Circuit board structure

Abstract

The present application provides a circuit board structure, which comprises a substrate, a cover circuit ground layer, an insulating structure, a first build-up structure, a top circuit layer, a bottom circuit layer, a first conductive via and a plurality of second conductive vias. The above structure defines a signal transmission structure. An equivalent circuit of the signal transmission structure comprises at least a first equivalent circuit, a second equivalent circuit, a third equivalent circuit and a fourth equivalent circuit, which correspond to different uniform transmission sections respectively. The first equivalent circuit, the second equivalent circuit, the third equivalent circuit and the fourth equivalent circuit are connected in series with each other in accordance with the ABCD transmission matrix series connection principle.

Description

Technical Field

[0001] This invention relates to a substrate structure, and more particularly to a circuit board structure. Background Technology

[0002] In existing circuit boards, coaxial via designs require one or more insulating layers between the inner and outer conductor layers for insulation. These insulating layers are formed through lamination. Consequently, impedance mismatch and electromagnetic interference (EMI) shielding gaps appear at the ends of the coaxial via, affecting high-frequency signal integrity. Furthermore, in coaxial via designs, the two ends of the signal path and the two ends of the ground path are located on different planes, and noise interference cannot be reduced. Summary of the Invention

[0003] This invention relates to a circuit board structure that can effectively transmit high-frequency and high-speed signals, reduce noise interference, and thus have better signal integrity.

[0004] According to an embodiment of the present invention, a circuit board structure includes a substrate, a wrap-around ground layer, an insulating structure, a first add-on structure, a top circuit layer, a bottom circuit layer, a first conductive via, and a plurality of second conductive vias. The substrate has a first surface and a second surface opposite to the first surface, wherein the substrate includes an opening penetrating the substrate. The wrap-around ground layer is disposed on the inner wall of the opening in the substrate. The insulating structure is disposed in the opening in the substrate. The first add-on structure is disposed on the first surface of the substrate. The top circuit layer is disposed on the first add-on structure, wherein the top circuit layer includes a first top circuit layer and a second top circuit layer. The bottom circuit layer is disposed on the second surface of the substrate, wherein the bottom circuit layer includes a first bottom circuit layer and a second bottom circuit layer. The first conductive vias penetrate the first add-on structure and the insulating structure, and electrically connect the first top circuit layer and the first bottom circuit layer, wherein the insulating structure is located between the wrap-around ground layer and the first conductive via. Multiple second conductive vias penetrate the substrate and the first additive layer structure and surround the first conductive via, electrically connecting the second top wiring layer and the second bottom wiring layer. A wraparound ground layer is located between the multiple second conductive vias and the first conductive via, and is electrically connected to the multiple second conductive vias. The first bottom wiring layer, the first conductive via, the first top wiring layer, the second bottom wiring layer, the wraparound ground layer, a portion of the multiple second conductive vias, the second top wiring layer, the insulating structure, and the portion of the first additive layer structure located between the first conductive via and the multiple second conductive vias define a signal transmission structure. The equivalent circuit of the signal transmission structure includes at least a first equivalent circuit, a second equivalent circuit, a third equivalent circuit, and a fourth equivalent circuit. The first equivalent circuit corresponds to the first bottom wiring layer and the second bottom wiring layer corresponding to the first bottom wiring layer. The second equivalent circuit corresponds to the wraparound ground layer, the insulating structure, and the portion of the first conductive via corresponding to the wraparound ground layer. The third equivalent circuit corresponds to a portion of the first add-on structure located between the first conductive via and multiple second conductive vias, and a portion of the first conductive vias and multiple second conductive vias located within the first add-on structure. The fourth equivalent circuit corresponds to the first top wiring layer and the second top wiring layer corresponding to the first top wiring layer. The first, second, third, and fourth equivalent circuits each correspond to different uniform transmission segments, and are connected in series with each other using the ABCD transmission matrix series connection principle.

[0005] In the circuit board structure according to an embodiment of the present invention, one end of the equivalent circuit of the above-described signal transmission structure is connected to a receiver or transmitter, and the other end of the equivalent circuit of the signal transmission structure is connected to an antenna.

[0006] In the circuit board structure according to an embodiment of the present invention, the unit length parameters of the first equivalent circuit, the second equivalent circuit, the third equivalent circuit, and the fourth equivalent circuit are different from each other.

[0007] In the circuit board structure according to an embodiment of the present invention, the above-mentioned unit length parameters include resistance, conductance, inductance, or capacitance.

[0008] In the circuit board structure according to an embodiment of the present invention, the first bottom line layer, the first conductive via and the first top line layer define a signal transmission path, and the second top line layer, the second conductive via, the enclosing loop ground layer and the second bottom line layer define a ground path, and the ground path surrounds the signal transmission path.

[0009] In the circuit board structure according to an embodiment of the present invention, the circuit board structure further includes a filling structure disposed in the first conductive via and a plurality of second conductive vias.

[0010] In the circuit board structure according to an embodiment of the present invention, the equivalent circuit of the above-described signal transmission structure further includes a fifth equivalent circuit, which is connected between the fourth equivalent circuit and the antenna.

[0011] In the circuit board structure according to an embodiment of the present invention, the fifth equivalent circuit described above is composed of multiple uniform transmission segments, and the equivalent circuits of the multiple uniform transmission segments are connected in series according to the ABCD transmission matrix series connection principle to achieve impedance matching.

[0012] In the circuit board structure according to an embodiment of the present invention, the first top wiring layer includes a first top pad portion and a first top wiring portion. The first top pad portion is disposed at the end of the first conductive via and electrically connected to the first conductive via. The first top wiring portion extends from the first top pad portion and is electrically connected to the first top pad portion. A fourth equivalent circuit corresponds to the first top pad portion, and a fifth equivalent circuit corresponds to the first top wiring portion.

[0013] In the circuit board structure according to an embodiment of the present invention, the equivalent circuit of the above-mentioned signal transmission structure further includes a sixth equivalent circuit, which is connected between the third equivalent circuit and the fourth equivalent circuit or between the first equivalent circuit and the second equivalent circuit, wherein the structure corresponding to the sixth equivalent circuit is a uniform transmission segment.

[0014] In the circuit board structure according to an embodiment of the present invention, the first layer addition structure includes a first dielectric layer, a first circuit layer, a second dielectric layer, and a second circuit layer. The first dielectric layer is disposed on a first surface of the substrate. The first circuit layer is disposed on the first dielectric layer. The second dielectric layer is disposed on the first circuit layer. The second circuit layer is disposed on the second dielectric layer. The top circuit layer is disposed on the second circuit layer. The third equivalent circuit corresponds to the first dielectric layer located between the first conductive via and the plurality of second conductive vias, and the sixth equivalent circuit corresponds to the second dielectric layer located between the first conductive via and the plurality of second conductive vias.

[0015] In the circuit board structure according to an embodiment of the present invention, the equivalent circuit of the above-described signal transmission structure further includes a seventh equivalent circuit, which is connected between the third equivalent circuit and the sixth equivalent circuit, wherein the seventh equivalent circuit corresponds to a portion of the first circuit layer located between the first conductive via and the plurality of second conductive vias.

[0016] In the circuit board structure according to an embodiment of the present invention, the first circuit layer includes a first inner pad located between a first conductive via and a plurality of second conductive vias, wherein the first inner pad is electrically connected to the first conductive via.

[0017] In the circuit board structure according to an embodiment of the present invention, the circuit board structure further includes a second add-on structure disposed on the second surface of the substrate, wherein the first conductive via and the plurality of second conductive vias penetrate the second add-on structure. The sixth equivalent circuit corresponds to the portion of the second add-on structure located between the first conductive via and the plurality of second conductive vias, and the first conductive via and the portion of the plurality of second conductive vias located within the second add-on structure.

[0018] In the circuit board structure according to an embodiment of the present invention, the second layer addition structure described above includes a third dielectric layer and a third circuit layer. The third dielectric layer is disposed on a second surface of the substrate. The third circuit layer is disposed on the third dielectric layer, wherein the bottom circuit layer is disposed on the third circuit layer.

[0019] In the circuit board structure according to an embodiment of the present invention, the first top line layer includes a first top line that extends from the end of the first conductive via and is electrically connected to the first conductive via, wherein the fourth equivalent circuit corresponds to the first top line.

[0020] In the circuit board structure according to an embodiment of the present invention, the circuit board structure further includes a first cover layer and a second cover layer. The first cover layer is disposed on the top circuit layer. The second cover layer is disposed on the bottom circuit layer.

[0021] Based on the above, the circuit board structure of the present invention has a signal transmission structure. The equivalent circuit of the signal transmission structure includes at least a first equivalent circuit, a second equivalent circuit, a third equivalent circuit, and a fourth equivalent circuit, which correspond to different uniform transmission segments. The signal transmission path of each uniform transmission segment is surrounded by a grounding path and is enclosed, which can reduce energy loss and noise interference, thereby forming a good high-frequency and high-speed signal transmission loop and improving the integrity and reliability of the signal. Attached Figure Description

[0022] Figure 1 This is a cross-sectional schematic diagram of a circuit board structure according to an embodiment of the present invention;

[0023] Figure 2 This is an equivalent circuit diagram of a signal transmission structure according to an embodiment of the present invention;

[0024] Figure 3 This is a partial equivalent circuit diagram of a uniform transmission segment according to an embodiment of the present invention;

[0025] Figure 4A This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention;

[0026] Figure 4B This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention;

[0027] Figure 4C This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention;

[0028] Figure 5 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention;

[0029] Figure 6 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention;

[0030] Figure 7 This is an equivalent circuit diagram of a signal transmission structure according to another embodiment of the present invention;

[0031] Figure 8 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention;

[0032] Figure 9 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention;

[0033] Figure 10 This is an equivalent circuit diagram of a signal transmission structure according to another embodiment of the present invention;

[0034] Figure 11 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention;

[0035] Figure 12 This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention;

[0036] Figure 13 This is an equivalent circuit diagram of a signal transmission structure according to another embodiment of the present invention. Detailed Implementation

[0037] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same component reference numerals are used in the drawings and description to denote the same or similar parts.

[0038] In the accompanying drawings, the thicknesses of layers, films, panels, regions, etc., are enlarged for clarity. Throughout the specification, the same reference numerals denote the same components. It should be understood that when a component such as a layer, film, region, or substrate is referred to as being "on" or "connected" to another component, it may be directly on or connected to the other component, or an intermediate component may also be present. Conversely, when a component is referred to as being "directly on" or "directly connected" to another component, no intermediate component is present. As used herein, "connection" can refer to physical and / or electrical connection. Furthermore, "electrical connection" or "coupling" may mean that other components exist between the two components.

[0039] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various components, parts, regions, layers, and / or portions, these components, parts, regions, and / or portions should not be limited by these terms. These terms are used only to distinguish one component, part, region, layer, or portion from another. Therefore, “first component,” “part,” “region,” “layer,” or “portion” discussed below may be referred to as a second component, part, region, layer, or portion without departing from the teachings of this document.

[0040] Figure 1 This is a cross-sectional schematic diagram of a circuit board structure according to an embodiment of the present invention. Figure 2 This is an equivalent circuit diagram of a signal transmission structure according to an embodiment of the present invention. Figure 3 This is a partial equivalent circuit diagram of a uniform transmission segment according to an embodiment of the present invention. Figure 4A This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention. Figure 4B This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention. Figure 4CThis is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention. Figure 1 It can be along Figure 4A Section line A-A' Figure 4B Section line B-B' or Figure 4C A cross-sectional view along section line C-C'. Figure 2 It can be Figure 1 The equivalent circuit diagram of the signal transmission structure is shown below. For clarity, Figures 4A to 4C Only the first top wiring layer 132a, the second top wiring layer 134a, the second dielectric layer 123, the first conductive via V1, and multiple second conductive vias V2 are shown in the diagram. Other omitted parts can be found in the reference diagram. Figure 1 To understand.

[0041] Please refer to Figure 1 and Figure 2 The circuit board structure 10 includes a substrate 110, a wrap-around ground layer 114c, an insulating structure 116, a first add-on structure 120, a top circuit layer 130a, a bottom circuit layer 130b, a first conductive via V1, and a plurality of second conductive vias V2. The substrate 110 has an opening OP1, a first surface 110a, and a second surface 110b opposite to the first surface 110a. The wrap-around ground layer 114c is disposed on the inner wall of the opening OP1 of the substrate 110. The insulating structure 116 is disposed in the opening OP1 of the substrate 110. The first add-on structure 120 is disposed on the first surface 110a of the substrate 110. The top circuit layer 130a is disposed on the first add-on structure 120. The top circuit layer 130a includes a first top circuit layer 132a and a second top circuit layer 134a. The bottom circuit layer 130b is disposed on the second surface 110b of the substrate 110. The bottom wiring layer 130b includes a first bottom wiring layer 132b and a second bottom wiring layer 134b. A first conductive via V1 penetrates the first add-on structure 120 and the insulating structure 116, and is electrically connected to the first top wiring layer 132a and the first bottom wiring layer 132b. The insulating structure 116 is located between the wrap-around ground layer 114c and the first conductive via V1. A plurality of second conductive vias V2 penetrate the substrate 110 and the first add-on structure 120 and surround the first conductive via V1, and are electrically connected to the second top wiring layer 134a and the second bottom wiring layer 134b. The wrap-around ground layer 114c is located between the plurality of second conductive vias V2 and the first conductive via V1, and is electrically connected to the plurality of second conductive vias V2.

[0042] A signal transmission structure ST1 is defined by a first bottom wiring layer 132b, a first conductive via V1, a first top wiring layer 132a, a second bottom wiring layer 134b, a grounding layer 114c, a portion of a second conductive via V2, a second top wiring layer 134a, an insulating structure 116, and a portion of a first add-on structure 120 located between the first conductive via V1 and the plurality of second conductive via V2. This structure is suitable for transmitting high-frequency, high-speed signals. Here, high frequency refers to a frequency greater than 1 GHz; and high speed refers to a data transmission speed greater than 100 Mbps. The equivalent circuit X1 of the signal transmission structure ST1 includes at least a first equivalent circuit C1, a second equivalent circuit C2, a third equivalent circuit C3, and a fourth equivalent circuit C4. The first equivalent circuit C1 corresponds to the first bottom wiring layer 132b and the second bottom wiring layer 134b corresponding to the first bottom wiring layer 132b, for example, it may correspond to... Figure 1 The first transmission segment S11 is shown in the diagram. The second equivalent circuit C2 corresponds to the encasing loop ground layer 114c, the insulating structure 116, and a portion of the first conductive via V1 corresponding to the encasing loop ground layer 114c, for example, it may correspond to... Figure 1 The second transmission segment S12 shown is illustrated. The third equivalent circuit C3 corresponds to a portion of the first layer structure 120 located between the first conductive via V1 and the plurality of second conductive vias V2, and to a portion of the first conductive vias V1 and a portion of the second conductive vias V2 located within the first layer structure 120. For example, it may correspond to... Figure 1 The third transmission segment S13 is shown. The fourth equivalent circuit C4 corresponds to the first top line layer 132a and the second top line layer 134a corresponding to the first top line layer 132a, for example, it may correspond to... Figure 1 The fourth transmission segment S14 is shown in the figure. In some embodiments, the signal transmission structure ST1 includes a signal transmission via ST11, which is composed of a first transmission segment S11, a second transmission segment S12, a third transmission segment S13, and a fourth transmission segment S14.

[0043] The first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4 each correspond to different uniform transmission segments. These circuits are connected in series using the ABCD transmission matrix principle. In this paper, a uniform transmission segment refers to a transmission segment whose equivalent circuit has a constant unit length parameter at a fixed signal frequency. Specifically, the equivalent circuit of a uniform transmission segment is as follows: Figure 3As shown, the circuit consists of multiple RLGC circuit units U connected in series. Each RLGC circuit unit U represents the equivalent circuit for a unit length of signal transmission from one cross section in this transmission segment. Each RLGC circuit unit U in the equivalent circuit of the uniform transmission segment has the same resistance (R), inductance (L), conductance (G), and capacitance (C) per unit length at a fixed signal frequency. That is, the unit length parameters (including inductance, capacitance, resistance, and conductance) of the equivalent circuit of the uniform transmission segment are constant.

[0044] The ABCD transmission matrix cascade principle refers to the fact that different equivalent circuits connected in series can be represented by multiplying their ABCD transmission matrices sequentially according to the order in which they are connected, thus obtaining the ABCD transmission matrix of the overall equivalent circuit. For example, such as... Figure 2 As shown, the equivalent circuit X11 of the signal transmission via ST11 is composed of the first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4 connected in series in sequence. That is, the ABCD transmission matrix of the equivalent circuit X11 is equal to the product of the ABCD transmission matrices of the first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4, as shown in equation (1) below.

[0045]

[0046] The ABCD transmission matrix is ​​composed of unit length resistance (R), unit length inductance (L), unit length conductance (G), and unit length capacitance (C) in the equivalent circuit. Equation (2) is an example of the representation of a general transmission line.

[0047]

[0048] Where l is the length of the uniform transmission section, Z0 is the reference impedance, and γ is the propagation constant expressed by equation (3).

[0049]

[0050] Where f is the frequency, and R(f), L(f), G(f), and C(f) are functions of frequency for resistance, inductance, conductance, and capacitance per unit length, respectively.

[0051] The ABCD transmission matrix can be further transformed to obtain the S-parameter matrix (also known as the scattering matrix) to obtain the frequency domain characteristics of the transmission segment. In other words, the frequency domain characteristics of the signal transmission via ST11 are related to the unit length parameters in the first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4. By adjusting the corresponding unit length parameters through the structural design of each transmission segment, the signal transmission via ST11 can meet the impedance matching requirements.

[0052] In some embodiments, the unit length parameters of the first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4 are different from each other. In other words, the uniform transmission segments corresponding to the first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4 have different electrical characteristics, such as having different geometries or containing different dielectric or conductive materials. The signal transmission via ST11 can select the structure or material of the corresponding uniform transmission segment through the design of the first equivalent circuit C1, the second equivalent circuit C2, the third equivalent circuit C3, and the fourth equivalent circuit C4 to achieve impedance matching requirements.

[0053] In some embodiments, a first bottom wiring layer 132b, a first conductive via V1, and a first top wiring layer 132a define a signal transmission path L11. A second bottom wiring layer 134b, a wraparound ground layer 114c, a second conductive via V2, and a second top wiring layer 134a define a ground path L12, which surrounds the signal transmission path L11. In this way, the signal transmission path L11 is surrounded and enclosed by the ground path L12, allowing high-frequency, high-speed signals to be transmitted through the signal transmission path L11 and generate a return signal via the ground path L12, thus forming a good high-frequency, high-speed loop.

[0054] In some embodiments, one end of the equivalent circuit X1 of the signal transmission structure ST1 is connected to the receiver Rx or the transmitter Tx, and the other end of the equivalent circuit X1 of the signal transmission structure ST1 is connected to the antenna A.

[0055] In some embodiments, the substrate 110 may include a core layer 111, inner circuit layers 112a, 112b, and 112c, a dielectric layer 113a, 113b, circuit layers 114a, 114b, and 114d. The core layer 111 has an opening OP3. The inner circuit layers 112a and 112b are disposed on opposite sides of the core layer 111, and the inner circuit layer 112c covers the inner wall of the opening OP3 and structurally and electrically connects the inner circuit layers 112a and 112b. The dielectric layer 113a covers the inner circuit layer 112a and is located between the inner circuit layers 112a and 114a. The dielectric layer 113b covers the inner circuit layer 112b and is located between the inner circuit layers 112b and 114b. Dielectric layers 113a and 113b fill opening OP3 and are interconnected. A circuit layer 114a is disposed on dielectric layer 113a, and a circuit layer 114b is disposed on dielectric layer 113b. Substrate 110 has openings OP1 and OP2. Opening OP1 extends through circuit layer 114a, dielectric layer 113a, inner circuit layer 112a, core layer 111, inner circuit layer 112b, dielectric layer 113b, and circuit layer 114b. A wrap-around ground layer 114c covers the inner wall of opening OP1 and structurally and electrically connects circuit layer 114a, inner circuit layer 112a, inner circuit layer 112b, and circuit layer 114b. In some embodiments, the wrap-around ground layer 114c surrounds a portion of the first conductive via V1. In some embodiments, an insulating structure 116 fills opening OP1 and is flush with circuit layers 114a and 114b. In some embodiments, dielectric layers 113a, 113b, and insulating structure 116 are preferably made of high-frequency, high-speed materials, and the dielectric constant of insulating structure 116 should take impedance matching into account. The dielectric loss of insulating structure 116 is greater than 0 and less than 0.1; lower dielectric loss results in higher signal quality. Opening OP2 penetrates line layer 114a, dielectric layer 113a, inner line layer 112a, core layer 111, inner line layer 112b, dielectric layer 113b, and line layer 114b. Line layer 114d covers the inner wall of opening OP2 and structurally and electrically connects line layer 114a, inner line layer 112a, inner line layer 112b, and line layer 114b. In some embodiments, the encapsulated loop ground layer 114c is electrically connected to the second conductive via V2 through line layer 114a. In some embodiments, opening OP1 is located between opening OP2 and opening OP3. Figure 1 The substrate 110 is shown only schematically and is not intended to limit the invention. The substrate 110 may have multiple circuit layers, dielectric layers and openings as needed, and its wiring design may be adjusted as required.

[0056] In some embodiments, the first add-on structure 120 includes a first dielectric layer 121, a first circuit layer 122, a second dielectric layer 123, and a second circuit layer 124. The first dielectric layer 121 is disposed on a first surface 110a of the substrate 110. The first circuit layer 122 is disposed on the first dielectric layer 121. The second dielectric layer 123 is disposed on the first circuit layer 122. The second circuit layer 124 is disposed on the second dielectric layer 123, wherein a top circuit layer 130a is disposed on the second circuit layer 124. Figure 1 The first layer structure 120 is shown only schematically and is not intended to limit the invention. The number of dielectric and circuit layers in the first layer structure 120 can be adjusted according to actual needs.

[0057] In some embodiments, the third transmission segment S13 includes a first dielectric layer 121 and a second dielectric layer 123 located between the first conductive via V1 and a plurality of second conductive vias V2, and a portion of the first conductive via V1 and a portion of the second conductive via V2 located within the first layering structure 120. The third transmission segment S13 does not include the first circuit layer 122. If the first dielectric layer 121 and the second dielectric layer 123 have the same material, then the third transmission segment S13 is a uniform transmission segment, which is equivalent to... Figure 2 The third equivalent circuit C3 in the figure. In other embodiments, the materials of the first dielectric layer 121 and the second dielectric layer 123 may be different, then the third transmission segment S13 can be regarded as two different uniform transmission segments, each corresponding to an equivalent circuit with different unit length parameters, and the present invention is not limited thereto.

[0058] In some embodiments, the first conductive via V1 includes a through-hole T1 and a conductive layer 130c, wherein the through-hole T1 penetrates the first add-on structure layer 120 and the insulating structure 116, and the conductive layer 130c covers the inner wall of the through-hole T1 and electrically connects the first top wiring layer 132a and the first bottom wiring layer 132b. The second conductive via V2 includes a through-hole T2 and a conductive layer 130d, wherein the through-hole T2 penetrates the first add-on structure layer 120 and the substrate 110, and the conductive layer 130d covers the inner wall of the through-hole T2 and electrically connects the second top wiring layer 134a and the second bottom wiring layer 134b. In some embodiments, the through-hole T1 penetrates the center of the insulating structure 116; that is, the through-hole T1 and the insulating structure 116 may have the same axis, but this is not a limitation of the invention. In other embodiments, the through-hole T1 may be offset from the center of the insulating structure 116.

[0059] In some embodiments, the circuit board structure 10 further includes a filling structure 150 disposed in the first conductive via V1 and the second conductive via V2. The filling structure 150 is made of, for example, resin, which can be considered a via-filling agent, or a dielectric material with a dielectric constant higher than 3.6 and a dielectric loss lower than 0.05. In some embodiments, the filling structure 150 can fill the first conductive via V1 and the second conductive via V2 so that the top surface of the filling structure 150 is flush with the top circuit layer 130a and the bottom surface of the filling structure 150 is flush with the bottom circuit layer 130b.

[0060] In some embodiments, the circuit board structure 10 further includes a first cover layer 140a and a second cover layer 140b. The first cover layer 140a is disposed on the top circuit layer 130a and the fill structure 150, and the second cover layer 140b is disposed on the bottom circuit layer 130b and the fill structure 150.

[0061] In some embodiments, the equivalent circuit X1 of the signal transmission structure ST1 further includes a fifth equivalent circuit C5, connected between the fourth equivalent circuit C4 and the antenna A. For example, the signal transmission structure ST1 also includes a signal transmission line ST12, which is connected to the signal transmission via ST11. The ABCD transmission matrix of the equivalent circuit X1 of the signal transmission structure ST1 is equal to the product of the ABCD transmission matrix of the equivalent circuit X11 of the signal transmission via ST11 and the ABCD transmission matrix of the equivalent circuit X12 of the signal transmission line ST12, as shown in equation (4) below, wherein the equivalent circuit X12 of the signal transmission line ST12 includes the fifth equivalent circuit C5, that is, the fifth equivalent circuit C5 corresponds to the signal transmission line ST12.

[0062]

[0063] In some embodiments, such as Figure 4A As shown, the first top wiring layer 132a includes a first top pad portion 132a-1 and a first top wiring portion 132a-2. The first top pad portion 132a-1 is disposed at the end of the first conductive via V1 and is electrically connected to the first conductive via V1. The first top wiring portion 132a-2 extends from the first top pad portion 132a-1 and is electrically connected to the first top pad portion 132a-1.

[0064] In some embodiments, the fourth equivalent circuit C4 may correspond to the first top pad portion 132a-1, and the fifth equivalent circuit C5 may correspond to the first top line portion 132a-2. That is, the first top line portion 132a-2 and the portion of the second top line layer 134a surrounding the first top line portion 132a-2 may constitute a portion of the signal transmission line ST12; the first top pad portion 132a-1 and the portion of the second top line layer 134a surrounding the first top pad portion 132a-1 may constitute a portion of the fourth transmission segment S14.

[0065] In some embodiments, the fifth equivalent circuit C5 may correspond to multiple uniform transmission segments, the equivalent circuits of which are connected in series according to the ABCD transmission matrix series connection principle to achieve impedance matching. For example, in Figure 4B In the embodiment, the first top line portion 132a-2 has a tapered linewidth near the first top pad portion 132a-1. Different linewidths can represent different uniform transmission segments. Through the tapered linewidth design of the first top line portion 132a-2, the fifth equivalent circuit C5 can have the expected resistance, inductance, conductance, and capacitance parameters, thereby achieving the impedance matching requirement. Figure 4C In the embodiment, the first top line portion 132a-2 can be formed by connecting multiple line segments a, b and c with different line widths. That is, the ABCD transmission matrix of the equivalent circuit (i.e. the fifth equivalent circuit C5) of the first top line portion 132a-2 is equal to the product of the ABCD transmission matrices of the equivalent circuits of multiple line segments a, b and c, as shown in the following equation (5).

[0066]

[0067] In this way, by designing the line width and length of multiple line segments a, b and c, the fifth equivalent circuit C5 can have the expected resistance, inductance, conductance and capacitance parameters, thereby achieving the impedance matching requirement.

[0068] Please refer to Figure 1 and Figure 4AIn some embodiments, the first top pad portion 132a-1 and the topmost line layer (i.e., the second line layer 124) and the first cover layer 140a of the corresponding first add-on structure 120 can constitute the first top pad p1. The second top line layer 134a and the topmost line layer (i.e., the second line layer 124) and the first cover layer 140a of the corresponding first add-on structure 120 can constitute the top ground structure p2. The top ground structure p2 surrounds the first top pad p1. In some embodiments, the fourth transmission segment S14 includes the first top pad p1 and a portion of the top ground structure p2, and the top line layer 130a, the second line layer 124, and the first cover layer 140a have the same material, such as copper. Therefore, the fourth transmission segment S14 is a uniform transmission segment, which is equivalent to Figure 2 The fourth equivalent circuit C4 in the diagram. In other embodiments, the materials of the top line layer 130a, the second line layer 124, and the first cover layer 140a may be different, in which case the fourth transmission segment S4 can be regarded as three different uniform transmission segments, each corresponding to an equivalent circuit with different unit length parameters. This invention is not limited to this. Figure 1 Although the top grounding structure p2 is shown as a whole surface structure, the present invention is not limited thereto. The top grounding structure p2 can also be patterned to form a plurality of top grounding pads (not shown) surrounding the first top pad p1.

[0069] In some embodiments, the sidewalls of the first top wiring layer 132a and its corresponding second wiring layer 124 and first cover layer 140a are flush with each other. The sidewalls of the second top wiring layer 134a and its corresponding second wiring layer 124 and first cover layer 140a are flush with each other.

[0070] In some embodiments, a first bottom wiring layer 132b and its corresponding second cover layer 140b may constitute a first bottom pad p3. A second bottom wiring layer 134b and its corresponding second cover layer 140b may constitute a plurality of second bottom pads p4. The plurality of second bottom pads p4 surround the first bottom pad p3. In some embodiments, the first transmission segment S1 includes the first bottom pad p3 and a plurality of second bottom pads p4, and the bottom wiring layer 130b and the second cover layer 140b have the same material, such as copper. Therefore, the first transmission segment S11 is a uniform transmission segment, which is equivalent to Figure 2 The first equivalent circuit C1 in the diagram. In other embodiments, the bottom line layer 130b and the second cover layer 140b may be made of different materials, in which case the first transmission segment S11 can be regarded as two different uniform transmission segments, each corresponding to an equivalent circuit with different unit length parameters. This invention is not limited thereto.

[0071] In some embodiments, the sidewalls of the first bottom wiring layer 132b and its corresponding second cover layer 140b are flush with each other. The sidewalls of the second bottom wiring layer 134b and its corresponding second cover layer 140b are flush with each other.

[0072] In some embodiments, the first bottom wiring layer 132b may have pad portions or wiring portions as the first top wiring layer 132a, but the invention is not limited thereto.

[0073] Figure 5 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention. It should be noted that... Figure 5 The embodiments follow Figure 1 The component reference numerals and partial content of the embodiments are described below, wherein the same or similar reference numerals are used to represent the same or similar components, and descriptions of the same technical content are omitted. For explanations of the omitted parts, please refer to the foregoing embodiments, and will not be repeated here. Figure 5 A top view diagram of an embodiment can be referred to. Figures 4A to 4C .

[0074] Please refer to Figure 5 The main difference between circuit board structure 20 and circuit board structure 10 is that the first add-on structure 220 of circuit board structure 20 includes a first dielectric layer 221 and a first circuit layer 222. The first dielectric layer 221 is disposed on the first surface 110a of the substrate 110. The first circuit layer 222 is disposed on the first dielectric layer 221, wherein the top circuit layer 130a is disposed on the second circuit layer 222.

[0075] The signal transmission structure ST2 is defined by a first bottom wiring layer 132b, a first conductive via V1, a first top wiring layer 132a, a second bottom wiring layer 134b, a portion of the second conductive via V2, a wrapping loop ground layer 114c, a second top wiring layer 134a, an insulating structure 116, and a portion of the first add-on structure 220 located between the first conductive via V1 and the plurality of second conductive via V2. The equivalent circuit of the signal transmission structure ST2 can be as follows: Figure 2 As shown, the first equivalent circuit C1 corresponds to the first bottom line layer 132b and the second bottom line layer 134b corresponding to the first bottom line layer 132b, for example, it can correspond to... Figure 5 The first transmission segment S21 shown is shown; the second equivalent circuit C2 corresponds to the encasing loop ground layer 114c, the insulating structure 116, and the portion of the first conductive via V1 corresponding to the encasing loop ground layer 114c, for example, it may correspond to Figure 5The second transmission segment S22 shown is illustrated. The third equivalent circuit C3 corresponds to the first dielectric layer 221 located between the first conductive via V1 and the plurality of second conductive vias V2, and to a portion of the first conductive via V1 and a portion of the second conductive via V2 located within the first layering structure 220. For example, it may correspond to... Figure 5 The third transmission segment S23 is shown. The fourth equivalent circuit C4 corresponds to the first top pad portion 132a-1 and the second top line layer 134a corresponding to the first top pad portion 132a-1, for example, it may correspond to... Figure 5 The fourth transmission segment S24 is shown in the diagram. The fifth equivalent circuit C5 corresponds to the first top line section 132a-2 and the second top line layer 134a corresponding to the first top line section 132a-2, as shown in the diagram. Figures 4A to 4C As shown. In some embodiments, the signal transmission structure ST2 includes a signal transmission via ST21 and a signal transmission line ST12 (see reference). Figures 4A to 4C The signal transmission via ST21 is composed of a first transmission segment S21, a second transmission segment S22, a third transmission segment S23, and a fourth transmission segment S24.

[0076] The first bottom wiring layer 132b, the first conductive via V1, and the first top wiring layer 132a define the signal transmission path L21. The second bottom wiring layer 134b, the wrapping loop ground layer 114c, the second conductive via V2, and the second top wiring layer 134a define the ground path L22, which surrounds the signal transmission path L21. In this way, the signal transmission path L21 is surrounded and enclosed by the ground path L22, allowing high-frequency, high-speed signals to be transmitted through the signal transmission path L21 and generate a return signal via the ground path L22, thus forming a good high-frequency, high-speed loop.

[0077] Figure 6 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention. Figure 7 This is an equivalent circuit diagram of a signal transmission structure according to another embodiment of the present invention. Figure 7 It can be Figure 6 The equivalent circuit diagram of the signal transmission structure ST3 is shown below. It must be noted that... Figure 6 The embodiments follow Figure 1 The component reference numerals and partial content of the embodiments are described below, wherein the same or similar reference numerals are used to represent the same or similar components, and descriptions of the same technical content are omitted. For explanations of the omitted parts, please refer to the foregoing embodiments, and will not be repeated here. Figure 6 A top view diagram of an embodiment can be referred to. Figures 4A to 4C .

[0078] Please refer to Figure 6The main difference between circuit board structure 30 and circuit board structure 10 is that the first circuit layer 122 of circuit board structure 30 includes a first inner pad 122a and a second inner pad 122b located between the first conductive via V1 and a plurality of second conductive via V2. The first inner pad 122a is electrically connected to the first conductive via V1, and the second inner pad 122b is electrically connected to the second conductive via V2. In other embodiments, the first circuit layer 122 located between the first conductive via V1 and the plurality of second conductive via V2 may include only the first inner pad 122a or the second inner pad 122b. The present invention is not limited thereto, and the arrangement of the first inner pad 122a and the second inner pad 122b can be adjusted according to actual needs to achieve impedance matching requirements.

[0079] A signal transmission structure ST3 is defined by a first bottom wiring layer 132b, a first conductive via V1, a first top wiring layer 132a, a second bottom wiring layer 134b, a portion of a second conductive via V2, a wrapping loop ground layer 114c, a second top wiring layer 134a, an insulating structure 116, and a portion of a first add-on structure 120 located between the first conductive via V1 and the plurality of second conductive vias V2. The signal transmission structure ST3 includes a signal transmission via ST31 and a signal transmission line ST12 (see reference). Figures 4A to 4C The signal transmission via ST31 can be composed of a first transmission segment S11, a second transmission segment S12, a third transmission segment S33, and a fourth transmission segment S14. The third transmission segment S33 includes multiple uniform sub-transmission segments S33a, S33b, and S33c. The uniform sub-transmission segment S33a includes a first dielectric layer 121 located between the first conductive via V1 and multiple second conductive vias V2, and a portion of the first conductive via V1 and a portion of the second conductive via V2 located within the first dielectric layer 121. The uniform sub-transmission segment S33b includes a first inner pad 122a, a second inner pad 122b, and a portion of the first dielectric layer 121 located between the first inner pad 122a and the second inner pad 122b. The uniform sub-transmission segment S33c includes a second dielectric layer 123 located between the first conductive via V1 and multiple second conductive vias V2, and a portion of the first conductive via V1 and a portion of the second conductive via V2 located within the second dielectric layer 123.

[0080] The equivalent circuit X3 of the signal transmission structure ST3 can be as follows: Figure 7 As shown, it includes a first equivalent circuit C1, a second equivalent circuit C2, a third equivalent circuit C3, a seventh equivalent circuit C7, a sixth equivalent circuit C6, a fourth equivalent circuit C4, and a fifth equivalent circuit C5 connected in sequence. The first equivalent circuit C1 corresponds to the first bottom line layer 132b and the second bottom line layer 134b corresponding to the first bottom line layer 132b, for example, it may correspond to... Figure 6The first transmission segment S11 shown; the second equivalent circuit C2 corresponds to the encasing loop ground layer 114c, the insulating structure 116, and a portion of the first conductive via V1 corresponding to the encasing loop ground layer 114c, for example, it may correspond to Figure 6 The second transmission segment S12 is shown. The third equivalent circuit C3 corresponds to the first dielectric layer 121 located between the first conductive via V1 and the plurality of second conductive vias V2, for example, it may correspond to... Figure 6 The uniform sub-transmission segment S33a of the third transmission segment S33 shown. The seventh equivalent circuit C7 corresponds to the first line layer 122 located between the first conductive via V1 and the plurality of second conductive via V2, for example, it may correspond to Figure 6 The uniform sub-transmission segment S33b of the third transmission segment S33 shown. The sixth equivalent circuit C6 corresponds to the second dielectric layer 123 located between the first conductive via V1 and the plurality of second conductive vias V2, for example, it may correspond to... Figure 6 The uniform sub-transmission segment S33c of the third transmission segment S33 shown. The fourth equivalent circuit C4 corresponds to the first top pad portion 132a-1 and the second top line layer 134a corresponding to the first top pad portion 132a-1, for example, it may correspond to... Figure 6 The fourth transmission segment S14 is shown. The fifth equivalent circuit C5 corresponds to the first top line portion 132a-2 and the second top line layer 134a corresponding to the first top line portion 132a-2, as shown. Figures 4A to 4C As shown. In some embodiments, the equivalent circuit X31 of the signal transmission via ST31 is composed of a first equivalent circuit C1, a second equivalent circuit C2, a third equivalent circuit C3, a seventh equivalent circuit C7, a sixth equivalent circuit C6, and a fourth equivalent circuit C4 connected in series according to the ABCD transmission matrix series connection principle.

[0081] The first bottom wiring layer 132b, the first conductive via V1, the first inner pad 122a, and the first top wiring layer 132a define the signal transmission path L31. The second bottom wiring layer 134b, the wrapping ground layer 114c, the second conductive via V2, the second inner pad 122b, and the second top wiring layer 134a define the ground path L32, which surrounds the signal transmission path L31. In this way, the signal transmission path L31 is surrounded and enclosed by the ground path L32, allowing high-frequency, high-speed signals to be transmitted through the signal transmission path L31 and generate a return signal via the ground path L32, thus forming a good high-frequency, high-speed loop.

[0082] Figure 8 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention. It should be noted that... Figure 8 The embodiments follow Figure 6The component reference numerals and partial content of the embodiments are described below, wherein the same or similar reference numerals are used to represent the same or similar components, and descriptions of the same technical content are omitted. For explanations of the omitted parts, please refer to the foregoing embodiments, and will not be repeated here. Figure 8 A top view diagram of an embodiment can be referred to. Figures 4A to 4C .

[0083] Please refer to Figure 8 The main difference between circuit board structure 40 and circuit board structure 30 is that the first circuit layer 122 of circuit board structure 40 includes a second inner pad 122b located between the first conductive via V1 and a plurality of second conductive via V2, but does not include the first inner pad. The first bottom circuit layer 132b, the first conductive via V1, the first top circuit layer 132a, the second bottom circuit layer 134b, a portion of the second conductive via V2, the encapsulating loop ground layer 114c, the second top circuit layer 134a, the insulating structure 116, and a portion of the first add-on structure 120 located between the first conductive via V1 and the plurality of second conductive via V2 define the signal transmission structure ST4. The signal transmission structure ST4 includes a signal transmission via ST41 and a signal transmission line ST12 (see reference). Figures 4A to 4C The signal transmission via ST41 can be composed of a first transmission segment S11, a second transmission segment S12, a third transmission segment S43, and a fourth transmission segment S14. The third transmission segment S43 includes multiple uniform sub-transmission segments S33a, S43b, and S33c, wherein the uniform sub-transmission segment S43b includes a second inner pad 122b, a first conductive via V1 corresponding to the second inner pad 122b, and a portion of the first dielectric layer 121 located between the second inner pad 122b and the first conductive via V1.

[0084] The equivalent circuit X4 of the signal transmission structure ST4 can be as follows: Figure 7 As shown, it includes a first equivalent circuit C1, a second equivalent circuit C2, a third equivalent circuit C3, a seventh equivalent circuit C7, a sixth equivalent circuit C6, a fourth equivalent circuit C4, and a fifth equivalent circuit C5 connected in sequence. The first equivalent circuit C1 corresponds to the first bottom line layer 132b and the second bottom line layer 134b corresponding to the first bottom line layer 132b, for example, it may correspond to... Figure 8 The first transmission segment S11 shown; the second equivalent circuit C2 corresponds to the encasing loop ground layer 114c, the insulating structure 116, and a portion of the first conductive via V1 corresponding to the encasing loop ground layer 114c, for example, it may correspond to Figure 8 The second transmission segment S12 is shown. The third equivalent circuit C3 corresponds to the first dielectric layer 121 located between the first conductive via V1 and the plurality of second conductive vias V2, that is, it corresponds to... Figure 8The uniform sub-transmission segment S33a of the third transmission segment S43 shown. The seventh equivalent circuit C7 can correspond to the first line layer 122 located between the first conductive via V1 and the plurality of second conductive via V2, that is, to... Figure 8 The uniform sub-transmission segment S43b of the third transmission segment S43 shown. The sixth equivalent circuit C6 corresponds to the second dielectric layer 123 located between the first conductive via V1 and the plurality of second conductive vias V2, that is, corresponding to Figure 8 The uniform sub-transmission segment S33c of the third transmission segment S43 shown. The fourth equivalent circuit C4 corresponds to the first top pad portion 132a-1 and the second top line layer 134a corresponding to the first top pad portion 132a-1, for example, it may correspond to... Figure 8 The fourth transmission segment S14 is shown. The fifth equivalent circuit C5 corresponds to the first top line portion 132a-2 and the second top line layer 134a corresponding to the first top line portion 132a-2, as shown. Figures 4A to 4C As shown.

[0085] The first bottom wiring layer 132b, the first conductive via V1, and the first top wiring layer 132a define the signal transmission path L41. The second bottom wiring layer 134b, the wrapping loop ground layer 114c, the second conductive via V2, the second inner pad 122b, and the second top wiring layer 134a define the ground path L42, which surrounds the signal transmission path L41. In this way, the signal transmission path L41 is surrounded and enclosed by the ground path L42, allowing high-frequency and high-speed signals to be transmitted through the signal transmission path L41 and generate a return signal through the ground path L42, thus forming a good high-frequency and high-speed loop.

[0086] Figure 9 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention. Figure 10 This is an equivalent circuit diagram of a signal transmission structure according to another embodiment of the present invention. Figure 10 It can be Figure 9 The equivalent circuit diagram of the signal transmission structure ST5 is shown below. It must be noted that... Figure 9 The embodiments follow Figure 1 The component reference numerals and partial content of the embodiments are described below, wherein the same or similar reference numerals are used to represent the same or similar components, and descriptions of the same technical content are omitted. For explanations of the omitted parts, please refer to the foregoing embodiments, and will not be repeated here.

[0087] Please refer to Figure 9The main difference between circuit board structure 50 and circuit board structure 10 is that circuit board structure 50 further includes a second add-on structure 520 disposed on the second surface 110b of substrate 110, with the first conductive via V1 and a plurality of second conductive via V2 penetrating the second add-on structure 520. For example, the second add-on structure 520 may include a third dielectric layer 522 and a third circuit layer 524. The third dielectric layer 522 is disposed on the second surface 110b of substrate 110, the third circuit layer 524 is disposed on the third dielectric layer 522, and the bottom circuit layer 130b is disposed on the third circuit layer 524. In some embodiments, the cover loop ground layer 114c is electrically connected to the second conductive via V2 through circuit layers 114a and 114b. Figure 9 The second layer structure 520 is shown only schematically and is not intended to limit the invention. The number of dielectric and circuit layers in the second layer structure 520 can be adjusted according to actual needs.

[0088] The signal transmission structure ST5 is defined by a first bottom wiring layer 132b, a first conductive via V1, a first top wiring layer 132a, a second bottom wiring layer 134b, a portion of a second conductive via V2, a wrapping loop ground layer 114c, a second top wiring layer 134a, an insulating structure 116, and a portion of a first add-on structure 120 located between the first conductive via V1 and the plurality of second conductive vias V2.

[0089] The equivalent circuit X5 of the signal transmission structure ST5 can be as follows: Figure 10 As shown, it includes a first equivalent circuit C1, a sixth equivalent circuit C6, a second equivalent circuit C2, a third equivalent circuit C3, a fourth equivalent circuit C4, and a fifth equivalent circuit C5 connected in sequence. The first equivalent circuit C1 corresponds to the first bottom line layer 132b and the second bottom line layer 134b corresponding to the first bottom line layer 132b, for example, it may correspond to... Figure 9 The first transmission segment S51 is shown. The sixth equivalent circuit C6 corresponds to a portion of the second layer structure 520 (e.g., the third dielectric layer 522) located between the first conductive via V1 and the plurality of second conductive via V1, and a portion of the first conductive via V1 and a portion of the second conductive via V2 located in the second layer structure 520. For example, it may correspond to... Figure 9 The fifth transmission segment S55 is shown. The second equivalent circuit C2 corresponds to the encasing loop ground layer 114c, the insulating structure 116, and a portion of the first conductive via V1 corresponding to the encasing loop ground layer 114c, for example, it may correspond to... Figure 9 The second transmission segment S52 is shown. The third equivalent circuit C3 corresponds to the first dielectric layer 121 located between the first conductive via V1 and the plurality of second conductive vias V2, that is, it corresponds to... Figure 9The third transmission segment S53 is shown. The fourth equivalent circuit C4 corresponds to the first top pad portion 132a-1 and the second top line layer 134a corresponding to the first top pad portion 132a-1, for example, it may correspond to... Figure 9 The fourth transmission segment S54 is shown. The fifth equivalent circuit C5 corresponds to the first top line portion 132a-2 and the second top line layer 134a corresponding to the first top line portion 132a-2, as shown. Figures 4A to 4C As shown. In some embodiments, the signal transmission structure ST5 includes a signal transmission via ST51 and a signal transmission line ST12 (see reference). Figures 4A to 4C The signal transmission via ST51 can be composed of a first transmission segment S51, a second transmission segment S52, a third transmission segment S53, a fourth transmission segment S54, and a fifth transmission segment S55. The equivalent circuit X51 of the signal transmission via ST51 is composed of a first equivalent circuit C1, a sixth equivalent circuit C6, a second equivalent circuit C2, a third equivalent circuit C3, and a fourth equivalent circuit C4 connected in series according to the ABCD transmission matrix principle.

[0090] In some embodiments, the first bottom wiring layer 132b and its corresponding second cover layer 140b and third wiring layer 524 may constitute a first bottom pad p3'. The second bottom wiring layer 134b and its corresponding second cover layer 140b and third wiring layer 524 may constitute a plurality of second bottom pads p4'. The plurality of second bottom pads p4' surround the first bottom pad p3'. In some embodiments, the first transmission segment S51 includes the first bottom pad p3' and a plurality of second bottom pads p4', and the bottom wiring layer 130b, the third wiring layer 524 and the second cover layer 140b have the same material, such as copper, therefore the first transmission segment S51 is a uniform transmission segment, which is equivalent to Figure 10 The first equivalent circuit C1 in the middle. In other embodiments, the materials of the bottom line layer 130b, the third line layer 524 and the second cover layer 140b may be different, then the first transmission segment S51 can be regarded as three different uniform transmission segments, each corresponding to an equivalent circuit with different unit length parameters, and the present invention is not limited thereto.

[0091] In some embodiments, the sidewalls of the first bottom wiring layer 132b and its corresponding third wiring layer 524 and second cover layer 140b are flush with each other. The sidewalls of the second bottom wiring layer 134b and its corresponding third wiring layer 524 and second cover layer 140b are flush with each other.

[0092] The first bottom wiring layer 132b, the first conductive via V1, and the first top wiring layer 132a define the signal transmission path L51. The second bottom wiring layer 134b, the second conductive via V2, wiring layer 114b, the enclosing loop ground layer 114c, wiring layer 114a, and the second top wiring layer 134a define the ground path L52, and the ground path L52 surrounds the signal transmission path L51. In this way, the signal transmission path L51 is surrounded and enclosed by the ground path L52, allowing high-frequency and high-speed signals to be transmitted through the signal transmission path L51 and generate a return signal through the ground path L52, thus forming a good high-frequency and high-speed loop.

[0093] Figure 11 This is a cross-sectional schematic diagram of a circuit board structure according to another embodiment of the present invention. Figure 12 This is a top view schematic diagram of a circuit board structure according to an embodiment of the present invention. Figure 13 This is an equivalent circuit diagram of a signal transmission structure according to another embodiment of the present invention. It must be noted here that... Figure 11 , Figure 12 The embodiments follow Figure 1 , Figure 4A The component reference numerals and partial content of the embodiments are described below, wherein the same or similar reference numerals are used to represent the same or similar components, and descriptions of the same technical content are omitted. For explanations of the omitted parts, please refer to the foregoing embodiments, and will not be repeated here. Figure 11 It can be along Figure 12 A cross-sectional view of section line D-D'. Figure 13 It can be Figure 11 The equivalent circuit diagram of the signal transmission structure ST6.

[0094] Please refer to Figure 11 and Figure 12 The main difference between circuit board structure 60 and circuit board structure 10 is that circuit board structure 60 does not include the first top pad, but exposes the surface of the filling structure 150 and part of the conductive layer 130c. That is, the first top wiring layer 132a only includes the first top wiring portion 132a-2, which extends from the end of the first conductive via V1 and is electrically connected to the first conductive via V1. In other words, the first top wiring portion 132a-2 extends from the exposed part of the conductive layer 130c and is electrically connected to the conductive layer 130c.

[0095] A signal transmission structure ST6 is defined by a first bottom wiring layer 132b, a first conductive via V1, a first top wiring layer 132a, a second bottom wiring layer 134b, a portion of a second conductive via V2, a grounding layer 114c covering the loop, a second top wiring layer 134a, an insulating structure 116, and a portion of a first add-on structure 120 located between the first conductive via V1 and the plurality of second conductive vias V2. The signal transmission structure ST6 includes a signal transmission via ST61 and a signal transmission line ST62. The signal transmission via ST61 is composed of a first transmission segment S11, a second transmission segment S12, and a third transmission segment S13. The signal transmission line ST62 is composed of the first top wiring portion 132a-2. The equivalent circuit X6 of the signal transmission structure ST6 includes a first equivalent circuit C1, a second equivalent circuit C2, a third equivalent circuit C3, and a fourth equivalent circuit C4 connected in sequence. The first equivalent circuit C1 corresponds to the first bottom line layer 132b and the second bottom line layer 134b corresponding to the first bottom line layer 132b. For example, it can correspond to... Figure 11 The first transmission segment S11 is shown in the diagram. The second equivalent circuit C2 corresponds to the encasing loop ground layer 114c, the insulating structure 116, and a portion of the first conductive via V1 corresponding to the encasing loop ground layer 114c, for example, it may correspond to... Figure 11 The second transmission segment S12 shown is illustrated. The third equivalent circuit C3 corresponds to a portion of the first layer structure 120 located between the first conductive via V1 and the plurality of second conductive vias V2, and to a portion of the first conductive vias V1 and a portion of the second conductive vias V2 located within the first layer structure 120. For example, it may correspond to... Figure 11 The third transmission segment S13 is shown. The fourth equivalent circuit C4 corresponds to... Figure 12 The first top line portion 132a-2 and the portion of the second top line layer 134a surrounding the first top line portion 132a-2 are shown. The equivalent circuit X61 of the signal transmission via ST61 is formed by connecting the first equivalent circuit C1, the second equivalent circuit C2, and the third equivalent circuit C3 in series according to the ABCD transmission matrix principle. The equivalent circuit X62 of the signal transmission line ST62 includes a fourth equivalent circuit C4. In other embodiments, the first top line portion 132a-2 may be formed by connecting multiple line segments with different line widths (similar to...). Figure 4C The first top line section 132a-2) is used to adjust the resistance, inductance, conductance and capacitance parameters of the fourth equivalent circuit C4 to meet the impedance matching requirements.

[0096] The first bottom wiring layer 132b, the first conductive via V1, and the first top wiring layer 132a define a signal transmission path L61. The second bottom wiring layer 134b, the wrapping loop ground layer 114c, the second conductive via V2, and the second top wiring layer 134a define a ground path L62, which surrounds the signal transmission path L61. In this way, the signal transmission path L61 is surrounded and enclosed by the ground path L62, allowing high-frequency, high-speed signals to be transmitted through the signal transmission path L61 and generate a return signal through the ground path L62, thus forming a good high-frequency, high-speed loop.

[0097] In summary, the circuit board structure of the present invention has a signal transmission structure. The equivalent circuit of the signal transmission structure includes at least a first equivalent circuit, a second equivalent circuit, a third equivalent circuit, and a fourth equivalent circuit, which correspond to different uniform transmission segments. The signal transmission path of each uniform transmission segment is surrounded by a grounding path and is enclosed, which can reduce energy loss and noise interference, thereby forming a good high-frequency and high-speed signal transmission loop and improving the integrity and reliability of the signal.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circuit board structure, characterized in that, include: A substrate having a first surface and a second surface opposite to the first surface, wherein the substrate includes an opening through the substrate; A grounding layer covering the loop is disposed on the inner wall of the opening in the substrate; An insulating structure is disposed in the opening of the substrate; A first add-layer structure is disposed on the first surface of the substrate; A top wiring layer is disposed on the first layered structure, wherein the top wiring layer includes a first top wiring layer and a second top wiring layer; A bottom circuit layer is disposed on the second surface of the substrate, wherein the bottom circuit layer includes a first bottom circuit layer and a second bottom circuit layer; The first conductive via penetrates the first added layer structure and the insulating structure, and electrically connects the first top circuit layer and the first bottom circuit layer, wherein the insulating structure is located between the encapsulated loop ground layer and the first conductive via. as well as A plurality of second conductive vias penetrate the substrate and the first additive layer and surround the first conductive via, and electrically connect the second top circuit layer and the second bottom circuit layer, wherein the encapsulation loop ground layer is located between the plurality of second conductive vias and the first conductive via, and is electrically connected to the plurality of second conductive vias. The signal transmission structure is defined by the first bottom wiring layer, the first conductive via, the first top wiring layer, the second bottom wiring layer, the encapsulation loop ground layer, a portion of the plurality of second conductive vias, the second top wiring layer, the insulating structure, and a portion of the first add-on structure located between the first conductive via and the plurality of second conductive vias. The equivalent circuit of the signal transmission structure includes at least: The first equivalent circuit corresponds to the first bottom line layer and the second bottom line layer corresponding to the first bottom line layer. The second equivalent circuit corresponds to the grounding layer of the encasing loop, the insulating structure, and the portion of the first conductive via corresponding to the grounding layer of the encasing loop; A third equivalent circuit corresponds to the portion of the first augmented layer structure located between the first conductive via and the plurality of second conductive vias, and the portion of the first conductive via and the portion of the plurality of second conductive vias located within the first augmented layer structure; and The fourth equivalent circuit corresponds to the first top line layer and the second top line layer corresponding to the first top line layer; The first equivalent circuit, the second equivalent circuit, the third equivalent circuit, and the fourth equivalent circuit correspond to different uniform transmission segments, and the first equivalent circuit, the second equivalent circuit, the third equivalent circuit, and the fourth equivalent circuit are connected in series with each other using the ABCD transmission matrix series connection principle.

2. The circuit board structure according to claim 1, characterized in that, One end of the equivalent circuit of the signal transmission structure is connected to a receiver or transmitter, and the other end of the equivalent circuit of the signal transmission structure is connected to an antenna.

3. The circuit board structure according to claim 1, characterized in that, The unit length parameters of the first equivalent circuit, the second equivalent circuit, the third equivalent circuit, and the fourth equivalent circuit are different from each other.

4. The circuit board structure according to claim 3, characterized in that, The unit length parameter includes resistance, conductance, inductance, or capacitance.

5. The circuit board structure according to claim 1, characterized in that, The first bottom line layer, the first conductive via, and the first top line layer define a signal transmission path, and the second top line layer, the second conductive via, the encapsulation loop ground layer, and the second bottom line layer define a ground path, and the ground path surrounds the signal transmission path.

6. The circuit board structure according to claim 1, characterized in that, Also includes: A filling structure is disposed in the first conductive via and the plurality of second conductive vias.

7. The circuit board structure according to claim 2, characterized in that, The equivalent circuit of the signal transmission structure further includes: The fifth equivalent circuit is connected between the fourth equivalent circuit and the antenna.

8. The circuit board structure according to claim 7, characterized in that, The fifth equivalent circuit consists of multiple uniform transmission segments, and the equivalent circuits of the multiple uniform transmission segments are connected in series according to the ABCD transmission matrix series connection principle to achieve impedance matching.

9. The circuit board structure according to claim 8, characterized in that, The first top line layer includes: A first top pad portion is disposed at the end of the first conductive through hole and electrically connected to the first conductive through hole; and A first top line portion extends from and is electrically connected to the first top pad portion, wherein the fourth equivalent circuit corresponds to the first top pad portion and the fifth equivalent circuit corresponds to the first top line portion.

10. The circuit board structure according to claim 1, characterized in that, The equivalent circuit of the signal transmission structure further includes: A sixth equivalent circuit is connected between the third equivalent circuit and the fourth equivalent circuit or between the first equivalent circuit and the second equivalent circuit, wherein the structure corresponding to the sixth equivalent circuit is a uniform transmission segment.

11. The circuit board structure according to claim 10, characterized in that, The first layered structure includes: A first dielectric layer is disposed on the first surface of the substrate; The first circuit layer is disposed on the first dielectric layer; A second dielectric layer is disposed on the first circuit layer; and A second circuit layer is disposed on the second dielectric layer, wherein the top circuit layer is disposed on the second circuit layer. The third equivalent circuit corresponds to the first dielectric layer located between the first conductive via and the plurality of second conductive vias, and the sixth equivalent circuit corresponds to the second dielectric layer located between the first conductive via and the plurality of second conductive vias.

12. The circuit board structure according to claim 11, characterized in that, The equivalent circuit of the signal transmission structure further includes: A seventh equivalent circuit is connected between the third equivalent circuit and the sixth equivalent circuit, wherein the seventh equivalent circuit corresponds to a portion of the first circuit layer located between the first conductive via and the plurality of second conductive vias.

13. The circuit board structure according to claim 12, characterized in that, The first circuit layer includes a first inner pad located between the first conductive via and the plurality of second conductive vias, wherein the first inner pad is electrically connected to the first conductive via.

14. The circuit board structure according to claim 10, characterized in that, Also includes: A second add-in structure is disposed on the second surface of the substrate, wherein the first conductive via and the plurality of second conductive vias penetrate the second add-in structure. The sixth equivalent circuit corresponds to a portion of the second augmentation structure located between the first conductive via and the plurality of second conductive vias, and the first conductive via and a portion of the plurality of second conductive vias located in the second augmentation structure.

15. The circuit board structure according to claim 14, characterized in that, The second layered structure includes: A third dielectric layer is disposed on the second surface of the substrate; and A third circuit layer is disposed on the third dielectric layer, wherein the bottom circuit layer is disposed on the third circuit layer.

16. The circuit board structure according to claim 1, characterized in that, The first top circuit layer includes a first top circuit that extends from the end of the first conductive via and is electrically connected to the first conductive via, wherein the fourth equivalent circuit corresponds to the first top circuit.

17. The circuit board structure according to claim 1, characterized in that, Also includes: A first overlay layer is disposed on the top wiring layer; as well as The second overlay layer is disposed on the bottom line layer.

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