connected to the bottom of the main groove 102a. In this document, the bottom of the groove refers to the portion of it that is away from the first side of the protrusion in the second direction and close to the central region of the main substrate.

[0069] In some embodiments, the second side surface S2 of the protruding sub-part 101a defines the main recess 102a, and the protruding sub-part 101a also has a third side surface S3 defining the additional recess 102b. A plurality of first pads 105a respectively cover the second side surface S2 of the protruding sub-parts 101a defining the main recess 102a, and adjacent first pads 105a are isolated from each other by an insulating isolation trench IO. For example, the insulating isolation trench IO may include a pad opening 105b between adjacent first pads 105a, and also includes an additional recess 102b between adjacent protruding sub-parts 101a. For example, the additional recess 102b is located on the side of the pad opening 105b near the center region of the main substrate 100 in the second direction D2, and is spatially connected to the pad opening 105b, thereby forming the insulating isolation trench IO together with the pad opening 105b.

[0070] In some embodiments, the main groove 102a is recessed in the second direction D2 from the first side surface S1 of the protrusion 101 toward the central region of the main substrate 100 and is defined by the second side surface S2 of the adjacent protrusion 101a; the additional groove 102b is further recessed in the second direction D2 from the bottom of the main groove 102a toward the central region of the main substrate 100 and is defined by the third side surface S3 of the adjacent protrusion 101a.

[0071] In some embodiments, the third side surface S3 of adjacent protruding sub-parts 101a is exposed by the board edge connection structure 105, that is, the board edge connection structure 105 does not cover the third side surface S3 of each protruding sub-part 101a. In some embodiments, the additional groove 102b exposes the dielectric layer of the main substrate 100. For example, the additional groove 102b may not expose the circuit layer of the main substrate 100.

[0072] In some embodiments, the width of the main body groove in the third direction is greater than the width of the insulating isolation groove in the third direction. In some embodiments, based on the process flow, the main body groove has a larger width, thereby ensuring that the plate edge connection structure has a portion covering the second side surface of the protrusion, and thus has a larger connection area.

[0073] In some embodiments, the main groove has a first depth in the second direction, the additional groove has a second depth in the second direction, and the overall depth of the groove in the second direction is the sum of the first depth and the second depth; the first depth is greater than the second depth. In some embodiments, the additional groove has a smaller depth, thereby improving the isolation performance of the insulating trench while avoiding the removal of too much of the main substrate, for example, preventing the circuit layers in the main substrate from being exposed in the additional groove.

[0074] In some embodiments, the width of the insulating groove in the third direction is 25% to 100% of the depth of the recess in the second direction. Setting the ratio of the width of the insulating groove to the depth of the recess within the above range ensures the insulating performance of the insulating groove. Here, the depth of the recess may be the depth of its main recess or the overall depth of the recess.

[0075] refer to Figure 3B In some embodiments, the size of the main groove 102a is larger than the size of the auxiliary groove 102b. For example, the width w1 of the main groove 102a in the third direction D3 is greater than the width w2 of the auxiliary groove 102b in the third direction D3. The width of each groove may be its average width or its maximum width. For example, the main groove 102a has a first depth h1 in the second direction D2, and the auxiliary groove 102b has a second depth h2 in the second direction D2. The overall depth of the groove 102 in the second direction D2 is the sum of the depths of the first depth h1 and the second depth h2. For example, the first depth h1 is greater than the second depth h2.

[0076] In some embodiments, the width of the pad opening 105b between adjacent first pads 105a in the board edge connection structure 105 in the third direction D3 may be approximately equal to the width of the additional groove 102b in the third direction D3. For example, the surface defining the pad opening 105b of the first pad 105a may be connected to and substantially coplanar with the third side surface S3 of the corresponding protruding sub-part 101a.

[0077] The depth of the pad opening 105b in the second direction D2 is approximately equal to the thickness of the first pad 105a, i.e., the thickness of the board edge connection structure 105. In some embodiments, the thickness T of the board edge connection structure 105 ranges from about 20 micrometers (μm) to about 50 micrometers. It should be understood that the thickness T of the board edge connection structure 105 refers to the thickness in a direction parallel to the main surface of the main substrate and perpendicular to the extension direction of the board edge connection structure 105.

[0078] In some embodiments, the additional groove 102b between the pad opening 105b and the corresponding protruding sub-part 101a is spatially connected to each other and together constitutes an insulating isolation groove 10. The depth h3 of the insulating isolation groove 10 in the second direction D2 is approximately equal to the sum of the depths of the pad opening 105b and the additional groove 102b in the second direction D2. The width of the insulating isolation groove 10 in the third direction D3 is approximately equal to the width w2 of the pad opening 105b and the additional groove 102b.

[0079] In some embodiments, the width w2 of the insulating groove IO can be set based on the voltage level carried by the corresponding first pad. For example, the voltage level specifies the minimum creepage distance between adjacent pads, and the width w2 of the insulating groove IO must be greater than or equal to this minimum creepage distance. Taking the voltage level of the first pad 105a as 50V as an example, the width of the insulating groove IO can be greater than or equal to about 0.3mm; the width of the insulating groove IO can be set and adjusted based on product design, voltage requirements, etc.

[0080] In some embodiments, the insulating groove IO has a sufficient width to prevent solder from filling the insulating groove and causing a short circuit when the first pad of the circuit board is soldered to other components. For example, the width W2 of the insulating groove IO can be 25% to 100% of the depth h1 of the semi-hole groove (e.g., the main groove 102a). For example, when the width of the insulating groove IO is about 0.3 mm, the depth h1 of the main groove 102a can be about 0.3 mm to 1.2 mm.

[0081] In some embodiments, the width of the groove gradually decreases as the groove moves away from the first side surface of the protrusion in a second direction.

[0082] For example, the width of the main groove gradually decreases as the main groove moves away from the first side surface of the protrusion in the second direction. In some embodiments, setting the width of the main groove to gradually decrease can make the second side surface of the protrusion generally arcuate or inclined, and the first pad also has a corresponding arcuate or inclined surface. This can reduce the rise height of the solder on the arcuate surface during soldering, thereby avoiding short circuits between solders connecting adjacent pads.

[0083] For example, the width of the insulating groove gradually decreases as it moves away from the main groove in the second direction. The structure of the insulating groove with a gradually narrowing width also achieves a similar technical effect to that described above regarding the main groove.

[0084] Continue to refer to Figure 3A and Figure 3B For example, the width of the main recess 102a gradually decreases as it moves away from the first side surface S1 of the protrusion 101 in the second direction D2. The main recess 102a may communicate with the insulating groove 10 at its minimum width. For example, the width of the insulating groove 10 may also gradually decrease as it moves away from the main recess 102a in the second direction D2. In some embodiments, the insulating groove 10 may also have a substantially uniform width, provided that the insulating groove 10 has sufficient isolation performance.

[0085] Figure 4A A schematic plan view of a circuit board according to other embodiments of the present disclosure is shown; Figure 4B Show Figure 4A A schematic enlarged view of the central plate edge area and the plate edge connection structure. Figure 4A and Figure 4B The circuit board shown is Figure 3A and Figure 3B Similar to the one shown, the difference lies in the structure of the groove 102.

[0086] refer to Figure 4A and Figure 4B In some embodiments, the groove 102 may have a semi-perforated structure, for example, it may be approximately semi-circular, semi-elliptical, or arc-shaped. In this embodiment, the groove 102 and... Figure 3A and Figure 3B The main groove 102a shown is substantially the same, and the groove 102 in this embodiment may not include... Figure 3B The additional groove 102b is shown.

[0087] For example, the board edge connection structure 105 lining a portion of the surface of the recess 102 and having pad openings 105b. For example, the pad openings 105b are located at the bottom of the recess 102, exposing a portion of the surface of the main substrate 100, such as a portion of the surface of the dielectric layer in the main substrate 100. A plurality of first pads 105a are isolated from each other by the pad openings 105b. In some embodiments, the insulating isolation trench 10 may consist only of the pad openings 105b; for example, the orthographic projection of the insulating isolation trench 100 onto a reference plane parallel to the main surface of the main substrate may lie within the orthographic projection of the semi-hole recess 102 onto the reference plane. The depth of the insulating isolation trench 100 in the second direction D2 may be approximately equal to the depth of the pad openings 105b in the second direction D2, i.e., approximately equal to the thickness of the board edge connection structure 105.

[0088] In this embodiment, the dimensions such as the width and depth of the groove 102 are similar to those of the main groove 102a in the aforementioned embodiment, and the dimensions (e.g., width) of the insulating isolation groove IO are similar to those in the aforementioned embodiment. For example, the ratio of the width of the insulating isolation groove IO to the depth of the groove 102 can also be in the range of 25% to 100%.

[0089] Figure 5A A side view of a circuit board according to some embodiments of the present disclosure is shown, for example, a corresponding Figure 1 A side view presented from the perspective of the edge area of ​​the circuit board in the second direction. Figure 5B A side view of a circuit board according to other embodiments of this disclosure is shown.

[0090] refer to Figure 1 and Figure 5AIn some embodiments, the plurality of first pads 105a of the board edge connection structure 105 correspond one-to-one with the plurality of protruding sub-parts 101a of the protrusion 101, and each first pad 105a may be a continuous pad, and the gap area (i.e., pad opening) between adjacent first pads 105a exposes the bottom of the groove 102.

[0091] In some embodiments, one or more of the plurality of first pads each include a plurality of sub-pads, the plurality of sub-pads covering the same protruding sub-part and spaced apart from each other in a first direction, the gap region between adjacent sub-pads exposing a portion of the first side surface of the protruding sub-part. Setting the first pads to include a plurality of sub-pads allows the board edge connection structure to include more pads, for example, enabling more functional partitions.

[0092] refer to Figure 5B For example, one or more first pads 105a may each include multiple sub-pads SP, and the multiple sub-pads SP may cover the same protruding sub-part 101a. In the first pads 105a corresponding to the same protruding sub-part 101a, the multiple sub-pads SP are arranged at intervals with each other, for example, at intervals in the first direction D1, and the gap area between adjacent sub-pads SP exposes a portion of the first side surface S1 of the protruding sub-part 101a.

[0093] In some embodiments, the board edge connection structure 105 includes various types of conductive pads, such as signal transmission pads, power transmission pads, or combinations thereof.

[0094] This disclosure provides a packaging module including a circuit board as described in any of the above embodiments, wherein the circuit board serves as a first circuit board of the packaging module; and a second circuit board, which is soldered to the edge connection structure of the first circuit board through a solder layer, and then electrically connected to one or more circuit layers of the first circuit board through the edge connection structure.

[0095] The packaging module of this disclosure embodiment has the same technical effects as described above regarding the circuit board. By setting the relevant configuration of the board edge connection structure of the first circuit board, the connection reliability between the first circuit board and the second circuit board can be improved, thereby improving the reliability of the packaging module and the device performance.

[0096] Figure 6A A schematic top view of a packaged module according to some embodiments of the present disclosure is shown; Figure 6B Show Figure 6A A schematic enlarged view of region A in the encapsulation module.

[0097] refer to Figure 6A and Figure 6BIn some embodiments, the packaging module 500 includes a circuit board 120 and a circuit board 220, where the circuit board 120 may be any of the circuit boards described in the above embodiments. For example, the circuit board 120 and the circuit board 220 may be referred to as the first circuit board and the second circuit board, respectively, or vice versa.

[0098] In some embodiments, circuit boards 120 and 220 are electrically connected by soldering to each other. For example, circuit board 220 can be soldered to the edge connection structure 105 of circuit board 120 via solder layer 180, and then electrically connected to one or more line layers of circuit board 120 via edge connection structure 105.

[0099] In some embodiments, at least a portion of the solder layer is located on the side of the protrusion of the first circuit board away from the central region of the first circuit board, and is located between the board edge connection structure and the second circuit board.

[0100] In some embodiments, the corner portion of the board edge connection structure of the first circuit board is covered by the solder layer, and the corner portion of the board edge connection structure covers the junction area of ​​the first side surface and the second side surface of the protrusion of the main substrate.

[0101] In some embodiments, based on the configuration of the main substrate and the edge connection structure of the first circuit board, the solder layer is used to weld the edge connection structure and the second circuit board. This increases the contact area between the solder layer and the connection structures of each circuit board, thereby reducing the risk of cold solder joints and improving the soldering yield. Simultaneously, because the edge connection structure is tightly bonded to the second circuit board through the solder layer, it effectively enhances the resistance to mechanical shock and thermal cycling fatigue at the connection points, preventing solder joint cracking or peeling caused by vibration and thermal expansion and contraction. This significantly improves the structural stability and environmental adaptability of the packaged module during long-term operation.

[0102] refer to Figure 6A and Figure 6B For example, at least a portion of the solder layer 180 is located on the side of the protrusion 101 of the circuit board 120 away from the center region of the circuit board 120 in the second direction D2, and is located between the board edge connection structure 105 and the circuit board 220.

[0103] For example, the board edge connection structure 105 includes a first pad portion covering a first side surface S1 of the protrusion 101 and a second pad portion covering a second side surface S2 of the protrusion 101. The first pad portion is located in the second direction D2 between the first side surface S1 of the protrusion 101 and the solder layer 180, and the second pad portion is located in the groove 102. The first pad portion and the second pad portion are connected to each other, and the intersection of the two is the corner portion 105c of the board edge connection structure 105. In some embodiments, the solder layer 180 covers the first pad portion of the board edge connection structure 105 and may further extend into the groove 102, covering a portion of the second pad portion.

[0104] In some embodiments, the corner portion 105c of the first pad 105a in the board edge connection structure 105 of the circuit board 120 (i.e., the junction of the first pad portion and the second pad portion) is covered by the solder layer 180, and the corner portion 105c of the board edge connection structure 105 covers the junction area of ​​the first side surface S1 and the second side surface S2 of the protrusion 101 of the main substrate.

[0105] In some embodiments, the solder layer 180 includes a plurality of solder portions 180a, which correspond one-to-one with a plurality of first pads 105a of the board edge connection structure 105 and are spaced apart.

[0106] In some embodiments, a portion of the solder layer is located within the groove, and the thickness of that portion of the solder layer in the second direction is less than the depth of the groove in the second direction. This ensures that multiple solder joints of the solder layer are spaced apart from each other, preventing adjacent solder joints from connecting within the groove and causing a short circuit between adjacent pads.

[0107] For example, the thickness of the portion of solder layer 180 located in the groove 102 in the second direction D2 is less than the depth of groove 102 in the second direction D2, for example, less than the depth of the main groove in the second direction D2 or the overall depth of groove 102. This thickness of solder layer 180 being less than the depth of the main groove prevents solder layer 180 from filling the insulating isolation groove 10. In other embodiments, the thickness of the portion of solder layer 180 located in the groove 102 may be thicker. In this case, since the insulating isolation groove 10 has sufficient dimensions, such as sufficient width, even if a portion of solder layer 180 fills the insulating isolation groove 10, adjacent solder portions 180a can be spaced apart from each other in the insulating isolation groove 10, thereby preventing adjacent solder portions 180a from connecting together and causing a short circuit.

[0108] In some embodiments, the edge connection structure of the first circuit board includes a plurality of first pads, and the second circuit board includes a plurality of second pads. The plurality of first pads are respectively disposed corresponding to and soldered to the plurality of second pads. In the correspondingly disposed first and second pads, the surface dimension of the second pad facing the first pad is larger than the surface dimension of the first pad facing the second pad. By setting the pad size of the second circuit board to be larger than the pad size of the first circuit board, it is beneficial to achieve sufficient contact between the solder layer and the edge connection structure of the first circuit board, for example, allowing the solder layer to cover multiple side surfaces of the edge connection structure.

[0109] Continue to refer to Figure 6A and Figure 6B For example, circuit board 220 includes a pad layer 205, and the pad layer 205 includes a plurality of second pads 205a spaced apart. The plurality of second pads 205a are respectively disposed corresponding to a plurality of first pads 105a and soldered to each other. For example, the plurality of second pads 205a of circuit board 220, the plurality of first pads 105a of circuit board 120, and the plurality of solder portions 180a of solder layer 180 are all disposed in a one-to-one correspondence.

[0110] In some embodiments, in the correspondingly configured first pad 105a and second pad 205a, the surface dimension of the second pad 205a facing the first pad 105a is larger than the surface dimension of the first pad 105a facing the second pad 205a. The surface dimension of each pad may be the width, area, etc. of the surface of the pad used for soldering in a direction parallel to the first side surface S1 of the circuit board 120. In some embodiments, setting the surface dimension of the second pad to be larger than that of the first pad can facilitate the solder layer extending into the groove to cover the corner of the first pad during soldering, thereby improving the stability of soldering.

[0111] For example, the width w4 of the surface of the second pad 205a (e.g., the solderable surface) in the third direction D3 is greater than the width w3 of the first pad 105a in the third direction D3.

[0112] Continue to refer to Figure 6A and Figure 6BIn some embodiments, the circuit board 220 includes a main substrate 200, which may include, for example, a core layer and a stacked layer. A pad layer 205 is located on one side of the main substrate 200, and each second pad 205a is electrically connected to a corresponding circuit layer (not shown) in the main substrate 200. The circuit board 220 may also include a solder mask layer 206 having solder mask openings to expose at least a portion of the surface of the second pad 205a. For example, the surface dimension of the second pad 205a near the first pad 105a mentioned above may be the dimension of the surface of the second pad 205a exposed by the solder mask layer 206. In some embodiments, the edges of the second pad 205a may be covered by the solder mask layer 206, but this disclosure is not limited thereto.

[0113] In some embodiments, the edge region of the first circuit board 120 facing the second circuit board 220 may not be provided with a solder mask layer, that is, no solder mask layer is provided around the first pad 105a.

[0114] This disclosure provides a method for manufacturing a circuit board, comprising: providing a main substrate having two main surfaces opposite each other in a first direction and an edge region connecting the two main surfaces; forming a protrusion and a groove defined by the protrusion in the edge region of the main substrate; the groove being recessed from a first side surface of the protrusion toward a central region of the main substrate in a second direction parallel to the main surfaces of the main substrate; and forming an edge connection structure in the edge region to cover the first side surface of the protrusion and at least one second side surface, the first side surface being the outermost side surface of the protrusion in the second direction, and the second side surface being the side surface of the protrusion defining the groove.

[0115] The circuit board manufacturing method of this disclosure has the same technical effects as described above regarding the circuit board, and will not be repeated here.

[0116] In some embodiments, forming the protrusion, the groove, and the edge connection structure includes: forming an initial groove with a semi-hole structure in the edge region of the main substrate using a semi-hole forming process, and forming an initial protrusion; performing an edge electroplating process to form a conductive material layer in the edge region of the main substrate, the conductive material layer covering the initial protrusion and the initial groove; and performing a removal process to remove at least the portion of the conductive material layer covering the bottom of the initial groove, and forming an insulating isolation groove that divides the conductive material layer into a plurality of spaced-apart first pads; wherein the initial groove forms at least a portion of the groove, the initial protrusion forms at least a portion of the protrusion, and the plurality of first pads together constitute the edge connection structure.

[0117] In some embodiments, the removal process further removes the portion of the main substrate exposed by the bottom of the initial groove and forms an additional groove in the main substrate, the initial groove serving as the main groove and together with the additional groove constituting the groove, the initial protrusion and the portion of the main substrate defining the additional groove constituting the protrusion.

[0118] In some embodiments, the method of manufacturing the circuit board further includes: performing an additional removal process to remove a portion of the first pad and divide the first pad into a plurality of sub-pads spaced apart in the first direction.

[0119] Figures 7A to 10B The diagram shows a structural schematic of each step in a method for manufacturing a circuit board according to some embodiments of the present disclosure, wherein... Figures 7A to 10A A three-dimensional diagram of the corresponding structure is shown. Figures 7B to 10B A plan view of the corresponding structure is shown, for example, a plan view taken along the middle layer of the corresponding three-dimensional view.

[0120] refer to Figure 7A and Figure 7B In some embodiments, a main substrate 100 is provided, having a first main surface 100a and a second main surface 100b opposite each other in a first direction D1, and a board edge region SR connecting the two main surfaces and located at the edge of the substrate. For example, the main substrate 100 may be a printed circuit board and may include a core layer 10, a first stacked layer 20, and a second stacked layer 30.

[0121] For example, core layer 10 includes an insulating layer and conductive vias penetrating the insulating layer. First stacked layer 20 and second stacked layer 30 each include stacked insulating layers and conductive wiring layers, the conductive wiring layers may be or include copper plating, and may include one or more conductive lines. In some embodiments, circuit board 20 may further include a solder mask layer (not shown) located on the side of each stacked layer away from the core layer, the solder mask layer covering a portion of the surface of the conductive wiring layer on the top layer.

[0122] In some embodiments, the portion of the circuit layer furthest from the core layer 10 in the board edge region SR of the first stacked layer 20 and / or the second stacked layer 30 may be exposed by solder mask for subsequent connection to the board edge connection structure. For example, the portion of the circuit layer 130' furthest from the core layer 10 in the board edge region SR of the first stacked layer 20 may be exposed. Figure 7BThe diagram shows that the circuit layer 103 in the first stacked layer 20 extends to the edge region SR and can be exposed at the side of the main substrate. In some embodiments, the edge region SR may not have a solder mask layer, thereby exposing one or more circuit layers of the main substrate and subsequent edge connection structures in the edge region. This provides an unshielded conductive contact surface for subsequent edge conductive connections, while avoiding copper plating discontinuities or insulation residues caused by solder mask opening errors, ensuring the integrity and process consistency of the electrical connection area.

[0123] refer to Figure 8A and Figure 8B In some embodiments, an initial groove 102' and an initial protrusion 101' with a half-hole structure are formed in the edge region SR of the main substrate 100 using a half-hole forming process. For example, the half-hole forming process may include removing a portion of the main substrate 100 in the edge region SR to drill a through hole forming a full-through hole in the main substrate 100 in a first direction D1, and then precisely cutting along the edge using CNC contour milling to remove the lower half of the hole in the second direction D2 away from the center region of the main substrate 100, leaving the upper half of the hole within the main substrate 100, forming an outward-facing half-hole structure. It should be understood that after the initial groove 102' is formed, other portions of the main substrate 100 protrude from the initial groove 102' and naturally form the initial protrusion 101'. In other words, the protrusion and the groove define each other; the formation of the groove defines the protrusion, and the side of the protrusion defines the surface of the groove.

[0124] In some embodiments, the initial groove 102' formed by the half-hole forming process can divide the circuit layer 103' into multiple segments spaced apart from each other. For example, these multiple segments of the circuit layer 103' can be broken at the bottom of the initial groove 102' and corresponding to a plurality of subsequently formed first pads. In other embodiments, the circuit layer 103' may not be broken at this step and can be broken in a subsequent process of forming an insulating isolation trench.

[0125] refer to Figure 9A and Figure 9B A conductive material layer 105' is formed in the edge region SR of the main substrate 100 to cover the initial protrusion 101' and the initial groove 102', and to cover and electrically connect one or more circuit layers exposed in the edge region SR. For example, the conductive material layer 105' covers multiple side surfaces of the initial protrusion 101' and their opposite surfaces in the first direction D1, and lining the surface of the initial groove 102'.

[0126] For example, a conductive material layer 105' can be formed by an edge electroplating process. The conductive material layer 105' may include a metal material such as copper, for example, a copper plating layer. In some embodiments, the conductive material layer 105' may be substantially conformal to the contour of the edge region SR of the main substrate 100. For example, by performing an edge copper plating process, after drilling and milling and surface cleaning (including desmearing, activation, and chemical copper plating), a continuous and dense copper layer is simultaneously deposited on the outer copper foil, the inner wall of the semi-hole, and the sidewall of the board edge of the PCB by whole-board electroplating or partial electroplating, achieving low-impedance electrical continuity between the board edge and the inner layer circuitry, forming a fully conductive edge, constructing a reliable path for power and signal transmission, and improving high current carrying capacity and heat dissipation efficiency.

[0127] refer to Figure 9A and Figures 9B to 10A and Figure 10B In some embodiments, a removal process is performed to remove at least the portion of the conductive material layer 105' covering the bottom of the initial groove 102', forming an insulating isolation trench 10. The insulating isolation trench 10 breaks the conductive material layer 105' and divides it into a plurality of spaced-apart conductive sublayers. Each conductive sublayer serves as a first pad 105a, and adjacent first pads 105a are isolated from each other by the insulating isolation trench 10. After the removal process, the remaining portion of the conductive material layer 105' forms the board edge connection structure 105. That is, the insulating isolation trench 100 divides the conductive material layer 105' into a plurality of spaced-apart first pads 105a, and the plurality of first pads 105a together constitute the board edge connection structure 105.

[0128] In some embodiments, the removal process removes a portion of the conductive material layer 105' and forms a pad opening located at the bottom of the initial groove, exposing a portion of the surface of the main substrate. The removal process then further removes the portion of the main substrate exposed at the bottom of the initial groove, forming an additional groove in the main substrate. In this embodiment, the initial groove 102' serves as the main groove 102a and together with the additional groove 102b, constitutes groove 102. The initial protrusion 101' and the portion of the main substrate 100 defining the additional groove 102b together constitute protrusion 101. In some embodiments, after forming the pad opening in the conductive material layer 105', further removing a portion of the main substrate 100 to form the additional groove 102b ensures that the conductive material layer 105' is completely disconnected, thereby ensuring insulation performance between adjacent first pads 105a.

[0129] Figure 10C Schematic plan views of the circuit boards formed after the removal process are shown in some other embodiments.

[0130] refer to Figure 10CIn other embodiments, the removal process may only remove the portion of the conductive material layer 105' located at the bottom of the initial groove. If the pad openings formed in the conductive material layer 105' can isolate adjacent pads, the removal process may also not further remove a portion of the main substrate 100, thus avoiding the formation of additional grooves, and the insulating isolation trench may only include the pad openings. In this embodiment, the initial groove 102' and the initial protrusion 101' are also the groove 102 and protrusion 101 in the final structure.

[0131] In some embodiments, the removal process may include high-precision CNC milling to precisely remove the copper layer at the bottom of the initial groove, or further milling away a portion of the main substrate surface layer, thereby forming an insulating isolation groove that penetrates to the dielectric layer. This blocks electrical connections between adjacent pads and prevents electrical connections between the circuit layer and the conductive material layer on the side of the main substrate near the bottom of the groove, ensuring that only the top of the groove is covered by the conductive connection layer, thus achieving functional partitioning. In some embodiments, the cutting depth and edge cleanliness can be strictly controlled in the removal process to avoid copper shavings residue and ensure that the insulating isolation groove meets the creepage distance and withstand voltage requirements of relevant standards, thereby constructing a highly reliable board edge connection structure.

[0132] In some embodiments, the removal process described above involves removing the conductive material layer 105' along the first direction D1 (e.g., milling) to form an insulating isolation groove IO extending along the first direction D1.

[0133] In some embodiments, after a plurality of first pads 105a are formed by a removal process, an additional removal process may be performed to remove portions of one or more first pads 105a and divide the respective first pads 105a into a plurality of sub-pads spaced apart in a first direction D1.

[0134] For example, along Figure 10A The removal path RL shown is subjected to an additional removal process, thereby separating each first pad 105a into a partition with... Figure 5B The two sub-pads SP are shown. In some embodiments, the additional removal process, in addition to removing a portion of the conductive material of the first pad 105a, may also remove a portion of the protrusion 101. For example, the protruding sub-part 101a may be divided into a plurality of protruding portions arranged in the first direction D1. This removal process forms an isolation groove between the plurality of protruding portions to isolate the plurality of sub-pads SP arranged in the first direction D1 from each other. At this time, the portion of the main substrate exposed in the gap area between the two sub-pads SP in the first direction D1 may protrude slightly relative to the adjacent groove, or it may not protrude. For ease of correspondence with the terminology of the aforementioned steps, this portion of the main substrate is still referred to as the protruding sub-part.

[0135] In this embodiment, by setting the aforementioned board-edge connection structure in the circuit board, control signals, feedback signals, and high-current power paths on the circuit board can be directly transmitted to other components such as another circuit board through the board-edge connection structure, realizing bidirectional and efficient interaction of signals and power. This eliminates the space occupation and signal integrity bottlenecks caused by traditional connectors, pin headers, or flexible cables, providing structural support for packaged modules (e.g., power modules) to achieve higher power density and better thermal management within a limited volume. For example, the pads of the board-edge connection structure in this embodiment can be used to carry large currents from 500 amps (A) to 600 A. The current value can be adjusted based on the pad area, and the pad area can also be designed based on the required current value. Furthermore, since the board-edge connection structure of the first circuit board forms a surface contact with the pads of the second circuit board through the solder layer, rather than a traditional point contact or line contact, the solder can more fully wet and fill the interface gaps during the soldering process, significantly reducing the risk of cold solder joints or false solder joints caused by insufficient solder, porosity, or oxidation, and greatly improving the soldering yield. Meanwhile, due to the tight bonding between the first and second pads, this structure effectively enhances the resistance to mechanical shock and thermal cycling fatigue at the connection points between circuit boards, avoiding solder joint cracking or peeling caused by vibration and thermal expansion and contraction. This significantly improves the structural stability and environmental adaptability of the entire package module (e.g., power system) during long-term operation.

[0136] The following points need to be explained:

[0137] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0138] (2) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure can be combined with each other.

[0139] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A circuit board, comprising: The main substrate has two main surfaces opposite each other in a first direction and a plate edge region connecting the two main surfaces. The main substrate includes a protrusion and a groove defined by the protrusion in the plate edge region. The groove is recessed from a first side surface of the protrusion toward the center region of the main substrate in a second direction parallel to the main surfaces of the main substrate. as well as The board edge connection structure covers the first side surface and at least one second side surface of the protrusion and is electrically connected to one or more circuit layers of the main substrate. The first side surface is the side surface of the protrusion located on the outermost side of the main substrate in the second direction, and the second side surface is the side surface of the protrusion that defines the groove.

2. The circuit board of claim 1, wherein the board edge connection structure further covers at least one of the first surface and the second surface of the protrusion opposite to each other in the first direction.

3. The circuit board according to claim 1, wherein the one or more circuit layers include circuit layers exposed on one or more of the two main surfaces of the main substrate and the side surfaces of the board edge region, and the exposed portions of the circuit layers are connected to the board edge connection structure.

4. The circuit board according to claim 1, wherein the board edge connection structure includes a plurality of spaced pads, and the gap area between adjacent pads is located at the bottom of the groove or exposes a portion of the first side surface of the protrusion.

5. The circuit board according to claim 1, wherein the protrusion includes a plurality of protruding sub-parts arranged in a third direction parallel to the main surface of the main substrate and perpendicular to the second direction, and the board edge connection structure includes a plurality of first pads arranged at intervals in the third direction and respectively covering the plurality of protruding sub-parts.

6. The circuit board of claim 5, wherein the plurality of first pads are isolated from each other by an insulating isolation groove, the insulating isolation groove being located in the groove and including at least a pad opening between adjacent first pads.

7. The circuit board of claim 5, wherein the groove comprises a main groove and an additional groove located between adjacent protrusions in the plurality of protrusions, the additional groove being located on one side of the main groove near the central region of the main substrate in the second direction, the main groove and the additional groove being spatially connected to each other and spacing adjacent protrusions apart; The plurality of first pads respectively cover the surfaces of the plurality of protruding sub-parts that define the main body groove, and adjacent first pads are isolated from each other by an insulating isolation groove, the insulating isolation groove including a pad opening between adjacent first pads and the additional groove, and the pad opening and the additional groove are spatially connected to each other.

8. The circuit board of claim 7, wherein the main body groove is recessed in the second direction from the first side surface of the protrusion toward the central region of the main substrate, and is defined by the second side surface of the adjacent protrusion sub-parts; The additional groove is recessed further toward the central region from the bottom of the main groove in the second direction, and the additional groove is defined by the third side surface of the adjacent protruding sub-part.

9. The circuit board of claim 8, wherein the third side surface of the adjacent protruding sub-parts is exposed by the board edge connection structure.

10. The circuit board according to claim 8, wherein The width of the main body groove in the third direction is greater than the width of the insulating groove in the third direction.

11. The circuit board according to claim 8, wherein The main groove has a first depth in the second direction, the additional groove has a second depth in the second direction, and the overall depth of the groove in the second direction is the sum of the first depth and the second depth; The first depth is greater than the second depth.

12. The circuit board according to claim 7, wherein The width of the main groove gradually decreases as the main groove moves away from the first side surface of the protrusion in the second direction.

13. The circuit board of claim 12, wherein the width of the insulating isolation groove gradually decreases as the insulating isolation groove moves away from the main body groove in the second direction.

14. The circuit board according to any one of claims 6-13, wherein The width of the insulating groove in the third direction is 25% to 100% of the depth of the groove in the second direction.

15. The circuit board according to any one of claims 5-13, wherein One or more of the plurality of first pads each include a plurality of sub-pads, the plurality of sub-pads covering the same protruding sub-part and spaced apart from each other in the first direction, the gap area between adjacent sub-pads exposing a portion of the first side surface of the protruding sub-part.

16. The circuit board according to any one of claims 1-13, wherein the board edge connection structure includes at least one of signal transmission pads and power transmission pads.

17. A packaging module, comprising: The circuit board as described in any one of claims 1-16, wherein the circuit board serves as the first circuit board of the packaging module; as well as The second circuit board is soldered to the edge connection structure of the first circuit board through a solder layer, and then electrically connected to one or more circuit layers of the first circuit board through the edge connection structure.

18. The packaging module of claim 17, wherein at least a portion of the solder layer is located on the side of the protrusion of the first circuit board away from the central region of the first circuit board, and is located between the board edge connection structure and the second circuit board.

19. The packaging module of claim 18, wherein the corner portion of the board edge connection structure of the first circuit board is covered by the solder layer, and the corner portion of the board edge connection structure covers the junction area of ​​the first side surface and the second side surface of the protrusion of the main substrate.

20. The packaging module of claim 19, wherein a portion of the solder layer is located within the groove, and the thickness of the portion of the solder layer in the second direction is less than the depth of the groove in the second direction.

21. The packaging module according to any one of claims 17-20, wherein the board edge connection structure of the first circuit board includes a plurality of first pads, the second circuit board includes a plurality of second pads, the plurality of first pads are respectively correspondingly disposed with the plurality of second pads and soldered to each other; wherein in the correspondingly disposed first pads and second pads, the surface dimension of the second pad facing the first pad is greater than the surface dimension of the first pad facing the second pad.

22. A method for manufacturing a circuit board, comprising: A main substrate is provided, the main substrate having two main surfaces opposite each other in a first direction and an edge region connecting the two main surfaces, a protrusion and a groove defined by the protrusion are formed in the edge region of the main substrate, the groove being recessed from a first side surface of the protrusion toward the center region of the main substrate in a second direction parallel to the main surfaces of the main substrate. as well as An edge connection structure is formed in the edge region to cover the first side surface and at least one second side surface of the protrusion, wherein the first side surface is the outermost side surface of the protrusion in the second direction on the main substrate, and the second side surface is the side surface of the protrusion that defines the groove.

23. The method of manufacturing a circuit board according to claim 22, wherein forming the protrusion, the groove, and the board edge connection structure comprises: An initial groove with a semi-hole structure is formed in the edge region of the main substrate through a semi-hole forming process, and an initial protrusion is formed. An edge electroplating process is performed to form a conductive material layer in the edge region of the main substrate, the conductive material layer covering the initial protrusion and the initial groove; as well as A removal process is performed to remove at least the portion of the conductive material layer covering the bottom of the initial groove and to form an insulating isolation trench that divides the conductive material layer into a plurality of spaced-apart first pads. The initial groove forms at least a portion of the groove, the initial protrusion forms at least a portion of the protrusion, and the plurality of first pads together constitute the board edge connection structure.

24. The method of manufacturing a circuit board according to claim 23, wherein the removal process further removes the portion of the main substrate exposed by the bottom of the initial groove and forms an additional groove in the main substrate, the initial groove serving as the main groove and together with the additional groove constituting the groove, the initial protrusion and the portion of the main substrate defining the additional groove constituting the protrusion.

25. The method for manufacturing a circuit board according to claim 24, further comprising: An additional removal process is performed to remove a portion of the first pad and divide the first pad into a plurality of sub-pads spaced apart in the first direction.

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