A buried resist metal foil and a method for manufacturing the same

Abstract

The application discloses a buried resistance metal foil and a preparation method thereof, and belongs to the technical field of circuit boards. The buried resistance metal foil comprises a first copper foil layer; at least two first resistance layers are arranged on the first copper foil layer at intervals, and the resistances of the at least two first resistance layers are different from each other; a first bonding layer comprises a bonding flat layer and a spacing beam which are connected with each other, the bonding flat layer is bonded to one side of the first resistance layer away from the first copper foil layer, the spacing beam is arranged at the interval between two adjacent first resistance layers, and the spacing beam is bonded to the first resistance layer and the first copper foil layer at the same time; and the first copper foil layer, the first resistance layer and the first bonding layer are integrated. The bonding force between the resistance layer and the copper foil layer is enhanced, and the effective operation of a circuit is ensured; because the resistances of the at least two first resistance layers are different from each other, the resistances of the effective resistance area of the metal foil are different, and the design space of the circuit formed in the later period is increased.

Description

Technical Field

[0001] This invention relates to the field of circuit board technology, and in particular to an embedded resist metal foil and a method for preparing the embedded resist metal foil. Background Technology

[0002] According to statistics from engineers in the electronics industry, in integrated circuit design, resistors account for about 30% of discrete components, capacitors account for about 40%, and other components account for only about 30% in total.

[0003] Since resistors make up the majority of components, placing them on the surface of the circuit board and connecting them to the circuit via leads greatly increases the complexity of the circuit. The unstable bonding between the resistor layer and the copper foil layer leads to a deterioration in the circuit's performance.

[0004] Therefore, there is an urgent need to provide a buried resist metal foil and a method for preparing the buried resist metal foil to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a buried resistive metal foil and a method for preparing the buried resistive metal foil, thereby enhancing the bonding force between the resistive layer and the copper foil layer and ensuring the effective operation of the circuit.

[0006] To achieve the above objectives, the following technical solution is provided:

[0007] An embedded resistive metal foil, comprising:

[0008] First copper foil layer;

[0009] At least two first resistive layers are disposed at intervals on the first copper foil layer, and the resistance values ​​of the at least two first resistive layers are different.

[0010] The first adhesive layer includes a connected adhesive flat layer and a spacer beam. The adhesive flat layer is bonded to the side of the first resistive layer away from the first copper foil layer. The spacer beam is disposed between two adjacent first resistive layers and is bonded to both the first resistive layer and the first copper foil layer.

[0011] The first copper foil layer, the first resistive layer, and the first adhesive layer are an integrated structure.

[0012] As an alternative to the buried resistive metal foil, the first copper foil layer has a protruding first protrusion limiting portion on the side near the first resistive layer, and the first resistive layer has a recessed first groove limiting portion on the side near the first copper foil layer, with the first protruding limiting portion disposed within the first groove limiting portion.

[0013] As an alternative to buried resistive metal foil, the first protruding limiting part has an arc-shaped or polygonal structure.

[0014] As an alternative to embedding the metal foil, the first copper foil layer has a second protruding limiting part protruding on the side near the spacer beam; the spacer beam has a second recessed limiting part on the side near the first copper foil layer, and the second protruding limiting part is disposed in the second recessed limiting part.

[0015] As an alternative to embedded resistive metal foil, the second protruding limiting portion has an arc-shaped or polygonal structure.

[0016] As an alternative to buried resistive metal foil, magnetron sputtering is used to sputter resistive material onto the surface of the first copper foil layer to form the first resistive layer.

[0017] As an alternative to the buried resistive metal foil, a first substrate is also included, which is disposed on the side of the first copper foil layer away from the first resistive layer.

[0018] As an alternative to the buried resistive metal foil, a second adhesive layer, a second resistive layer, and a second copper foil layer are sequentially disposed on the side of the first adhesive layer away from the first resistive layer.

[0019] As an alternative to the buried resistive metal foil, a second substrate is also included, which is disposed on the side of the second copper foil layer away from the second resistive layer.

[0020] As an alternative to the buried resistive metal foil, a third substrate is also included, which is disposed on the side of the adhesive layer away from the first resistive layer.

[0021] A method for preparing buried resist metal foil, for preparing any of the above-mentioned buried resist metal foil, includes the following steps:

[0022] S1. Divide a strip-shaped blocking area and at least two resistor forming areas on the first copper foil layer along the length direction of the first copper foil layer. The strip-shaped blocking area is located between the two resistor forming areas, and the widths of the at least two resistor forming areas are different.

[0023] S2. Adhere the strip-shaped shielding layer to the strip-shaped shielding area;

[0024] S3. A first resistive layer is formed on the resistive forming area using a resistive material, and at least two of the first resistive layers have different resistance values.

[0025] S4. Peel off the strip-shaped shielding layer from the strip-shaped shielding area;

[0026] S5. The first adhesive layer is disposed on the first resistive layer, and the spacer beam of the first adhesive layer covers the strip-shaped shielding area.

[0027] As an optional method for preparing buried resistive metal foil, step S3 further includes the following steps:

[0028] S31. Orient the magnetron sputtering device toward the first copper foil layer and sputter the resistive material for a first set duration;

[0029] S32. After sputtering is completed, the first copper foil layer is cooled down for a duration of the second set time.

[0030] As an optional method for preparing buried resistive metal foil, step S1 further includes the following steps:

[0031] S11. Apply a peeling agent to the strip-shaped shielding area.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The embedded resistive metal foil provided by this invention is sequentially provided with a first copper foil layer, at least two first resistive layers, and a first adhesive layer. Each first resistive layer is spaced apart on the first copper foil layer along a horizontal plane. A spacer beam is provided at the interval between two connected first resistive layers. An adhesive flat layer is provided on the side of the first resistive layer away from the first copper foil layer. By using the spacer beam and adhesive flat layer to space the first resistive layers, the contact area between the first adhesive layer and the first resistive layer is increased. The spacer beam is also bonded to the first copper foil layer, which enhances the bonding force between the resistive layer and the copper foil layer and ensures the effective operation of the circuit. Since the resistance values ​​of the at least two first resistive layers are different, the effective resistance area of ​​the metal foil is also different, which increases the design space for subsequent circuit formation.

[0034] The method for preparing buried resistive metal foil provided by this invention enhances the bonding force between the resistive layer and the copper foil layer, ensuring the effective operation of the circuit. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0036] Figure 1 This is a cross-sectional schematic diagram of the embedded resistive metal foil in Embodiment 1 of the present invention;

[0037] Figure 2 This is a cross-sectional schematic diagram of the first substrate provided in Embodiment 1 of the present invention;

[0038] Figure 3This is a schematic diagram of the structure of the first copper foil layer in Embodiment 1 of the present invention;

[0039] Figure 4 This is a flowchart illustrating the preparation process of the embedded resistive metal foil in Embodiment 1 of the present invention;

[0040] Figure 5 This is a cross-sectional schematic diagram of the embedded resistive metal foil in Embodiment 2 of the present invention;

[0041] Figure 6 This is a cross-sectional schematic diagram of the embedded resistive metal foil in Embodiment 3 of the present invention.

[0042] Figure label:

[0043] 1. First copper foil layer; 2. First resistive layer; 3. First adhesive layer; 4. First substrate; 5. Second adhesive layer; 6. Second resistive layer; 7. Second copper foil layer; 8. Second substrate; 9. Third substrate;

[0044] 11. First protruding limiting part; 12. Second protruding limiting part; 13. Strip-shaped blocking area; 14. Resistor forming area;

[0045] 21. First groove limiting part; 321. Second groove limiting part;

[0046] 31. Bonded flat layer; 32. Spacing beam. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0053] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0054] Since resistors make up the majority of components, placing them on the surface of the circuit board and connecting them to the circuit via leads greatly increases the complexity of the circuit. The bonding force between the resistor layer and the copper foil layer is unstable, leading to a deterioration in the circuit's performance.

[0055] To enhance the adhesion between the resistive layer and the copper foil layer and ensure the effective operation of the circuit, this embodiment provides an embedded resistive metal foil, which is described below. Figures 1 to 6 The specific content of this embodiment will be described in detail.

[0056] Example 1

[0057] like Figure 1 As shown, the embedded resistive metal foil includes a first copper foil layer 1, a first resistive layer 2, and a first adhesive layer 3. At least two first resistive layers 2 are spaced apart on the first copper foil layer 1, and the resistance values ​​of the at least two first resistive layers 2 are different. The first adhesive layer 3 includes a connected adhesive flat layer 31 and a spacer beam 32. The adhesive flat layer 31 is bonded to the side of the first resistive layer 2 away from the first copper foil layer 1, and the spacer beam 32 is disposed at the interval between two adjacent first resistive layers 2, and is bonded to both the first resistive layer 2 and the first copper foil layer 1. The first copper foil layer 1, the first resistive layer 2, and the first adhesive layer 3 are sequentially stacked and pressed into an integrated structure. The adhesive layer 3 is a semi-cured adhesive sheet. The thickness of the copper foil layer 1 is 2μm-20μm, more preferably 13μm-15μm. For example, 13μm, 13.1μm, 13.2μm, 13.3μm, 13.4μm, 13.5μm, 13.6μm, 13.7μm, 13.8μm, 13.9μm, 14 .0μm, 14.1μm, 14.2μm, 14.3μm, 14.4μm, 14.5μm, 14.6μm, 14.7μm, 14.8μm, 14.9μm, 15μm.

[0058] In summary, the embedded resistive metal foil provided by this invention is sequentially provided with a first copper foil layer 1, at least two first resistive layers 2, and a first adhesive layer 3. Each first resistive layer 2 is spaced apart on the first copper foil layer 1 along a horizontal plane. A spacer beam 32 is provided at the interval between two connected first resistive layers 2. An adhesive flat layer 31 is provided on the side of the first resistive layer 2 away from the first copper foil layer 1. By using the spaced arrangement of the first resistive layers 2, the contact area between the first adhesive layer 3 and the first resistive layer 2 is increased through the spacer beam 32 and the adhesive flat layer 31. The spacer beam 32 is also bonded to the first copper foil layer 1, enhancing the bonding force between the resistive layer and the copper foil layer and ensuring the effective operation of the circuit. Since the resistance values ​​of at least two first resistive layers 2 are different, the effective resistance area of ​​the metal foil is different, increasing the design space for subsequent circuit formation.

[0059] Furthermore, a first protruding limiting portion 11 is provided on the side of the first copper foil layer 1 near the first resistive layer 2, and a first recessed limiting portion 21 is provided on the side of the first resistive layer 2 near the first copper foil layer 1. The first protruding limiting portion 11 is disposed within the first recessed limiting portion 21. The shapes of the first protruding limiting portion 11 and the first recessed limiting portion 21 are adapted to each other.

[0060] Furthermore, the first protrusion limiting portion 11 has an arc-shaped structure, which enhances the connection between the first protrusion limiting portion 11 and the first groove limiting portion 21. In other embodiments, the first protrusion limiting portion 11 may also be a polygonal structure.

[0061] Furthermore, a second protruding limiting part 12 is provided on the side of the first copper foil layer 1 near the spacer beam 32; a second groove limiting part 321 is recessed on the side of the spacer beam 32 near the first copper foil layer 1, and the second protruding limiting part 12 is disposed in the second groove limiting part 321.

[0062] Furthermore, the second protrusion limiting portion 12 has an arc-shaped structure, which enhances the connection between the second protrusion limiting portion 12 and the second groove limiting portion 321. In other embodiments, the second protrusion limiting portion 12 may also be a polygonal structure.

[0063] Furthermore, the surfaces of both the first protrusion limiting portion 11 and the second protrusion limiting portion 12 are roughened to form a roughened layer. The average roughness Rz of the roughened layer ranges from 3μm to 5μm, and more preferably from 2μm to 4μm. For example, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3.0μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm, and 4μm.

[0064] In other embodiments, resistive material is sputtered onto the surface of the first copper foil layer 1 using magnetron sputtering to form a first resistive layer 2. This ensures that the first resistive layer 2 is firmly bonded to the first copper foil layer 1, guaranteeing a good adhesion between the first resistive layer 2 and the first copper foil layer 1.

[0065] In some applications, the resistive material can also be formed on the surface of the first copper foil layer 1 by chemical plating or electroplating.

[0066] Furthermore, such as Figure 2 As shown, the buried resistive metal foil also includes a first substrate 4, which is disposed on the side of the first copper foil layer 1 away from the first resistive layer 2.

[0067] like Figure 3 and Figure 4 As shown, this embodiment also provides a method for preparing buried resist metal foil, which includes the following steps:

[0068] S1. A strip-shaped shielding area 13 and at least two resistor forming areas 14 are divided on the first copper foil layer 1 along the length direction of the first copper foil layer 1. The strip-shaped shielding area 13 is located between the two resistor forming areas 14, and the widths of the at least two resistor forming areas 14 are different.

[0069] S2. Adhere the strip-shaped shielding layer to the strip-shaped shielding area 13;

[0070] S3. A first resistive layer 2 is formed on the resistive forming region 14 using a resistive material, and the resistance values ​​of at least two first resistive layers 2 are different.

[0071] S4. Peel off the strip-shaped shielding layer from the strip-shaped shielding area 13;

[0072] S5. The first adhesive layer 3 is disposed on the first resistive layer 2, and the spacer beam 32 of the first adhesive layer 3 covers the strip shielding area 13.

[0073] The buried resistor metal foil preparation method in this embodiment enhances the bonding force between the resistor layer and the copper foil layer, ensuring effective circuit operation. The varying widths of the resistor forming region 14 result in different resistance values ​​for each first resistor layer 2, and consequently, different resistance values ​​in the effective resistance region of the metal foil, increasing the design space for subsequent circuit formation.

[0074] Furthermore, step S3 also includes the following steps:

[0075] S31. Orient the magnetron sputtering device toward the first copper foil layer 1 and sputter the resistive material for a first set duration;

[0076] S32. After sputtering, the first copper foil layer 1 is cooled for a duration of the second preset time. Based on actual experience, the specific durations of the first and second preset times are manually set in advance.

[0077] Furthermore, step S1 also includes the following steps: S11, applying a release agent to the strip-shaped masking area 13. This facilitates the peeling of the strip-shaped masking layer from the strip-shaped masking area 13.

[0078] Example 2

[0079] This embodiment provides an embedded resistive metal foil. Compared with Embodiment 1, the basic structure of the embedded resistive metal foil provided in this embodiment is the same as that in Embodiment 1. The only difference is the arrangement of the first adhesive layer 3 on the side away from the first resistive layer 2. This embodiment will not describe the same structure as Embodiment 1 again.

[0080] like Figure 5 As shown, in this embodiment, the buried resistive metal foil has a second adhesive layer 5, a second resistive layer 6, and a second copper foil layer 7 sequentially disposed on the side of the first adhesive layer 3 away from the first resistive layer 2.

[0081] Furthermore, the buried resistive metal foil also includes a second substrate 8, which is disposed on the side of the second copper foil layer 7 away from the second resistive layer 6.

[0082] The materials of the first resistive layer 2 and the second resistive layer 6 may include at least one elemental metal selected from nickel, chromium, platinum, palladium, and titanium, and / or alloys comprising at least two combinations of nickel, chromium, platinum, palladium, titanium, silicon, phosphorus, and aluminum. For example, they may be nickel-chromium alloy (NiCr) or nickel-phosphorus alloy (NiP) with low resistivity, or chromium-silicon alloy (CrSi) with high resistivity.

[0083] The conductivity of the copper foil layer is 2-1000 times that of the resistive layer.

[0084] Example 3

[0085] This embodiment provides an embedded resistive metal foil. Compared with Embodiment 1, the basic structure of the embedded resistive metal foil provided in this embodiment is the same as that in Embodiment 1. The only difference is the arrangement of the first adhesive layer 3 on the side away from the first resistive layer 2. This embodiment will not describe the same structure as Embodiment 1 again.

[0086] like Figure 6 As shown, the buried resistive metal foil in this embodiment also includes a third substrate 9, which is disposed on the side of the adhesive layer 3 away from the first resistive layer 2.

[0087] The first substrate 4, the second substrate 8, and the third substrate 9 are made of insulating materials with a certain load-bearing capacity. For example, the materials may be resin glue, polyimide (PI), modified polyimide, fiberglass cloth, fiberglass cloth composite material, paper substrate, composite substrate, HDI board, modified epoxy resin, modified acrylic resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene (PE), etc.

[0088] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A buried resistive metal foil, characterized in that, include: First copper foil layer (1); At least two first resistive layers (2) are disposed at intervals on the first copper foil layer (1), and the resistance values ​​of the at least two first resistive layers (2) are different. The first adhesive layer (3) includes a connected adhesive flat layer (31) and a spacer beam (32). The adhesive flat layer (31) is bonded to the side of the first resistive layer (2) away from the first copper foil layer (1). The spacer beam (32) is disposed between two adjacent first resistive layers (2) and is bonded to both the first resistive layer (2) and the first copper foil layer (1). The first copper foil layer (1) has a first protruding limiting part (11) protruding on the side near the first resistor layer (2), and the first resistor layer (2) has a first recessed limiting part (21) recessed on the side near the first copper foil layer (1). The first protruding limiting part (11) is disposed in the first recessed limiting part (21). The first copper foil layer (1) has a second protruding limiting part (12) protruding on the side near the spacer beam (32); the spacer beam (32) has a second recessed limiting part (321) recessed on the side near the first copper foil layer (1), and the second protruding limiting part (12) is disposed in the second recessed limiting part (321); The first copper foil layer (1), the first resistive layer (2), and the first adhesive layer (3) are an integrated structure.

2. The embedded resistive metal foil according to claim 1, characterized in that, The first protruding limiting part (11) has an arc shape or a polygonal structure.

3. The embedded resistive metal foil according to claim 1, characterized in that, The second protruding limiting part (12) has an arc-shaped or polygonal structure.

4. The embedded resistive metal foil according to claim 1, characterized in that, The resistive material is sputtered onto the surface of the first copper foil layer (1) by magnetron sputtering to form the first resistive layer (2).

5. The embedded resistive metal foil according to any one of claims 1-4, characterized in that, It also includes a first substrate (4), which is disposed on the side of the first copper foil layer (1) away from the first resistive layer (2).

6. The embedded resistive metal foil according to claim 5, characterized in that, A second adhesive layer (5), a second resistive layer (6), and a second copper foil layer (7) are sequentially disposed on the side of the first adhesive layer (3) away from the first resistive layer (2).

7. The embedded resistive metal foil according to claim 6, characterized in that, It also includes a second substrate (8), which is disposed on the side of the second copper foil layer (7) away from the second resistive layer (6).

8. The embedded resistive metal foil according to claim 5, characterized in that, It also includes a third substrate (9), which is disposed on the side of the adhesive layer (3) away from the first resistive layer (2).

9. A method for preparing embedded resistive metal foil, characterized in that, The method for preparing the buried resist metal foil as described in any one of claims 1-8 includes the following steps: S1. A strip-shaped blocking area (13) and at least two resistor forming areas (14) are divided on the first copper foil layer (1) along the length direction of the first copper foil layer (1). The strip-shaped blocking area (13) is located between the two resistor forming areas (14), and the widths of the at least two resistor forming areas (14) are different. S2. Adhere the strip-shaped shielding layer to the strip-shaped shielding area (13). S3. A first resistive layer (2) is formed on the resistive forming area (14) by means of a resistive material, and the resistance values ​​of at least two of the first resistive layers (2) are different. S4. Peel off the strip-shaped shielding layer from the strip-shaped shielding area (13). S5. The first adhesive layer (3) is disposed on the first resistive layer (2), and the spacer beam (32) of the first adhesive layer (3) covers the strip shielding area (13).

10. The method for preparing buried resistive metal foil according to claim 9, characterized in that, Step S3 further includes the following steps: S31. Orient the magnetron sputtering device toward the first copper foil layer (1) and sputter the resistive material for a first set duration; S32. After sputtering is completed, the first copper foil layer (1) is cooled down for a duration of the second set time.

11. The method for preparing buried resistive metal foil according to claim 10, characterized in that, Step S1 further includes the following steps: S11. Apply a stripping agent to the strip-shaped shielding area (13).

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