TWI440416B - Multilayered circuit board having coil structure surrounding embedded component and manufacturing method of the same - Google Patents

Description

Multilayer circuit board having coil structure surrounding embedded component and manufacturing method thereof

The present invention relates to a circuit board and a method of fabricating the same, and more particularly to a multilayer circuit board having a coil structure surrounding a buried component and a method of fabricating the same.

The integration of various electronic components into printed circuit boards has been a development technology that has attracted attention in recent years. The development of advanced semiconductor technology is constantly creating a variety of electronic products with complex functions and more compact. In response to this trend, there is an increasing demand for board functions and the need to integrate more electronic components. In order to meet this demand, it is necessary to continuously improve the structure and manufacturing method of the multilayer circuit board.

In one aspect, the present invention provides a method of fabricating a multilayer circuit board having a coil structure surrounding a buried component, comprising: providing a first double-sided conductive substrate, a second double-sided conductive substrate, and at least a third The double-sided conductive substrate is disposed between the first double-sided conductive substrate and the second double-sided conductive substrate, wherein the double-sided conductive substrate comprises a bottom conductor layer and a lower layer coil circuit formed thereon a first intermediate layer coil line and a second middle layer coil line are formed on the third double-sided conductive substrate, and an upper layer coil line and a top conductor layer are formed on the second double-sided conductive substrate. Providing at least two insulating films respectively interposed between the lower layer coil line and the first intermediate layer coil line and between the second middle layer coil line and the upper layer coil line; pressing the double-sided conductive substrates and The insulating film; forming a plurality of via holes includes: a first via hole electrically connecting the lower layer coil line and the first middle layer coil line and at least one second via hole electrically connected to the first a middle layer coil line and the second middle layer coil line; and a third via hole electrically connecting the second middle layer coil line and the upper layer coil line, thereby forming the coil structure; and forming an opening at a center of the coil structure, and The buried component is disposed in the opening.

In another aspect, the present invention provides a multilayer circuit board having a coil structure surrounding a buried component fabricated by the above method.

In addition, the present invention is intended to cover other problems and the various aspects described above are disclosed in detail in the following embodiments.

Preferred embodiments of the present invention will be exemplified below with reference to the accompanying drawings. Like components in the drawings have the same component symbols. It should be noted that the various elements of the present invention are not drawn to the true aspect of the present invention, and in order to avoid obscuring the present invention, the following description also omits the known components, related materials, and related processing techniques.

1 through 14 are schematic views of an embodiment of the present invention showing a manufacturing process of a multilayer circuit board having a coil structure surrounding a buried component. According to various embodiments of the present invention, one or more coil structures of the embedded components can be fabricated at the same time, and other circuits can be formed in the manufacturing process. For the sake of clarity, only the manufacturing area of a single embedded component is shown in FIGS. 1 to 9; the manufacturing area with a plurality of embedded components is shown in FIGS. 10 to 11; and the printed ones are shown in FIGS. 12 to 13 A multilayer circuit board structure of a buried component; FIG. 14 is a schematic diagram showing a circuit in which the coil circuits of the respective layers are connected by via holes in the multilayer circuit board structure shown in FIG.

First, referring to Fig. 1, four double-sided conductive substrates A, B, C, and D are provided, which are sequentially arranged from top to bottom. The double-sided conductive substrates each include a double-sided conductor layer and a dielectric layer D' interposed therebetween. The conductor layer may be a copper foil or other suitable material, and the dielectric layer D' may be a glass fiber and epoxy resin composite or other suitable material. It should be noted that four double-sided conductive substrates are described herein as preferred embodiments, but it should be understood that the present invention also includes three double-sided conductive substrates, five double-sided conductive substrates, or more double-sided conductive substrates. An example. As shown in FIG. 1, four top-sided conductive substrates A, B, C, and D are stacked from top to bottom to define a top conductor layer S1 and a first conductor layer 1 on the double-sided conductive substrate A; The conductor layer 2 and the third conductor layer 3 are on the double-sided conductive substrate B; a fourth conductor layer 4 and a fifth conductor layer 5 are on the double-sided conductive substrate C; a sixth conductor layer 6 and a bottom conductor layer S6 are Double-sided conductive substrate D.

Next, referring to FIG. 2, the first conductor layer 1, the second conductor layer 2, the third conductor layer 3, the fourth conductor layer 4, and the fifth conductor layer of the four double-sided conductive substrates A, B, C, and D, respectively. 5 and the sixth conductor layer 6 are etched to form coil-type lines L1, L2, L3, L4, L5, L6 as shown, wherein the lines L1, L2, L3, L4, L5, L6 each comprise a coil pattern, The via holes formed by the subsequent processes are electrically connected to each other to form a coil structure that is continuous with the four double-sided conductive substrates A, B, C, and D. In a subsequent process, the surrounding portion of the coil structure will form an opening to place a buried component. Note that since the lines L1, L3, and L5 are respectively located on the back sides of the double-sided conductive substrates A, B, and C, the line shape is indicated by a broken line in the drawing. In detail, the line L1 includes an upper input/output terminal 1x, a coil portion 1y, and a vertical contact 1e. The line L2 includes a vertical contact 2e, a coil portion 2y and a vertical contact 2d, and the vertical contact _{2e is} connected to the vertical contact le through a via hole SH _1e-2e formed by a subsequent process. The line L3 includes a vertical contact 3d, a coil portion 3y and a vertical contact 3c, and the vertical contact _{3d is} connected to the vertical contact 2d through a via hole SH _2d-3d formed by a subsequent process. The line L4 includes a vertical contact 4c, a coil portion 4y and a vertical contact 4b, and the vertical contact 4c connects the via hole _SH3c-4c formed by the subsequent process to the vertical contact 3c. The line L5 includes a vertical contact 5b, a coil portion 5y and a vertical contact 5a, and the vertical contact _{5b is} connected to the vertical contact 4b through a via hole SH _4b-5b formed by a subsequent process. The line L6 includes a vertical contact 6a, a coil portion 6y and a lower input/output terminal 6x, and the vertical contact _{6a is} connected to the vertical contact 5a through the via hole SH _5a-6a formed by the subsequent process. Note that the portion of the line L6 near the vertical contact 6a in the figure is indicated by a broken line because it is covered by the double-sided conductive substrate C. In this embodiment, the lines L2 and L3 on the double-sided conductive substrate B form a complete circle from the upper view, surrounding the components to be buried later; the lines L4 and L5 on the double-sided conductive substrate C are Another complete circle is formed to surround the buried component to be placed subsequently; the lines L1 and L6 on the double-sided conductive substrates A and D each have an input/output terminal 1x, 6x as the beginning and end of the coil structure. The input and output terminals 1x, 6x extend outwardly to the outer edge of the manufacturing region of the single buried component and its coil structure, respectively, for further connection with the side contact electrode 1100 (shown in Figure 12) in a subsequent step.

Then, referring to FIG. 3 and FIG. 4, three insulating sheets P1, P2 and P3 are provided between the double-sided conductive substrates A and B, B and C, and C and D, respectively. The double-sided conductive substrates A, B, C, D and the insulating films P1, P2 and P3 are laminated in the order shown in Fig. 3, and hot pressed to form a structure as shown in Fig. 4.

Referring to FIG. 4, drilling is performed to form through holes H _{1e-2e for} connecting the vertical contacts le to the vertical contacts _2e ; via holes H _{2d-3d for} connecting the vertical contacts 2d to the vertical contacts _3d ; a through hole H _3c- 4c from the point 4c to the vertical contact 3c; a through hole H _4b-5b connecting the vertical contact 5b to the vertical contact 4b; and a through hole H _5a connecting the vertical contact 6a to the vertical contact 5a _6a . The through holes H _{1e - 2e} , H _{2d - 3d} , H _{3c - 4c} , H _{4b - 5b ,} and H _{5a - 6a} all penetrate the double-sided conductive substrates A, B, C, D and the insulating films P1, P2, and P3. Figure 4 is rotated 180 degrees horizontally with respect to Figure 3.

Next, referring to FIG. 5, the through holes are plated through the via holes, and the top conductor layer S1 and the bottom conductor layer S6 are etched so that the respective via holes become the via holes SH _1e-2e and SH _2d-3d as shown in the drawing. SH _3c-4c , SH _4b-5b and SH _5a-6a . In this embodiment, the via holes SH _2d-3d and SH _{4b-5b are} tied at one side with respect to the coil structure (shown as J side in the drawing) and are spaced apart from each other; the via holes SH _1e-2e , SH _3c-4c And SH _5a-6a are located on the other side (shown as K side in the figure) and are spaced apart from each other. The J side and the K side are opposite and not adjacent. If necessary, the top conductor layer S1 and the bottom conductor layer S6 may be etched to have other wiring or additional layers to serve as other component assembly layers, thereby providing other functions.

Then, referring to FIG. 6 and FIG. 7, an opening 601 is formed in the center of the coil structure for placing an electronic component 701 in the structure completed in FIG. Electronic component 701 can be a magnetic component or other suitable component. The iron core can be used as a magnetic element, but it is a solid structure rather than a hollow finger ring element. The opening 601 can be formed by various suitable processes such as mechanical hole drilling or chemical etching. The structure shown in Fig. 6 is hereinafter referred to as a multilayer circuit board 600 having a coil structure.

Referring next to the drawing, after the electronic component 701 is placed in the opening 601 of the multilayer circuit board 600 having the coil structure, two single-sided conductive substrates 801 and 802, and two sheets of insulating films P4 and P5 are provided. The single-sided conductive substrates 801 and 802 each have a single surface conductor layer 801a, 802a and a dielectric layer 801b and 802b, and the material can be similar to the above-described double-sided conductive substrate. The above-described elements are stacked in the order shown in Fig. 8 and hot pressed. The structure 900 of the press fit is shown in FIG.

In order to clearly illustrate the manufacturing process of the coil structure of the multilayer circuit board of the present invention, the manufacturing regions of the single embedded component and its coil structure are shown in FIGS. 1 to 9. 10 to 11 are views showing the contact structure and the dicing manufacturing of the multilayer circuit board of the present invention, so that a plurality of manufacturing regions of the embedded components are shown. In FIGS. 10 to 11, the inner layer structure of the structure 900 is omitted.

Referring to Figure 10, drilling is performed to form a plurality of nicked recesses 1001 aligned along a predetermined line I-I'. A single or multiple apertures 1003 and/or 1004 may be formed at the same time as desired, and may be used as a vent, or for other suitable purposes, and may be located as shown or at other suitable locations. Electronic component 701 is embedded in structure 900 and is shown in dashed lines.

Next, referring to FIG. 11, a plated through hole and an etching process are performed on each of the dicing notches 1001 and the surface conductor layers 801a, 802a of the single-sided conductive substrates 801 and 802. By the plated through hole process, the inner side of the dicing recess 1001 is plated with a conductor, and can be used as the side contact electrode 1100 after cutting. It should be noted that each of the single buried component and its coil structure have two side contact electrodes 1100 on opposite sides, which respectively contact the output terminals on the lines L1 and L6 on the double-sided conductive substrates A and D. Point 1x, 6x. At the same time, the surface conductor layers 801a and 802a are patterned by an etching process to form a top contact electrode 1200 and a bottom contact electrode 1400 (not shown in FIG. 11, which can be seen in FIG. 13). If necessary, the surface conductor layer 801a or 802a can be etched with other traces or layers to serve as an additional component assembly layer to provide other functionality. After the plated through hole and the etching process, a conductive protective layer (not shown) may be further formed as needed, such as general chemical nickel gold at the top contact. The electrode 1200, the bottom contact electrode 1400 and the side contact electrode 1100; and an insulating solder mask (not shown) are formed on the surface of the exposed dielectric layers 801b and 802b as is conventionally solder-proof.

After the steps shown in Fig. 11 are completed, cutting can be performed. Referring to Figure 12, a single multilayer circuit board 1500 having a coil structure surrounding the buried component is formed after dicing.

Figure 13 is a cross-sectional view showing a portion of the structure of the multilayer circuit board 1500, which does not show an insulating solder mask. As shown, SH _3c-4c penetrates from the top conductor layer S1 to the bottom conductor layer S6 for the conduction lines L3 and L4; and SH _4b-5b penetrates from the top conductor layer S1 to the bottom conductor layer S6 for conduction Lines L4 and L5.

14 shows a multilayer circuit board shown in FIG. 12, each layer of coil lines L1, L2, L3, L4, L5, L6 with via holes SH _1e-2e , SH _2d-3d , SH _3c-4c , SH _4b-5b and Schematic diagram of the circuit in which SH _{5a-6a is} connected.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; all other equivalent changes or modifications which are not departing from the spirit of the present invention should be included in the following. Within the scope of the patent application.

A, B, C, D. . . Double-sided conductive substrate

D'. . . Dielectric layer

S1. . . Top conductor layer

1. . . First conductor layer

2. . . Second conductor layer

3. . . Third conductor layer

4. . . Fourth conductor layer

5. . . Fifth conductor layer

6. . . Sixth conductor layer

S6. . . Bottom conductor layer

L1. . . line

1x. . . Upper and lower input and output

1y. . . Coil part

1e. . . Vertical contact

L2. . . line

2e. . . Vertical contact

2y. . . Coil part

2d. . . Vertical contact

L3. . . line

3d. . . Vertical contact

3y. . . Coil part

3c. . . Vertical contact

L4. . . line

4c. . . Vertical contact

4y. . . Coil part

4b. . . Vertical contact

L5. . . line

5b. . . Vertical contact

5y. . . Coil part

5a. . . Vertical contact

L6. . . line

6a. . . Vertical contact

6y. . . Coil part

6x. . . Input and output endpoint

P1, P2 and P3. . . Insulating film

H _1e-2e , H _2d-3d , H _3c-4c , H _4b-5b , H _5a-6a . . . Through hole

SH _1e-2e , SH _2d-3d , SH _3c-4c , SH _4b-5b , SH _5a-6a . . . Via

J. . . J side

K. . . K side

600. . . Multi-layer circuit board

601. . . Opening

701. . . Electronic component

P4, P5. . . Insulating film

801,802. . . Single-sided conductive substrate

801a, 802a. . . Surface conductor layer

801b, 802b. . . Dielectric layer

900. . . structure

1001. . . Notch

1003, 1004. . . hole

1100. . . Side contact electrode

1200. . . Top contact electrode

1400. . . Bottom contact electrode

1500. . . Multi-layer circuit board

1 through 13 are schematic views showing a manufacturing process of a multilayer circuit board having a coil structure surrounding a buried component, in accordance with an embodiment of the present invention.

FIG. 14 is a schematic view showing a circuit in which the coil circuits of the respective layers are connected by via holes in the multilayer circuit board structure shown in FIG.

S1. . . Top conductor layer

S6. . . Bottom conductor layer

701. . . Electronic component

SH _3c-4c , SH _4b-5b . . . Via

P1, P2, P3, P4, P5. . . Insulating film

L1, L2, L3, L4, L5, L6. . . line

801b, 802b. . . Dielectric layer

1200. . . Top contact electrode

1400. . . Bottom contact electrode

Claims (3)

A multi-layer circuit board having a coil structure surrounding a buried component, comprising: a first double-sided conductive substrate having a lower layer coil circuit; and a second double-sided conductive substrate over the first double-sided conductive substrate, the first The two double-sided conductive substrate has an upper layer coil line; at least one third double-sided conductive substrate is between the first double-sided conductive substrate and the second double-sided conductive substrate, and the third double-sided conductive substrate has a middle layer coil line a plurality of insulating films respectively interposed between the double-sided conductive substrates; a plurality of conductive vias electrically connecting the lower layer coil lines, the middle layer coil lines, and the upper layer coil lines, thereby forming a continuous two-sided conductive The coil structure of the substrate, wherein the upper layer coil line and the lower layer coil line each have an input and output end point as a beginning and an end of the coil structure, and the input/output end point extends outward to an edge of the multilayer circuit board; An opening penetrating the double-sided conductive substrate, wherein the coil structure surrounds the opening, the buried component is disposed in the opening; an upper dielectric layer and a lower dielectric layer The layers are respectively above and below the coil structure to cover the coil structure and the buried component; a top contact electrode and a bottom contact electrode are respectively disposed on the dielectric layers; and a side contact electrode is connected to the top contact And an electrode and the bottom contact electrode electrically connected to the output terminal of the upper coil line or the lower layer coil line. The multi-layer circuit board of claim 1, further comprising: a vent hole located in the upper dielectric layer or the lower dielectric layer. A manufacturing method for a multilayer circuit board having a coil structure surrounding a buried component, comprising: providing a first double-sided conductive substrate, a second double-sided conductive substrate, and at least one third double-sided conductive substrate disposed on the first Between a double-sided conductive substrate and the second double-sided conductive substrate, wherein the double-sided conductive substrate comprises a bottom conductor layer and a lower layer coil circuit formed on the first double-sided conductive substrate from bottom to top, a first middle layer coil line and a second middle layer coil line are formed on the third double-sided conductive substrate, and an upper layer coil line and a top conductor layer are formed on the second double-sided conductive substrate; at least two insulating films are provided Inserting between the lower layer coil line and the first middle layer coil line and between the second middle layer coil line and the upper layer coil line; pressing the double-sided conductive substrate and the insulating film; forming a plurality of The via hole includes: a first via hole electrically connecting the lower layer coil line and the first middle layer coil line, and at least one second via hole electrically connecting the first middle layer coil line and the second a layer coil line; and a third via hole electrically connecting the second middle layer coil line and the upper layer coil line, thereby forming the coil structure; forming an opening in a center of the coil structure, and disposing the buried element in the opening Providing two single-sided conductive substrates covering the coil structure and the embedded component up and down; forming a cutting recess on the periphery of the coil structure; and performing the dicing recess and the single-sided conductive substrate The vias are etched and etched to form a top contact electrode, a bottom contact electrode and a side contact electrode, the side contact electrodes being electrically connected to the upper layer coil line or the lower layer coil line.