Circuit board manufacturing method

Abstract

A circuit board manufacturing method includes: etching two board bodies to form a front hole with exposed local conductive pads and a first observation hole with exposed first alignment pads for each board body; connecting the two board bodies by pressing to form a circuit board; forming a through hole through the circuit board and the two conductive pads along the two front holes according to the position of each conductive pad; forming a second observation hole with exposed second alignment pads from each first observation hole according to the position of each first alignment pad; and forming a blind hole with exposed target metal pads from the corresponding board body according to the position of each second alignment pad, the bottom wall of which is completely formed by the corresponding target metal pad.

Description

Technical Field

[0001] This invention relates to a manufacturing method, and more particularly to a method for manufacturing a circuit board that precisely shapes blind vias on a target metal pad. Background Technology

[0002] Existing circuit board manufacturing methods form blind vias based on the location of through-holes and then form them at the corresponding metal pads. However, the board lamination step performed before forming the through-holes in existing circuit board manufacturing methods can easily cause the two laminated boards to shift, thus causing a shift in the relative position between the through-holes and the corresponding metal pads. Therefore, the blind vias are prone to missing connections (e.g., the bottom wall of the blind via is not entirely composed of the metal pads).

[0003] Therefore, the inventor believed that the above-mentioned defects could be improved. He devoted himself to research and applied scientific principles, and finally proposed an invention that is reasonably designed and effectively improves the above-mentioned defects. Summary of the Invention

[0004] This invention provides a circuit board manufacturing method that can effectively improve the defects that may occur in existing circuit board manufacturing methods.

[0005] This invention discloses a circuit board manufacturing method, comprising: a preparation step: providing two boards; wherein each board has a conductive pad, a first alignment pad, a second alignment pad corresponding to the first alignment pad along a thickness direction, and a target metal pad spaced apart from the second alignment pad; a first alignment step: etching the outer surfaces of the two boards to form a front hole exposing a portion of the conductive pad and a first observation hole exposing the first alignment pad in each board; a lamination step: laminating the inner surfaces of the two boards together to form a circuit board; and a through-hole forming step: forming a through hole based on the exposed portion of each front hole. The steps include: a partial alignment step: forming a through hole along the thickness direction of the circuit board and through the two conductive pads by positioning the conductive pads locally and along the front holes of the two boards; a second alignment step: forming a second observation hole along the thickness direction of each first observation hole to expose the corresponding second alignment pad based on the position of the first alignment pad exposed in each first observation hole; and a blind hole forming step: forming a blind hole from the outer surface of the corresponding board to expose the target metal pad based on the position of the second alignment pad exposed in each second observation hole; wherein the bottom wall of each blind hole is entirely composed of the corresponding target metal pad.

[0006] In summary, the circuit board manufacturing method disclosed in the embodiments of the present invention, by implementing the first alignment step and the second alignment step, enables the blind holes of each board body to be precisely formed on the corresponding target metal pad, thereby avoiding the problem of missing connections of the blind holes.

[0007] To further understand the features and technical content of this invention, please refer to the following detailed description and accompanying drawings. However, these descriptions and drawings are only for illustrating the invention and are not intended to limit the scope of protection of the invention in any way. Attached Figure Description

[0008] Figure 1 This is a schematic flowchart of a circuit board manufacturing method according to an embodiment of the present invention;

[0009] Figure 2 This is a schematic diagram of the preparation steps in the circuit board manufacturing method according to an embodiment of the present invention;

[0010] Figure 3A This is a schematic diagram of the first alignment step in the circuit board manufacturing method according to an embodiment of the present invention;

[0011] Figure 3B for Figure 3A A partial top-view diagram;

[0012] Figure 4 This is a schematic diagram of the lamination step in the circuit board manufacturing method according to an embodiment of the present invention;

[0013] Figure 5 This is a schematic diagram of the through-hole forming step in the circuit board manufacturing method according to an embodiment of the present invention;

[0014] Figure 6 This is a schematic diagram of the second alignment step in the circuit board manufacturing method according to an embodiment of the present invention;

[0015] Figure 7 This is a schematic diagram of the blind hole forming step in the circuit board manufacturing method of this invention, and a cross-sectional schematic diagram of the circuit board of this invention.

[0016] Symbol Explanation

[0017] 100: Circuit board

[0018] 10: Board body

[0019] 101: Outer panel

[0020] 102: Inner panel surface

[0021] 1: Conductive pad

[0022] 2: First alignment pad

[0023] 21: Alignment Hole

[0024] 3: Second alignment pad

[0025] 4: Target metal pad

[0026] 5: Insulation layer

[0027] 51: Front hole

[0028] 52: First observation hole

[0029] 53: Second observation hole

[0030] 54: Blind hole

[0031] P: Through hole

[0032] T: Thickness direction

[0033] L1: Centerline

[0034] S100: Circuit Board Manufacturing Method

[0035] S110: Preparation Steps

[0036] S120: First alignment step

[0037] S130: Pressing Step

[0038] S140: Through-hole forming steps

[0039] S150: Second alignment step

[0040] S160: Blind Hole Forming Steps Detailed Implementation

[0041] The following specific embodiments illustrate the implementation of the "circuit board manufacturing method" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated in advance. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention.

[0042] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the associated listed items.

[0043] Please see Figures 1 to 7 As shown, this is one embodiment of the present invention. This embodiment discloses a circuit board manufacturing method S100 and a circuit board 100, and the circuit board 100 is preferably manufactured by implementing the circuit board manufacturing method S100, but the present invention is not limited thereto. That is, in other embodiments of the present invention not shown, the circuit board 100 may be manufactured by methods other than the circuit board manufacturing method S100.

[0044] For ease of explanation, the circuit board manufacturing method S100 of this embodiment will be described first, and then the circuit board 100 will be described. Furthermore, the accompanying drawings corresponding to the following description are presented as one of the cross-sectional views parallel to a thickness direction T, but it is understood that any cross-sectional view parallel to the thickness direction T is substantially the same, but the present invention is not limited thereto.

[0045] [Circuit Board Manufacturing Methods]

[0046] like Figure 1 As shown, the circuit board manufacturing method S100 in this embodiment sequentially includes a preparation step S110, a first alignment step S120, a pressing step S130, a through-hole forming step S140, a second alignment step S150, and a blind hole forming step S160, thereby manufacturing the circuit board 100 (e.g.: Figure 7 However, it is not limited to this.

[0047] For example, in other embodiments of the present invention not illustrated, the circuit board manufacturing method S100 may perform a blackening process after the lamination step S130, or an electroplating operation after the blind via forming step S160. The various steps of the circuit board manufacturing method S100 in this embodiment will now be described.

[0048] The preparation step S110: as follows: Figure 1 and Figure 2As shown, two plates 10 are provided; each plate 10 has a conductive pad 1, a first alignment pad 2, a second alignment pad 3 corresponding to the first alignment pad 2 along a thickness direction T, and a target metal pad 4 disposed at an oblique interval from the second alignment pad 3. In this embodiment, the conductive pad 1, the first alignment pad 2, the second alignment pad 3, and the target metal pad 4 in each plate 10 are described as copper pads embedded within multiple insulating layers 5, but the present invention is not limited thereto.

[0049] It should be noted that the component distribution in the two plates 10 has a substantially similar configuration principle, so the following paragraph only describes the construction of one of the plates 10, but the present invention is not limited thereto. For example, in other embodiments of the present invention not illustrated, the two plates 10 may have different constructions and component configurations.

[0050] Furthermore, the plate 10 is a multilayer board structure, and is designed with a non-functional area (or waste area) and a functional area. The first alignment pad 2 and the second alignment pad 3 are both located in the non-functional area, while the target metal pad 4 is located in the functional area. Specifically, the first alignment pad 2 and the corresponding target metal pad 4 are located in the same layer of the corresponding multilayer board structure (or the plate 10) (that is, the first alignment pad 2 and the target metal pad 4 are separated by the same depth from the outer surface 101 of the plate 10), and the first alignment pad 2 and the second alignment pad 3 are respectively located in two adjacent layers of the multilayer board structure. Moreover, in this embodiment, the first alignment pad 2 is annular and surrounds a pair of alignment holes 21, and the alignment holes 21 correspond to the second alignment pad 3 along the thickness direction T.

[0051] First alignment step S120: as follows Figure 1 , Figure 3A ,and Figure 3B As shown, the outer surfaces 101 of the two plates 10 are etched to form a front hole 51 exposing a portion of the conductive pad 1 and a first observation hole 52 exposing the first alignment pad 2 in each plate 10. The first observation hole 52 of each plate 10 exposes the entire corresponding first alignment pad 2.

[0052] The pressing step S130: as follows: Figure 1 and Figure 4As shown, the inner surfaces 102 of two plates 10 are pressed together facing each other to form a circuit board 100. During the pressing process, the two plates 10 will inevitably shift from each other, so that the center line L1 of the conductive pad 1 of one plate 10 does not overlap with the center line L1 of the conductive pad 1 of the other plate 10.

[0053] The through-hole forming step S140: as follows: Figure 1 and Figure 5 As shown, based on the position of the partially exposed conductive pad 1 in each of the two front holes 51, a through hole P is formed along the front holes 51 of the two plates 10, penetrating the circuit board 100 and passing through the two conductive pads 1 in the thickness direction T. Furthermore, when the circuit board 100 is based on the through hole P, the relative position between the conductive pad 1 and the target metal pad 4 of any one plate 10 will differ from the relative position between the conductive pad 1 and the target metal pad 4 of the other plate 10 due to the offset between the two plates 10.

[0054] The second alignment step S150: as follows Figure 1 and Figure 6 As shown, based on the position of the first alignment pad 2 exposed in each of the first observation holes 52, a second observation hole 53 is formed in each of the first observation holes 52 along the thickness direction T, exposing the corresponding second alignment pad 3. In this embodiment, each second observation hole 53 is formed by recessing the corresponding first observation hole 52 at the alignment hole 21 along the thickness direction T, and each second observation hole 53 is preferably formed by laser ablation, but the present invention is not limited thereto.

[0055] The blind hole forming step S160: as follows Figure 1 and Figure 7 As shown, based on the position of the second alignment pad 3 exposed in each of the second observation holes 53, a blind hole 54 is formed from the outer plate surface 101 corresponding to the plate body 10 to expose the target metal pad 4. The bottom wall of each blind hole 54 is entirely composed of the corresponding target metal pad 4, and each blind hole 54 is preferably formed by laser ablation.

[0056] Accordingly, in this embodiment, the circuit board manufacturing method S100 implements the first alignment step S120 and the second alignment step S150 to ensure that the blind holes 54 of each board body 10 can be precisely formed on the corresponding target metal pads 4, thereby avoiding the problem of missing connections of the blind holes 54. Furthermore, in this embodiment, the circuit board manufacturing method S100, through the compensation mechanism established by the first alignment step S120 and the second alignment step S150, can effectively eliminate the misalignment between the two board bodies 10.

[0057] [Circuit Board]

[0058] The above is a description of the circuit board manufacturing method S100. The circuit board 100 manufactured by implementing the circuit board manufacturing method S100 will be described below. Therefore, the specific structure of the circuit board 100 can also be referred to the content of the circuit board manufacturing method S100, but the present invention is not limited thereto. For example, in other embodiments of the present invention not shown, the circuit board 100 may be manufactured by methods other than the circuit board manufacturing method S100; or, the specific structure of the circuit board 100 may differ from the description below.

[0059] like Figure 7 As shown, the circuit board 100 includes two boards 10 pressed together. In this embodiment, each board 10 is a multilayer board structure and is designed to have a non-functional area (or waste area) and an functional area. Each board 10 includes a plurality of insulating layers 5 stacked along a thickness direction T. Each board 10 has a conductive pad 1, a first alignment pad 2 (horizontally spaced from the conductive pad 1), a second alignment pad 3 (corresponding to the first alignment pad 2 along the thickness direction T), and a target metal pad 4 (obliquely spaced from the second alignment pad 3) embedded within it (the plurality of insulating layers 5).

[0060] More specifically, the center line L1 of the conductive pad 1 of any one of the plate bodies 10 does not overlap with the center line L1 of the conductive pad 1 of another plate body 10. Within each plate body 10, the first alignment pad 2 and the second alignment pad 3 are both located in the non-functional area, while the target metal pad 4 is located in the functional area. The first alignment pad 2 and the corresponding target metal pad 4 are located in the same layer of the corresponding multilayer board structure (or plate body 10) (that is, the first alignment pad 2 and the target metal pad 4 are separated by the same depth from the outer surface 101 of the plate body 10), and the first alignment pad 2 and the second alignment pad 3 are respectively located in two adjacent layers of the multilayer board structure.

[0061] In other words, the circuit board 100 has a through hole P, two first observation holes 52 recessed in the two board bodies 10, two second observation holes 53 recessed from the bottom of the two first observation holes 52, and two blind holes 54 recessed in the two board bodies 10.

[0062] The through hole P is a through hole that extends along the thickness direction T and passes through both conductive pads 1. The two first observation holes 52 are respectively recessed into the outer plate surface 101 of the two plates 10 to expose the first alignment pads 2 of the two plates 10 respectively (e.g., in each plate 10, the first observation hole 52 preferably exposes the corresponding entire first alignment pad 2, but is not limited thereto).

[0063] Furthermore, the two second observation holes 53 are respectively formed by recessing the two first observation holes 52 along the thickness direction T, so as to expose the second alignment pads 3 of the two plates 10 respectively. It should be further noted that, in this embodiment, the first alignment pad 2 of each plate 10 is annular and surrounds a pair of alignment holes 21, and each second observation hole 53 is formed by recessing the corresponding first observation hole 52 at the alignment hole 21 along the thickness direction T, but the present invention is not limited thereto.

[0064] Furthermore, the two blind holes 54 are respectively recessed on the outer plate surface 101 of the two plates 10 to expose the target metal pads 4 of the two plates 10 respectively, and the bottom wall of each blind hole 54 is defined to be entirely composed of the corresponding target metal pads 4, thereby completely avoiding the problem of missing connection.

[0065] [Technical Effects of the Embodiments of the Invention]

[0066] In summary, the circuit board manufacturing method disclosed in the embodiments of the present invention effectively weakens the alignment role previously required for the through holes by implementing the first alignment step and the second alignment step, so that the blind holes of each board body can be accurately formed on the corresponding target metal pad, thereby avoiding the problem of missing connections of the blind holes.

[0067] Furthermore, the circuit board disclosed in the embodiments of the present invention, through overall structural planning (e.g., each board body is provided with a corresponding first alignment pad and the first observation hole, and a corresponding second alignment pad and the second observation hole), ensures that the position of any blind hole is no longer constrained by the through hole, thereby enabling any blind hole to be precisely matched with the corresponding target metal pad, thus avoiding the problem of missing connection of the blind hole.

[0068] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the patent scope of the present invention. Therefore, all equivalent technical changes made based on the content of the present invention specification and drawings are included within the patent scope of the present invention.

Claims

1. A method for manufacturing a circuit board, comprising: Preparation steps: Provide two plates; wherein each plate has a conductive pad, a first alignment pad, a second alignment pad corresponding to the first alignment pad along a thickness direction, and a target metal pad spaced apart from the second alignment pad; First alignment step: Etching is performed on the outer surfaces of the two plates to form a front hole that exposes a portion of the conductive pad and a first observation hole that exposes the first alignment pad in each plate; Pressing step: The inner surfaces of the two plates are pressed together facing each other to form a circuit board; Through-hole forming step: Based on the position of the local conductive pad exposed in each of the front holes, through-holes are formed along the front holes of the two plates to penetrate the circuit board and pass through the two conductive pads in the thickness direction; The second alignment step: based on the position of the first alignment pad exposed in each of the first observation holes, a second observation hole is formed along the thickness direction in each of the first observation holes to expose the corresponding second alignment pad; and Blind hole forming step: Based on the position of the second alignment pad exposed in each second observation hole, a blind hole is formed from the outer plate surface corresponding to the plate body to expose the target metal pad; wherein, the bottom wall of each blind hole is entirely composed of the corresponding target metal pad. Each of the plates is a multi-layer plate structure, and each of the first alignment pads and the corresponding target metal pads are located in the same layer of the corresponding multi-layer plate structure. In each of the plates, the first alignment pad and the second alignment pad are respectively located in two adjacent layers of the multilayer plate structure.

2. The circuit board manufacturing method as described in claim 1, wherein, In the first alignment step, the first observation hole of each plate exposes the entire first alignment pad corresponding to it.

3. The circuit board manufacturing method as described in claim 1, wherein, In the preparation step, the first alignment pad of each plate and the target metal pad are separated by the same depth from the outer plate surface.

4. The circuit board manufacturing method as described in claim 1, wherein, In the preparation step, the first alignment pad of each plate is annular and surrounds an alignment hole; in the second alignment step, each second observation hole is formed by recessing a corresponding first observation hole at the alignment hole along the thickness direction.

5. The circuit board manufacturing method as described in claim 1, wherein, In the preparation step, each of the plates is defined with a non-functional area, and the first alignment pad and the second alignment pad of each plate are located in the non-functional area.

6. The circuit board manufacturing method as described in claim 1, wherein, During the pressing step, the center line of the conductive pad of one of the plates does not overlap with the center line of the conductive pad of the other plate.

7. The circuit board manufacturing method as described in claim 1, wherein, Each of the second observation holes was formed by laser ablation.

8. The circuit board manufacturing method as described in claim 1, wherein, Each of the aforementioned blind holes is formed by laser ablation.

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