Printed circuit board and method for manufacturing the same

Abstract

The application provides a printed circuit board and a preparation method thereof, and the complete printed circuit board structure is formed by adopting glass as a PCB medium layer material and combining the step-by-step construction of a multi-layer build-up structure and a pressing process, high-density interconnection of a complex circuit is realized, and problems such as signal attenuation and poor reliability caused by insufficient dielectric properties, thermal stability or mechanical strength of a traditional PCB medium layer material in a high-frequency high-speed transmission scene are solved.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing technology, and in particular to a printed circuit board and its manufacturing method. Background Technology

[0002] With the rapid development of 5G communication, millimeter-wave radar, high-speed data centers, and artificial intelligence, the requirements for signal transmission rates and frequencies in electronic devices are continuously increasing. Printed circuit boards (PCBs), as the core interconnect carrier of electronic systems, directly affect signal integrity, transmission rates, and system reliability due to the performance of their dielectric layer materials. Traditional PCB dielectric layers often use materials such as epoxy resin (FR-4), polyimide (PI), and polytetrafluoroethylene (PTFE). However, in high-frequency (e.g., millimeter-wave bands above 28 GHz) and high-speed (e.g., 112 Gbps and above) transmission scenarios, their inherent limitations have become a technical bottleneck. Taking FR-4 as an example, its dielectric constant (Dk≈4.5-5.5) and loss factor (Df≈0.01-0.02) are relatively high. At high frequencies, due to the skin effect and increased dielectric loss, signal attenuation increases significantly (e.g., loss is approximately 0.5 dB / cm at 10 GHz), failing to meet the low-loss requirements of 5G base stations, high-speed backplanes, and other scenarios. While polyimide (PI) has a relatively low dielectric constant (Dk) (≈3.0-3.5), its high hygroscopicity (water absorption rate ≈1%-2%) easily leads to a mismatch in the coefficient of thermal expansion (CTE) (CTE ≈50ppm / ℃, far higher than copper's 17ppm / ℃), resulting in reliability issues such as interface delamination and circuit breakage. Polytetrafluoroethylene (PTFE), despite its excellent Dk (≈2.1) and Df (≈0.0004), suffers from high processing difficulty (requiring special sintering processes), low mechanical strength (poor bending resistance), weak adhesion to copper foil (requiring surface roughening treatment), and high cost, limiting its application to high-end aerospace or RF devices and hindering large-scale commercialization. Therefore, developing a novel dielectric layer material that combines low Dk / Df, high CTE matching, high mechanical strength, and process compatibility has become a key requirement in the high-frequency, high-speed PCB field. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a printed circuit board and its manufacturing method, which solves the problem that traditional PCB dielectric layer materials are insufficient in dielectric properties, thermal stability or mechanical strength, making it difficult to meet the requirements of high-frequency and high-speed transmission scenarios.

[0004] To achieve the above and other related objectives, the present invention provides a method for manufacturing a printed circuit board, the method comprising:

[0005] S1, a glass core board is provided, the glass core board including a glass substrate and a plurality of first through holes penetrating the glass substrate;

[0006] S2, forming a core metal layer that fills the first through hole and covers both opposite sides of the glass substrate;

[0007] S3, the core metal layer is etched using a subtractive etching method, while retaining the core metal layer inside the first through hole and the patterned core metal layer on the surface of the glass substrate;

[0008] S4, two first layered glass substrates are provided, and the two first layered glass substrates are respectively pressed onto the opposite sides of the glass core board through a layering adhesive film; wherein, the first layered glass substrate includes a first layered glass substrate and a plurality of second through holes that penetrate the first layered glass substrate and expose the metal layer of the core board.

[0009] S5, forming a first layer of metal that fills the second through hole and covers the surface of the first layered glass substrate;

[0010] S6, the first additive metal layer is etched using a subtractive etching method, retaining the first additive metal layer in the second through hole and the first additive metal layer patterned on the surface of the first additive glass substrate; wherein, the first additive metal layer in the second through hole is in contact with the core metal layer in the first through hole, and the first additive glass substrate and the first additive metal layer constitute the first additive layer.

[0011] S7, replace the glass core plate in step S4 with the structure obtained after step S6, and replace the core plate metal layer in step S4 with the first added metal layer of the structure obtained after step S6, and repeat steps S4 to S6.

[0012] S8, repeat step S7 until the desired number of add-on layers are obtained; wherein, the outermost add-on layer of the structure includes an add-on glass substrate and a plurality of add-on through holes penetrating the add-on glass substrate, and also includes an add-on metal layer filled in the add-on through holes and an add-on metal layer patterned on the surface of the add-on glass substrate, the add-on metal layer in the add-on through holes being electrically connected to the first add-on metal layer in the second through hole and the core metal layer in the first through hole;

[0013] S9, a solder resist photoresist layer is attached to the two opposite sides of the obtained structure, and the solder resist photoresist layer is patterned to expose the outer layer metal layer located on the surface of the outer layer glass substrate and electrically connected to the first layer metal layer in the second through hole.

[0014] S10, perform surface anti-oxidation treatment on the exposed external metal layer;

[0015] S11, Remove the solder resist photoresist layer and the reinforcing film from the preset cutting area;

[0016] S12, cut along the preset cutting area.

[0017] Optionally, the glass substrate is made of alkali-free glass, the first add-on glass substrate is made of alkali-free glass, and the outer add-on glass substrate is made of alkali-free glass.

[0018] Optionally, the thickness of the glass substrate is less than or equal to 150 μm, the thickness of the first add-on glass substrate is less than or equal to 150 μm, and the thickness of the outer add-on glass substrate is less than or equal to 150 μm; the aperture of the first through-hole is less than or equal to 50 μm, the aperture of the second through-hole is less than or equal to 50 μm, and the aperture of the outer add-on through-hole is less than or equal to 50 μm; and the distance between two adjacent first through-holes is less than or equal to 150 μm, the distance between two adjacent second through-holes is less than or equal to 150 μm, and the distance between two adjacent outer add-on through-holes is less than or equal to 150 μm.

[0019] Optionally, in step S1, an organic buffer layer is formed on the inner wall of all the first through holes and on the two opposite surfaces of the glass substrate; in step S4, an organic buffer layer is formed on the inner wall of all the second through holes and on the surface of the first added-layer glass substrate.

[0020] Optionally, before step S4, a step of roughening the core metal layer patterned on the surface of the glass substrate using an acidic solution is included.

[0021] Optionally, the admixture film is an ABF film; in step S4, the method of pressing the two first admixture glass substrates onto opposite sides of the glass core board using the admixture film includes:

[0022] S41, the adhesive film is attached to the two opposite sides of the glass core board;

[0023] S42, the two first laminated glass substrates are respectively adhered to the laminated adhesive film on opposite sides of the glass core board;

[0024] S43, vacuum pressing and high-temperature curing are performed, and adhesive overflow is formed in the second through hole;

[0025] S44, The excess adhesive from step S43 is removed using a plasma cleaning process.

[0026] Optionally, in step S5, an electroplating process is used to form the first augmented metal layer that fills the second through hole and covers the surface of the first augmented glass substrate; before step S5, an electroplating seed layer is formed on the inner wall and bottom wall of the second through hole and on the surface of the first augmented glass substrate.

[0027] Optionally, in step S6, the method of etching the first augmentation metal layer using a subtractive etching method to retain the first augmentation metal layer within the second via and the patterned first augmentation metal layer on the surface of the first augmentation glass substrate includes:

[0028] S61, a photoresist layer is attached to the surface of the first added metal layer;

[0029] S62, the photoresist layer is exposed and developed to form a patterned photoresist layer;

[0030] S63, the first add-on metal layer is etched based on the patterned photoresist layer to remove the first add-on metal layer not covered by the patterned photoresist layer, and then the patterned photoresist layer is removed.

[0031] Optionally, in step S10, the method for performing surface anti-oxidation treatment on the exposed externally reinforced metal layer includes electroplating on the surface of the exposed externally reinforced metal layer to form an anti-oxidation layer; wherein the material of the anti-oxidation layer includes one or more of nickel, palladium and gold.

[0032] Optionally,

[0033] In step S11, the method for removing the solder resist photoresist layer and the reinforcing film in the preset cutting area includes:

[0034] S111, the solder resist photoresist layer in the preset cutting area is grooved using an infrared laser ablation process;

[0035] S112, the picosecond green laser ablation process is used to remove the thickened adhesive film in the preset cutting area;

[0036] In step S12, laser-induced infrared laser cutting technology is used to cut along the preset cutting area.

[0037] Optionally, the number of layers in the added-layer stack is 2 to 10.

[0038] The present invention also provides a printed circuit board, the printed circuit board comprising:

[0039] A glass core board includes a glass substrate and a plurality of first through holes penetrating the glass substrate, and also includes a core board metal layer within the first through holes and the core board metal layer patterned on the surface of the glass substrate.

[0040] The required number of addenda layers are disposed on both sides of the glass core board; each addenda layer is pressed onto the glass core board or the lower addenda layer by an addenda film. The lower addenda layer includes a first addenda glass substrate, a plurality of second through holes penetrating the first addenda glass substrate, and a first addenda metal layer. The first addenda metal layer includes a first addenda metal layer filling the second through holes and a first addenda metal layer patterned on the surface of the first addenda glass substrate. The upper first addenda metal layer is in contact with the core board metal layer or the lower first addenda metal layer. The outermost addenda layer of the structure includes an outer addenda glass substrate and a plurality of outer addenda through holes penetrating the outer addenda glass substrate, and also includes an outer addenda metal layer filling the outer addenda through holes and an outer addenda metal layer patterned on the surface of the outer addenda glass substrate. The outer addenda metal layer in the outer addenda through holes is electrically connected to the lower first addenda metal layer and the core board metal layer.

[0041] A solder resist photoresist layer is formed on the surface of the superplastic glass substrate and the surface of the superplastic metal layer in a predetermined solder resist area.

[0042] An anti-oxidation layer is formed on the exposed surface of the externally reinforced metal layer.

[0043] As described above, the printed circuit board and its fabrication method of the present invention have the following beneficial effects: By using glass as the PCB dielectric layer material and combining it with a multilayer build-up structure and lamination process to form a complete printed circuit board structure, the problems of signal attenuation and poor reliability caused by insufficient dielectric properties, thermal stability, or mechanical strength of traditional PCB dielectric layer materials in high-frequency and high-speed transmission scenarios are solved. Specifically, this method utilizes the low dielectric constant (Dk), low loss factor (Df), high thermal stability and low hygroscopicity, high mechanical strength and chemical resistance, and low signal interference characteristics of the glass substrate to significantly reduce signal transmission loss and improve the performance of the PCB under high-frequency and high-speed conditions. Simultaneously, through the gradual construction of a multilayer build-up structure, high-density interconnection of complex circuits is achieved, enhancing the overall mechanical strength and reliability of the PCB. Furthermore, this method also reduces manufacturing costs and improves production efficiency by optimizing the process flow, thereby achieving the beneficial effects of improving the performance of high-frequency and high-speed PCBs, expanding their application scenarios, and reducing overall costs.

[0044] The beneficial effects of this invention are specifically reflected in the following aspects:

[0045] Economic Benefits: Expanding high-frequency and high-speed application scenarios and increasing market size. Traditional dielectric layer materials (such as FR-4) are only suitable for low-frequency (<10GHz) scenarios due to high high-frequency losses; although PTFE has excellent performance, it is limited by cost and processing difficulty, and is mainly used in high-end niche fields such as aerospace and military. This invention, through the low Dk / Df (0.001-0.005) and high-frequency stability of the glass dielectric layer, can extend the application scenarios of PCBs from traditional low-frequency fields to the following high-value-added markets.

[0046] Beneficial effects of the technology: Reduces the overall cost of end products and enhances market competitiveness. Traditional high-frequency, high-speed PCBs (such as PCBs using PTFE or modified PI) suffer from high material costs (PTFE resin is about 5-8 times more expensive than FR-4) and complex processing techniques (requiring special sintering or surface roughening treatment), resulting in high manufacturing costs for end products (such as 5G base stations, millimeter-wave radar, and high-speed switches). This invention, however, significantly reduces costs by optimizing the material system of the glass dielectric layer (such as custom-designed low Dk / Df glass) and supporting processes (such as surface treatment and interface bonding technology).

[0047] Beneficial social effects: By applying glass materials to the dielectric layer of high-frequency, high-speed PCBs, not only are the performance bottlenecks of traditional materials in high-frequency scenarios resolved, but significant economic benefits are also generated for enterprises by reducing overall costs, expanding high-value-added markets, improving product reliability, and promoting supply chain collaboration. Furthermore, the widespread application of the printed circuit board and its fabrication method of this invention will accelerate the popularization of high-frequency, high-speed electronic devices (such as 5G and autonomous driving), providing support for the technological upgrading and high-quality economic development of the entire electronic information industry. Attached Figure Description

[0048] Figure 1 The diagram shown is a flowchart illustrating the method for preparing a printed circuit board according to the present invention.

[0049] Figures 2 to 20 The diagram shows the process flow of the printed circuit board manufacturing method of the present invention.

[0050] Component designation explanation

[0051] 10 Glass core board

[0052] 100 glass substrate

[0053] 101 First Through Hole

[0054] 103 Organic Buffer Layer

[0055] 11 Core board metal layer

[0056] 12 First Addition Glass Substrate

[0057] 121 First layered glass substrate

[0058] 122 Second Through Hole

[0059] 13 First Addition Film

[0060] 130 Excess Adhesive

[0061] 14 Electroplated seed layer

[0062] 15 First Addition Metal Layer

[0063] 16. Externally laminated glass substrate

[0064] 17 External layer through-hole

[0065] 18 External metal layers

[0066] 19 Second layer adhesive film

[0067] 20 Solder resist photoresist layer

[0068] 201 Non-photosensitive solder resist layer

[0069] 202 Photosensitive solder resist layer

[0070] 21 Anti-oxidation layer

[0071] 22 Infrared lasers

[0072] 23 Picosecond Green Laser

[0073] 24 Laser-induced infrared laser

[0074] 25. Rear edge of the cleavage

[0075] 26 Photoresist layer

[0076] 261 Unexposed photoresist layer

[0077] 262 Photosensitive photoresist layer

[0078] Steps S1 to S12 Detailed Implementation

[0079] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0080] Please see Figures 1 to 20It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0081] This embodiment provides a method for manufacturing a printed circuit board, such as... Figure 1 As shown, the preparation method includes:

[0082] S1, a glass core board is provided, the glass core board including a glass substrate and a plurality of first through holes penetrating the glass substrate;

[0083] S2, forming a core metal layer that fills the first through hole and covers both opposite sides of the glass substrate;

[0084] S3, the core metal layer is etched using a subtractive etching method, while retaining the core metal layer inside the first through hole and the patterned core metal layer on the surface of the glass substrate;

[0085] S4, two first layered glass substrates are provided, and the two first layered glass substrates are respectively pressed onto the opposite sides of the glass core board through a layering adhesive film; wherein, the first layered glass substrate includes a first layered glass substrate and a plurality of second through holes that penetrate the first layered glass substrate and expose the metal layer of the core board.

[0086] S5, forming a first augmentation metal layer that fills the second through hole and covers the surface of the first augmentation glass substrate;

[0087] S6, the first additive metal layer is etched using a subtractive etching method, retaining the first additive metal layer in the second through hole and the first additive metal layer patterned on the surface of the first additive glass substrate; wherein, the first additive metal layer in the second through hole is in contact with the core metal layer in the first through hole, and the first additive glass substrate and the first additive metal layer constitute the first additive layer.

[0088] S7, replace the glass core plate in step S4 with the structure obtained after step S6, and replace the core plate metal layer in step S4 with the first added metal layer of the structure obtained after step S6, and repeat steps S4 to S6.

[0089] S8, repeat step S7 until the desired number of add-on layers are obtained; wherein, the outermost add-on layer of the structure includes an add-on glass substrate and a plurality of add-on through holes penetrating the add-on glass substrate, and also includes an add-on metal layer filled in the add-on through holes and an add-on metal layer patterned on the surface of the add-on glass substrate, the add-on metal layer in the add-on through holes being electrically connected to the first add-on metal layer in the second through hole and the core metal layer in the first through hole;

[0090] S9, a solder resist photoresist layer is attached to the two opposite sides of the obtained structure, and the solder resist photoresist layer is patterned to expose the outer layer metal layer located on the surface of the outer layer glass substrate and electrically connected to the first layer metal layer in the second through hole.

[0091] S10, perform surface anti-oxidation treatment on the exposed external metal layer;

[0092] S11, Remove the solder resist photoresist layer and the reinforcing film from the preset cutting area;

[0093] S12, cut along the preset cutting area.

[0094] The printed circuit board (PCB) fabrication method of this embodiment uses glass as the PCB dielectric layer material and combines a multilayer build-up structure with a lamination process to form a complete PCB structure. This solves the problems of signal attenuation and poor reliability caused by insufficient dielectric properties, thermal stability, or mechanical strength of traditional PCB dielectric layer materials in high-frequency, high-speed transmission scenarios. Specifically, this method utilizes the low dielectric constant (Dk), low loss factor (Df), high thermal stability and low moisture absorption, high mechanical strength and chemical resistance, and low signal interference characteristics of the glass substrate to significantly reduce signal transmission loss and improve PCB performance under high-frequency, high-speed conditions. Simultaneously, the gradual construction of the multilayer build-up structure enables high-density interconnection of complex circuits, enhancing the overall mechanical strength and reliability of the PCB. Furthermore, this method optimizes the process flow, reduces manufacturing costs, and improves production efficiency, thereby achieving the beneficial effects of improving the performance of high-frequency, high-speed PCBs, expanding their application scenarios, and reducing overall costs.

[0095] Specifically, the dielectric constant (Dk) of the glass is typically 3.0–4.0, close to that of PTFE; its dielectric constant (Df) can be as low as 0.001–0.005, only 1 / 10–1 / 20 of that of FR-4, resulting in minimal dielectric loss at high frequencies and significantly reduced signal attenuation. The coulombic conductivity (CTE) of the glass can be adjusted to match that of copper (15 ppm / ℃–20 ppm / ℃) through compositional control (e.g., adding boron, aluminum, etc.), and its water absorption rate is less than 0.1%, far lower than the 1%–2% of PI and the 0.1%–0.3% of FR-4, effectively reducing thermal stress and interfacial hydrolysis, and improving long-term reliability. The glass has a Mohs hardness of 5–7, higher than 2–3 of PI and 3–4 of FR-4, high flexural strength (approximately 100 MPa–200 MPa), and is resistant to acid and alkali corrosion, making it suitable for harsh environments. The glass also has excellent insulation properties, with a volume resistivity greater than 10 Ω·cm. 14 With a strength of Ω·cm, it can suppress leakage current and electromagnetic interference (EMI), making it suitable for high-density interconnect (HDI) and radio frequency (RF) circuits.

[0096] The method for manufacturing the printed circuit board of this embodiment will be described in detail below with reference to the specific accompanying drawings.

[0097] like Figure 2 As shown, step S1 is performed first, providing a glass core plate 10, which includes a glass substrate 100 and a plurality of first through holes 101 penetrating the glass substrate 100.

[0098] As an example, the thickness of the glass substrate 10 is less than or equal to 150 μm, enabling the printed circuit board to achieve a smaller size and higher integration, which is crucial for meeting the miniaturization and high performance requirements of modern electronic devices. The thickness of the glass substrate 10 can also be adjusted according to actual needs and is not limited to this embodiment.

[0099] As an example, the diameter of the first via 101 is less than or equal to 50 μm, and the spacing between two adjacent first vias 101 is less than or equal to 150 μm. The small diameter and spacing of the first vias 101 further improve the wiring density of the printed circuit board, allowing more circuit components to be interconnected within a limited space, thereby improving the performance and functionality of the entire circuit system. Furthermore, the small diameter and spacing design also helps reduce crosstalk and electromagnetic interference during signal transmission, improves signal integrity, and further enhances high-frequency and high-speed signal transmission capabilities. The diameter of the first via 101 and the spacing between two adjacent first vias 101 can also be adjusted according to actual needs and are not limited to this embodiment.

[0100] Preferably, the glass substrate 10 in this embodiment is made of alkali-free glass to ensure compatibility with current glass manufacturing processes and achieve a smaller target thickness. This allows the glass substrate 10 to achieve smaller size and higher integration in high-frequency, high-speed PCBs, meeting the miniaturization and high-performance requirements of modern electronic devices. The material of the glass substrate 10 can be selected based on the actual process and target thickness, and is not limited to this embodiment.

[0101] As a preferred example, in step S1, an organic buffer layer 103 is formed on the inner wall of all the first through holes 101 and on the two opposing surfaces of the glass substrate 100 to effectively reduce stress and provide additional buffer protection for the glass substrate 100.

[0102] like Figure 3 As shown, step S2 is then performed to form a core metal layer 11 that fills the first through hole 101 and covers the two opposite sides of the glass substrate 100.

[0103] Specifically, step S2 can employ core board manufacturing technology commonly used in the field, namely, using a single-board pulse electroplating process to electroplat and fill the first through hole 101.

[0104] Continue to refer to Figure 3 Next, step S3 is performed, in which the core metal layer 11 is etched using a subtractive etching method, retaining the core metal layer 11 within the first through hole 101 and the core metal layer 11 patterned on the surface of the glass substrate 100.

[0105] like Figure 6 As shown, step S4 is then performed, providing two first layered glass substrates 12, and pressing the two first layered glass substrates 12 onto opposite sides of the glass core plate 10 respectively through a layering adhesive film; wherein, the first layered glass substrate 12 includes a first layered glass substrate 121 and a plurality of second through holes 122 penetrating the first layered glass substrate 121 and exposing the core plate metal layer 11.

[0106] As a better example, such as Figure 3 As shown, before step S4, the process further includes a step of roughening the core metal layer 11 patterned on the surface of the glass substrate 100 with an acid solution to increase the bonding force between the glass core 10 and the first added-layer glass substrate 12, thereby improving product reliability.

[0107] Preferably, the material of the first layered glass substrate 121 in this embodiment is alkali-free glass, and the beneficial effects it can achieve can be found in the description of the material of the glass substrate 10, which will not be repeated here.

[0108] As an example, the thickness of the first layered glass substrate 121 is less than or equal to 150 μm, the aperture of the second through hole 122 is less than or equal to 50 μm, and the spacing between two adjacent second through holes 122 is less than or equal to 150 μm. The beneficial effects that can be achieved can be found in the description of the glass substrate 10 and the first through hole 101, which will not be repeated here.

[0109] Furthermore, the hole spacing of the second through holes 122 in the two first augmented glass substrates 12 on opposite sides of the glass core plate 10 can be different. That is, the positions of the second through holes 122 in the two first augmented glass substrates 12 do not need to be completely aligned vertically. In this embodiment, the second through hole 122 located below the glass core plate 10 is used to conduct components with larger pitches, while the second through hole 122 located above is used to conduct components with smaller pitches. The hole diameter and spacing of the second through holes 122 can be adjusted according to design requirements and are not limited to this embodiment.

[0110] As a preferred example, an organic buffer layer (not shown) is formed on the inner wall of all the second through holes 122 and on the surface of the first laminated glass substrate 121 to effectively reduce stress and provide additional buffer protection for the first laminated glass substrate 12.

[0111] As a specific example, such as Figures 4 to 6 As shown, in step S4, the method of pressing the two first laminated glass substrates 12 onto opposite sides of the glass core plate 10 using the laminated adhesive film includes:

[0112] S41, as Figure 4 As shown, the add-on film is attached to both opposite sides of the glass core plate 10. Specifically, the add-on film is a first add-on film 13. Preferably, in this embodiment, the first add-on film 13 is ABF (Ajinomoto Build-up Film). ABF is attached using ABF vacuum lamination equipment to achieve fine wiring and improve the input / output pin (I / O) density and wiring flexibility of the package structure.

[0113] S42, as Figure 4 As shown, two first-layer glass substrates 12 are respectively adhered to the layered adhesive film on opposite sides of the glass core plate 10.

[0114] S43, as Figure 5 As shown, vacuum pressing and high-temperature curing are performed, and an overflow adhesive 130 is formed in the second through hole 122;

[0115] S44, as Figure 6As shown, the excess adhesive 130 in step S43 is removed using a plasma cleaning process.

[0116] like Figure 8 As shown, step S5 is then performed to form a first augmented metal layer 15 that fills the second through hole 122 and covers the surface of the first augmented glass substrate 121.

[0117] As an example, the first augmented metal layer 15, which fills the second through-hole 122 and covers the surface of the first augmented glass substrate, can be formed using an electroplating process; and preferably, such as Figure 7 As shown, before step S5, the method further includes forming an electroplating seed layer 14 on the inner wall and bottom wall of the second through hole 122 and on the surface of the first laminated glass substrate 121.

[0118] like Figure 12 As shown, step S6 is then performed, in which the first augmentation metal layer 15 is etched using a subtractive etching method, retaining the first augmentation metal layer 15 within the second through hole 122 and the first augmentation metal layer 15 patterned on the surface of the first augmentation glass substrate 121; wherein, the first augmentation metal layer 15 within the second through hole 122 is in contact with the core metal layer 11 within the first through hole 101, and the first augmentation glass substrate 12 and the first augmentation metal layer 15 constitute the first augmentation layer.

[0119] As a specific example, such as Figures 9 to 12 As shown, in step S6, the method of etching the first augmentation metal layer 15 using a subtractive etching method to retain the first augmentation metal layer 15 within the second via 122 and the patterned first augmentation metal layer 15 on the surface of the first augmentation glass substrate 121 includes:

[0120] S61, such as Figure 9 As shown, a photoresist layer 26 is attached to the surface of the first added metal layer 15.

[0121] S62, such as Figure 10 and Figure 11 As shown, the photoresist layer 26 is exposed and developed to form a patterned photoresist layer 26. Specifically, the material and photosensitive type of the photoresist layer 26 can be selected according to actual needs. This embodiment uses a negative photoresist as an example for illustration. Figure 10 As shown, the photoresist layer 26 is patterned and exposed to form an unexposed photoresist layer 261 and a photosensitive photoresist layer 262. The photosensitive photoresist layer 262 illustratively includes patterns of the first augmented metal layer 15 such as holes, disks, and lines. Then, the unexposed photoresist layer 261 is removed using a developing solution corresponding to the photoresist.

[0122] S63, such as Figure 12 As shown, the first add-on metal layer 15 is etched based on the patterned photoresist layer 26 to remove the first add-on metal layer 15 not covered by the patterned photoresist layer 26, and then the patterned photoresist layer 26 is removed.

[0123] Specifically, such as Figure 12 As shown, when the electroplating seed layer 14 is formed on the surface of the first layered glass substrate 121, step S63 further includes the step of removing the electroplating seed layer 14 that is not covered by the patterned photoresist layer 26.

[0124] like Figure 13 As shown, step S7 is then performed, in which the structure obtained after step S6 replaces the glass core plate 10 in step S4, and the first added metal layer 15 of the structure obtained after step S6 replaces the core plate metal layer 11 in step S4, and steps S4 to S6 are repeated.

[0125] like Figure 13 As shown, step S8 is then performed, and step S7 is repeated until the desired number of layers is obtained; wherein, the outermost layer of the structure includes an outer layer glass substrate 16 and a plurality of outer layer through holes 17 penetrating the outer layer glass substrate 16, and also includes an outer layer metal layer 18 filled in the outer layer through holes 17 and an outer layer metal layer 18 patterned on the surface of the outer layer glass substrate 16, the outer layer metal layer 18 in the outer layer through holes 17 is electrically connected to the first layer metal layer 15 in the second through hole 122 and the core board metal layer 11 in the first through hole 101.

[0126] As an example, each of the aforementioned addenda layers is bonded together by laminating an addenda film, specifically, as shown below. Figure 13 As shown, the additive film is a second additive film 19. Preferably, in this embodiment, the second additive film 19 is ABF, and ABF is attached using an ABF vacuum lamination device to achieve fine wiring and improve the input / output pin (I / O) density and wiring flexibility of the package structure.

[0127] As an example, the number of layers in the added-layer stack is 2 to 10, to increase the wiring density and interconnect complexity of the PCB, thereby meeting the needs of modern electronic devices for high-density, high-performance circuits. Figure 13 As shown in the figure, this embodiment takes a stack of 2 layers as an example for illustration. The 2-layer stack of 2 layers are the first stack and the outer stack.

[0128] Preferably, the material of the outer layer glass substrate 16 in this embodiment is alkali-free glass, and the beneficial effects it can achieve can be referred to the description of the material of the glass substrate 10, which will not be repeated here.

[0129] As an example, the thickness of the outer layer glass substrate 16 is less than or equal to 150 μm, the aperture of the outer layer through hole 17 is less than or equal to 50 μm, and the spacing between two adjacent outer layer through holes 17 is less than or equal to 150 μm. The beneficial effects that can be achieved can be referred to the description of the glass substrate 10 and the first through hole 101, which will not be repeated here.

[0130] like Figures 14 to 16 As shown, step S9 is then performed, where a solder resist photoresist layer 20 is attached to both opposite sides of the obtained structure, and the solder resist photoresist layer 20 is patterned to expose the outer layer metal layer 18 located on the surface of the outer layer glass substrate 16 and electrically connected to the first layer metal layer 15 in the second through hole 122.

[0131] Specifically, the material and photosensitive type of the solder resist photoresist layer 20 can be selected according to actual needs. This embodiment uses a negative photoresist as an example for illustration. Figure 15 As shown, the solder resist photoresist layer 20 is patterned and exposed to form an unexposed solder resist photoresist layer 201 and an exposed solder resist photoresist layer 202. Then, the unexposed solder resist photoresist layer 201 is removed using the developing solution corresponding to the photoresist.

[0132] like Figure 17 As shown, step S10 is then performed to perform surface anti-oxidation treatment on the exposed external metal layer 18.

[0133] Specifically, as an example, in step S10, the method for performing surface anti-oxidation treatment on the exposed externally reinforced metal layer 18 includes electroplating the exposed externally reinforced metal layer 18 to form an anti-oxidation layer 21; wherein, the material of the anti-oxidation layer 21 includes one or more of nickel, palladium and gold, and can be selected according to actual needs, without excessive restrictions here.

[0134] like Figure 18 and Figure 19 As shown, step S11 is then performed to remove the solder resist photoresist layer 20 (refer to) in the preset cutting area. Figure 18 ) and the aforementioned thickening film (reference) Figure 19 ).

[0135] Specifically, the solder resist photoresist layer 20 in the preset cutting area is the photosensitive solder resist photoresist layer 202 left in step S9. The add-on film includes the add-on film between all the add-on layers and the first add-on film 13 between the first add-on layer and the glass core board 10, that is, the add-on film includes the first add-on film 13 and all the second add-on films 19, so as to achieve the effect of clearing the cutting path.

[0136] In step S11, the method for removing the solder resist photoresist layer 20 and the reinforcing film from the preset cutting area includes:

[0137] S111, such as Figure 18 The process involves using an infrared laser 22 ablation technique to create grooves in the solder resist photoresist layer within the pre-defined cutting area. The infrared laser 22 is described as follows: Figure 18 As shown.

[0138] S112, as Figure 19 The aforementioned process involves using a picosecond green laser ablation technique to remove the thickened adhesive film from the pre-defined cutting area, wherein the picosecond green laser 23, as described above... Figure 19 As shown.

[0139] like Figure 20 As shown, step S12 is then performed, exemplarily employing a laser-induced infrared laser cutting process to cut along the preset cutting path area, wherein the laser-induced infrared laser 24 and the resulting cleavage edge 25 are as follows: Figure 20 As shown.

[0140] This embodiment also provides a printed circuit board, such as Figures 2 to 17 As shown, the printed circuit board includes:

[0141] The glass core board 10 includes a glass substrate 100 and a plurality of first through holes 101 penetrating the glass substrate 100, and also includes a core board metal layer 11 in the first through holes 101 and the core board metal layer 11 patterned on the surface of the glass substrate 100.

[0142] The required number of addendum layers are disposed on both sides of the glass core board 10; each addendum layer is pressed onto the glass core board 10 or the lower addendum layer by an addendum film. The lower addendum layer includes a first addendum glass substrate 121, a plurality of second through holes 122 penetrating the first addendum glass substrate 121, and a first addendum metal layer 15. The first addendum metal layer 15 includes a first addendum metal layer 15 filling the second through holes 122 and a first addendum metal layer 15 patterned on the surface of the first addendum glass substrate 121. The upper first addendum metal layer 15 is in contact with the core board metal layer 11 or the lower first addendum metal layer 15.

[0143] The outermost layer of the structure includes an outer layer glass substrate 16 and a plurality of outer layer through holes 17 penetrating the outer layer glass substrate 16, and also includes an outer layer metal layer 18 filled in the outer layer through holes 17 and an outer layer metal layer 18 patterned on the surface of the outer layer glass substrate 16. The outer layer metal layer 18 in the outer layer through holes 17 is electrically connected to the lower first layer metal layer 15 and the core board metal layer 11.

[0144] A solder resist photoresist layer 20 is formed on the surface of the outer glass substrate 16 and the surface of the outer metal layer 18 in a predetermined solder resist area.

[0145] An anti-oxidation layer 21 is formed on the exposed surface of the externally reinforced metal layer 18.

[0146] The printed circuit board can be prepared using the above-described method, but it is not limited to this method. Other suitable methods are also possible, and their beneficial effects can be found in the specific description of the preparation method, which will not be repeated here.

[0147] In summary, the printed circuit board and its fabrication method of this invention, by using glass as the PCB dielectric layer material and combining it with a multilayer build-up structure and lamination process to form a complete printed circuit board structure, solves the problems of signal attenuation and poor reliability caused by insufficient dielectric properties, thermal stability, or mechanical strength of traditional PCB dielectric layer materials in high-frequency and high-speed transmission scenarios. Specifically, this method utilizes the low dielectric constant (Dk), low loss factor (Df), high thermal stability and low moisture absorption, high mechanical strength and chemical resistance, and low signal interference characteristics of the glass substrate to significantly reduce signal transmission loss and improve the performance of the PCB under high-frequency and high-speed conditions. Simultaneously, the gradual construction of the multilayer build-up structure achieves high-density interconnection of complex circuits, enhancing the overall mechanical strength and reliability of the PCB. Furthermore, this method also reduces manufacturing costs and improves production efficiency by optimizing the process flow, thereby achieving the beneficial effects of improving the performance of high-frequency and high-speed PCBs, expanding their application scenarios, and reducing overall costs. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability.

[0148] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method of manufacturing a printed circuit board, characterized by, The preparation method includes: S1, a glass core board is provided, the glass core board including a glass substrate and a plurality of first through holes penetrating the glass substrate; S2, forming a core metal layer that fills the first through hole and covers both opposite sides of the glass substrate; S3, the core metal layer is etched using a subtractive etching method, while retaining the core metal layer inside the first through hole and the patterned core metal layer on the surface of the glass substrate; S4, two first layered glass substrates are provided, and the two first layered glass substrates are respectively pressed onto the opposite sides of the glass core board through a layering adhesive film; wherein, the first layered glass substrate includes a first layered glass substrate and a plurality of second through holes that penetrate the first layered glass substrate and expose the metal layer of the core board. S5, forming a first layer of metal that fills the second through hole and covers the surface of the first layered glass substrate; S6, the first additive metal layer is etched using a subtractive etching method, retaining the first additive metal layer in the second through hole and the first additive metal layer patterned on the surface of the first additive glass substrate; wherein, the first additive metal layer in the second through hole is in contact with the core metal layer in the first through hole, and the first additive glass substrate and the first additive metal layer constitute the first additive layer. S7, replace the glass core plate in step S4 with the structure obtained after step S6, and replace the core plate metal layer in step S4 with the first added metal layer of the structure obtained after step S6, and repeat steps S4 to S6. S8, repeat step S7 until the desired number of add-on layers are obtained; wherein, the outermost add-on layer of the structure includes an add-on glass substrate and a plurality of add-on through holes penetrating the add-on glass substrate, and also includes an add-on metal layer filled in the add-on through holes and an add-on metal layer patterned on the surface of the add-on glass substrate, the add-on metal layer in the add-on through holes being electrically connected to the first add-on metal layer in the second through hole and the core metal layer in the first through hole; S9, a solder resist photoresist layer is attached to the two opposite sides of the obtained structure, and the solder resist photoresist layer is patterned to expose the outer layer metal layer located on the surface of the outer layer glass substrate and electrically connected to the first layer metal layer in the second through hole. S10, perform surface anti-oxidation treatment on the exposed external metal layer; S11, Remove the solder resist photoresist layer and the reinforcing film from the preset cutting area; S12, cut along the preset cutting area.

2. The method of manufacturing a printed circuit board according to claim 1, characterized by: The glass substrate is made of alkali-free glass, the first add-on glass substrate is made of alkali-free glass, and the outer add-on glass substrate is made of alkali-free glass.

3. The method of manufacturing a printed circuit board according to claim 1, characterized by: The thickness of the glass substrate is less than or equal to 150 μm, the thickness of the first layered glass substrate is less than or equal to 150 μm, and the thickness of the outer layered glass substrate is less than or equal to 150 μm. The diameter of the first through hole is less than or equal to 50 μm, the diameter of the second through hole is less than or equal to 50 μm, and the diameter of the through hole of the outer layer is less than or equal to 50 μm; and the distance between two adjacent first through holes is less than or equal to 150 μm, the distance between two adjacent second through holes is less than or equal to 150 μm, and the distance between two adjacent through holes of the outer layer is less than or equal to 150 μm.

4. The method of manufacturing a printed circuit board according to claim 1, characterized by: In step S1, an organic buffer layer is formed on the inner wall of all the first through holes and on the two opposite sides of the glass substrate; in step S4, an organic buffer layer is formed on the inner wall of all the second through holes and on the surface of the first added-layer glass substrate.

5. The method of manufacturing a printed circuit board according to claim 1, characterized by: Before step S4, the process also includes a step of roughening the core metal layer patterned on the surface of the glass substrate using an acidic solution.

6. The method of manufacturing a printed circuit board according to claim 1, characterized by: The adhesive film used for layering is an ABF film. In step S4, the method of pressing the two first laminated glass substrates onto opposite sides of the glass core board using the laminated adhesive film includes: S41, the adhesive film is attached to the two opposite sides of the glass core board; S42, the two first laminated glass substrates are respectively adhered to the laminated adhesive film on opposite sides of the glass core board; S43, vacuum pressing and high-temperature curing are performed, and adhesive overflow is formed in the second through hole; S44, The excess adhesive from step S43 is removed using a plasma cleaning process.

7. The method of manufacturing a printed circuit board according to claim 1, characterized by: In step S5, an electroplating process is used to form the first augmented metal layer that fills the second through hole and covers the surface of the first augmented glass substrate. Before step S5, an electroplating seed layer is formed on the inner wall and bottom wall of the second through hole and on the surface of the first augmented glass substrate.

8. The method for preparing a printed circuit board according to claim 1, characterized in that: In step S6, the method of etching the first additive metal layer using a subtractive etching method, while retaining the first additive metal layer within the second via and the patterned first additive metal layer on the surface of the first additive glass substrate, includes: S61, a photoresist layer is attached to the surface of the first added metal layer; S62, the photoresist layer is exposed and developed to form a patterned photoresist layer; S63, the first add-on metal layer is etched based on the patterned photoresist layer to remove the first add-on metal layer not covered by the patterned photoresist layer, and then the patterned photoresist layer is removed.

9. The method for manufacturing a printed circuit board according to claim 1, characterized in that: In step S10, the method for performing surface anti-oxidation treatment on the exposed externally reinforced metal layer includes electroplating on the surface of the exposed externally reinforced metal layer to form an anti-oxidation layer; wherein the material of the anti-oxidation layer includes one or more of nickel, palladium and gold.

10. The method for preparing a printed circuit board according to claim 1, characterized in that: In step S11, the method for removing the solder resist photoresist layer and the reinforcing film in the preset cutting area includes: S111, the solder resist photoresist layer in the preset cutting area is grooved using an infrared laser ablation process; S112, the picosecond green laser ablation process is used to remove the thickened adhesive film in the preset cutting area; In step S12, laser-induced infrared laser cutting technology is used to cut along the preset cutting area.

11. The method for preparing a printed circuit board according to claim 1, characterized in that: The number of layers in the added-layer stack is 2 to 10.

12. A printed circuit board, characterized in that: The printed circuit board includes: A glass core board includes a glass substrate and a plurality of first through holes penetrating the glass substrate, and also includes a core board metal layer within the first through holes and the core board metal layer patterned on the surface of the glass substrate. The required number of addenda layers are disposed on both sides of the glass core board; each addenda layer is pressed onto the glass core board or the lower addenda layer by an addenda film. The lower addenda layer includes a first addenda glass substrate, a plurality of second through holes penetrating the first addenda glass substrate, and a first addenda metal layer. The first addenda metal layer includes a first addenda metal layer filling the second through holes and a first addenda metal layer patterned on the surface of the first addenda glass substrate. The upper first addenda metal layer is in contact with the core board metal layer or the lower first addenda metal layer. The outermost addenda layer of the structure includes an outer addenda glass substrate and a plurality of outer addenda through holes penetrating the outer addenda glass substrate, and also includes an outer addenda metal layer filling the outer addenda through holes and an outer addenda metal layer patterned on the surface of the outer addenda glass substrate. The outer addenda metal layer in the outer addenda through holes is electrically connected to the lower first addenda metal layer and the core board metal layer. A solder resist photoresist layer is formed on the surface of the superplastic glass substrate and the surface of the superplastic metal layer in a predetermined solder resist area. An anti-oxidation layer is formed on the exposed surface of the externally reinforced metal layer.

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