Printed circuit board, solid state disk and electronic equipment

Abstract

The invention discloses a printed circuit board, a solid state disk and electronic equipment. The printed circuit board comprises a plurality of stacked conducting layers, the conducting layers comprise a top conducting layer and a bottom conducting layer which are located on the outermost side in the direction perpendicular to the printed circuit board, and the printed circuit board comprises a top golden finger arranged on the top surface and a bottom golden finger arranged on the bottom surface. In the direction perpendicular to the printed circuit board, the distance between the opposite side surfaces of the top conductive layer and the bottom conductive layer is a first distance, the distance between the opposite side surfaces of the top golden finger and the bottom golden finger is a second distance, and the first distance is larger than the second distance.

Description

Technical Field

[0001] This article relates to but is not limited to printed circuit board technology, and in particular to a printed circuit board, a solid state drive, and an electronic device. Background Art

[0002] Solid State Disk (SSD) includes a printed circuit board (PCB) and a main control chip, flash memory particles, cache chips and other structures arranged on the printed circuit board. These structures are connected by wires on the PCB. With the increase in SSD application scenarios, the working environment of SSD is becoming more and more harsh, and people's demand for SSD storage capacity and robustness is getting higher and higher.

[0003] However, PCB is prone to deformation, making the SSD vulnerable to damage. Summary of the invention

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0005] The embodiments of the present application provide a printed circuit board, a solid state drive, and an electronic device, which can solve the problem that the PCB is prone to deformation.

[0006] In a first aspect, an embodiment of the present application provides a printed circuit board, comprising a plurality of stacked conductive layers, wherein in a direction perpendicular to the printed circuit board, the plurality of conductive layers include a top conductive layer and a bottom conductive layer located at the outermost sides, and the printed circuit board includes a top gold finger arranged on the top surface and a bottom gold finger arranged on the bottom surface, respectively; in a direction perpendicular to the printed circuit board, a distance between opposite side surfaces of the top conductive layer and the bottom conductive layer is a first distance, a distance between opposite side surfaces of the top gold finger and the bottom gold finger is a second distance, and the first distance is greater than the second distance.

[0007] In an exemplary embodiment, the multiple conductive layers also include multiple intermediate conductive layers located between the top conductive layer and the bottom conductive layer; wherein the top gold finger is located in one of the intermediate conductive layers, and the bottom gold finger is located in the bottom conductive layer; or, the top gold finger is located in the top conductive layer, and the bottom gold finger is located in one of the intermediate conductive layers; or, the top gold finger and the bottom gold finger are respectively located in different intermediate conductive layers.

[0008] In an exemplary embodiment, the multiple conductive layers also include a first stack, and the multiple intermediate conductive layers are sandwiched on both sides of the first stack, and the first stack includes at least two stacked signal layers or at least two stacked plane layers; wherein the signal layer is used to transmit signals, and the plane layer is configured to provide power or grounding.

[0009] In an exemplary embodiment, the first stack includes two stacked planar layers; in a direction away from the first stack, the multiple conductive layers include signal layers and planar layers alternately arranged in sequence, and in a direction perpendicular to the printed circuit board, the thickness of at least one of the planar layers is greater than the thickness of the signal layer.

[0010] In an exemplary embodiment, the first stack includes two stacked signal layers, in a direction away from the first stack, the multiple conductive layers include the planar layers and the signal layers alternately arranged in sequence, and in a direction perpendicular to the printed circuit board, the thickness of at least one of the planar layers is greater than the thickness of the signal layer.

[0011] In an exemplary embodiment, the first stack includes a first plane layer and a second plane layer, and the thickness of the first plane layer and the thickness of the second plane layer are both greater than the thickness of the signal layer.

[0012] In an exemplary embodiment, in a direction perpendicular to the printed circuit board, the thickness of the first planar layer is greater than or equal to 60 microns and less than or equal to 80 microns, and the thickness of the second planar layer is greater than or equal to 60 microns and less than or equal to 80 microns.

[0013] In an exemplary embodiment, the first plane layer and the second plane layer are configured to provide power; or, one of the first plane layer and the second plane layer is configured to provide power, and the other is configured to be grounded.

[0014] In a second aspect, an embodiment of the present application further provides a solid state drive comprising the printed circuit board as described above.

[0015] In a third aspect, an embodiment of the present application further provides an electronic device, comprising the printed circuit board as described above.

[0016] The printed circuit board provided in the embodiment of the present application makes the maximum thickness of the printed circuit board greater than the standard thickness of the printed circuit board in the PCI-SIG association specification by setting the first distance between the relative side surfaces of the top conductive layer and the bottom conductive layer greater than the second distance between the relative side surfaces of the top gold finger and the bottom gold finger, thereby increasing the rigidity of the printed circuit board, making the printed circuit board more resistant to deformation and less prone to warping. Without replacing materials with better thermal expansion coefficients, the printed circuit board can withstand alternating hot and cold temperatures within a larger temperature range, ensuring the long-term stable operation of the printed circuit board in harsh working environments, saving costs, and being suitable for popularization and use. The problem of PCB being easily deformed is solved.

[0017] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0019] Figure 1 A top view of a solid state hard disk; Figure 2 for Figure 1 A cross-sectional view of a printed circuit board in a solid-state drive; Figure 3 is a cross-sectional view of a printed circuit board in an exemplary embodiment; Figure 4 is a cross-sectional view of a printed circuit board in yet another exemplary embodiment; Figure 5 is a cross-sectional view of a printed circuit board in yet another exemplary embodiment. DETAILED DESCRIPTION

[0020] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0021] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0022] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0023] With the development of storage technology, solid-state drives can be used in many fields, such as industrial production, automobiles, etc. In these application scenarios, the demand for the capacity of solid-state drives is increasing, while the working environment of solid-state drives is becoming increasingly harsh, which puts higher requirements on the performance of solid-state drives.

[0024] Figure 1 FIG. 1 is a top view of a solid state drive, illustrating the top surface of an M.2 2280 solid state drive. Figure 1 As shown, the solid state drive 100 includes a printed circuit board 101 and a plurality of components 102 arranged on the printed circuit board 101. The plurality of components 102 can be connected through wires on the PCB to form different signal links. A gold finger area is arranged on one side edge of the top surface of the printed circuit board 101, and the gold finger area includes a plurality of gold fingers 103. The gold finger area and a plurality of gold fingers 103 can be symmetrically arranged on the same side edge of the bottom surface of the printed circuit board 101. The solid state drive 100 can be connected to other devices through the plurality of gold fingers 103, for example, it can be connected to the motherboard of a computer. Figure 1As shown, according to the specification of the Peripheral Component Interconnect Special Interest Group (PCI-SIG) Association, the meaning of "2280" in the 2280 solid state drive is: the width D of the solid state drive 100 is 22 mm, the length L of the solid state drive 100 is 80 mm, and the overall shape of the M.2 2280 solid state drive is a long strip, such as Figure 1 As shown, a plurality of components 102 are arranged on the surface of the M.2 2280 solid state drive. Due to the size requirements of the M.2 2280 solid state drive, the plurality of components 102 are closely arranged and very close to each other. This long strip-shaped solid state drive also includes a 22110 solid state drive. According to the PCI-SIG Association's specifications, "22110" means that the width D of the solid state drive is 22mm, and the length L of the solid state drive is 110mm. The shape of the 22110 solid state drive is more narrow and long. Figure 1 Only the top view structure of the M.2 2280 solid-state drive is illustrated. The structures of other types of solid-state drives are similar to that of the M.2 2280 solid-state drive and are not described here.

[0025] Figure 2 for Figure 1 A cross-sectional view of a printed circuit board in a solid-state drive. Figure 2 As shown, the printed circuit board 101 includes a plurality of conductive layers 11, and an insulating layer 10 arranged between adjacent conductive layers 11, and the conductive layers 11 and the insulating layers 10 are alternately stacked in sequence. In the direction perpendicular to the printed circuit board 101, the thicknesses of the plurality of conductive layers 11 are substantially the same. The plurality of conductive layers 11 may include a top conductive layer 11-1 and a bottom conductive layer 11-2, and the top conductive layer 11-1 and the bottom conductive layer 11-2 sandwich the remaining conductive layers 11 and the insulating layer 10 in the middle. According to the specification of the PCI-SIG Association, the thickness H of the 2280 solid state drive is 0.8 mm, and the thickness H is the distance between the opposite side surfaces of the gold fingers 103 arranged on the top surface and the bottom surface of the printed circuit board 101. The gold fingers arranged on the top surface of the printed circuit board 101 can be referred to as top gold fingers, and the gold fingers arranged on the bottom surface of the printed circuit board 101 can be referred to as bottom gold fingers. Combined with Figure 2 As shown, a plurality of gold fingers 103 may be located at the same side edges of the top conductive layer 11 - 1 and the bottom conductive layer 11 - 2 , respectively, and the material of the conductive layer 11 may include copper.

[0026] by Figure 1Taking the M.2 2280 solid-state drive shown in the figure as an example, when the size of the solid-state drive is a fixed parameter, increasing the storage capacity will inevitably require the arrangement of higher density flash memory particles, such as NAND flash memory particles, on the printed circuit board 101. The more flash memory particles there are, the denser the components 102 and wiring that need to be arranged on the printed circuit board 101 will be. The inventor of the present application has found through research that in the process of assembling the components 102 with the printed circuit board 101 using the surface mount technology (SMT), the printed circuit board 101 is prone to warping and deformation after reflow soldering, such as Figure 1 The warping degree of the printed circuit board 101 in the shape of a long strip is particularly obvious. When the components 102 and the wiring are densely arranged on the printed circuit board 101, this warping deformation is not only easy to damage the physical structure on the signal link, such as solder balls, pads, copper holes, etc., so that the solid state drive 100 loses its function due to damage, but also easily causes signal crosstalk between adjacent wirings on the printed circuit board 101, affecting the operation of the solid state drive 100. In addition, in the subsequent reliability test of the solid state drive 100, the thermal expansion and contraction under high and low temperatures will increase the internal stress of the printed circuit board 101, aggravate the severity of the warping, and further increase the probability of damage to the solid state drive or signal crosstalk. When the solid state drive 100 is used in an application scenario with large temperature changes, the service life of the solid state drive 100 is relatively low.

[0027] An embodiment of the present application provides a printed circuit board, comprising a plurality of stacked conductive layers, wherein in a direction perpendicular to the printed circuit board, the plurality of conductive layers include a top conductive layer and a bottom conductive layer located at the outermost sides, and the printed circuit board includes a top gold finger arranged on a top surface and a bottom gold finger arranged on a bottom surface, respectively; in a direction perpendicular to the printed circuit board, a distance between opposite side surfaces of the top conductive layer and the bottom conductive layer is a first distance, a distance between opposite side surfaces of the top gold finger and the bottom gold finger is a second distance, and the first distance is greater than the second distance.

[0028] The printed circuit board provided in the embodiment of the present application sets the first distance between the opposite side surfaces of the top conductive layer and the bottom conductive layer to be greater than the second distance between the opposite side surfaces of the top gold finger and the bottom gold finger, so that the maximum thickness of the printed circuit board is greater than the standard thickness of the printed circuit board in the PCI-SIG association specification, increases the rigidity of the printed circuit board, makes the printed circuit board more resistant to deformation, and is less likely to warp. Without replacing materials with better thermal expansion coefficients, the printed circuit board can withstand alternating hot and cold in a larger temperature range, ensuring the long-term stable operation of the printed circuit board in harsh working environments, saving costs, and being suitable for popularization and use.

[0029] Figure 3 FIG. 4 is a cross-sectional view of a printed circuit board in an exemplary embodiment. Figure 3 As shown, the printed circuit board 101 includes a plurality of stacked conductive layers 11 and an insulating layer 10 disposed between adjacent conductive layers 11. Figure 3 In the figure, a printed circuit board 101 including ten stacked conductive layers 11 is used as an example for illustration. The printed circuit board 101 can be configured to include more or fewer conductive layers 11 as needed, and the present application does not limit this. The multiple conductive layers 11 include a signal layer and a plane layer. The plane layer can be a power layer or a ground layer. The power layer can provide power, and the ground layer can have a grounding effect. The printed circuit board 101 includes a first stack 12, and signal layers and plane layers alternately arranged on both sides of the first stack 12. The first stack 12 includes at least two signal layers or at least two plane layers. Figure 3 As shown, the first stack 12 includes adjacent first and second plane layers 21-1, 21-2. The first and second plane layers 21-1, 21-2 may both be power layers, or the first and second plane layers 21-1, 21-2 may include a power layer and a ground layer, which is not limited in the present application. When the first stack 12 is a planar layer, signal layers and planar layers can be alternately arranged on both sides of the first stack 12. For example, the first signal layer 22-1, the third planar layer 21-3, the third signal layer 22-3, the fifth planar layer 21-5, the fifth signal layer 22-5 and the seventh planar layer 21-7 can be arranged in sequence above the first stack 12, and the seventh planar layer 21-7 can be a top conductive layer. The second signal layer 22-2, the fourth planar layer 21-4, the fourth signal layer 22-4, the sixth planar layer 21-6, the sixth signal layer 22-6 and the eighth planar layer 21-8 can be arranged in sequence below the first stack 12, and the eighth planar layer 21-8 can be a bottom conductive layer. Subsequently, components can be arranged on at least one of the top conductive layer and the bottom conductive layer. The film layer located between the top conductive layer and the first stack 12, and the film layer located between the first stack 12 and the bottom conductive layer can be called intermediate conductive layers. The number of intermediate conductive layers can be set as needed, and the above-mentioned multiple planar layers can be set as power layers or ground layers as needed. This application does not impose any restrictions on this.

[0030] like Figure 3As shown, in a direction perpendicular to the printed circuit board 101, the distance between the opposite side surfaces of the top conductive layer and the bottom conductive layer of the printed circuit board 101 is H1, the first distance H1 is the maximum thickness of the printed circuit board 101, the distance between the opposite side surfaces of the gold fingers 103 arranged on the top surface and the bottom surface of the printed circuit board 101 is the second distance H2, the second distance H2 is the standard thickness specified by the PCI-SIG association, and the first distance H1 is greater than the second distance H2. By setting the first distance H1 to be greater than the second distance H2, the thickness of the printed circuit board 101 itself and the number of film layers included can be increased when the printed circuit board 101 meets the thickness specification of the PCI-SIG Association, which not only increases the rigidity of the printed circuit board 101, making the printed circuit board 101 more resistant to deformation and less prone to warping, but also increases the number of film layers for arranging wiring in the printed circuit board 101, making the wiring space of the printed circuit board 101 more sufficient, helping to flexibly adjust the spacing between wirings, reducing the probability of signal crosstalk between wirings, and ensuring the integrity of the transmission signal, providing more possibilities for wiring layout design, and ensuring normal and stable operation even when the printed circuit board 101 is warped to a certain extent. In addition, the printed circuit board 101 provided in this embodiment can be prepared using existing materials, with little change to the existing process, and does not need to replace materials with better thermal expansion coefficients, which can save costs and is suitable for popularization.

[0031] In an exemplary embodiment, Figure 3 As shown, the gold finger 103 on the top surface of the printed circuit board 101 can be set on the third plane layer 21-3, and the gold finger 103 on the bottom surface of the printed circuit board 101 can be set on the bottom conductive layer. In the direction perpendicular to the printed circuit board 101, the orthographic projections of the multiple film layers located in the third plane layer 21-3 away from the first stack 12 on the printed circuit board 101 do not overlap with the orthographic projections of the gold finger 103, and the multiple film layers located in the third plane layer 21-3 away from the first stack 12 can be set outside the gold finger area on the top surface of the printed circuit board 101. The number and thickness of the film layers included in the printed circuit board 101 and the film layers where the gold finger 103 is located can be set as needed, and this application does not limit this.

[0032] In other embodiments, the first stack 12 may include two adjacent signal layers. When the first stack 12 is a signal layer, planar layers and signal layers may be alternately arranged on both sides of the first stack 12, and the top conductive layer and the bottom conductive layer may also be signal layers. This application does not impose any restrictions on this.

[0033] In an exemplary embodiment, Figure 3 When the printed circuit board 101 is applied to a solid state drive, Figure 3The second distance H2 of the printed circuit board 101 is the thickness H of the solid state drive. While meeting the PCI-SIG association specifications, the printed circuit board 101 has better rigidity and stronger bending resistance, and a solid state drive with better stability and reliability can be obtained, reducing the risk of damage to the solid state drive.

[0034] Figure 4 is a cross-sectional view of a printed circuit board in yet another exemplary embodiment. Figure 4 and Figure 3 The difference is that the thickness of the first plane layer 21-1 and the second plane layer 21-2 is greater than the thickness of the signal layer. The rest of the content can refer to the above description. Figure 3 The description will not be repeated here.

[0035] In an exemplary embodiment, Figure 4 As shown, the thickness H3 of the first plane layer 21-1 may be greater than or equal to 60 microns and less than or equal to 80 microns. For example, the thickness H3 of the first plane layer 21-1 may be about 70 microns. During preparation, the thickness H3 of the first plane layer 21-1 may be about 2 oz. 1 oz means that 1 ounce (oz) of copper is evenly spread on 1 square foot (FT 2 ) The thickness H4 of the second plane layer 21-2 can refer to the description of the thickness H3 of the first plane layer 21-1, which will not be repeated here. The thickness H3 of the first plane layer 21-1 and the thickness H4 of the second plane layer 21-2 can be set as needed. For example, the thickness H3 of the first plane layer 21-1 and the thickness H4 of the second plane layer 21-2 can be substantially equal, and the present application does not limit this.

[0036] In this embodiment, since the first plane layer 21-1 and the second plane layer 21-2 are located in the middle of multiple conductive layers, by setting the thickness of the first plane layer 21-1 and the second plane layer 21-2 to be greater than the thickness of the remaining conductive layers, the rigidity of the printed circuit board 101 can be significantly improved, making the printed circuit board 101 more resistant to deformation. In addition, since the first plane layer 21-1 and the second plane layer 21-2 include a power layer, by increasing the thickness of the power layer, the current flow capacity and heat dissipation capacity of the power supply can be increased, thereby improving the performance of the printed circuit board 101 and helping to ensure the long-term stable operation of the printed circuit board 101.

[0037] In an exemplary embodiment, since different conductive layers are electrically connected through through holes, when designing, the thickness of the first plane layer 21-1 can be set according to the "thickness-to-diameter ratio" requirement of the through holes set in the first plane layer 21-1, or other conditions can be used to set the thickness of the first plane layer 21-1, and this application does not limit this. The thickness design principle of the second plane layer 21-2 can be similar to that of the first plane layer 21-1, and will not be repeated here.

[0038] In other embodiments, the thickness of any of the remaining plane layers of the printed circuit board 101 can be set to be greater than the thickness of the signal layer, which helps to further increase the anti-deformation ability of the printed circuit board 101. This application does not limit this. Figure 4 The solid state drive formed by the printed circuit board 101 of the structure shown can withstand the thermal shock of -40°C to 125°C, and can continue to work stably within this temperature range, which greatly improves the working reliability of the solid state drive.

[0039] Figure 5 is a cross-sectional view of a printed circuit board in yet another exemplary embodiment. Figure 5 and Figure 4 The difference is that the position of the gold finger 103 on the bottom surface of the printed circuit board 101 is different. The rest of the content can refer to the above Figure 4 The description will not be repeated here.

[0040] In an exemplary embodiment, Figure 5 As shown, the gold finger 103 on the bottom surface of the printed circuit board 101 can be set on the fourth plane layer 21-4, the orthographic projection of multiple film layers located in the fourth plane layer 21-4 away from the first stack 12 on the printed circuit board 101 does not overlap with the orthographic projection of the gold finger 103, and the multiple film layers located in the fourth plane layer 21-4 away from the first stack 12 can be set outside the gold finger area on the top surface of the printed circuit board 101. The number and thickness of the film layers included in the printed circuit board 101 and the film layers where the gold finger 103 is located can be set as needed, and this application does not limit this.

[0041] In this embodiment, by setting the gold finger 103 located on the top surface of the printed circuit board 101 on the film layer of the top conductive layer close to the first stack 12, and setting the gold finger 103 located on the bottom surface of the printed circuit board 101 on the film layer of the bottom conductive layer close to the first stack 12, so that the thickness of the printed circuit board 101 itself and the number of film layers included are further increased when the printed circuit board 101 meets the thickness specification of the PCI-SIG association. The number of film layers included in the printed circuit board 101, the film layers where the gold finger 103 on the top surface of the printed circuit board 101 and the gold finger 103 on the bottom surface are located, and the thickness of each film layer and other parameters can be set as needed, and this application does not impose any restrictions on this.

[0042] The following is formed Figure 4 The process of the printed circuit board 101 shown is briefly described, and any incomplete description can refer to the existing preparation technology.

[0043] S1: Cut the core board into appropriate size.

[0044] In this step, the core board can be cut into appropriate sizes as needed.

[0045] S2: forming a circuit pattern of the first stack 12.

[0046] In this step, the circuit patterns of the first plane layer 21-1 and the second plane layer 21-2 can be formed respectively by electroplating or the like, and the thickness of the first plane layer 21-1 and the second plane layer 21-2 can be adjusted by controlling the electroplating process.

[0047] S3: The first signal layer 22 - 1 , the second signal layer 22 - 2 and the first laminate 12 are laminated using a prepreg to form a four-layer board.

[0048] In this step, the prepreg may be a PP film, and the first signal layer 22 - 1 and the second signal layer 22 - 2 may be sandwiched outside the first laminate 12 to form a four-layer board after lamination.

[0049] S4: forming a circuit pattern of the third plane layer 21-3 and a circuit pattern of the fourth plane layer 21-4.

[0050] In this step, the circuit patterns of the third plane layer 21-3 and the circuit patterns of the fourth plane layer 21-4 can be formed respectively by electroplating or the like, and the thickness of the third plane layer 21-3 and the thickness of the fourth plane layer 21-4 can be set as needed.

[0051] S5: Using a prepreg, the third planar layer 21 - 3 , the fourth planar layer 21 - 4 and the four-layer board obtained in step S3 are laminated to form a six-layer board.

[0052] In this step, the third plane layer 21 - 3 and the fourth plane layer 21 - 4 may be sandwiched outside the aforementioned four-layer board to form a six-layer board after lamination.

[0053] S6: Make a solder resist on the third plane layer 21 - 3 and attach a tape.

[0054] In this step, a solder mask window can be opened on the side of the third planar layer 21-3 away from the first stack 12, a plurality of electroplating tanks can be formed in the gold finger area, and a tape can be attached to the gold finger area to protect the gold finger area. Subsequently, a gold finger 103 can be formed in the electroplating tank, and the size of the electroplating tank can be larger than the size of the gold finger 103.

[0055] S7: Repeat steps S4 and S5 to form the third signal layer 22-3 and the fourth signal layer 22-4, the fifth plane layer 21-5 and the sixth plane layer 21-6, the fifth signal layer 22-5 and the sixth signal layer 22-6, the seventh plane layer 21-7 and the eighth plane layer 21-8 on both sides of the six-layer board by lamination to form a multilayer board.

[0056] S8: Drilling and electroplating the multilayer board obtained in step S7 to form electrical connections between different conductive layers.

[0057] S9: forming a circuit pattern of the top conductive layer and a circuit pattern of the bottom conductive layer.

[0058] S10: Make solder mask on the bottom conductive layer to form the gold finger area at the bottom.

[0059] S11: Surface treatment is performed on the top conductive layer and the bottom conductive layer in areas other than the gold finger areas.

[0060] S12: performing depth-controlled electric milling on the surface layer of the gold finger area to mill out the gold fingers of the third plane layer 21 - 3 .

[0061] In this step, the third signal layer 22-3, the fifth plane layer 21-5, the fifth signal layer 22-5 and the seventh plane layer 21-7 located in the gold finger area can be removed in a direction perpendicular to the multilayer board to expose the adhesive tape attached in step S6. In the aforementioned lamination process, the third signal layer 22-3, the fifth plane layer 21-5, the fifth signal layer 22-5 and the seventh plane layer 21-7 maintain a whole surface structure, which can ensure that the pressure from the top and bottom during the lamination process is uniform and the lamination effect is ensured. By attaching the adhesive tape in advance, the surface film layer of the gold finger area can be protected from being damaged during the process of exposing the gold finger area in this step.

[0062] S13: Tear off the adhesive film attached to the gold finger area and perform chemical cleaning.

[0063] S14: forming a gold finger 103 in the gold finger region by electroplating.

[0064] So far, Figure 4 The printed circuit board 101 of the structure shown is prepared, and components can be subsequently welded on the surface of the top conductive layer and the surface of the bottom conductive layer to form a solid state drive. The printed circuit board 101 can also be used to form other electronic products, and this application does not impose any restrictions on this.

[0065] An embodiment of the present application also provides a solid state drive, comprising the printed circuit board as described above.

[0066] The embodiment of the present application also provides an electronic device, including the printed circuit board as described above. For example, the electronic device may include a storage device, and the storage device may include a solid state drive as described above, or the electronic device may directly include the printed circuit board as described above, and the present application does not limit this.

[0067] In the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", etc. may explicitly or implicitly include at least one of the features.

[0068] In the description of the present application, “plurality” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0069] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0071] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A printed circuit board, comprising a plurality of stacked conductive layers, wherein in a direction perpendicular to the printed circuit board, the plurality of conductive layers include a top conductive layer and a bottom conductive layer located at the outermost sides, and the printed circuit board includes a top gold finger disposed on the top surface and a bottom gold finger disposed on the bottom surface, respectively; characterized in that: In a direction perpendicular to the printed circuit board, the distance between the opposite side surfaces of the top conductive layer and the bottom conductive layer is a first distance, the distance between the opposite side surfaces of the top gold finger and the bottom gold finger is a second distance, and the first distance is greater than the second distance.

2. The printed circuit board according to claim 1, characterized in that: The plurality of conductive layers further include a plurality of intermediate conductive layers located between the top conductive layer and the bottom conductive layer; wherein, The top gold finger is located in one of the middle conductive layers, and the bottom gold finger is located in the bottom conductive layer; or, the top gold finger is located in the top conductive layer, and the bottom gold finger is located in one of the middle conductive layers; or, the top gold finger and the bottom gold finger are respectively located in different middle conductive layers.

3. The printed circuit board according to claim 2, characterized in that: The multiple conductive layers also include a first stack, and the multiple intermediate conductive layers are sandwiched on both sides of the first stack. The first stack includes at least two stacked signal layers or at least two stacked plane layers; wherein the signal layer is used to transmit signals, and the plane layer is configured to provide power or grounding.

4. The printed circuit board according to claim 3, characterized in that: The first stack includes two stacked planar layers; in the direction away from the first stack, the multiple conductive layers include signal layers and planar layers that are alternately arranged in sequence, and in the direction perpendicular to the printed circuit board, the thickness of at least one of the planar layers is greater than the thickness of the signal layer.

5. The printed circuit board according to claim 3, characterized in that: The first stack includes two stacked signal layers. In the direction away from the first stack, the multiple conductive layers include the planar layers and the signal layers that are alternately arranged in sequence. In the direction perpendicular to the printed circuit board, the thickness of at least one of the planar layers is greater than the thickness of the signal layer.

6. The printed circuit board according to claim 4, characterized in that: The first stack includes a first plane layer and a second plane layer, and the thickness of the first plane layer and the thickness of the second plane layer are both greater than the thickness of the signal layer.

7. The printed circuit board according to claim 6, characterized in that: In a direction perpendicular to the printed circuit board, the thickness of the first planar layer is greater than or equal to 60 micrometers and less than or equal to 80 micrometers, and the thickness of the second planar layer is greater than or equal to 60 micrometers and less than or equal to 80 micrometers.

8. The printed circuit board according to claim 6, characterized in that: The first plane layer and the second plane layer are configured to provide power; or, one of the first plane layer and the second plane layer is configured to provide power, and the other is configured to be grounded.

9. A solid state hard disk, characterized in that: Comprising a printed circuit board as claimed in any one of claims 1 to 8.

10. An electronic device, characterized in that: Comprising a printed circuit board as claimed in any one of claims 1 to 8.

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