CN215529424U - Circuit board with embedded capacitor and resistor - Google Patents

Abstract

The utility model discloses a circuit board embedded with capacitors and resistors, which relates to the technical field of circuit board processing.

Description

Circuit board with embedded capacitor and resistor

Technical Field

The utility model relates to the technical field of circuit board processing, in particular to a circuit board with embedded capacitors and resistors.

Background

With the development of electronic products toward being lighter, thinner, shorter and higher in integration degree, more electronic products require the circuit board to reserve more space for the mounted chip, and therefore, the technology of embedding the passive device gradually becomes a development trend of the printed circuit board.

In the printed circuit board process of traditional technique, need fix electric capacity, resistance element on insulating PP substrate through soldering tin technique, because of electric capacity, resistance element set up in the outside of insulating PP substrate, drop easily to influence printed circuit board normal work, the fixed soldering tin that needs of electric capacity, resistance simultaneously, the flow is complicated, and manufacturing cost is high. The embedded passive device technology can not only reduce the mounting cost and reduce the design size of the board surface, but also greatly improve the reliability of the product.

However, the currently mainstream capacitor embedding technology mainly adopts a processing technology combining a step groove embedded capacitor and solder paste printing and packaging, wherein the step groove has two processing modes, one mode is a mechanical depth control milling plate, the mode mainly depends on the depth precision control capability of the step groove, and the other mode is a filling/embedding high-temperature-resistant gasket, such as a teflon (Tefion) gasket, but the technology depends on the control of the flow rate; in summary, the above two processing techniques all put forth extremely high requirements on the equipment, however, the existing equipment generally cannot meet the processing requirements of the embedded capacitor technology, and the reliability of the circuit board is reduced, and meanwhile, the embedded capacitor technology is extremely dependent on the use of solder paste, and has low production efficiency and high cost, that is, the existing embedded capacitor technology has high cost and low reliability.

At present, the mainstream embedded resistor technology mainly adopts a planar thin film resistor technology or a screen printing resistor ink technology, wherein the planar thin film resistor is expensive and needs to occupy a large area, the screen printing resistor ink has poor precision control capability, and particularly, the large resistor design is difficult to control the precision of the large resistor, namely, the existing embedded resistor technology has low precision and low reliability.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a circuit board with embedded capacitors and resistors, which solves the problems of the technology of embedding capacitors and resistors in the prior art.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a circuit board for embedding capacitors and resistors comprises a circuit board body, wherein the circuit board body comprises a first core board, a PP composite layer and a second core board which are sequentially stacked; the second side of the first core plate is provided with a blind groove, the PP composite layer is provided with a hollow pattern matched with the shape of the blind groove, the second core plate comprises a groove bottom pattern, a second PP layer, a capacitor substrate, a capacitor core plate, a first PP layer and a first copper foil layer which are sequentially stacked, and the groove bottom pattern is matched with the shape of the blind groove;

a finished product blind groove is formed in the first side of the first core plate and extends to the blind groove;

the circuit board body is further provided with a first through hole, the first through hole penetrates through the first core plate, the PP composite layer and the second core plate, a first conductive ink column is filled in the first through hole, a second ink hole is formed in the central area of the first conductive ink column, and a second conductive ink column is filled in the second ink hole.

Optionally, an outer layer circuit including a capacitor ground pattern is further etched on the first copper foil layer;

a semi-cured resin sheet and a third copper foil layer are further pressed on the second side of the first copper foil layer;

the circuit board body is further provided with a first blind hole, and the first blind hole penetrates through the semi-solidified resin sheet, the first copper foil layer and the capacitor core plate from the third copper foil layer in sequence and extends to the capacitor pattern on the capacitor substrate.

Optionally, the first core plate includes at least one inner copper foil layer and an outer copper foil layer, and the outer copper foil layer is disposed on a first side of the inner copper foil layer.

Optionally, an outer layer circuit and a solder resist layer are disposed on both the outer layer copper foil layer and the third copper foil layer.

Optionally, a copper-deposited electroplated layer is disposed on the hole wall of the first blind hole.

Optionally, the second ink hole has an aperture no larger than four-fifths of the first through hole.

Optionally, the second conductive ink pillar is a high conductivity ink pillar, the conductivity of the high conductivity ink pillar is greater than the conductivity of the first conductive ink pillar;

or the second conductive ink column is a high-resistivity ink column, and the conductivity of the high-resistivity ink column is smaller than that of the first conductive ink column.

Compared with the prior art, the utility model has the following beneficial effects:

according to the circuit board embedded with the capacitor and the resistor, the first core board with the blind groove, the second core board with the capacitor core board and the PP composite layer are arranged in a laminated mode, so that the blind groove, the groove bottom graph and the hollow graph are aligned conveniently, the finished blind groove is processed on the first side of the first core board in a mode of depth control, uncovering, electric milling and the like, the finished blind groove extends to the blind groove, the groove bottom graph at the bottom of the blind groove is exposed, the step groove processing of the circuit board is completed, then the accurate control of the resistor is achieved by setting the aperture of the first through hole and the aperture and the depth of the second ink hole, the table top and the depth of the step groove of the circuit board embedded with the capacitor and the resistor are uniform, the accuracy of the capacitor and the resistor can be effectively controlled, meanwhile, the traditional packaging process of printing solder paste is omitted, the production efficiency is greatly improved, the cost is reduced, and the reliability of the product is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

The structure, proportion, size and the like shown in the drawings are only used for matching with the content disclosed in the specification, so that the person skilled in the art can understand and read the description, and the description is not used for limiting the limit condition of the implementation of the utility model, so the method has no technical essence, and any structural modification, proportion relation change or size adjustment still falls within the scope of the technical content disclosed by the utility model without affecting the effect and the achievable purpose of the utility model.

Fig. 1 is a schematic structural diagram of a first core board according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a second core board according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a PP composite layer according to an embodiment of the utility model;

FIG. 4 is a schematic structural view of an inner panel of the embodiment of the present invention;

FIG. 5 is a schematic diagram of the structure of the embedded capacitor and resistor inner plate according to the embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a circuit board matrix according to an embodiment of the utility model;

FIG. 7 is a schematic structural diagram of a semi-finished circuit board according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a circuit board body according to an embodiment of the present invention.

Illustration of the drawings: 10. a first core board; 10a, blind grooves; 10b, an inner copper foil layer; 10c, an outer copper foil layer;

20. a second core board; 20a, a capacitor core plate; 20b, a capacitor substrate; 201c, a first PP layer; 202c, a second PP layer; 201d, a first copper foil layer; 202d, a second copper foil layer; 20e, a capacitance pattern; 20f, groove bottom pattern;

30. a PP composite layer; 30a, hollowing out the patterns;

40. an inner plate;

50. embedding a capacitor and a resistor inner plate; 50a, a first through hole; 50b, a first conductive ink column; 50c, a second ink hole; 50d, a second conductive ink column; 50e, a capacitive ground pattern;

60. a circuit board matrix; 60a, a semi-cured resin sheet; 60b, a third copper foil layer; 60c, a first blind hole;

70. a semi-finished circuit board; 70a, an outer layer circuit; 70b, a solder resist layer;

80. a circuit board body; 80a and finished product blind grooves.

Detailed Description

In order to make the objects, features and advantages of the present invention more apparent and understandable, the embodiments of the present invention will be described in detail and completely with reference to the accompanying drawings, and it is to be understood that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. It should be noted that when one component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present.

The technical scheme of the utility model is further explained by the specific implementation mode in combination with the attached drawings.

Referring to fig. 1 to 8, fig. 1 is a schematic structural diagram of a first core board according to an embodiment of the present invention, fig. 2 is a schematic structural diagram of a second core board according to an embodiment of the present invention, fig. 3 is a schematic structural diagram of a PP composite layer according to an embodiment of the present invention, fig. 4 is a schematic structural diagram of an inner board according to an embodiment of the present invention, fig. 5 is a schematic structural diagram of an embedded capacitor and resistor inner board according to an embodiment of the present invention, fig. 6 is a schematic structural diagram of a circuit board body according to an embodiment of the present invention, fig. 7 is a schematic structural diagram of a semi-finished circuit board according to an embodiment of the present invention, and fig. 8 is a schematic structural diagram of a circuit board body according to an embodiment of the present invention.

The stepped circuit board embedded with the capacitor and the resistor, provided by the embodiment of the utility model, can finish the installation of the capacitor and the resistor on the premise of not needing solder paste, and has the advantages of high precision, low cost and the like.

As shown in fig. 1 to 8, the circuit board for embedding capacitors and resistors of the present embodiment includes a circuit board body 80, wherein the circuit board body 80 includes a first core board 10, a PP composite layer 30 and a second core board 20 stacked in sequence; the second side of the first core board 10 is provided with a blind groove 10a, the PP composite layer 30 is provided with a hollow pattern 30a matched with the blind groove 10a in shape, the second core board 20 comprises a groove bottom pattern 20f, a second PP layer 202c, a capacitor substrate 20b, a capacitor core board 20a, a first PP layer 201c and a first copper foil layer 201d which are sequentially stacked, wherein the groove bottom pattern 20f is matched with the blind groove 10a in shape;

a finished product blind groove 80a is further formed in the first side of the first core plate 10, and the finished product blind groove 80a extends to the blind groove 10 a;

the circuit board body 80 is further provided with a first through hole 50, the first through hole 50a penetrates through the first core board 10, the PP composite layer 30 and the second core board 20, the first through hole 50 is filled with a first conductive ink column 50b, a second ink hole 50c is formed in the central area of the first conductive ink column 50b, and a second conductive ink column 50d is filled in the second ink hole 50 c.

Specifically, the first core board 10 with the blind groove 10a, the second core board 20 with the capacitor core board 20a and the PP composite layer 30 are arranged in a stacking mode, so that the blind groove 10a, the groove bottom graph 20f and the hollow graph 30a are aligned conveniently, the finished blind groove 80a is processed on the first side of the first core board 10 in a depth-controlled uncovering electric milling mode and the like, the finished blind groove 80a extends to the blind groove 10a to expose the groove bottom graph 20f at the bottom of the blind groove 10a, the step groove processing of the circuit board is completed, then the accurate control of the resistor is realized by setting the aperture of the first through hole 50a and the aperture and the depth of the second ink hole 50c, the table top and the depth of the step groove of the circuit board with the capacitor and the resistor embedded are uniform, the accuracy of the capacitor and the resistor can be effectively controlled, the traditional packaging process of printing solder paste is omitted, the production efficiency is greatly improved, and the cost is reduced, and the reliability of the product is improved.

Further, as shown in fig. 5 and 6, an outer layer circuit including a capacitor ground pattern 50e is etched on the first copper foil layer 201 d;

a semi-cured resin sheet 60a and a third copper foil layer 60b are pressed on the second side of the first copper foil layer 201 d;

the circuit board body 80 further has a first blind via 60c, and the first blind via 60c sequentially passes through the semi-cured resin sheet 60a, the first copper foil layer 201d and the capacitor core board 20a from the third copper foil layer 60b to extend to the capacitor pattern 20 e.

Further, as shown in fig. 1, the first core board 10 includes at least one inner copper foil layer 10b and an outer copper foil layer 10c, and the outer copper foil layer 10c is disposed on a first side of the inner copper foil layer 10 b.

Further, as shown in fig. 7, an outer layer wiring 70a and a solder resist layer 70b are provided on each of the outer layer copper foil layer 10c and the third copper foil layer 60 b.

Further, as shown in fig. 6, a copper-deposited plating layer is provided on the hole wall of the first blind via 60 c.

Further, as shown in fig. 5, the second ink hole 50c has an aperture not larger than four fifths of the first through hole 50 a.

Further, the second conductive ink pillar 50d is a high conductivity ink pillar, the conductivity of which is greater than that of the first conductive ink pillar 50 b;

alternatively, the second conductive ink pillar 50d is a high resistivity ink pillar having a conductivity less than that of the first conductive ink pillar 50 b.

Next, the advantages of the step circuit board with embedded capacitors and resistors will be described with reference to the forming process of the step circuit board:

s0100, providing a first core plate 10; the first core plate 10 comprises at least one inner copper foil layer 10b and an outer copper foil layer 10c arranged on the first side of the first core plate, and a blind groove 10a formed through pre-control deep electric milling blind groove treatment is formed in the surface of the second side of the first core plate 10; as shown in fig. 1, the first side of the first core plate refers to an upper side of the first core plate, the second side refers to a lower side of the first core plate, and the first and second sides of the remaining core plates are similar as above.

S0200, providing a second core plate 20; the second core board 20 comprises a second copper foil layer 202d, a second PP layer 202c, a capacitor substrate 20b, a first PP layer 201c and a first copper foil layer 201d which are sequentially stacked, wherein a capacitor core board 20a is arranged on the surface of one side, away from the second PP layer 202c, of the capacitor substrate 20b, a capacitor pattern 20e is formed on the capacitor substrate 20b through etching, and a groove bottom pattern 20f matched with the shape of the blind groove 10a is formed on the second copper foil layer 202d through etching; specifically, the structure of the second core plate 20 is as shown in fig. 2.

S0300, providing a PP composite layer 30; hollow patterns 30a with the sizes matched with the shapes of the blind grooves 10a are formed on the PP composite layer 30; specifically, the structure of the PP composite layer 30 is shown in fig. 3.

S0410, performing brown oxidation treatment on the first core plate 10, the second core plate 20 and the pp composite layer 30;

s0420, sequentially laminating the browned second core plate 20, the PP composite layer 30 and the first core plate 10 to align the positions of the blind groove 10a, the groove bottom pattern 20f and the hollow pattern 30a, and pressing to form the inner plate 40; the outer copper foil layer 10c is arranged on the first side of the inner plate 40, and the first copper foil layer 201d is arranged on the second side of the inner plate 40; specifically, the structure of the inner plate 40 is as shown in fig. 4.

S0510, drilling a first through hole 50a on the inner plate, and filling first conductive ink into the first through hole 50a to form a first conductive ink column 50 b;

s0520, drilling a second ink hole 50c in a central region of one end of the conductive ink column, and filling a second conductive ink in the second ink hole 50c to form a second conductive ink column 50 d;

s0530, etching the first copper foil layer 201d to form an outer layer circuit pattern, wherein the outer layer circuit pattern comprises a capacitor ground pattern 50 e; specifically, the inner plate 40 is processed in step S0530 to form the embedded capacitor and resistor inner plate 50, and the structure of the embedded capacitor and resistor inner plate 50 is specifically shown in fig. 5.

S0610, laminating a semi-cured resin sheet 60a and a third copper foil layer 60b on the second side of the inner plate 40 in sequence;

s0620, drilling a first blind via hole 60c from the third copper foil layer 60b in the direction of the capacitor pattern 20e, sequentially penetrating through the third copper foil layer 60b, the semi-cured resin sheet 60a, the capacitor ground pattern 50e and the capacitor core board 20a, and extending to the capacitor pattern 20 e;

s0630, carrying out copper deposition and electroplating on the first blind hole 60c to obtain a circuit board matrix 60; specifically, the structure of the wiring board mother body 60 is shown in fig. 6.

S0710, arranging an outer layer circuit 70a on the outer layer copper foil layer 10c and the third copper foil layer 60b, and conducting the outer layer circuit 70a and the capacitor pattern 20 e;

s0720, arranging solder mask layers 70b on the outer copper foil layer 10c and the third copper foil layer 60 b;

s0730, performing character generation process and surface treatment process on the circuit board matrix 60; specifically, the circuit board body 60 is processed in step S0730 to be a semi-finished circuit board 70, and the specific structure is shown in fig. 7.

And S800, carrying out depth-controlled uncovering electric milling treatment on the position of the blind groove 10a on the first side of the first core plate 10 to obtain the circuit board body 80. The specific structure of the circuit board body 80 is shown in fig. 8.

In summary, the step circuit board embedded with the capacitor and the resistor provided by this embodiment omits the traditional packaging process of printing solder paste, can effectively control the precision of the capacitor and the resistor, greatly improves the production efficiency and reduces the cost of the step circuit board embedded with the capacitor and the resistor, and improves the reliability.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (6)

1. A circuit board for embedding capacitors and resistors is characterized by comprising a circuit board body (80), wherein the circuit board body (80) comprises a first core board (10), a PP composite layer (30) and a second core board (20) which are sequentially stacked; a blind groove (10a) is formed in the second side of the first core board (10), a hollow pattern (30a) matched with the shape of the blind groove (10a) is formed in the PP composite layer (30), the second core board (20) comprises a groove bottom pattern (20f), a second PP layer (202c), a capacitor substrate (20b), a capacitor core board (20a), a first PP layer (201c) and a first copper foil layer (201d) which are sequentially stacked, and the groove bottom pattern (20f) is matched with the shape of the blind groove (10 a);

a finished product blind groove (80a) is further formed in the first side of the first core plate (10), and the finished product blind groove (80a) extends to the blind groove (10 a);

the circuit board body (80) is further provided with a first through hole (50a), the first through hole (50a) penetrates through the first core plate (10), the PP composite layer (30) and the second core plate (20), a first conductive ink column (50b) is filled in the first through hole (50a), a second ink hole (50c) is formed in the central area of the first conductive ink column (50b), and a second conductive ink column (50d) is filled in the second ink hole (50 c);

an outer layer circuit comprising a capacitor ground pattern (50e) is etched on the first copper foil layer (201 d);

a semi-cured resin sheet (60a) and a third copper foil layer (60b) are pressed on the second side of the first copper foil layer (201 d);

the circuit board body (80) is further provided with a first blind hole (60c), and the first blind hole (60c) penetrates through the semi-solidified resin sheet (60a), the first copper foil layer (201d) and the capacitor core board (20a) from the third copper foil layer (60b) in sequence and extends to the capacitor pattern (20e) on the capacitor substrate (20 b).

2. An embedded capacitive and resistive circuit board according to claim 1, wherein the first core board (10) comprises at least one inner copper foil layer (10b) and an outer copper foil layer (10c), the outer copper foil layer (10c) being disposed on a first side of the inner copper foil layer (10 b).

3. The embedded capacitor and resistor wiring board of claim 2, wherein an outer layer circuit (70a) and a solder mask (70b) are disposed on the outer copper foil layer (10c) and the third copper foil layer (60 b).

4. The embedded capacitor and resistor circuit board of claim 2, wherein the wall of the first blind via (60c) is provided with a copper plating layer.

5. An embedded capacitor and resistor wiring board as claimed in claim 1, wherein the second ink hole (50c) has an aperture no larger than four fifths of the first via hole (50 a).

6. The embedded capacitive and resistive circuit board of claim 1, wherein the second conductive ink pillar (50d) is a high conductivity ink pillar having a conductivity greater than the conductivity of the first conductive ink pillar (50 b);

alternatively, the second conductive ink pillar (50d) is a high resistivity ink pillar having a conductivity less than the conductivity of the first conductive ink pillar (50 b).

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