A method for manufacturing an embedded substrate with a cavity embedded in a base material layer

Abstract

The present invention relates to the field of circuit board manufacturing, and more particularly to a method for manufacturing an embedded substrate with a cavity embedded in a base material layer. The method for manufacturing an embedded substrate with a cavity embedded in a base material layer provided by the present invention differs from conventional drilling methods, which can only produce circular embedded cavities. Plasma equipment, acting on ABF dielectric materials, can produce embedded cavities of varying sizes and shapes, and thickness control is more effective than laser or mechanical drilling. Furthermore, the present invention overcomes the difficulty of fabricating embedded circuitry in existing base material layers, providing a method for fabricating embedded circuitry in a base material layer, with better control over the width and thickness of the embedded circuitry.

Description

Technical Field

[0001] The present invention belongs to the field of circuit board manufacturing, and in particular relates to a manufacturing method of an embedded substrate in which a cavity is embedded in a base material layer. Background Art

[0002] In recent years, electronic products have been widely used in daily work and life, and light, thin, and small electronic products are becoming increasingly popular. As a key component of electronic products, flexible circuit boards occupy a large space in these products. Therefore, the volume of flexible circuit boards greatly affects the size of these electronic products. Large flexible circuit boards are bound to be difficult to meet the trend of light, thin, short, and small electronic products.

[0003] During the manufacturing process of existing circuit boards, cavities are made in the substrate layer by drilling, which is only applicable to the production of circular cavities and cannot control the depth of embedded components. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method for manufacturing an embedded substrate by embedding a cavity in a base material layer, so as to overcome the deficiencies in the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] According to a first aspect of an embodiment of the present invention, a method for manufacturing an embedded substrate in which a cavity is embedded in a base material layer is provided, comprising the following steps:

[0007] P1. Select a BT substrate containing an upper attached copper layer and a lower attached copper layer as a base material layer, and remove the upper attached copper layer and the lower attached copper layer on the surface of the base material layer.

[0008] P2. Opening a through hole on the substrate layer and forming a resin plug on the through hole;

[0009] P3, forming a first metal copper layer on the upper surface and the lower surface of the substrate layer respectively;

[0010] P4. Open a window on the first metal copper layer, and open an embedded cavity on the substrate layer corresponding to the window;

[0011] P5. Place the magnetic material assembly in the embedded cavity and fix it;

[0012] P6. Remove the first metal copper layer on the upper and lower surfaces of the substrate layer, attach a first ABF to the surface of the substrate layer, and press the first ABF into the embedded cavity and the surface of the substrate layer;

[0013] P7. Disposing a second metal copper layer on the first ABF, and opening a window in the second metal copper layer;

[0014] P8. Opening an embedded circuit cavity on the first ABF and the substrate layer corresponding to the window opening;

[0015] P9. Remove the second metal copper layer and form a third metal copper layer on the surface of the first ABF and the embedded circuit cavity;

[0016] P10, thickening the third metal copper layer until the embedded circuit cavity is completely filled;

[0017] P11, remove the third metal copper layer and the first ABF to form an embedded circuit;

[0018] P12. Attach a second ABF to the surface of the substrate layer, provide a fourth metal copper layer on the second ABF, and make circuit windows on the fourth metal copper layer;

[0019] P13. A conductive blind via is provided at the circuit window, wherein the conductive blind via passes through the second ABF and is connected to the embedded circuit;

[0020] P14, making an embedded circuit slot at the conductive blind via and removing the fourth metal copper layer;

[0021] P15. Dispose a fourth metal copper layer on the surface of the second ABF and the inner buried circuit slot, fill the inner buried circuit slot, and thicken the fourth metal copper layer to form an outer circuit build-up layer;

[0022] P16. Remove the fourth electroplated copper layer.

[0023] Furthermore, in step P2, a via layer is opened on the substrate layer by mechanical or laser processing.

[0024] Furthermore, the step P2 includes:

[0025] (1) In the opened via hole layer, a layer of metal copper is covered on the surface of the substrate layer and the hole wall through the electroplating process;

[0026] (2) Filling the insulating resin material into the via layer through the resin plugging process;

[0027] (3) Use a brushing device to brush off the resin material and the metal copper on the surface of the substrate layer that protrudes after the above-mentioned plugging. At this time, only the substrate layer material and the resin plugging hole are left.

[0028] Furthermore, the step P3 includes: forming a layer of metal copper on the surface of the substrate layer through a SputterE-less process.

[0029] Furthermore, the step P4 includes:

[0030] (1) Covering the light-transmitting dry film on the copper layer where the embedded cavity is to be made by a hot pressing process, and revealing the position where the embedded component cavity is to be made by an exposure and development process;

[0031] (2) Use a rapid etching method to etch away the unprotected copper layer, revealing the underlying substrate layer;

[0032] (3) using a plasma device to dig a cavity for an embedded component in the substrate layer at a location not protected by the copper layer, wherein the plasma device acts on the substrate layer to decompose the substrate layer material downward;

[0033] (4) The remaining dry film covering the metal copper layer in step (1) is removed, and only the metal copper on the base material layer and the embedded cavity remain on the surface of the substrate.

[0034] Furthermore, in step (3), the substrate material is decomposed downwards, and the size, shape, thickness of the magnetic component is determined.

[0035] The benchmark is based on the thickness of the embedded components + / - 5um greater than the thickness required by the customer.

[0036] Furthermore, the step P5 includes: picking up a magnetic material attached to the tape, and placing it into the cavity after positioning; when placing it into the cavity, the position deviation must be less than + / - 5um.

[0037] Furthermore, the step P6 includes:

[0038] (1) by rapid etching bite, removing the copper metal described in step P3;

[0039] (2) Take two portions of dielectric ABF dry film material, and attach the ABF dry film to the upper and lower surfaces of the substrate layer through a lamination and hot pressing process, so that the upper and lower surfaces of the substrate layer are covered with a layer of ABF dry film and the embedded cavity space on the upper surface of the substrate layer is filled at the same time;

[0040] Furthermore, the step P7 includes:

[0041] (1) Using a SputterE-less process, a layer of metallic copper is gradually plated on the surface of the ABF described in step P6 above;

[0042] (2) A light-transmitting dry film is attached to the thin copper layer on both sides through a lamination and hot pressing process. A circuit pattern is produced on the dry film through a UV exposure machine. Subsequently, exposure and development are performed to reveal the inner layer circuit groove position;

[0043] (3) Use a rapid etching method to etch away the unprotected copper layer, exposing the underlying ABF dielectric layer.

[0044] Furthermore, the step P8 includes: using a plasma device to act on the light-transmitting ABF dry film to decompose the ABF material downwards, and continuously decompose the resin material of the substrate layer downwards to form the embedded wiring groove position.

[0045] Furthermore, the step P9 includes:

[0046] (1) Using a rapid etching method to remove the copper metal described in step P7(1);

[0047] (2) Through the SputterE-less process, a layer of metal copper is gradually plated on the cavity and ABF surface in step P7(2).

[0048] Furthermore, the step P10 includes: making an embedded inner layer circuit by an additive method, thickening the metal copper in the above step P9 (2), and filling the embedded circuit groove to form an embedded circuit.

[0049] Compared with the prior art, the advantages of the present invention include:

[0050] (1) The present invention provides a method for manufacturing an embedded substrate by embedding a cavity in a base material layer. Unlike the previous drilling operation method which can only produce circular embedded cavities, the plasma device can be used on the ABF dielectric material to produce embedded cavities of different sizes and shapes, and the thickness can be controlled more effectively than laser or mechanical drilling.

[0051] (2) It is difficult to make embedded circuits in the existing substrate layer. The present invention provides a method for making embedded circuits in the substrate layer, and the width and thickness of the embedded circuits can be better controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments.

[0053] The accompanying drawings are only used to illustrate the preferred embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0054] Figure 1 A schematic structural diagram of a substrate layer in a typical embodiment of the present invention;

[0055] Figure 2 A schematic diagram of a structure for making a resin plug hole on a through hole in a typical embodiment of the present invention;

[0056] Figure 3 Schematic diagram of a structure in which a first metal copper layer is formed on the surface of a substrate layer in a typical embodiment of the present invention;

[0057] Figure 4aThis is a schematic structural diagram of a typical embodiment of the present invention in which an embedded cavity is provided on a substrate layer corresponding to a window opening;

[0058] Figure 4b Schematic diagram of a structure in which a buried cavity is opened on a substrate layer corresponding to a window opening by a plasma device in a typical embodiment of the present invention; Figure 5 A schematic diagram of a structure in which a magnetic material is placed in a cavity in a typical embodiment of the present invention;

[0059] Figure 6 This is a schematic structural diagram of attaching a first ABF to the surface of the substrate layer in a typical embodiment of the present invention;

[0060] Figure 7a This is a schematic structural diagram of a typical embodiment of the present invention in which a second metal copper layer is provided on a first ABF;

[0061] Figure 7b This is a schematic structural diagram of a window opened on the second metal copper layer in a typical embodiment of the present invention;

[0062] Figure 8 A schematic diagram of the structure of the position of the internal buried wire routing groove in a typical embodiment of the present invention;

[0063] Figure 9a A schematic diagram of a structure in which the second metal copper layer is removed in a typical embodiment of the present invention;

[0064] Figure 9b This is a schematic structural diagram of a typical embodiment of the present invention in which a third metal copper layer is provided on the surface of the first ABF and the embedded circuit cavity;

[0065] Figure 10 A schematic diagram of a structure in which a cavity for embedded circuits is filled in a typical embodiment of the present invention;

[0066] Figure 11 This is a schematic diagram of a structure in which the third metal copper layer and the first ABF are removed to form an embedded circuit in a typical embodiment of the present invention;

[0067] Figure 12 This is a schematic structural diagram of a typical embodiment of the present invention in which a fourth metal copper layer is provided on the first ABF and circuit windows are formed on the fourth metal copper layer;

[0068] Figure 13 This is a structural diagram of a typical embodiment of the present invention in which a conductive blind hole is provided at a circuit window;

[0069] Figure 14a A schematic diagram of a structure in which an embedded circuit slot is formed in a conductive blind hole in a typical embodiment of the present invention;

[0070] Figure 14bA schematic diagram of a structure in which the fourth metal copper layer is removed in a typical embodiment of the present invention; Figure 15 A schematic diagram of a structure for forming an outer circuit build-up layer in a typical embodiment of the present invention;

[0071] Figure 16 A schematic structural diagram of removing the fourth electroplated copper layer in a typical embodiment of the present invention;

[0072] Markings in the figure: substrate layer 101, resin plug hole 102, first metal copper layer 103, buried cavity 104, magnetic material 105, first ABF 106, second metal copper layer 107, window 108, third metal copper layer 109, second ABF 110,

[0073] a fourth metal copper layer 111 and a fourth electroplated copper layer 112 . DETAILED DESCRIPTION

[0074] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The following will further explain this technical solution, its implementation process and principles.

[0075] The present invention will be further described in detail below in conjunction with specific embodiments. The examples provided are only for illustrating the present invention and are not intended to limit the scope of the present invention. The examples provided below can serve as a guide for further improvements by those skilled in the art and are not intended to limit the present invention in any way.

[0076] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0077] An embodiment of the present invention provides a method for manufacturing an embedded substrate by embedding a cavity in a base material layer, comprising the following steps:

[0078] P1. Select a BT substrate containing an upper attached copper layer and a lower attached copper layer as the base material layer 101, and remove the upper attached copper layer and the lower attached copper layer on the surface of the base material layer 101; in a specific implementation, a BT substrate without an upper attached copper layer and a lower attached copper layer can also be directly selected as the base material layer 101; Figure 1 As shown;

[0079] P2, opening a through hole on the substrate layer 101, and making a resin plug hole 102 on the through hole; Figure 2 Specifically, the following steps are included:

[0080] (1) In the via hole layer, a layer of metal copper is covered on the surface of the substrate layer 101 and the hole wall by an electroplating process;

[0081] (2) Filling the via hole layer with insulating resin material through the resin plugging process;

[0082] (3) Use a brushing device to brush off the resin material and the metal copper on the surface of the substrate layer 101 that protrudes after the plugging. At this time, only the substrate layer 101 material and the resin plugging hole are left.

[0083] P3, respectively forming a first metal copper layer 103 on the upper surface and the lower surface of the substrate layer 101; forming the first metal copper layer 103 on the surface of the substrate layer 101 through the SputterE-less process; Figure 3 shown.

[0084] P4, opening a window 108 on the first metal copper layer 103, and opening an embedded cavity 104 on the substrate layer 101 corresponding to the window 108; Figure 4a and 4b Specifically, the following steps are included:

[0085] (1) Covering the light-transmitting dry film on the copper layer where the embedded cavity 104 is to be made by a hot pressing process, and exposing and developing the position where the embedded component cavity is to be made is exposed;

[0086] (2) using a rapid copper etching method to etch away the unprotected copper layer, thereby exposing the underlying substrate layer 101;

[0087] (3) Use Plasma equipment to dig the embedded component cavity of the substrate layer 101 at the position without copper layer protection. When the Plasma equipment acts on the substrate layer 101, the substrate layer 101 material is decomposed downward. Specifically, the substrate layer 101 material is decomposed downward. According to the size and shape of the magnetic component, the thickness is based on the thickness of the embedded component required by the customer + / - 5um. Figure 4b As shown;

[0088] (4) The remaining dry film covering the metal copper layer in step (1) is removed, and only the metal copper on the base material layer 101 and the buried cavity 104 remain on the surface of the substrate.

[0089] P5. Place the magnetic material 105 component in the embedded cavity 104 and fix it; specifically, pick up a magnetic material 105 attached to the tape, align the position, and place it in the cavity; when placing it in the cavity, the position deviation must be less than + / - 5um; Figure 5 shown.

[0090] P6, remove the first metal copper layer 103 on the upper and lower surfaces of the substrate layer 101, attach a first ABF 106 to the surface of the substrate layer 101, and press the first ABF 106 into the embedded cavity 104 and the surface of the substrate layer 101; Figure 6 Specifically, the following steps are included:

[0091] P7, disposing a second metal copper layer 107 on the first ABF 106, and opening a window 108 on the second metal copper layer 107; Figure 7a As shown, a second metal copper layer is provided on the first ABF; Figure 7b As shown, a schematic structural diagram of opening a window on the second metal copper layer;

[0092] P8, opening an embedded circuit cavity on the first ABF 106 and the substrate layer 101 corresponding to the window 108;

[0093] The process involves using a plasma device to act on the translucent ABF dry film, decomposing the ABF material downwards, and continuously decomposing the resin material of the substrate layer 101 downwards to form an embedded wiring trench. The width and depth of the embedded wiring trench formed by decomposing the resin material of the substrate layer downwards must meet the customer's line width and copper thickness specifications of + / - 5um.

[0094] P9. Remove the second metal copper layer 107 and form a third metal copper layer 109 on the surface of the first ABF 106 and the embedded circuit cavity;

[0095] Figure 9a A schematic diagram of the structure for removing the second metal copper layer; Figure 9b A schematic diagram of a structure for providing a third metal copper layer on the surface of the first ABF and the embedded circuit cavity; specifically, the following steps are included:

[0096] (1) using a rapid etching method to remove the copper metal described in step P7 (1);

[0097] (2) Through the SputterE-less process, a layer of metal copper is sputtered on the cavity and ABF surface in step P7(2).

[0098] P10, thickening the third metal copper layer 109 until the embedded circuit cavity is filled; Figure 10 Specifically, it includes making an embedded inner layer circuit by an additive method, thickening the metal copper in step P9 (2) above, and filling the embedded circuit groove to form an embedded circuit.

[0099] P11, remove the third metal copper layer 109 and the first ABF 106 on the surface of the first ABF to form an embedded circuit, such as Figure 11 As shown;

[0100] P12, attaching a second ABF 110 to the surface of the substrate layer 101, and setting a fourth metal

[0101] Copper layer 111, a circuit window 108 is made on the fourth metal copper layer 111, such as Figure 12 As shown;

[0102] P13, a conductive blind hole is opened at the circuit window 108, and the conductive blind hole passes through the second ABF 110 and is connected to the embedded circuit. Figure 13 As shown;

[0103] P14, making an embedded circuit slot at the conductive blind via and removing the fourth metal copper layer 111; Figure 14a This is a schematic diagram of the structure of the embedded circuit slot in the conductive blind hole; Figure 14b A schematic diagram of the structure for removing the fourth metal copper layer;

[0104] P15, a fourth electroplated copper layer 112 is provided on the surface of the second ABF 110 and the inner buried line slot, the inner buried line slot is filled and the fourth electroplated copper layer 112 is thickened to form an outer layer circuit build-up layer; Figure 15 Specifically, the following steps are included:

[0105] (1) The embedded circuit slot body is made in the outer ABF by two plasma devices. The embedded circuit slot body includes the outer circuit slot and the conductive hole slot. The conductive hole slot needs to be connected downward to the inner circuit copper layer.

[0106] (2) After forming the line trench and the via trench, a thin copper layer is formed on the surface of the trench and the ABF dielectric layer through an E-less process;

[0107] (3) The outer buried circuit copper layer is produced through the build-up electroplating process, and the slot layer is filled simultaneously.

[0108] P16, remove the fourth electroplated copper layer 112, as shown in FIG. Figure 16 Specifically, it includes brushing off the electroplated copper on the upper and lower surfaces through the CMP (Chemical Mechanical Plating) process to form an outer layer embedded circuit.

[0109] The above are only some embodiments of the present invention. It should be pointed out that for ordinary technicians in this field, other variations and improvements can be made without departing from the creative concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for manufacturing an embedded substrate by embedding a cavity and an embedded circuit in a base material layer, characterized in that: The following steps are involved: P1. Select a BT substrate containing an upper attached copper layer and a lower attached copper layer as a base layer, and remove the upper attached copper layer and the lower attached copper layer on the surface of the base layer; P2. Opening a through hole on the substrate layer and forming a resin plug on the through hole; P3, forming a first metal copper layer on the upper surface and the lower surface of the substrate layer respectively; P4. Open a window on the first metal copper layer, and open an embedded cavity on the substrate layer corresponding to the window; P5. Place the magnetic material assembly in the embedded cavity and fix it; P6. Remove the first metal copper layer on the upper and lower surfaces of the substrate layer, attach a first ABF to the surface of the substrate layer, and press the first ABF into the embedded cavity and the surface of the substrate layer; P7. Disposing a second metal copper layer on the first ABF, and opening a window in the second metal copper layer; P8. Opening an embedded circuit cavity on the first ABF and the substrate layer corresponding to the window opening; P9. Remove the second metal copper layer and form a third metal copper layer on the surface of the first ABF and the embedded circuit cavity; P10, thickening the third metal copper layer until the embedded circuit cavity is completely filled; P11, remove the third metal copper layer and the first ABF to form an embedded circuit; P12. Attach a second ABF to the surface of the substrate layer, provide a fourth metal copper layer on the second ABF, and make circuit windows on the fourth metal copper layer; P13. A conductive blind via is provided at the circuit window, wherein the conductive blind via passes through the second ABF and is connected to the embedded circuit; P14, making an embedded circuit slot at the conductive blind via and removing the fourth metal copper layer; P15. Disposing a fourth electroplated copper layer on the surface of the second ABF and the inner buried circuit slot, filling the inner buried circuit slot and thickening the fourth electroplated copper layer to form an outer circuit build-up layer; P16. Remove the fourth electroplated copper layer. Specifically, this includes brushing off the electroplated copper on the upper and lower surfaces through a CMP process to form an outer layer embedded circuit.

2. The method for manufacturing an embedded substrate having a cavity embedded in a base material layer according to claim 1, wherein: In step P2, a via layer is opened on the substrate layer by mechanical or laser processing.

3. The method for manufacturing an embedded substrate by embedding a cavity and an embedded circuit in a base material layer according to claim 1, wherein: The step P3 comprises: A first metal copper is formed on the surface of the substrate layer using a Sputter E-less process.

4. The method for manufacturing an embedded substrate by embedding a cavity and an embedded circuit in a base material layer according to claim 1, wherein: The step P4 comprises: (1) Covering the light-transmitting dry film on the copper layer where the embedded cavity is to be made by a hot pressing process, and revealing the position where the embedded component cavity is to be made by an exposure and development process; (2) Use a rapid etching method to etch away the unprotected copper layer, revealing the underlying substrate layer; (3) using a plasma device to dig a cavity for an embedded component in the substrate layer at a location not protected by the copper layer, wherein the plasma device acts on the substrate layer to decompose the substrate layer material downward; (4) The remaining dry film covering the copper layer in step (1) is removed, and only the metal copper on the base material layer and the buried cavity remain on the surface of the substrate.

5. The method for manufacturing an embedded substrate with a cavity and embedded circuits embedded in a base material layer according to claim 4, characterized in that: In step (3), the substrate layer material is decomposed downwards. According to the size and shape of the magnetic component, the thickness is based on the thickness of the embedded component required by the customer, which is + / - 5um.

6. The method for manufacturing an embedded substrate with a cavity embedded in a base material layer according to claim 1, wherein: The step P5 includes: picking up a magnetic material attached to the tape, and placing it into the cavity after positioning.

7. The method for manufacturing an embedded substrate by embedding a cavity and an embedded circuit in a base material layer according to claim 1, wherein: The step P7 comprises: (1) Sputtering a layer of copper on the surface of the ABF described in step P6 by a Sputter E-less process; (2) A light-transmitting dry film is attached to the sputtered copper layer on both sides through a lamination and hot pressing process. A circuit pattern is generated on the dry film through a UV exposure machine. Subsequently, exposure and development are performed to reveal the inner layer circuit groove position; (3) Use a rapid copper etching method to etch away the unprotected copper layer, revealing the underlying ABF dielectric layer.

8. The method for manufacturing an embedded substrate with a cavity embedded in a base material layer according to claim 1, wherein: The step P8 includes: using a plasma device to act on the light-transmitting ABF dry film to decompose the ABF material downwards, and continuously decompose the resin material of the substrate layer downwards to form a location for the embedded wiring groove.

9. The method for manufacturing an embedded substrate with a cavity embedded in a base material layer according to claim 8, wherein: The width and depth of the embedded wiring groove of the resin material in the substrate layer must meet the customer's line width and copper thickness specifications of + / - 5um.

10. The method for manufacturing an embedded substrate by embedding a cavity and an embedded circuit in a base material layer according to claim 1, wherein: The step P15 comprises: (1) The embedded circuit slot body is made in the outer ABF by two plasma equipments. The embedded circuit slot body includes the outer circuit slot and the conductive hole slot. The conductive hole slot needs to be connected downward to the inner circuit copper layer; (2) After forming the line trench and the via trench, a thin copper layer is formed on the surface of the trench and the ABF dielectric layer through an E-less process; (3) The outer buried circuit copper layer is produced through the build-up electroplating process, and the slot layer is filled simultaneously.

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