Circuit board structure capable of shortening backflow path

Abstract

The utility model discloses a circuit board structure capable of shortening a backflow path in the field of circuit board design, which comprises a circuit board body with a plurality of laminated layers, the circuit board body is provided with a plurality of capacitor bonding pad groups, each bonding pad group comprises two capacitor bonding pad pairs, the lamination layer right below each capacitor bonding pad is correspondingly provided with a hollowed-out area, a copper sheet is laid in the middle of each hollowed-out area, and the length of each copper sheet is equal to that of each hollowed-out area. According to the utility model, the problem that the backflow path is lengthened due to backflow of the existing signal line along the edge of the hollowed-out area is solved, the backflow path does not need to flow back along the edge of the hollowed-out area, and backflow can be directly carried out through the copper sheet, so that the loop path can be shortened, parasitic inductance and loss in the backflow process are reduced, and the service life of the signal line is prolonged. And noise interference is reduced, so that the quality and stability of signal transmission are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit board design technical field, specifically, relate to a circuit board structure of shortening reflow path. BACKGROUND

[0002] In the field of circuit board design, high-speed serial differential bus as the nerve plexus connecting various high-speed components, undertakes the heavy responsibility of high-speed data transmission. In order to ensure the efficiency and quality of data transmission, the designer will usually connect an AC (alternating current) coupling capacitor at both ends of such bus, not only can filter out the direct current component, only allow alternating current signal to pass through, but also can effectively reduce the reflection of signal in the transmission process, so as to maintain the integrity and clarity of signal.

[0003] In order to realize the best impedance matching, usually hollow out the copper skin of 1 to 2 layers directly below the AC coupling capacitor, so as to adjust the characteristic impedance of the region, make it match the impedance of high-speed differential line, thereby effectively reducing the reflection of signal in the transmission process, improving signal quality. However, after hollowing out the copper skin, the reflow path of the signal line will be along the edge of the hollowed-out area, resulting in the reflow path will be longer.

[0004] The above defects need to be solved urgently. CONTENT OF THE UTILITY MODEL

[0005] In order to solve the problem that the existing signal line reflows along the edge of the hollowed-out area, resulting in the reflow path will be longer, the utility model provides a circuit board structure of shortening reflow path.

[0006] The technical scheme of the utility model is as follows:

[0007] A circuit board structure of shortening reflow path, comprising a circuit board body with a plurality of layers, a plurality of capacitor pad groups are arranged on the circuit board body, each capacitor pad group comprises two capacitor pad pairs, a hollowed-out area is arranged below each capacitor pad pair, a copper skin is laid in the middle of the hollowed-out area, and the length of the copper skin is equal to the length of the hollowed-out area.

[0008] According to the utility model of the above scheme, the width of the copper skin is 6 mil.

[0009] According to the utility model of the above scheme, the capacitor pad pair is provided with the hollowed-out area in 1-2 layers below.

[0010] According to the utility model of the above scheme, a silk screen frame is arranged on the periphery of each capacitor pad pair.

[0011] According to the utility model of the above scheme, the size of the silk screen frame is equal to the size of the hollowed-out area.

[0012] According to the utility model of above-mentioned scheme, the capacitor pad group is connected with high speed serial differential bus.

[0013] According to the utility model of above-mentioned scheme, the high speed serial differential bus includes the first differential line, the second differential line of symmetric setting, two capacitor pads in the capacitor pad group are divided into the first pad pair, the second pad pair, the first differential line is connected with the first pad pair, the second differential line is connected with the second pad pair.

[0014] According to the utility model of above-mentioned scheme, the four corners of silk screen frame are divided into the first corner, the second corner, the third corner, the fourth corner, the silk screen frame of the first pad pair periphery is the first silk screen frame, the silk screen frame of the second pad pair periphery is the second silk screen frame, the first differential line is wired from the second corner, the third corner of the first silk screen frame, the second differential line is wired from the first corner, the fourth corner of the second silk screen frame.

[0015] According to the utility model of above-mentioned scheme, the first differential line is parallelly arranged with the second differential line.

[0016] According to the utility model of above-mentioned scheme, the width of the first differential line is equal to the width of the second differential line.

[0017] According to the utility model of above-mentioned scheme, the width of the first differential line, the width of the second differential line are 12mil~22mil.

[0018] According to the utility model of above-mentioned scheme, it has the beneficial effects of:

[0019] In the circuit board structure of shortening reflow path above, the layer directly below each capacitor pad pair is provided with a hollow area, the middle part of the hollow area is paved with copper skin, and the length of the copper skin is equal to the length of the hollow area. When the signal line reflows, its reflow path does not need to reflow along the edge of the hollow area, but can directly reflow through the copper skin, thereby shortening the circuit path, reducing the parasitic inductance and loss in the reflow process, reducing noise interference, and improving the quality and stability of signal transmission. In addition, due to the setting of the hollow area, the requirement of impedance matching can be met, and the stability and reliability of the high speed serial differential bus in the transmission process are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0021] Figure 1 It is one of the structural schematic diagrams of the present application.

[0022] Figure 2 It is the second structural schematic diagram of the present application.

[0023] In the drawings, 1, circuit board body; 2, capacitor pad pair; 21, first pad pair; 22, second pad pair; 3, hollow area; 4, copper skin; 5, silk screen frame; 51, first corner; 52, second corner; 53, third corner; 54, fourth corner; 6, high-speed serial differential bus; 61, first differential line; 62, second differential line. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical schemes and beneficial effects of the present application more clearly understood, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0025] As shown in Figure 1 The present application provides a circuit board structure for shortening the reflow path, comprising a circuit board body 1 with a plurality of layers, a plurality of capacitor pad groups are arranged on the circuit board body 1, each pad group comprises two capacitor pad pairs 2, a hollow area 3 is arranged below each capacitor pad pair 2, a copper skin 4 is laid in the middle of the hollow area 3, and the length of the copper skin 4 is equal to the length of the hollow area 3. When the signal line is reflowed, the reflow path does not need to reflow along the edge of the hollow area 3, but can directly reflow through the copper skin 4, thereby shortening the loop path, reducing the parasitic inductance and loss in the reflow process, reducing noise interference, and improving the quality and stability of signal transmission. In addition, due to the arrangement of the hollow area 3, the requirement of impedance matching can be met, and the stability and reliability of the high-speed serial differential bus 6 in the transmission process can be ensured.

[0026] In the embodiment, the width of the copper sheet 4 is 6 mil. When the width of the copper sheet 4 is less than 6 mil, due to the small size, challenges in precision control may be encountered in the processing process, such as uneven etching, rough edges and other problems, which will increase the risk of breaking the copper sheet 4; when the width of the copper sheet 4 is greater than 6 mil, the copper sheet 4 is wider, which affects the reference plane of the hollowing of the capacitor pad pair 2, thereby affecting the impedance. When the width of the copper sheet 4 is 6 mil, the width of 6 mil not only ensures the stability of the copper sheet 4 in the processing process, but also ensures the structural integrity of the copper sheet 4 on the circuit board, reduces the risk of circuit failure caused by improper processing, helps to maintain the integrity of the signal, and reduces the signal attenuation and distortion caused by the excessive length of the reflow path or the excessive resistance and inductance.

[0027] In the embodiment, due to the large pad of the capacitor pad pair 2, the impedance is relatively small, and only the distance between the pad of the capacitor pad pair 2 and the reference layer can be increased to increase the impedance for matching. The hollowing area 3 is arranged in 1-2 layers directly below the capacitor pad pair 2, thereby increasing the distance between the pad of the capacitor pad pair 2 and the reference layer, and further meeting the requirement of impedance.

[0028] In the embodiment, the outer periphery of each capacitor pad pair 2 is provided with a silk screen frame 5, which serves as a visual mark of the capacitor pad pair 2 and improves the recognition of the capacitor pad pair 2 on the circuit board. In the production, assembly and debugging process, the operator can quickly and accurately identify the position of the capacitor pad pair 2, thereby avoiding the error assembly or damage caused by misidentification or misoperation. In addition, the size of the silk screen frame 5 is equal to the size of the hollowing area 3, which ensures the accurate correspondence between the silk screen frame 5 and the capacitor pad pair 2 and the hollowing area 3 thereof. This not only helps to accurately position the capacitor pad pair 2 in the manufacturing process, but also provides a reliable reference benchmark for subsequent assembly and debugging work.

[0029] As shown in Figure 1 , Figure 2 In the embodiment, the capacitor pad group is connected with the high-speed serial differential bus 6. Through the transmission of differential signals, the quality and stability of the signal in the high-speed and long-distance transmission process can be ensured. At the same time, the capacitor pad group plays a decoupling role by connecting the high-speed serial differential bus 6. The capacitor pad group can absorb and release electric charge, thereby stabilizing the power supply voltage and reducing the interference of power supply noise on signal transmission. Specifically, the high-speed serial differential bus 6 includes a first differential line 61 and a second differential line 62 arranged symmetrically. The two capacitor pad pairs 2 in the capacitor pad group are divided into a first pad pair 21 and a second pad pair 22. The first differential line 61 is connected with the first pad pair 21, and the second differential line 62 is connected with the second pad pair 22, thereby ensuring the balance of the differential signal in the transmission process and further enhancing the stability and integrity of the signal.

[0030] As shown in Figure 2As shown, in the embodiment, the four corners of the silk screen frame 5 are divided into a first corner 51, a second corner 52, a third corner 53, and a fourth corner 54, the silk screen frame 5 surrounding the first pad pair 21 is a first silk screen frame, the silk screen frame 5 surrounding the second pad pair 22 is a second silk screen frame, the first differential line 61 is drawn out from the second corner 52 and the third corner 53 of the first silk screen frame, and the second differential line 62 is drawn out from the first corner 51 and the fourth corner 54 of the second silk screen frame, thereby optimizing the signal transmission path, reducing the crosstalk and interference between signals, and improving the integrity and stability of the signal.

[0031] In the embodiment, the first pad pair 21 and the second pad pair 22 each include two capacitor pads, which are connected to the corresponding high-speed serial differential bus 6, thereby stabilizing the transmission of differential signals. Capacitors play a role in filtering and decoupling in circuits, can absorb and release charges, thereby stabilizing the power supply voltage and reducing the interference of power supply noise on signal transmission.

[0032] In the embodiment, the first differential line 61 and the second differential line 62 are arranged in parallel, which helps to maintain the balance between differential signals and ensures that the two signal lines receive the same electromagnetic interference during transmission, thereby effectively canceling out the interference and maintaining the integrity of the signal. In addition, the width of the first differential line 61 is equal to the width of the second differential line 62, which helps to achieve impedance matching and can reduce signal reflection and loss, thereby improving the transmission efficiency and quality of the signal.

[0033] In the embodiment, the width of the first differential line 61 and the width of the second differential line 62 are each 12mil-22mil, and the width of the first differential line 61 and the width of the second differential line 62 can be designed to be any value within the interval of 12mil, 13mil, 14mil, 15mil, 16mil, 17mil, 18mil, 19mil, 20mil, 21mil, and 22mil. In actual design, the width of the first differential line 61 and the width of the second differential line 62 can be designed according to actual needs.

[0034] It should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship commonly used when the product of the application is used, which is only for the convenience of describing the application and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0035] It should be understood that, for those skilled in the art, improvements or changes can be made according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the utility model.

[0036] The utility model patent is exemplarily described above in combination with the drawings, and obviously the implementation of the utility model patent is not limited by the above-mentioned mode. As long as various improvements are made by adopting the method concept and technical scheme of the utility model patent, or the concept and technical scheme of the utility model patent is directly applied to other occasions without improvement, it is within the protection scope of the utility model.

Claims

1. A circuit board structure for shortening the return path, characterized in that, The application relates to a circuit board body with several layers, wherein the circuit board body is provided with several capacitor pad groups, each of the pad groups comprises two capacitor pad pairs, each of the layers directly below the capacitor pad pairs is provided with a hollow area, the middle part of the hollow area is paved with copper skin, and the length of the copper skin is equal to the length of the hollow area.

2. The short-reflow-path circuit board structure according to claim 1, characterized by The width of the copper skin is 6 mil.

3. The short-reflow-path circuit board structure according to claim 1, characterized by The 1-2 layers directly below the capacitor pad pairs are provided with the hollow areas.

4. The circuit board structure for shortening a reflow path according to claim 1, wherein The outer periphery of each of the capacitor pad pairs is provided with a silk screen frame.

5. The circuit board structure of claim 4, wherein The size of the silk screen frame is equal to the size of the hollow area.

6. The circuit board structure of claim 4, wherein The capacitor pad groups are connected with high-speed serial differential buses.

7. The short reflow path circuit board structure of claim 6, wherein, The high-speed serial differential buses comprise symmetrically arranged first differential lines and second differential lines, two capacitor pad pairs in the capacitor pad groups are divided into first pad pairs and second pad pairs, the first differential lines are connected with the first pad pairs, and the second differential lines are connected with the second pad pairs.

8. The short reflow path circuit board structure of claim 7, wherein, The four corners of the silk screen frame are divided into a first corner, a second corner, a third corner and a fourth corner, the silk screen frame around the first pad pairs is a first silk screen frame, the silk screen frame around the second pad pairs is a second silk screen frame, the first differential lines are led out from the second corner and the third corner of the first silk screen frame, and the second differential lines are led out from the first corner and the fourth corner of the second silk screen frame.

9. The short reflow path circuit board structure of claim 7, wherein, The first differential lines and the second differential lines are arranged in parallel.

10. The circuit board structure of claim 7, wherein The width of the first differential lines and the width of the second differential lines are both 12 mil-22 mil.

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