Composite substrates and circuit boards

Abstract

The present invention provides a composite substrate and a circuit board. The composite substrate includes a first resistance layer and a base layer. The first resistance layer is laminated on at least one surface of the base layer. The surface of the base layer facing the first resistance layer has a plurality of protrusions. The surface roughness Ra of the base layer having the protrusions is 0.5 μm to 5 μm, and the number of protrusions is 0.1×10 3 pieces / mm to 3×10 3 pieces / mm. Due to the above limitations, the uniformity of the first resistance layer deposited on the surface of the base layer is improved, thereby improving the sheet resistance uniformity of the first resistance layer, which is useful for the manufacture of high-precision embedded resistors and beneficial to the performance of circuit boards and even electronic components.

Description

[Technical Field]

[0001] The present invention relates to the technical field of composite substrates, and in particular to composite substrates and circuit boards. [Background technology]

[0002] With the rapid development of wireless communications and electronic devices, electronic devices are becoming more precise, smaller, and thinner. This requires that the components inside electronic devices be as small and thin as possible. Resistive elements inside electronic devices have evolved from pin-type plug-in resistors to chip resistors, and then from chip resistors to embedded resistors, gradually becoming thinner. The application process for embedded resistors generally involves attaching a composite substrate to a circuit board and forming the embedded resistor through an etching process. The composite substrate includes a base layer and a resistive layer located on one surface of the base layer, with the surface of the resistive layer away from the base layer being suitable for attachment to a circuit board.

[0003] However, the sheet resistance uniformity of existing composite substrates is low, which is disadvantageous for manufacturing high-precision embedded resistors. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is how to improve the sheet resistance uniformity of the embedded resistor to provide a composite substrate and a circuit board.

[0005] The present invention provides a composite substrate, the composite substrate including a first resistive layer and a base layer, the first resistive layer being laminated on at least one surface of the base layer, the surface of the base layer facing the first resistive layer having a plurality of protrusions, the surface roughness Ra of the base layer having the protrusions being 0.5 μm to 5 μm, and the number of the protrusions being 0.1×10 3 pieces / mm~3×10 3 pcs / mm.

[0006] Preferably, the axis of the center of the top of the protrusion on the base layer is the central axis of the protrusion, and the horizontal interval between the central axes of adjacent protrusions is 1 μm to 20 μm.

[0007] Preferably, the protrusions on the surface of the base layer are distributed such that the distance between the central axes of adjacent protrusions is D, and the proportion of protrusions with a number of protrusions that is 2 μm≦D≦11 μm is 70% or more.

[0008] Preferably, the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions with a size of 2 μm≦D<4 μm is 10% to 40%, the proportion of the number of protrusions with a size of 4 μm≦D<6 μm is 40% to 70%, the proportion of the number of protrusions with a size of 6 μm≦D<8 μm is 10% to 40%, the proportion of the number of protrusions with a size of 8 μm≦D<11 μm is 5% to 20%, and the proportion of the number of protrusions with a size of 2 μm≦D<11 μm is 100% or less.

[0009] Preferably, the thickness of the first resistive layer is 5 nm to 3 μm.

[0010] Preferably, the material of the base layer is a conductive material or a dielectric material, and the conductive material includes at least one of copper, aluminum, titanium, zinc, iron, nickel, chromium, cobalt, silver, and gold.

[0011] Preferably, the first resistive layer contains at least one element selected from the group consisting of Ni, Cr, Si, P, N, Ti, Pt, Ta, Mo, Sn, and O.

[0012] Preferably, the material of the first resistance layer includes at least one of NiCrSi, NiCrAlSi, NiP, AlN, NiCr, TiN, Pt, Cr, Cr—SiO, Cr—Si, Ti—Si, Ti—W, TaN, Mo, and Ni—Sn.

[0013] Preferably, the composite substrate includes a film layer located on a surface of the first resistive layer remote from the base layer.

[0014] Preferably, the thickness of the film layer is 0.5 μm to 100 μm.

[0015] Preferably, a conductive layer is provided on the side of the film layer remote from the first resistive layer.

[0016] Preferably, the conductive layer is a single layer conductive layer or a multi-layer conductive layer.

[0017] Preferably, a second resistive layer is provided between the film layer and the conductive layer.

[0018] Preferably, the first resistive layer is formed by one or more of the following methods: electroplating, electroless plating, physical vapor deposition, and chemical vapor deposition.

[0019] The present invention also provides a circuit board comprising the composite substrate.

[0020] The technical solution of the present invention has the following advantages:

[0021] In the composite substrate and circuit board according to the present invention, the surface roughness of the base layer and the number of protrusions are controlled to improve the uniformity of the first resistor layer deposited on the surface of the base layer, thereby improving the sheet resistance uniformity. Furthermore, when the resistor thus manufactured is applied to a circuit board, a good bonding effect is obtained, improving the structural stability of the electronic device. [Brief explanation of the drawings]

[0022] In order to more clearly describe the specific embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings that need to be used to describe the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative efforts. [Figure 1] 1 is a schematic diagram of a longitudinal cross-sectional structure of a composite substrate according to an embodiment of the present invention. [Figure 2] FIG. 2 is a SEM scan of the base layer in FIG. 1. [Figure 3] FIG. 2 is a longitudinal cross-sectional SEM scan of a composite substrate according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram showing a layering relationship of another composite substrate according to an embodiment of the present invention. [Figure 5] FIG. 2 is a schematic diagram showing a layering relationship of another composite substrate according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic diagram showing a layering relationship of another composite substrate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The technical solutions of the present invention will be described clearly and completely below with reference to the drawings, but it is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.

[0024] In addition, in the description of the present invention, the orientations or positional relationships indicated by terms such as "upper," "lower," "inner," and "outer" are based on the orientations or positional relationships shown in the drawings, and are merely for the convenience of explaining the present invention and simplifying the description. They are not intended to suggest or imply that the referenced devices or elements have a particular orientation or must be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

[0025] It should be appreciated that to improve the peel strength between the composite substrate and the circuit board and to make peeling more difficult, the base layer is typically treated to form a plurality of protrusions on one surface of the base layer, such that one surface of the base layer has a certain roughness, and the resistive layer deposited on the rough surface of the base layer has a correspondingly rough surface.

[0026] The applicant discovered that too many or too few protrusions on the surface of the base layer, or too large or small roughness of the base layer, can reduce the deposition uniformity of the resistive layer, resulting in reduced sheet resistance uniformity. Existing composite films have a sheet resistance uniformity of approximately ±10%, which is not conducive to the manufacture of high-precision embedded resistors and can affect the performance of circuit boards and even electronic components. Specifically, if the number of protrusions is too large, a large amount of resistive material is likely to fail to deposit in the areas between adjacent protrusions, resulting in reduced deposition uniformity of the resistive layer. On the other hand, if the number of protrusions is too small, the peel strength between the composite substrate and the circuit board is reduced, preventing the composite substrate from being stably fixed to the circuit board.

[0027] Based on this, and with reference to FIGS. 1 and 3, this embodiment provides a composite substrate comprising:

[0028] The base layer 1 has a plurality of closely arranged protrusions 11 on at least one surface thereof, the surface roughness Ra of the base layer 1 having the protrusions 11 being 0.5 μm to 5 μm, and the number of the protrusions 11 being 0.1×10 3 pieces / mm~3×10 3 The surface roughness Ra of the base layer 1 having the protrusions 11 is preferably 0.5 μm to 1.5 μm.

[0029] A first resistive layer 2 is located on the surface of a base layer 1 having protrusions 11. The thickness of the first resistive layer is very thin, and the shape of the first resistive layer is such that it covers the base layer, and the shapes of the two are essentially the same. The roughness of the base layer in this invention is measured from the side of the first resistive layer away from the base layer. Figure 2 is an SEM scan of the base layer, and the magnification of Figure 2 is 5000 times. In Figure 3, the first resistive layer is deposited on the surface of the base layer having protrusions, but is not visible in Figure 3 because the first resistive layer is thin.

[0030] By limiting the number of protrusions 11, it is possible to deposit as much resistive material as possible in the areas between adjacent protrusions 11, and by limiting the surface roughness of the base layer 1, the uniformity of the first resistive layer 2 deposited on the surface of the base layer 1 is improved, thereby improving the sheet resistance uniformity of the first resistive layer 2, which has a sheet resistance uniformity in the range of about ±5%, which is useful for manufacturing high-precision embedded resistors and is also beneficial to the performance of circuit boards and even electronic components.

[0031] Furthermore, the first resistive layer 2 is arranged in the same shape as the base layer 1, i.e., the surface of the first resistive layer 2 also has corresponding protrusions 11. Furthermore, by limiting the number of the protrusions 11, an appropriate peel strength is ensured between the composite substrate and the circuit board, and therefore the composite substrate can be stably fixed onto the circuit board, making the composite substrate less likely to peel off from the circuit board, and improving the structural stability of the electronic device.

[0032] Preferably, the number of the protrusions 11 is 0.1×10 3 pieces / mm~2×10 3 For example, the number of the protrusions 11 is 0.1×10 3 pieces / mm, 0.5×10 3 pieces / mm, 1×10 3 pieces / mm, 1.5×10 3 pieces / mm, 2×10 3 The number of particles per mm may be in the range of 1000 to 10000, or any number of combinations thereof.

[0033] Furthermore, the axis perpendicular to the base layer 1 and passing through the center of the top of the protrusion 11 is the central axis of the protrusion 11, and the horizontal spacing between the central axes of adjacent protrusions 11 is 1 μm to 20 μm. For example, the horizontal spacing between the central axes of adjacent protrusions 11 may be in the range of 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, or any combination of the above. Preferably, the spacing between the central axes of adjacent protrusions 11 is 1 μm to 11 μm. Long-term experimental verification has shown that sheet resistance uniformity is better within the above range.

[0034] Furthermore, the protrusions on the surface of the base layer are distributed such that the distance between the central axes of adjacent protrusions is D, and the proportion of the number of protrusions with a size of 2 μm≦D≦11 μm is 70% or more. The above distribution reduces the presence of surface defects in the base layer, which in turn further reduces defects in the first resistive layer deposited on its surface, making the thickness of the first resistive layer more uniform and ultimately improving the sheet resistance uniformity of the first resistive layer produced.

[0035] To improve the sheet resistance uniformity of the first resistor layer, the protrusions on the surface of the base layer are distributed so that the ratio of the number of protrusions within the range of 2 μm≦D<4 μm is 10% to 40% (e.g., 17%), the ratio of the number of protrusions within the range of 4 μm≦D<6 μm is 40% to 70% (e.g., 55%), the ratio of the number of protrusions within the range of 6 μm≦D<8 μm is 10% to 40% (e.g., 19%), the ratio of the number of protrusions within the range of 8 μm≦D≦11 μm, and the ratio of the number of protrusions within the range of 2 μm≦D≦11 μm. The sheet resistance uniformity of resistors manufactured within the above ranges of the spacing between the central axes and the ratio of the number of protrusions is further improved.

[0036] In this embodiment, "proportion" refers to the proportion of the number of protrusions that meet a certain condition to the total number of protrusions in at least a portion of the surface of the base layer. For example, "the proportion of the number of protrusions that meet 2 μm≦D<4 μm is 10% to 40%" can mean that the proportion of the number of protrusions that meet 2 μm≦D<4 μm on the surface of the entire base layer to the total number of protrusions on the surface of the entire base layer is 10% to 40%, and can also mean that the proportion of the number of protrusions that meet 2 μm≦D<4 μm in a portion of the surface of the base layer to the total number of protrusions in that region is 10% to 40%.

[0037] In this embodiment, the thickness of the first resistive layer 2 is 5 nm to 3 μm. Preferably, the thickness of the first resistive layer 2 is 5 nm to 200 nm. Because the thickness of the first resistive layer 2 is thin, the shape of the first resistive layer 2 basically matches the shape of the surface of the base layer having the protrusions 11. That is, the first resistive layer 2 is arranged in the same shape as the base layer 1. Specifically, the surface of the first resistive layer 2 also has protrusions 11 corresponding to the protrusions 11 of the base layer, and their dimensions are also basically the same. For example, the thickness of the base layer 1 may be 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, or 18 μm, and the thickness of the first resistive layer 2 may be 10 nm, 25 nm, 50 nm, 75 nm, 100 nm, 125 nm, 150 nm, 175 nm, or 200 nm.

[0038] In this embodiment, the material of the base layer is a conductive material or a dielectric material, and the base layer may have a single-layer structure or a laminated multi-layer structure.

[0039] Conductive materials include, but are not limited to, at least one of copper, aluminum, titanium, zinc, iron, nickel, chromium, cobalt, silver, and gold. Specifically, the base layer may be copper foil, aluminum foil, titanium foil, zinc foil, iron foil, nickel foil, chromium foil, cobalt foil, silver foil, or gold foil; an alloy foil containing at least two of copper, aluminum, titanium, zinc, iron foil, nickel foil, chromium foil, cobalt foil, silver, and gold; or a composite substrate containing at least two of copper foil, aluminum foil, titanium foil, zinc foil, iron foil, nickel foil, chromium foil, cobalt foil, silver foil, and gold foil. Dielectric materials include, but are not limited to, PET, PP, PS, ABF film, BT resin, polyacrylic acid, polyurethane, polyimide, etc. In a multilayer base layer, the materials of each layer may be the same or different.

[0040] The first resistive layer is an important functional layer in the composite substrate and is used to realize the resistive function of the embedded resistor. Different materials can be selected for the first resistive layer according to different functional requirements, thereby resulting in different resistive characteristics. Specifically, the material of the first resistive layer includes at least one element selected from the group consisting of Ni, Cr, Si, P, N, Ti, Pt, Ta, Mo, Sn, and O. Specifically, the material can be at least one of NiCrSi, NiCrAlSi, NiP, NiCr, AlN, TiN, Pt, Cr, Cr-SiO, Cr-Si, Ti-Si, Ti-W, TaN, Mo, and Ni-Sn materials. The first resistive layer can have a single-layer structure or a multilayer structure. In a multilayer first resistive layer, the materials of each layer can be the same or different.

[0041] In this embodiment, the first resistive layer is formed using at least one method among electroplating, chemical plating, physical vapor deposition, and chemical vapor deposition, and the sheet resistance of the first resistive layer is 1Ω to 2000Ω.

[0042] It should be noted that all relevant parameters in this example, such as the thickness of the base layer, the thickness and maximum width of the first resistive layer, were obtained by preparing slices of the composite substrate sample and then measuring them under a scanning electron microscope with a magnification of 2000 to 70,000 times.

[0043] 4 , in an optional embodiment, the composite substrate further includes a film layer 3 located on the surface of the first resistive layer 2, away from the base layer 1. On the one hand, the film layer can protect the first resistive layer 2 and prevent it from being damaged by external forces. On the other hand, when the composite substrate is attached to a circuit board, the film layer can bond the first resistive layer 2 to the circuit board, thereby further improving the peel strength between the composite substrate and the circuit board, making the composite substrate less likely to peel off from the circuit board and improving the structural stability of the electronic device. Furthermore, after providing the film layer, a foil-clad board can be manufactured and directly applied to a PCB rigid or flexible substrate.

[0044] Specifically, the thickness of the film layer is 0.5 μm to 100 μm. For example, the thickness of the film layer is 2 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 20 μm, 30 μm, 40 μm, 55 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm. The film layer is made of at least one selected from polystyrene-based thermoplastic resins, vinyl acetate-based thermoplastic resins, polyester-based thermoplastic resins, polyethylene-based thermoplastic resins, polyamide-based thermoplastic resins, rubber-based thermoplastic resins, acrylic-based thermoplastic resins, phenol-based thermosetting resins, epoxy-based thermosetting resins, thermoplastic polyimide-based thermosetting resins, urethane-based thermosetting resins, melamine-based thermosetting resins, alkyd-based thermosetting resins, and ABF resins.

[0045] For example, the film layer may be selected from at least one of modified epoxy resin, modified acrylic resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene, polyethylene naphthalate, polystyrene, polyvinyl chloride, polysulfone, polyphenylene sulfide, polyether ether ketone, polyphenylene ether, polytetrafluoroethylene, liquid crystal polymer, polyparabanic acid, epoxy glass cloth, and BT resin. The specific thickness and material of the film layer can be selected and set by those skilled in the art according to actual needs.

[0046] Referring further to FIG. 5 , in one embodiment, a film layer 3 is provided on the composite substrate, and a conductive layer 4 is provided on the side of the film layer 3 away from the first resistive layer 2, thereby forming a foil-clad board including the first resistive layer. This foil-clad board has a four-layer structure and can be directly applied to a rigid or flexible substrate. Specifically, the conductive layer may have a single-layer structure or a multi-layer structure. That is, the conductive layer may be copper foil, aluminum foil, titanium foil, zinc foil, iron foil, nickel foil, chromium foil, cobalt foil, silver foil, or gold foil, or may be an alloy foil containing at least two of copper, aluminum, titanium, zinc, iron, nickel, chromium, cobalt, silver, and gold, or may be a composite substrate containing at least two of copper foil, aluminum foil, titanium foil, zinc foil, iron foil, nickel foil, chromium foil, cobalt foil, silver foil, and gold foil. The materials of the conductive layer and the base layer may be the same or different, and can be determined by those skilled in the art according to actual needs.

[0047] 6, in one embodiment, a second resistive layer 5 is provided between the film layer 3 and the conductive layer 4, thereby forming an asymmetric structure. The material of the second resistive layer and the material used for the first resistive layer 2 can be the same or different, and can be determined by those skilled in the art according to actual needs. In this embodiment, the second resistive layer is formed using at least one method of electroplating, electroless plating, physical vapor deposition, and chemical vapor deposition.

[0048] The protrusions in this example are formed by the accumulation of fine crystal grains, and as shown in FIG. 1, the height of the protrusions is higher than the bottom surface of the conductive layer.

[0049] This embodiment also provides a circuit board including the composite substrate, which has all the advantages of the composite substrate, but these are omitted here.

[0050] In order to demonstrate the technical effects of the technical solution of the present application, specific examples and comparative examples are provided below, where the composite substrate in each of the examples and comparative examples includes a base layer and a first resistive layer, one surface of the base layer has some protrusions, the first resistive layer is laminated on the surface of the base layer with the protrusions, the base layer is copper foil with a thickness of 18 μm, the material of the first resistive layer is NiCr alloy, and the thickness of the first resistive layer is 22 nm.

[0051] Example 1 In this example, the surface roughness Ra of the base layer having the protrusions is 0.8 μm, and the number of protrusions is 1.0×10 3 The number of protrusions / mm is 2 μm, the distance between the central axes of adjacent protrusions is D, and the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions with D being 2 μm≦D<4 μm is 10%, the proportion of the number of protrusions with D being 4 μm≦D<6 μm is 50%, the proportion of the number of protrusions with D being 6 μm≦D<8 μm is 30%, and the proportion of the number of protrusions with D being 8 μm≦D<11 μm is 10%.

[0052] Example 2 The only difference between the composite substrate of this example and the composite substrate of Example 1 is that the number of protrusions in the composite substrate of this example is 0.1 × 10 3 The number of pieces / mm.

[0053] Example 3 The only difference between the composite substrate of this example and the composite substrate of Example 1 is that the number of protrusions in the composite substrate of this example is 3.0 × 10 3 The number of pieces / mm.

[0054] Example 4 In this example, the surface roughness Ra of the base layer having the protrusions is 0.8 μm, and the number of protrusions is 0.1×10 3The number of protrusions is / mm, the distance between the central axes of adjacent protrusions is D, and the proportion of the number of protrusions that is 2 μm≦D≦11 μm is 70%. Specifically, the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions that is 2 μm≦D<4 μm is 10%, the proportion of the number of protrusions that is 4 μm≦D<6 μm is 40%, the proportion of the number of protrusions that is 6 μm≦D<8 μm is 10%, and the proportion of the number of protrusions that is 8 μm≦D<11 μm is 10%.

[0055] Example 5 In this example, the surface roughness Ra of the base layer having the protrusions is 0.8 μm, and the number of protrusions is 0.1×10 3 The number of protrusions is 10% / mm, the distance between the central axes of adjacent protrusions is D, and the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions with D being 2 μm≦D<4 μm is 10%, the proportion of the number of protrusions with D being 40%, the proportion of the number of protrusions with D being 6 μm≦D<8 μm is 40%, and the proportion of the number of protrusions with D being 8 μm≦D<11 μm is 10%.

[0056] Example 6 In this example, the surface roughness Ra of the base layer having the protrusions is 0.8 μm, and the number of protrusions is 0.1×10 3 The number of protrusions is / mm, the distance between the central axes of adjacent protrusions is D, and the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions with 2 μm≦D<4 μm is 40%, the proportion of the number of protrusions with 4 μm≦D<6 μm is 45%, the proportion of the number of protrusions with 6 μm≦D<8 μm is 10%, and the proportion of the number of protrusions with 8 μm≦D<11 μm is 5%.

[0057] Example 7 In this example, the surface roughness Ra of the base layer having the protrusions is 0.8 μm, and the number of protrusions is 0.1×10 3 The number of protrusions is / mm, the distance between the central axes of adjacent protrusions is D, and the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions with 2 μm≦D<4 μm is 20%, the proportion of the number of protrusions with 4 μm≦D<6 μm is 50%, the proportion of the number of protrusions with 6 μm≦D<8 μm is 10%, and the proportion of the number of protrusions with 8 μm≦D<11 μm is 20%.

[0058] Example 8 In this example, the surface roughness Ra of the base layer having the protrusions is 0.8 μm, and the number of protrusions is 0.1×10 3 The number of protrusions / mm is 2 μm, the distance between the central axes of adjacent protrusions is D, and the protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions with D being 2 μm≦D<4 μm is 10%, the proportion of the number of protrusions with D being 4 μm≦D<6 μm is 70%, the proportion of the number of protrusions with D being 6 μm≦D<8 μm is 15%, and the proportion of the number of protrusions with D being 8 μm≦D<11 μm is 5%.

[0059] (Comparative Example 1) The only difference between the composite substrate according to this comparative example and the composite substrate according to Example 1 is that in the composite substrate according to this comparative example, the surface roughness Ra of the base layer having the protrusions is 6 μm.

[0060] (Comparative Example 2) The only difference between the composite substrate of this comparative example and the composite substrate of Example 1 is that the number of protrusions in the composite substrate of this comparative example is 4.0 × 10 3 The number of pieces / mm.

[0061] (Comparative Example 3) The only difference between the composite substrate of this comparative example and the composite substrate of Example 1 is that the number of protrusions in the composite substrate of this comparative example is 0.05 × 10 3 The number of pieces / mm.

[0062] (Test example) The composite substrates according to Examples 1 to 8 and Comparative Examples 1 to 3 were subjected to a sheet resistance uniformity test and a peel force test. In the sheet resistance uniformity test, the sheet resistance M at different positions on the composite substrate was first tested. The sheet resistance test points were evenly distributed on the surface of the composite substrate, and the number of sheet resistance test points was 20. Next, the average sheet resistance M at different positions on the composite substrate was measured. ave Calculate the maximum sheet resistance M max and the minimum sheet resistance M min Finally, the sheet resistance uniformity upper limit = (M max -M ave ) / M ave ×100%, sheet resistance uniformity lower limit = (Mmin -M ave ) / M ave The upper and lower limits of the sheet resistance uniformity were calculated according to the formula: × 100%. The test results are shown in Table 1.

[0063] [Table 1]

[0064] It can be seen that the technical solution in this embodiment has better sheet resistance uniformity and more stable performance.

[0065] Obviously, the above examples are merely examples for clarifying the description and are not intended to limit the embodiments. Those skilled in the art can make other different types of changes or modifications based on the above description. It is not necessary or possible to comprehensively list all the embodiments here. Moreover, obvious changes or modifications derived from this specification still fall within the protection scope of the present invention. [Explanation of symbols]

[0066] 1...base layer, 11...protrusion, 2...first resistive layer, 3...film layer, 4...conductive layer, 5...second resistive layer.

Claims

1. The device includes a first resistive layer and a base layer, the first resistive layer being laminated on at least one surface of the base layer, the surface of the base layer facing the first resistive layer having a plurality of protrusions, the surface of the base layer having the protrusions having a roughness Ra of 0.5 μm to 5 μm, and the number of the protrusions being 0.1×10 3 pieces / mm ~ 3×10 3 the number of protrusions on the surface of the base layer is 70% or more, and the axis of the center of the top of the protrusion on the base layer is the central axis of the protrusion, the distance between the central axes of adjacent protrusions is D, and the proportion of protrusions with a number of protrusions within the range of 2 μm≦D≦11 μm is 70% or more. Composite base material.

2. The horizontal spacing between the central axes of adjacent protrusions is 1 μm to 20 μm. The composite substrate according to claim 1 .

3. The protrusions on the surface of the base layer are distributed so that the proportion of the number of protrusions within the range of 2 μm≦D<4 μm is 10% to 40%, the proportion of the number of protrusions within the range of 4 μm≦D<6 μm is 40% to 70%, the proportion of the number of protrusions within the range of 6 μm≦D<8 μm is 10% to 40%, the proportion of the number of protrusions within the range of 8 μm≦D<11 μm is 5% to 20%, and the proportion of the number of protrusions within the range of 2 μm≦D<11 μm is 100% or less. The composite substrate according to claim 1 .

4. the thickness of the first resistive layer is 5 nm to 3 μm; The composite substrate according to claim 1 .

5. the material of the base layer is a conductive material or a dielectric material; The composite substrate according to claim 1 .

6. the composite substrate includes a film layer located on a surface of the first resistive layer remote from the base layer; The composite substrate according to claim 1 .

7. The thickness of the film layer is 0.5 μm to 100 μm. The composite substrate according to claim 6.

8. a conductive layer is provided on the side of the film layer away from the first resistive layer; The composite substrate according to claim 6.

9. the conductive layer is a single-layer conductive layer or a multi-layer conductive layer; The composite substrate according to claim 8.

10. a second resistive layer disposed between the film layer and the conductive layer; The composite substrate according to claim 8.

11. the first resistive layer is formed by one or more of electroplating, electroless plating, physical vapor deposition, and chemical vapor deposition; The composite substrate according to claim 1 .

12. Comprising a composite substrate according to any one of claims 1 to 11, Circuit board.

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