Circuit board and SMD (Surface Mount Device) resistor

Abstract

The utility model provides a circuit board and a surface-mounted resistor, the circuit board comprises a substrate, the substrate is provided with a plurality of parallel first through grooves and a plurality of second through grooves uniformly arranged along the direction of the first through grooves, and the first through grooves are communicated with the second through grooves; the multiple carbon oil layers are arranged on the end face of one side of the base plate, and the carbon oil layers are arranged between the second through groove and the first through groove in the width direction of the base plate; and the solder mask layer is arranged on the end face of one side of the substrate and wraps the carbon oil layer. In this way, mechanization and automation of preparation of corresponding products can be effectively improved, and the preparation efficiency of the products is improved.

Description

Circuit boards and surface mount resistors Technical Field

[0001] This application relates to the technical field of circuit board fabrication, and in particular to a circuit board and a surface mount resistor. Background Technology

[0002] Carbon film resistors are a type of film resistor. They were once the most widely used resistors in electronic, electrical, and information products, but are now mostly used in low-value, low-end products such as power supplies and adapters, or in early-designed products. However, current technologies for manufacturing carbon film resistors mostly involve individual fabrication, resulting in low manufacturing efficiency. Summary of the Invention

[0003] This application provides a circuit board to solve the problem of low fabrication efficiency of surface mount resistors in the prior art.

[0004] To solve the above-mentioned technical problems, the first aspect of this application provides a circuit board, comprising: a substrate, wherein a plurality of parallel first through slots are formed on the substrate, and a plurality of second through slots are formed evenly arranged along the direction of the first through slots, the first through slots and the second through slots being connected; a carbon oil layer, wherein a plurality of carbon oil layers are disposed on one side end face of the substrate and disposed between the second through slots and the first through slots along the width direction of the substrate; and a solder resist layer, wherein the solder resist layer is disposed on one side end face of the substrate and encapsulates the carbon oil layers.

[0005] The first through groove is provided along the length direction of the substrate, and the second through groove is provided along the width direction of the substrate, and they are spaced apart along the width direction of the substrate.

[0006] Conductive layers are provided on both end faces of the substrate, on the first through groove, and on the second through groove.

[0007] The conductive layer has a carbon oil layer in the area where a circuit layer is formed, and the circuit layer is disposed between adjacent first through slots along the length of the substrate; wherein the circuit layer is flush with the edge of the second through slot along the width of the substrate.

[0008] The carbon oil layer is at least partially exposed to the circuit layer along the width direction of the substrate, and the carbon oil layer is spaced apart along the length direction of the substrate; the solder resist layer is disposed on one end face of the substrate along the length direction of the substrate, and its dimension along the width direction of the substrate is the same as that of the carbon oil layer along the width direction of the substrate.

[0009] The substrate has solder pads located in the area outside the solder resist layer.

[0010] To address the aforementioned issues, this application also provides a surface mount resistor, which is fabricated from any of the circuit boards described above, comprising: a support plate; a carbon oil layer disposed on one side end face of the support plate, the carbon oil layer being located in the central region of the substrate and recessed within the substrate; and a solder resist layer disposed on one side end face of the substrate and enclosing the carbon oil layer.

[0011] The support plate is located between the adjacent first through slot and the adjacent second through slot.

[0012] The support plate is provided with a conductive layer, which covers the support plate; a circuit layer is formed in the area where the conductive layer is provided with a carbon oil layer, and the carbon oil layer is at least partially exposed to the circuit layer.

[0013] The support plate has solder pads located outside the solder resist layer.

[0014] The beneficial effects of this application are as follows: Unlike the prior art, this application forms a first through groove and a second through groove on the substrate, and forms a carbon oil layer and a solder resist layer between the first through groove and the second through groove, which can effectively improve the mechanization and automation of the preparation of the corresponding products and improve the preparation efficiency of the products. Moreover, the resistance value of the products can be changed by changing the thickness and length of the carbon oil, so that the products are more adaptable. Attached Figure Description

[0015] Figure 1 is a schematic diagram of the connection between the first through slot and the second through slot on the substrate of this application;

[0016] Figure 2 is a schematic diagram of the cross-sectional view of the circuit board of this application;

[0017] Figure 3 is a schematic diagram of the conductive layer connection on the substrate of this application;

[0018] Figure 4 is a schematic diagram of the connection between the conductive layer and the circuit layer in this application;

[0019] Figure 5 is a schematic diagram of the connection between the circuit layer and the carbon oil layer in this application;

[0020] Figure 6 is a schematic diagram of the structure of the present application with a solder resist layer on the carbon oil layer;

[0021] Figure 7 is a schematic diagram of the connection between the substrate and the pads in this application;

[0022] Figure 8 is a structural schematic diagram of the cross-sectional view of the surface mount resistor of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0026] Please refer to Figure 1, which is a schematic diagram of the connection between the first through slot and the second through slot on the substrate provided in this application.

[0027] This application provides a circuit board. As shown in Figures 1 and 2, the circuit board of this embodiment includes a substrate 10, a carbon oil layer 20, and a solder resist layer 30. The substrate 10 has a plurality of parallel first through slots 101 and a plurality of second through slots 102 evenly arranged along the direction of the first through slots 101. The first through slots 101 and the second through slots 102 are connected. A plurality of carbon oil layers 20 are disposed on one end face of the substrate 10, and are disposed between the second through slots 102 and the first through slots 101 along the width direction of the substrate 10. The solder resist layer 30 is disposed on one end face of the substrate 10 and covers the carbon oil layers 20. The substrate 10 can be a single-layer board or a multi-layer board; that is, the substrate 10 is the basic material for fabricating the circuit board.

[0028] In this embodiment, the substrate 10 can be made of an insulating material, such as a resin material. It is manufactured by impregnating a reinforcing material with resin adhesive and then processing it through drying, cutting, and lamination. This application does not impose specific limitations on this process.

[0029] In an optional embodiment, a first through groove 101 is formed on the substrate 10, and the first through grooves 101 are arranged in parallel with each other, that is, the first through grooves 101 are arranged parallel to each other on the substrate 10. Second through grooves 102 are arranged evenly in sequence along the direction in which the first through grooves 101 are laid, that is, the second through grooves 102 are connected to the first through grooves 101. The first through grooves 101 are arranged along the length direction of the substrate 10, and the second through grooves 102 are arranged along the width direction of the substrate 10.

[0030] In this embodiment, the first through-slot 101 and the second through-slot 102 penetrate the substrate 10 and are intersecting each other. The first through-slot 101 and the second through-slot 102 can be formed on the substrate 10 using laser drilling or mechanical drilling. The spacing and width between the first through-slots 101 and the spacing and width between the second through-slots 102 on the substrate 10 can be set according to actual needs, and this application does not impose specific limitations here.

[0031] In an optional embodiment, a carbon oil layer 20 is disposed on a substrate 10. The carbon oil layer 20 is disposed on one side end face of the substrate 10, and is located between adjacent first through slots 101 and between two adjacent second through slots 102 along the width direction of the substrate 10. That is, a carbon oil layer 20 is disposed in the area formed by the first through slots 101 and the second through slots 102. When the carbon oil layer 20 is disposed on the substrate 10, the carbon oil can be printed onto the substrate 10 by printing, and after the carbon oil is printed, it is cured by drying or other methods, thereby forming a carbon oil layer 20 on one side end face of the substrate 10. The carbon oil layer 20 is located at the center of the area enclosed by the adjacent first through slots 101 and the adjacent second through slots 102, that is, the projection of the carbon oil layer 20 on the substrate 10 is located at the center of the area enclosed by the adjacent first through slots 101 and the adjacent second through slots 102.

[0032] In this embodiment, a carbon oil layer 20 is formed on the substrate 10. Since the carbon oil has a corresponding resistance value, the circuit board can form a corresponding resistor. The resistance value of the carbon oil is R = ρL / WTX. Where ρ represents the sheet resistance of the carbon oil, L represents the length of the carbon oil, W represents the width of the carbon oil, T represents the thickness of the carbon oil, and X represents a coefficient. It should be noted that the coefficient X is different for different materials. That is, the resistance value R of the carbon oil can be adjusted according to the length, width, thickness of the carbon oil that the product can accommodate, as well as the sheet resistance of the carbon oil. In other words, by printing carbon oil of different lengths, widths, and thicknesses, circuit boards with different resistance values ​​can be prepared. Specifically, this can be calculated according to the above formula.

[0033] In some embodiments, after a carbon oil layer 20 is printed and formed on the substrate 10, a solder resist layer 30 can be formed on one side end face of the substrate 10. The solder resist layer 30 can wrap around the carbon oil layer 20, thereby protecting the carbon oil layer 20. Specifically, after forming the carbon oil layer 20, a solder resist ink is printed or rolled onto one side end face of the substrate 10. After the solder resist ink is formed on the substrate 10, the solder resist ink is exposed, for example, by irradiating the solder resist ink with UV (ultraviolet) light. It is understood that when the solder resist ink is irradiated with ultraviolet light, the corresponding resin monomers will generate free radical impacts and break the double bonds to produce a polymerization crosslinking reaction, thereby forming the solder resist layer 30 on the substrate 10.

[0034] In a specific application scenario, after forming a carbon oil layer 20 and a solder resist layer 30 on the substrate 10, laser cutting can be used to cut along the edge of the second through groove 102, thereby cutting the circuit board into several resistor units containing the carbon oil layer 20. This effectively improves the fabrication efficiency of small-sized devices such as resistor units.

[0035] In the above embodiments, by forming a first through groove 101 and a second through groove 102 on the substrate 10, and forming a carbon oil layer 20 and a solder resist layer 30 between the first through groove 101 and the second through groove 102, this application can effectively improve the mechanization and automation of the preparation of the corresponding products, and improve the preparation efficiency of the products. Moreover, the resistance value of the products can be changed by changing the thickness and length of the carbon oil, so that the product adaptability is higher.

[0036] In an optional embodiment, the first through-slot 101 is disposed along the length direction of the substrate 10, and the second through-slot 102 is disposed along the width direction of the substrate 10 and spaced apart along the width direction of the substrate 10, that is, the first through-slot 101 and the second through-slot 102 are perpendicularly disposed, thereby effectively improving the utilization rate of the surface of the substrate 10. The second through-slots 102 are arranged evenly and sequentially along the first through-slots 101 on the substrate 10, thereby forming a plurality of units between the first through-slots 101 and the second through-slots 102, and the second through-slots 102 are spaced apart along the width direction of the substrate 10, that is, the second through-slots 102 are not connected along the width direction of the substrate 10, thereby facilitating the subsequent deposition of the carbon oil layer 20 on the plurality of units and the deposition of the solder resist layer 30 on the substrate 10. The first through-slots 101 and the second through-slots 102 are spaced apart from the edge of the substrate 10.

[0037] In other embodiments, the second through groove 102 is provided along the width direction of the substrate 10, the first through groove 101 is provided along the length direction of the substrate 10, the second through groove 102 is connected along the width direction of the substrate 10, the first through groove 101 is arranged at intervals along the direction of the second through groove 102, and the first through groove 101 is arranged at intervals along the width direction of the substrate 10.

[0038] In an optional embodiment, as shown in FIG3, conductive layers 40 are provided on both end faces of the substrate 10, on the first through groove 101, and on the second through groove 102. That is, after the first through groove 101 and the second through groove 102 are formed on the substrate 10, the substrate 10 is electroplated to form conductive layers 40 on the substrate 10, the first through groove 101, and the second through groove 102. In other words, carbon oil layer 20 is disposed on conductive layer 40 of substrate 10.

[0039] The conductive circuit layer 401 may be made of materials including but not limited to copper, aluminum, iron, nickel, gold, silver, platinum group metals, chromium, magnesium, tungsten, molybdenum, lead, tin, indium, zinc or other alloys.

[0040] In this embodiment, before forming the conductive layer 40 on the substrate 10, the circuit board can be prepared for electroplating. Processes such as black hole treatment can be used to treat the substrate 10, the second through-hole 102, and the second through-hole 102. For example, after forming the first through-hole 101 and the second through-hole 102 on the substrate 10, the hole walls of the first through-hole 101 and the second through-hole 102 are cleaned to remove impurities and oxides, ensuring clean hole walls, which is beneficial for the subsequent fabrication of the conductive layer 40 on the substrate 10. After cleaning, the first through-hole 101 and the second through-hole 102 are treated with black hole treatment, that is, carbon powder is physically adsorbed onto the surface of the hole walls of the first through-hole 101 and the second through-hole 102 to form a conductive carbon layer. After the carbon powder is attached to the hole walls, the first through-hole 101 and the second through-hole 102 can be fixed to ensure that the carbon powder is stably attached to the hole walls. Based on this, the first through groove 101 and the second through groove 102 are micro-etched to increase the roughness of the hole walls, thereby improving the adhesion of metal during subsequent electroplating. Furthermore, the substrate 10 can be subjected to anti-oxidation treatment to prevent the hole walls of the first through groove 101 and the second through groove 102 from being oxidized during subsequent fabrication processes, thus affecting the subsequent electroplating effect.

[0041] In other embodiments, a conductive layer 40 is formed on the substrate 10, or other methods may be used, such as spraying, etc., which are not specifically limited here.

[0042] In an optional embodiment, as shown in FIG4, a circuit layer 401 is formed in the area where the carbon oil layer 20 is disposed on the conductive layer 40. The circuit layer 401 is disposed between adjacent first through slots 101 along the length direction of the substrate 10. After the conductive layer 40 is electroplated on the substrate 10, the conductive layer 40 can be fabricated to form the circuit layer 401 in the area where the carbon oil layer 20 is disposed on the substrate 10. Specifically, after the conductive layer 40 is formed on the substrate 10, pattern transfer can be performed on one end face of the carbon oil layer 20 to complete the fabrication of the circuit layer 401. That is, when fabricating the circuit layer 401, pattern transfer can be performed between two adjacent first through slots 101 along the length direction of the substrate 10 to complete the fabrication of the corresponding circuit layer 401. The circuit layer 401 is flush with the edge of the second through slot 102 along the width direction of the substrate 10. When the carbon oil layer 20 is disposed on the substrate 10, the length of the carbon oil layer 20 along the width direction of the substrate 10 can be greater than the length of the circuit layer 401 along the width direction of the substrate 10.

[0043] In some embodiments, as shown in FIG5, the carbon oil layer 20 is at least partially exposed to the circuit layer 401 along the width direction of the substrate 10, and the carbon oil layer 20 is spaced apart along the length direction of the substrate 10. Specifically, the carbon oil layer 20 is disposed at the center of two adjacent second through slots 102 and at the center of two adjacent first through slots 101, and is spaced apart from the first through slots 101, and its dimension in the width direction of the substrate 10 is larger than the dimension of the circuit layer 401 in the width direction of the substrate 10.

[0044] In this embodiment, as shown in FIG6, the solder resist layer 30 is disposed on one side end face of the substrate 10 along the length direction of the substrate 10, and its dimension along the width direction of the substrate 10 is the same as that of the carbon oil layer 20 along the width direction of the substrate 10. That is, the solder resist layer 30 is continuously laid on one side surface of the substrate 10 along the length direction of the substrate 10, and is located between two adjacent first through slots 101, and is spaced apart from the first through slots 101. Moreover, the dimension of the solder resist layer 30 along the width direction of the substrate 10 is the same as that of the carbon oil layer 20 along the width direction of the substrate 10, so that when the solder resist layer 30 is disposed, the carbon oil layer 20 can be effectively protected by the solder resist layer 30.

[0045] In other embodiments, the dimension of the solder resist layer 30 along the width direction of the substrate 10 is larger than the dimension of the carbon oil layer 20 along the width direction of the substrate 10, as long as the solder resist layer 30 can cover the carbon oil layer 20. This application does not make specific limitations here.

[0046] In an optional embodiment, as shown in FIG7, pads 50 are provided on the area outside the solder resist layer 30 of the substrate 10. That is, after the solder resist layer 30 is formed on the substrate 10, the substrate 10 can be further surface treated to form pads 50 on the area outside the solder resist layer 30 of the substrate 10.

[0047] In this embodiment, the surface of the substrate 10 on which the solder resist layer 30 is formed is subjected to tin melting treatment. During the tin melting treatment, a tin layer can be formed on the area of ​​the substrate 10 other than the solder resist layer 30 and on the sidewalls of the first through groove 101 and the second through groove 102 to wrap the substrate 10.

[0048] In other embodiments, when surface treatment is performed on the surface of the substrate 10, the area other than the solder resist layer 30 on the substrate 10, the sidewalls of the first through groove 101 and the second through groove 102 may also be subjected to gold plating treatment. The specific settings are determined according to actual needs, and this application does not make specific limitations here.

[0049] In some embodiments, the steps for fabricating the circuit board are as follows: A substrate 10 is prepared, and a first through-slot 101 and a second through-slot 102 are formed on the substrate 10 by means of mechanical milling or laser drilling. The first through-slot 101 and the second through-slot 102 are connected. The first through-slot 101 is continuously arranged along the length direction of the substrate 10, and the second through-slot 102 is arranged along the width direction of the substrate 10 and spaced apart. The substrate 10 is then electroplated to electroplat the surface of the substrate 10, the sidewalls of the first through-slot 101 and the second through-slot 102, thereby forming a conductive layer 40 on the substrate 10, the sidewalls of the first through-slot 101 and the second through-slot 102. After forming the conductive layer 40, the conductive layer 40 is patterned to form a circuit layer 401 flush with the edge of the second through-slot 102 in the width direction of the substrate 10. After forming the circuit layer 401, carbon ink is printed and coated on the circuit layer 401, and the carbon ink is dried to form a carbon ink layer 20. The resistance of the carbon ink layer 20 can be changed by adjusting its length, thickness, etc., and the carbon ink layer 20 is at least partially exposed on the circuit layer 401. After forming the carbon ink layer 20, a solder resist layer 30 can be formed on the substrate 10, that is, a solder resist layer 30 is formed on the carbon ink layer 20, so that the solder resist layer 30 completely covers the carbon ink layer 20, thereby protecting the carbon ink layer 20. After forming the solder resist layer 30, surface treatment is performed on the area of ​​the substrate 10 other than the solder resist layer 30, thereby forming pads 50 on the sidewalls of the substrate 10, the first through-slot 101, and the second through-slot 102.

[0050] This application also provides a surface mount resistor, as shown in FIG8. This surface mount resistor is fabricated from a circuit board according to any of the above-mentioned methods, comprising: a support plate 60, a carbon oil layer 20, and a solder resist layer 30. The carbon oil layer 20 is disposed on one side end face of the support plate 60, located in the central region of the substrate 10 and recessed within the substrate 10. The solder resist layer 30 is disposed on one side end face of the substrate 10 and encloses the carbon oil layer 20. The substrate 10 is cut into the support plate 60 by laser cutting or mechanical cutting along the edge of the second through slot 102, thereby forming the surface mount resistor. The support plate 60 has the carbon oil layer 20 and the solder resist layer 30 formed on it.

[0051] In this embodiment, the support plate 60 is located between the adjacent first through groove 101 and the adjacent second through groove 102. That is, after the circuit board is formed, it is cut along the edge of the second through groove 102 or the first through groove 101, so that the circuit board forms multiple units, each unit including the support plate 60, the carbon oil layer 20 and the solder resist layer 30.

[0052] In some embodiments, a conductive layer 40 is disposed on the support plate 60, and the conductive layer 40 covers the support plate 60. A circuit layer 401 is formed in the area of ​​the conductive layer 40 where the carbon oil layer 20 is disposed, and the carbon oil layer 20 is at least partially exposed in the circuit layer 401. That is, after the conductive layer 40 and the circuit layer 401 are formed on the circuit board, a carbon oil layer 20 and a solder resist layer 30 are disposed on the circuit layer 401, and the remaining areas of the solder resist layer 30 are then subjected to tinning treatment to form a circuit board. Based on this, the substrate 10 is cut to form a surface mount resistor.

[0053] In this embodiment, character identifiers can be set on each surface mount resistor during fabrication.

[0054] In summary, those skilled in the art will readily understand that the beneficial effects of this application are: by forming a first through-slot 101 and a second through-slot 102 on a substrate 10, and then fabricating a conductive layer 40, a circuit layer 401, a carbon oil layer 20, a solder resist layer 30, and a pad 50 on the substrate 10, a circuit board is formed. Based on this, the circuit board is cut to form multiple units, each unit being a surface-mount resistor. This results in higher automation and mechanization in the fabrication of surface-mount resistors, effectively improving the fabrication efficiency of surface-mount resistors.

[0055] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A circuit board, characterized in that, The circuit board includes: a substrate having a plurality of parallel first through slots and a plurality of second through slots evenly arranged along the direction of the first through slots, the first through slots being connected to the second through slots; a carbon oil layer having a plurality of the carbon oil layers disposed on one side end face of the substrate and disposed between the second through slots and the first through slots along the width direction of the substrate; and a solder resist layer disposed on one side end face of the substrate and encapsulating the carbon oil layers.

2. The circuit board according to claim 1, characterized in that, The first through slot is provided along the length direction of the substrate, and the second through slot is provided along the width direction of the substrate, and they are spaced apart along the width direction of the substrate.

3. The circuit board according to claim 1, characterized in that, Conductive layers are provided on both end faces of the substrate, on the first through groove, and on the second through groove.

4. The circuit board according to claim 3, characterized in that, A circuit layer is formed in the area where the conductive layer has a carbon oil layer, and the circuit layer is disposed between adjacent first through slots along the length direction of the substrate; wherein, the circuit layer is flush with the edge of the second through slot along the width direction of the substrate.

5. The circuit board according to claim 4, characterized in that, The carbon oil layer is at least partially exposed on the circuit layer along the width direction of the substrate, and the carbon oil layer is spaced apart along the length direction of the substrate; the solder resist layer is disposed on one end face of the substrate along the length direction of the substrate, and its dimension along the width direction of the substrate is the same as that of the carbon oil layer along the width direction of the substrate.

6. The circuit board according to claim 1, characterized in that, The substrate has solder pads in the area outside the solder resist layer.

7. A surface mount resistor, said surface mount resistor being manufactured from the circuit board according to any one of claims 1-6, characterized in that, The surface mount resistor includes: a support plate; a carbon oil layer disposed on one side end face of the support plate, the carbon oil layer being located in the central region of the substrate and recessed within the substrate; and a solder resist layer disposed on one side end face of the substrate and enclosing the carbon oil layer.

8. The surface mount resistor according to claim 7, characterized in that, The support plate is located between the adjacent first through slot and the adjacent second through slot.

9. The surface mount resistor according to claim 7, characterized in that, A conductive layer is provided on the support plate, and the conductive layer covers the support plate; a circuit layer is formed in the area of ​​the conductive layer where the carbon oil layer is disposed, and the carbon oil layer is at least partially exposed to the circuit layer.

10. The surface mount resistor according to claim 7, characterized in that, The support plate is provided with solder pads, which are located in the area outside the solder resist layer.

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