TW202301930A - Circuit board and method of manufacturing the same - Google Patents

Abstract

A circuit board and a method of manufacturing the circuit board, the circuit board includes a first circuit substrate and a second circuit substrate. The first circuit substrate includes a first wiring layer, a first insulating layer, and a second wiring layer. The first circuit substrate further includes at least two spaced conductive blocks exposed from the first wiring layer and the second wiring layer. Each block includes a first conductive portion and a second conductive portion. The second conductive portion is embedded in the first insulating layer. Two opposite surfaces of the second conductive portion are flush with two sides of the first insulating layer. The first conductive portion protrudes from the second conductive portion, and a width of the first conductive portion is less than a width of the second conductive portion. The circuit substrate is combined with the first circuit substrate through a second insulating layer. The circuit board further includes a conductive pillar embedded in the second insulating layer and corresponding to each conductive block. The conductive portion is embedded in the conductive pillar.

Description

Circuit board and manufacturing method thereof

The invention relates to a circuit board and a manufacturing method thereof.

Under the market trend of portable electronic products, circuit boards used in electronic products are also developing towards high-density and high-precision integration. However, when the electronic components are mounted on the circuit board, due to poor flatness of the circuit board, the electrical connection between the electronic components and the circuit board is likely to be unstable or even have poor electrical conduction.

In view of this, it is necessary to provide a method for manufacturing a circuit board that is beneficial to improving flatness.

It is also necessary to provide a circuit board that is conducive to improving flatness.

A method for manufacturing a circuit board, comprising the steps of:

A double-sided metal substrate is provided, including a first metal foil, a first insulating layer and a second metal foil sequentially stacked;

At least two stepped blind holes at intervals are formed on the double-sided metal substrate, wherein each of the stepped blind holes includes a first portion penetrating through the first metal foil along the stacking direction and penetrating through the first metal foil along the stacking direction. The second part of the first insulating layer, the first part communicates with the second part, and on any cross-section along the stacking direction, the width of the first part in each of the stepped blind holes is smaller than the the width of the second part;

filling each of the step blind holes with conductive paste to form a conductive block corresponding to each of the step blind holes, and each of the conductive blocks includes a first conductive part filling the first part and a second conductive part filling the second part. part of the second conductive portion;

performing wiring fabrication on the first metal foil provided with the first conductive portion to form a corresponding first wiring layer;

A second insulating layer is disposed on the first wiring layer, the first insulating layer exposed from the first wiring layer, and the conductive block, and the second insulating layer is patterned to correspond to each of the The conductive block forms a first opening, the first opening opens around the first conductive part to expose the first conductive part and at least part of the second conductive part; and

Corresponding to each of the first openings, a conductive post is formed to fill the first opening, and a circuit substrate is formed on the patterned second insulating layer, and a circuit is made on the second copper foil to correspond to A second circuit layer is formed, wherein the conductive column is electrically connected to the circuit substrate, and at least one second opening is formed in the second circuit layer corresponding to the conductive block.

A circuit board, comprising a stacked first circuit substrate and a second circuit substrate, the first circuit substrate includes a first circuit layer, a first insulating layer and a second circuit layer sequentially stacked along the stacking direction, the first A circuit substrate further includes at least two spaced conductive blocks exposed from the gap of the first circuit layer and the gap of the second circuit layer, each of the conductive blocks includes a first conductive part and a second conductive part ; the second conductive portion is embedded in the first insulating layer, and the two surfaces of the second conductive portion spaced along the stacking direction are respectively separated from the first insulating layer along the stacking direction. The sides are flush; the first conductive part protrudes from the surface of the second conductive part away from the second circuit layer, and on any cross-section along the stacking direction, the width of the first conductive part is smaller than the The width of the second conductive part; the second circuit substrate is combined with the first circuit layer, the first insulating layer and the conductive block exposed from the first circuit layer through a second insulating layer; the circuit board It also includes at least two spaced conductive posts embedded in the second insulating layer, each conductive post is provided corresponding to one of the conductive blocks, and the first conductive part is embedded in the conductive post, and the conductive post The conductive block is electrically connected to the second circuit substrate.

In the circuit board and its manufacturing method of the present application, since the side of the second conductive part in each of the conductive blocks away from the first circuit layer and the side of the first insulating layer away from the first circuit layer One side is flush, which improves the flatness of the circuit board, which is conducive to improving the stability and effectiveness of the electrical connection with the electronic components when the electronic components are subsequently electrically connected. The first conductive part is embedded in the conductive column, which is beneficial to improve the stability of the electrical connection between the circuit layers in the circuit board.

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the application. The terms used herein in the description of the application are for the purpose of describing specific embodiments only, and are not intended to limit the application.

Some implementations of the present application will be described in detail below with reference to the drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

Please refer to FIG. 1 to FIG. 10 in conjunction with the manufacturing method of a circuit board according to an embodiment of the present invention, which includes the following steps:

Step S1 , please refer to FIG. 1 , providing a double-sided metal substrate 10 , the double-sided metal substrate 10 includes a first metal foil 11 , a first insulating layer 13 and a second metal foil 15 stacked in sequence.

The first insulating layer 13 may include but not limited to polyimide film (polyimide, PI), liquid crystal polymer film (liquid crystal polymer, LCP), polyethylene terephthalate film (Polyethylene Terephthalate, PET ) and at least one of polyethylene naphthalate film (Polyethylene Naphthalate, PEN).

The material of the first metal foil 11 and the second metal foil 15 can be but not limited to at least one of copper, silver, nickel, gold and other metals and their alloys.

In this embodiment, the double-sided metal substrate 10 can be a double-sided copper clad board.

Step S2, please refer to FIG. 2, forming at least two stepped blind holes 16 on the double-sided metal substrate 10, wherein each of the stepped blind holes 16 includes a hole penetrating through the first metal foil 11 along the above lamination direction. The first portion 161 and the second portion 163 penetrating through the first insulating layer 13 along the stacking direction. The first part 161 communicates with the second part 163, and on any cross-section along the stacking direction, the width of the first part 161 in each of the stepped blind holes 16 is smaller than that of the second part 163. width.

Preferably, on any cross-section along the stacking direction, the cross-section of each stepped blind hole 16 is substantially inverted T-shaped. More preferably, the central axis of the first portion 161 and the central axis of the second portion 163 in each of the stepped blind holes 16 may coincide.

Specifically, the stepped blind hole 16 can be formed by, but not limited to, the following methods:

First, referring to FIG. 3 , the first metal foil 11 is etched to form at least two first portions 161 penetrating through the first metal foil 11 along the stacking direction.

Second, referring to FIG. 2 , the first insulating layer 13 is etched by each of the first portions 161 to form a second portion 163 penetrating through the first insulating layer 13 along the stacking direction. Wherein, on any section along the stacking direction, the width of the first portion 161 is smaller than the width of the corresponding second portion 163 .

Since the materials of the first metal foil 11 and the first insulating layer 13 are different, the first part 161 and the second part 163 can be formed respectively by selecting different etching solutions, and when the first part 161 and the second part 163 are formed, The second portion 163 does not affect the already formed first portion 161 .

Step S3 , please refer to FIG. 4 , filling each step blind hole 16 with conductive paste to form a conductive block 20 corresponding to each step blind hole 16 . Wherein, each of the conductive blocks 20 includes a first conductive portion 21 filling the first portion 161 and a second conductive portion 23 filling the second portion 163 . The shape of each conductive block 20 is consistent with the shape of the corresponding stepped blind hole 16 .

Preferably, the conductive paste can be silver paste. The conductive paste can be filled in the stepped blind holes 16 by but not limited to printing.

In step S4 , please refer to FIG. 5 , performing wiring fabrication on the first metal foil 11 provided with the first conductive portion 21 , so that the first metal foil 11 forms a corresponding first wiring layer 110 .

When the circuit in the first circuit layer 110 is electrically connected to the conductive block 20, due to the particularity of the structure of the conductive block 20, the circuit can be directly arranged on the surface of the second conductive part 21 of the conductive block 20 to realize The electrical connection does not need to form an annular ring, which is beneficial to saving wiring space and improving wiring density. In some embodiments, in order to further improve the stability of the electrical connection between the circuit and the conductive block 20 , the circuit may further contact the first conductive portion 23 or even surround the first conductive portion 23 .

Step S5, please refer to FIG. 6 and FIG. 7, a second insulating layer 30 is provided on the first wiring layer 110, the first insulating layer 13 exposed from the first wiring layer 110 and the conductive block 20, and The second insulating layer 30 is patterned to form a first opening 301 corresponding to each of the conductive blocks 20 . Wherein, the first opening 301 is opened around the first conductive portion 21 to expose the first conductive portion 21 and part of the second conductive portion 23 .

In this embodiment, preferably, along the stacking direction, the thickness of the second insulating layer 30 may be greater than the height of the first conductive portion 21 . In some implementations, along the stacking direction, the thickness of the second insulating layer 30 may also be less than or equal to the height of the first conductive portion 21 .

Step S6, please refer to FIG. 8 , corresponding to each of the first openings 301, a conductive pillar 35 filling the first opening 301 is formed, and the patterned second insulating layer 30 is away from the first insulating layer. A circuit substrate 50 is formed on one side of the layer 13 , and circuit fabrication is performed on the second metal foil 15 to form a second circuit layer 150 correspondingly. Wherein, the conductive pillar 35 is electrically connected to the circuit substrate 50 , and the second circuit layer 150 forms at least one second opening 151 corresponding to the conductive block 20 .

Specifically, the surface of each conductive post 35 facing the corresponding second conductive portion 23 is recessed to form a groove 350 in a direction away from the second conductive portion 23, and the corresponding first conductive portion 21 is embedded in the groove 350 .

At least one of the conductive blocks 20 is exposed from a second opening 151 . In this embodiment, the conductive blocks 20 are plural and arranged at intervals, and the plural conductive blocks 20 are exposed from a second opening 151 . A surface of the second conductive portion 23 facing away from the first conductive portion 21 in each of the conductive blocks 20 is flush with a side of the first insulating layer 13 facing away from the first circuit layer 110 .

In this embodiment, the circuit substrate 50 can be a single-layer circuit substrate, which includes a circuit layer 53 . The conductive pillars 35 are electrically connected to the circuit layer 53 . In some embodiments, the circuit substrate 50 may also be a double-layer circuit substrate or a multi-layer circuit layer substrate, that is, the circuit substrate 50 includes at least two circuit layers spaced apart and stacked. The conductive pillars 35 are electrically connected to the adjacent circuit layers.

Step S7 , please refer to FIG. 9 , covering the first protection layer 61 on the circuit substrate 50 , and covering the second protection layer 63 on the second circuit layer 150 . Wherein, the second protection layer 63 includes at least one opening 630 , and at least one of the conductive blocks 20 is exposed through the opening 630 .

In this embodiment, a plurality of the conductive blocks 20 are exposed through a window 630 .

Step S8 , please refer to FIG. 10 , install at least one electronic component 70 in the window 630 , and each electronic component 70 is electrically connected to at least two conductive blocks 20 .

Specifically, each of the electronic components 70 may include at least two spaced connection pads 71, and each connection pad 71 is electrically connected to a second conductive portion 23 in the conductive block 20 that is away from the first conductive portion. 21 surfaces.

Each of the electronic components 70 and each of the conductive blocks 20 can be electrically connected and fixed by, but not limited to, anisotropic conductive glue or solder paste (not shown).

In some implementations, the above step S8 can be omitted. In some embodiments, the above steps S7 and S8 can be omitted.

Please refer to FIG. 11 , a circuit board 100 according to an embodiment of the present invention includes a first circuit substrate 10 a and a second circuit substrate 40 stacked. The first circuit substrate 10 a includes a first circuit layer 110 , a first insulating layer 13 and a second circuit layer 150 sequentially stacked along the stacking direction. Wherein, the first circuit substrate 10a further includes at least two spaced conductive blocks 20 exposed from the gaps of the first circuit layer 110 and the gap of the second circuit layer 150, each of the conductive blocks 20 It includes a first conductive portion 21 and a second conductive portion 23 . Wherein, the second conductive portion 23 is embedded in the first insulating layer 13, and the two surfaces of the second conductive portion 23 spaced along the stacking direction are respectively connected to the first insulating layer 13 along the The two sides of the interval in the stacking direction are flush. The first conductive portion 21 protrudes from the surface of the second conductive portion 23 away from the second circuit layer 150, and on any cross-section along the stacking direction, the width of the first conductive portion 21 is smaller than the The width of the second conductive portion 23 . The second circuit substrate 40 is combined with the first circuit layer 110 , the first insulating layer 13 exposed from the first circuit layer 110 and the conductive block 20 through a second insulating layer 30 . The circuit board 100 also includes at least two spaced conductive pillars 35 embedded in the second insulating layer 30, each conductive pillar 35 is set corresponding to one of the conductive blocks 20, and the first conductive part 21 is embedded In the conductive pillar 35 . The conductive pillar 35 is electrically connected to the conductive block 20 and the second circuit substrate 40 .

In this embodiment, along the stacking direction, the height of the first conductive portion 21 may be consistent with the thickness of the first circuit layer 110 .

Preferably, the conductive block 20 can be a silver block.

Preferably, on any cross section along the stacking direction, the cross section of each conductive block 20 is substantially inverted T-shaped. More preferably, the central axis of the first conductive portion 21 along the stacking direction in each conductive block 20 can coincide with the central axis of the second conductive portion 23 along the stacking direction.

Preferably, along the stacking direction, the thickness of the second insulating layer 30 may be greater than the height of the first conductive portion 21 . In some implementations, along the stacking direction, the thickness of the second insulating layer 30 may also be less than or equal to the height of the first conductive portion 21 .

In some implementations, the circuit board 100 may further include a first protection layer 61 and a second protection layer 63 . The first protective layer 61 covers the second circuit substrate 40, the second protective layer 63 covers the second circuit layer 150, and the second protective layer 63 includes at least one opening 630 to expose the Conductive block 20.

In some implementations, the circuit board 100 may further include at least one electronic component 70 installed in the opening 630 , and each electronic component 70 is electrically connected to the conductive block 20 .

Specifically, each of the electronic components 70 may include at least two spaced connection pads 71, and each connection pad 71 is electrically connected to a second conductive portion 23 in the conductive block 20 that is away from the first conductive portion. 21 surfaces.

Each of the electronic components 70 and each of the conductive blocks 20 can be electrically connected and fixed by, but not limited to, anisotropic conductive glue or solder paste.

In the circuit board and its manufacturing method of the present application, since the side of the second conductive portion 23 in each of the conductive blocks 20 away from the first circuit layer 110 and the first insulating layer 13 away from the first One side of the circuit layer 110 is flush, which improves the flatness of the circuit board, so that it is beneficial to improve the stability and effectiveness of the electrical connection with the electronic component 70 when the electronic component 70 is subsequently electrically connected. The first conductive part 21 is embedded in the conductive column 35, which is beneficial to improve the stability of the electrical connection between the circuit layers in the circuit board.

Further, the conductive block 20 is formed by silver paste, which is beneficial to reduce the contact resistance of the conductive block 20, thereby helping to ensure the integrity of the circuit board signal, and at the same time, the conductive block 20 formed by silver paste does not need surface treatment, Subsequent electronic components can be directly connected electrically, which is beneficial to reduce the manufacturing process and cost.

100: circuit board 10: Double-sided metal substrate 11: The first metal foil 13: The first insulating layer 15: Second metal foil 16: Ladder blind hole 161: Part 1 163: Part Two 20: Conductive block 21: The first conductive part 23: The second conductive part 110: The first line layer 30: Second insulating layer 301: first opening 35: Conductive column 50: circuit substrate 150: Second line layer 151: second opening 350: Groove 53: Line layer 61: The first protective layer 63:Second protective layer 630: open window 70: Electronic components 71: Connection pad 10a: the first circuit substrate 40: Second circuit substrate

1-10 are the manufacturing method of the circuit board according to one embodiment of the present invention.

Fig. 11 is a circuit board according to an embodiment of the present invention.

none

100: circuit board

13: The first insulating layer

20: Conductive block

21: The first conductive part

23: The second conductive part

110: The first line layer

30: Second insulating layer

35: Conductive column

150: Second line layer

61: The first protective layer

63:Second protective layer

630: open window

70: Electronic components

71: Connection pad

10a: the first circuit substrate

40: Second circuit substrate

Claims (10)

A method for manufacturing a circuit board, comprising the steps of: A double-sided metal substrate is provided, including a first metal foil, a first insulating layer and a second metal foil sequentially stacked; At least two stepped blind holes at intervals are formed on the double-sided metal substrate, wherein each of the stepped blind holes includes a first portion penetrating through the first metal foil along the stacking direction and penetrating through the first metal foil along the stacking direction. The second part of the first insulating layer, the first part communicates with the second part, and on any cross-section along the stacking direction, the width of the first part in each of the stepped blind holes is smaller than the the width of the second part; filling each of the step blind holes with conductive paste to form a conductive block corresponding to each of the step blind holes, and each of the conductive blocks includes a first conductive part filling the first part and a second conductive part filling the second part. part of the second conductive portion; performing wiring fabrication on the first metal foil provided with the first conductive portion to form a corresponding first wiring layer; A second insulating layer is disposed on the first wiring layer, the first insulating layer exposed from the first wiring layer, and the conductive block, and the second insulating layer is patterned to correspond to each of the The conductive block forms a first opening, the first opening opens around the first conductive part to expose the first conductive part and at least part of the second conductive part; and Corresponding to each of the first openings, a conductive post is formed to fill the first opening, and a circuit substrate is formed on the patterned second insulating layer, and a circuit is made on the second copper foil to correspond to A second circuit layer is formed, wherein the conductive column is electrically connected to the circuit substrate, and at least one second opening is formed in the second circuit layer corresponding to the conductive block. The method for manufacturing a circuit board according to Claim 1, wherein, on any cross-section along the stacking direction, the cross-section of each stepped blind hole is an inverted T-shape. The method for manufacturing a circuit board according to claim 1, wherein the conductive paste is silver paste. The method for manufacturing a circuit board as described in claim 1, further comprising: A first protective layer is covered on the side of the circuit substrate away from the first circuit layer, and a second protective layer is covered on the second circuit layer, wherein the second protective layer includes at least one window to expose the conductive block. The method for manufacturing a circuit board according to claim 4, wherein at least one electronic component is installed in the window, and each electronic component is electrically connected to at least two of the conductive blocks. The method for manufacturing a circuit board according to claim 5, wherein each of the electronic components and each of the conductive blocks is electrically connected and fixed by an anisotropic conductive glue or solder paste. A circuit board, comprising a stacked first circuit substrate and a second circuit substrate, the first circuit substrate includes a first circuit layer, a first insulating layer and a second circuit layer sequentially stacked along the stacking direction, the first A circuit substrate further includes at least two spaced conductive blocks exposed from the gap of the first circuit layer and the gap of the second circuit layer, the improvement is that each of the conductive blocks includes a first conductive part and a The second conductive part; the second conductive part is embedded in the first insulating layer, and the two surfaces of the second conductive part along the stacking direction are respectively connected with the first insulating layer along the stacking direction The two sides spaced apart in the direction are flush; the first conductive part protrudes from the surface of the second conductive part away from the second circuit layer, and on any cross-section along the stacking direction, the first conductive part The width is smaller than the width of the second conductive part; the second circuit substrate is combined with the first circuit layer, the first insulating layer and the conductive block exposed from the first circuit layer through a second insulating layer; The circuit board also includes at least two spaced conductive posts embedded in the second insulating layer, each conductive post is provided corresponding to one of the conductive blocks, and the first conductive part is embedded in the conductive post, The conductive column is electrically connected to the conductive block and the second circuit substrate. The circuit board according to claim 7, wherein, on any cross-section along the lamination direction, the cross-section of each of the conductive blocks is an inverted T shape; the conductive blocks are silver blocks. The circuit board according to claim 7, wherein the circuit board further includes a first protective layer and a second protective layer, and the first protective layer is arranged on the side of the second circuit substrate away from the first circuit substrate On one side, the second protection layer covers the second circuit layer, and the second protection layer includes at least one opening to expose the conductive block. The circuit board according to claim 9, wherein the circuit board further includes at least one electronic component installed in the window, and each electronic component is connected to each conductive block by means of different parties. Conductive adhesive or solder paste for electrical connection and fixation.

Images