Circuit board structure

Abstract

The utility model discloses a circuit board structure. The circuit board structure comprises a circuit substrate, an electroplated layer and a resin structure. The circuit substrate comprises a first surface and a second surface. A through hole and an alignment hole are formed in the circuit substrate, the through hole penetrates through the circuit substrate, and the alignment hole is formed in the first surface and communicated with the through hole. The electroplated layer is formed in the alignment hole and a part of the through hole. And the inner side of the electroplated layer is filled with the resin structure. The circuit substrate further comprises a blind hole structure, the blind hole structure is formed on the second surface, the blind hole structure comprises a side portion and a bottom portion, the hole wall of the through hole is defined as the side portion, and the bottom portion comprises an annular electroplating area and a central resin area located on the inner side of the annular electroplating area. The circuit board structure disclosed by the utility model can effectively improve the problem that the accuracy of the existing circuit board structure is not high enough.

Description

Technical Field

[0001] The utility model relates to a circuit board structure, in particular to a circuit board structure with high precision. Background Art

[0002] In the existing drilling method of the circuit board structure, a through hole is first formed on the circuit substrate, and then the position where the through hole is formed on the circuit substrate is drilled to form a machine-drilled hole. However, such an approach will make the diameter of the machine-drilled hole much larger than the diameter of the through hole, resulting in the problem of insufficient precision of the circuit board structure. As a result, a larger safety distance needs to be reserved on the circuit substrate when drilling to form the machine-drilled hole, resulting in the overall area of ​​the circuit board structure formed subsequently being too large.

[0003] Therefore, how to improve the existing circuit board structure to overcome the above-mentioned defects has become one of the important issues that this industry wants to solve. Utility Model Content

[0004] The technical problem to be solved by the present invention is to provide a circuit board structure in view of the deficiencies of the prior art, which can effectively improve the problem that the existing circuit board structure has insufficient precision.

[0005] In order to solve the above technical problems, one of the technical solutions adopted by the utility model is to provide a circuit board structure, which includes: a circuit substrate, which includes a first surface and a second surface opposite to each other; wherein the circuit substrate is formed with a through hole and an alignment hole, the through hole passes through the circuit substrate, the alignment hole is formed on the first surface and connected to the through hole, and a first aperture of the through hole is smaller than a second aperture of the alignment hole; an electroplating layer is formed on the alignment hole and part of the through hole; a resin structure is filled on the inner side of the electroplating layer; wherein the circuit substrate also includes a blind hole structure, the blind hole structure is formed on the second surface, the blind hole structure includes a side and a bottom, the hole wall of the through hole of the circuit substrate is defined as the side of the blind hole structure, the bottom of the blind hole structure includes a ring electroplating area and a central resin area located inside the ring electroplating area, and the ring electroplating area and the central resin area are respectively formed by the top of the electroplating layer and the top of the resin structure.

[0006] Preferably, an absolute value of a difference between the second aperture of the alignment hole and the first aperture of the through hole is between 0.025 mm and 0.075 mm.

[0007] Preferably, a third hole diameter of the blind hole structure is between 0.25 mm and 0.35 mm.

[0008] Preferably, the alignment hole includes a constant section and a tapered section connected to the constant section, and the constant section is opened on the first surface of the circuit substrate; wherein the aperture of the tapered section gradually decreases from the first surface to the second surface and the aperture of the constant section does not change from the first surface to the second surface.

[0009] The circuit board structure as described in claim 1, wherein a plating thickness of the electroplating layer is between 700 microns and 1,100 microns.

[0010] Preferably, the inner diameter of the electroplating layer tapers along the first surface toward the second surface in the tapered section, and the width of the resin structure tapers along the first surface toward the second surface in the tapered section.

[0011] Preferably, the electroplating layer includes an electroplating bottleneck portion formed in the through hole and an electroplating body portion formed in the alignment hole, and the resin structure includes a resin bottleneck portion formed in the through hole and a resin body portion formed in the alignment hole.

[0012] Preferably, the inner diameter of the electroplated bottle neck is smaller than the inner diameter of the electroplated bottle body, and the width of the resin bottle neck is smaller than the width of the resin bottle body.

[0013] Preferably, the depth of the blind hole structure gradually increases from the ring electroplating area toward the center of the bottom.

[0014] Preferably, the depth of the blind hole structure is between 40% and 60% of the depth of the through hole.

[0015] One of the beneficial effects of the present invention is that the circuit board structure provided by the present invention can effectively improve the problem of insufficient precision of the existing circuit board structure through the technical solution of "the circuit substrate also includes a blind hole structure, the blind hole structure is formed on the second surface, the blind hole structure includes a side and a bottom, the hole wall of the through hole of the circuit substrate is defined as the side of the blind hole structure, the bottom of the blind hole structure includes a ring plating area and a central resin area located inside the ring plating area, and the ring plating area and the central resin area are respectively formed by the top of the plating layer and the top of the resin structure".

[0016] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1The present invention is a flowchart of a method for drilling a hole in a circuit board structure according to an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the preparatory steps of the drilling method for the circuit board structure according to the embodiment of the utility model.

[0019] Figure 3 It is a schematic diagram of the first drilling step of the drilling method for a circuit board structure according to an embodiment of the utility model.

[0020] Figure 4 It is a schematic diagram of the second drilling step of the drilling method for a circuit board structure according to an embodiment of the utility model.

[0021] Figure 5 It is a schematic diagram of the electroplating step of the drilling method for the circuit board structure according to an embodiment of the utility model.

[0022] Figure 6 It is a schematic diagram of the resin filling step of the drilling method of the circuit board structure according to the embodiment of the utility model.

[0023] Figure 7 It is a schematic diagram of a circuit board structure according to an embodiment of the utility model. DETAILED DESCRIPTION

[0024] The following is an explanation of the disclosed implementation mode of the utility model through specific specific embodiments. Those skilled in the art can understand the advantages and effects of the utility model from the contents disclosed in this specification. The utility model can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without deviating from the concept of the utility model. In addition, the drawings of the utility model are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following implementation modes will further explain the relevant technical contents of the utility model in detail, but the disclosed contents are not intended to limit the scope of protection of the utility model.

[0025] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0026] [Drilling method for circuit board structure]

[0027] See also Figure 1 As shown, Figure 1This is a flow chart of a drilling method for a circuit board structure according to an embodiment of the utility model. The embodiment of the utility model provides a drilling method for a circuit board structure. The drilling method for the circuit board structure includes a pre-step S110, a first drilling step S120, a second drilling step S130, a plating step S140, a resin filling step S150, and a third drilling step S160. Of course, the drilling method for the circuit board structure may include other feasible steps according to actual needs, but the utility model is not limited thereto.

[0028] See also Figure 1 Match with Figure 2 As shown, Figure 2 Schematic diagram of the pre-step of the drilling method of the circuit board structure of the embodiment of the utility model. In the pre-step S110, a circuit substrate 1 is provided, and the circuit substrate 1 includes a first surface 1a and a second surface 1b opposite to each other. The circuit substrate 1 can be a circuit substrate of various forms, and the circuit substrate 1 can include various components according to requirements, but the utility model is not limited to this. For example, two bottom copper layers (not numbered in the figure) can be formed on both sides of the circuit substrate 1, but the utility model is not limited to this.

[0029] See also Figure 1 Match with Figure 3 As shown, Figure 3 The schematic diagram of the first drilling step of the drilling method for the circuit board structure of an embodiment of the utility model. In the first drilling step S120, the circuit substrate 1 is drilled to form a through hole 11 that passes through the circuit substrate 1, and the through hole 11 has a first aperture D1. Preferably, the first aperture D1 of the through hole 11 is between 0.15 mm and 0.25 mm, but the utility model is not limited to this. More preferably, the first aperture D1 of the through hole 11 is between 0.175 mm and 0.225 mm. In the first drilling step S120, the through hole 11 can be formed by mechanical drilling, but the utility model is not limited to this.

[0030] See also Figure 1 Match with Figure 4 As shown, Figure 4The schematic diagram of the second drilling step of the drilling method for the circuit board structure of the embodiment of the utility model. In the second drilling step S130, drilling is performed at the position where the through hole 11 is formed on the first surface 1a to form an alignment hole 12 connected to the through hole 11, and the first aperture D1 of the through hole 11 is smaller than a second aperture D2 of the alignment hole 12. Preferably, the absolute value of the difference between the second aperture D2 of the alignment hole 12 and the first aperture D1 of the through hole is between 0.025 mm and 0.075 mm. More preferably, the absolute value of the difference between the second aperture D2 of the alignment hole 12 and the first aperture D1 of the through hole 11 is approximately 0.05 mm. From another perspective, the second aperture D2 of the alignment hole 12 can be between 0.2 mm and 0.3 mm.

[0031] In this embodiment, the alignment hole 12 may include a constant section 121 and a tapered section 122 connected to the constant section 121, and the constant section 121 is opened on the first surface 1a of the circuit substrate 1. The aperture of the tapered section 122 gradually decreases from the first surface 1a to the second surface 1b, and the aperture of the constant section 121 does not change from the first surface 1a to the second surface 1b.

[0032] It is worth mentioning that in the second drilling step S130 of the present embodiment, the alignment hole 12 may be formed by mechanical drilling, so the alignment hole 12 may have the constant section 121 and the tapered section 122 corresponding to the shape of the drilling tool. In other words, the alignment hole that is not formed by mechanical drilling will not have the constant section 121 and the tapered section 122 of the alignment hole 12 of the present embodiment, so it is not suitable for comparison with the alignment hole 12 of the present embodiment.

[0033] See also Figure 1 Match with Figure 5 As shown, Figure 5 Schematic diagram of the electroplating step of the drilling method of the circuit board structure of the embodiment of the utility model. In the electroplating step S140, the circuit substrate 1 is electroplated to form an electroplating layer 2 in the through hole 11 and the alignment hole 12. In this embodiment, a plating thickness T of the electroplating layer 2 can be between 700 microns and 1,100 microns, but the utility model is not limited thereto.

[0034] Specifically, the electroplating layer 2 includes an electroplating bottleneck portion 21 formed in the through hole 11 and an electroplating bottle body portion 22 formed in the alignment hole, the inner diameter of the electroplating bottleneck portion 21 is smaller than the inner diameter of the electroplating bottle body portion 22, and the inner diameter of the electroplating layer 2 gradually decreases in the tapered section 122 along the first surface 1a toward the second surface 1b.

[0035] See also Figure 1 Match with Figure 6 As shown, Figure 6 The present invention is a schematic diagram of the resin filling step of the drilling method for the circuit board structure of an embodiment of the present invention. In the resin filling step S150, a resin material is filled inside the electroplating layer 2 to form a resin structure. Specifically, the resin structure 3 includes a resin bottleneck 31 formed in the through hole 11 and a resin bottle body 32 formed in the alignment hole 12, the width of the resin bottleneck 31 is smaller than the width of the resin bottle body 32, and the width of the resin structure 3 gradually decreases from the first surface 1a to the second surface 1b in the tapered section 122. The resin material may have the property of not being easy to generate bubbles and cracks, and the model of the resin material may be, for example, Sanrong IR-93S, but the present invention is not limited thereto.

[0036] See also Figure 1 Match with Figure 7 As shown, Figure 7 1 is a schematic diagram of a circuit board structure of an embodiment of the present invention, and can also be regarded as a schematic diagram of the third drilling step of the drilling method of the circuit board structure of the embodiment of the present invention. In the third drilling step S160, drilling is performed at the position where the through hole is formed on the second surface 1b to remove part of the electroplating layer 2 and part of the resin structure 3 in the through hole 11, thereby forming a blind hole structure 4 on the second surface 1b of the circuit substrate 1 and forming a circuit board structure 100.

[0037] Specifically, in the third drilling step S160, part of the electroplated bottle neck 21 and part of the resin bottle body 32 are removed. It is worth mentioning that the alignment hole 12 formed in the second drilling step S130 can provide an alignment effect, so that the blind hole structure 4 can be formed more accurately on the second surface 1b. In addition, in the third drilling step S160 of this embodiment, part of the hole wall of the through hole 11 can also be removed, so that a third hole diameter D3 of the blind hole structure 4 is between 0.25 mm and 0.35 mm.

[0038] The blind hole structure 4 includes a side portion 41 and a bottom portion 42, the hole wall of the through hole 11 of the circuit substrate 1 is defined as the side portion 41 of the blind hole structure 4, and the bottom portion 42 of the blind hole structure 4 includes a ring electroplating area 421 and a central resin area 422 located inside the ring electroplating area 421. After the third drilling step S160, the top of the electroplating layer 2 and the top of the resin structure 3 are respectively formed as the ring electroplating area 421 and the central resin area 422 of the bottom portion 42 of the blind hole structure 4. In the embodiment where the third drilling step S160 further removes part of the hole wall of the through hole 11, the bottom portion 42 of the blind hole structure 4 is formed by the ring electroplating area 421, the central resin area 422, and the portion of the circuit substrate 1 around the ring electroplating area 421.

[0039] In addition, in the third drilling step S160 of the present embodiment, the blind hole structure 4 may be formed by mechanical drilling, so the shape of the blind hole structure 4 may correspond to the shape of the drilling tool, and the depth of the blind hole structure 4 gradually increases from the ring electroplating area 421 to the center of the bottom 42, but the present invention is not limited thereto.

[0040] [PCB structure]

[0041] See also Figure 7 As shown, the embodiment of the present invention further provides a circuit board structure 100, which can be obtained by executing the aforementioned circuit board structure manufacturing method, but the present invention is not limited thereto. The circuit board structure 100 includes a circuit substrate 1, an electroplating layer 2 and a resin structure 3.

[0042] The circuit substrate 1 includes a first surface 1a and a second surface 1b opposite to each other. The circuit substrate 1 is formed with a through hole 11 and an alignment hole 12, wherein the through hole 11 penetrates the circuit substrate 1, the alignment hole 12 is formed on the first surface 1a and communicates with the through hole 11, and a first aperture D1 of the through hole is smaller than a second aperture D2 of the alignment hole.

[0043] In this embodiment, the first aperture D1 of the through hole 11 is between 0.15 mm and 0.25 mm, and the absolute value of the difference between the second aperture D2 of the alignment hole 12 and the first aperture D1 of the through hole 11 can be between 0.025 mm and 0.075 mm, but the present invention is not limited thereto.

[0044] The electroplating layer 2 is formed in the alignment hole 12 and a portion of the through hole 11, and the resin structure 3 is filled inside the electroplating layer 2. One end of the electroplating layer 2 and one end of the resin structure 3 are adjacent to the first surface 1a, and the other end of the electroplating layer 2 and the other end of the resin structure 3 extend toward the second surface 1b but do not extend to the second surface 1b.

[0045] The electroplating layer 2 and the resin structure 3 may have a wine bottle-like appearance. Specifically, the electroplating layer 2 includes an electroplating bottle neck 21 formed in the through hole 11 and an electroplating bottle body 22 formed in the alignment hole 12, and the resin structure 3 includes a resin bottle neck 31 formed in the through hole 11 and a resin bottle body 32 formed in the alignment hole 12, the inner diameter of the electroplating bottle neck 21 is smaller than the inner diameter of the electroplating bottle body 22, and the width of the resin bottle neck 31 is smaller than the width of the resin bottle body 32.

[0046] The alignment hole 12 includes a constant section 121 and a tapered section 122 connected to the constant section 121, and the constant section 121 is opened on the first surface 1a of the circuit substrate 1. The aperture of the tapered section 122 tapers from the first surface 1a to the second surface 1b, and the aperture of the constant section 121 does not change from the first surface 1a to the second surface 1b. The inner diameter of the electroplating layer 2 tapers from the first surface 1a to the second surface 1b at the tapered section 122, and the width of the resin structure 3 tapers from the first surface 1a to the second surface 1b at the tapered section 122.

[0047] The circuit substrate 1 further includes a blind hole structure 4. The blind hole structure 4 is formed on the second surface 1b, and includes a side portion 41 and a bottom portion 42. The hole wall of the through hole 11 of the circuit substrate 1 is defined as the side portion 41 of the blind hole structure 4. The bottom portion 42 of the blind hole structure 4 includes a ring electroplating area 421 and a central resin area 422 located inside the ring electroplating area 421. The ring electroplating area 421 and the central resin area 422 are formed by the top of the electroplating layer 2 and the top of the resin structure 3, respectively.

[0048] In this embodiment, the depth of the blind hole structure 4 gradually increases from the ring electroplating area 421 to the center of the bottom 42, and the depth of the blind hole structure 4 is between 40% and 60% of the overall depth of the through hole 11 (that is, the distance between the first surface 1a and the second surface 1b), but the present invention is not limited thereto. In addition, the depth of the blind hole structure 4 (that is, the distance between the first surface 1a and the second surface 1b) can be between 1 mm and 5 mm, but the present invention is not limited thereto.

[0049] [Beneficial Effects of Embodiments]

[0050] One of the beneficial effects of the present invention is that the circuit board structure provided by the present invention can effectively improve the problem of insufficient precision of the existing circuit board structure through the technical solution of "the circuit substrate also includes a blind hole structure, the blind hole structure is formed on the second surface, the blind hole structure includes a side and a bottom, the hole wall of the through hole of the circuit substrate is defined as the side of the blind hole structure, the bottom of the blind hole structure includes a ring plating area and a central resin area located inside the ring plating area, and the ring plating area and the central resin area are respectively formed by the top of the plating layer and the top of the resin structure".

[0051] The contents disclosed above are only preferred feasible embodiments of the present utility model, and are not intended to limit the scope of the patent application of the present utility model. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present utility model are included in the scope of the patent application of the present utility model.

Claims

1. A circuit board structure, characterized in that: The circuit board structure comprises: A circuit substrate, comprising a first surface and a second surface opposite to each other; wherein the circuit substrate is formed with a through hole and an alignment hole, the through hole passes through the circuit substrate, the alignment hole is formed on the first surface and communicates with the through hole, and a first aperture of the through hole is smaller than a second aperture of the alignment hole; an electroplating layer formed on the alignment hole and a portion of the through hole; a resin structure filled inside the electroplating layer; Wherein, the circuit substrate also includes a blind hole structure, which is formed on the second surface, and the blind hole structure includes a side and a bottom. The hole wall of the through hole of the circuit substrate is defined as the side of the blind hole structure, and the bottom of the blind hole structure includes a ring electroplating area and a central resin area located inside the ring electroplating area, and the ring electroplating area and the central resin area are respectively formed by the top of the electroplating layer and the top of the resin structure.

2. The circuit board structure according to claim 1, characterized in that: An absolute value of a difference between the second aperture of the alignment hole and the first aperture of the through hole is between 0.025 mm and 0.075 mm.

3. The circuit board structure according to claim 1, characterized in that: A third hole diameter of the blind hole structure is between 0.25 mm and 0.35 mm.

4. The circuit board structure according to claim 1, characterized in that: The alignment hole includes a constant section and a tapered section connected to the constant section, and the constant section is opened on the first surface of the circuit substrate; wherein the aperture of the tapered section gradually decreases from the first surface to the second surface and the aperture of the constant section does not change from the first surface to the second surface.

5. The circuit board structure according to claim 1, characterized in that: A coating thickness of the electroplating layer is between 700 micrometers and 1,100 micrometers.

6. The circuit board structure according to claim 4, characterized in that: The inner diameter of the electroplating layer gradually decreases in the tapered section along the direction from the first surface to the second surface, and the width of the resin structure gradually decreases in the tapered section along the direction from the first surface to the second surface.

7. The circuit board structure according to claim 1, characterized in that: The electroplating layer includes an electroplating bottleneck portion formed in the through hole and an electroplating body portion formed in the alignment hole, and the resin structure includes a resin bottleneck portion formed in the through hole and a resin body portion formed in the alignment hole.

8. The circuit board structure according to claim 7, characterized in that: The inner diameter of the electroplating bottle neck is smaller than the inner diameter of the electroplating bottle body, and the width of the resin bottle neck is smaller than the width of the resin bottle body.

9. The circuit board structure according to claim 1, characterized in that: The depth of the blind hole structure gradually increases from the ring plating area toward the center of the bottom.

10. The circuit board structure according to claim 1, characterized in that: The depth of the blind hole structure is between 40% and 60% of the depth of the through hole.

Images