Circuit board structure

Abstract

The utility model discloses a circuit board structure. The circuit board structure comprises a substrate and a resin filling material. A drill hole is formed in the substrate. And the resin filling material is filled in the drilling holes of the substrate. Wherein the bore has an aspect ratio of between 20 and 40. Wherein the end face of the resin filling material is not recessed from the surface of the substrate. Therefore, the yield of the circuit board structure can be improved.

Description

Circuit board structure Technical Field

[0001] This utility model relates to a circuit board, and more particularly to a circuit board structure. Background Technology

[0002] In the prior art, as circuit boards develop towards higher density and higher layer counts, the board thickness increases and the aperture shrinks, resulting in a higher aspect ratio for the holes. However, when resin plugging is performed on these high aspect ratio holes, if the screen nodes of the printing stencil overlap with the hole positions, it often causes uneven ink application, leading to notch defects at the hole openings, which in turn affects product yield.

[0003] Therefore, the inventor believed that the above-mentioned defects could be improved. So he devoted himself to research and combined with the application of scientific principles, and finally proposed a utility model with reasonable design and effective improvement of the above-mentioned defects. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to improve the uneven ink application caused by the overlap of the screen nodes and the hole positions of the printing screen during resin plugging operations in holes with high aspect ratios, thereby reducing the formation of notch defects at the hole openings and improving product yield.

[0005] One embodiment of this utility model discloses a circuit board structure, the circuit board structure comprising: a substrate having drilled holes; and a resin filler material filling the drilled holes in the substrate; wherein the drilled holes have an aspect ratio between 20 and 40; and wherein the end face of the resin filler material is not recessed from the surface of the substrate.

[0006] Optionally, the drilling of the substrate is defined with a drilling diameter, and the drilling diameter is between 6 mils and 30 mils.

[0007] Optionally, the drilling depth of the substrate is defined, and the drilling depth is between 3.2 and 6.0 mm.

[0008] Optionally, the substrate thickness is between 3.2 mm and 6.0 mm.

[0009] Optionally, the aspect ratio is between 25 and 30.

[0010] Optionally, one end of the resin filler material is cut flush with the surface of the substrate where the drilled hole is formed.

[0011] Optionally, one end of the resin filler material protrudes from the surface of the substrate where a drilled hole is formed.

[0012] Optionally, the protrusion height between the end face of the resin filler and the substrate is between 10 micrometers and 60 micrometers.

[0013] Optionally, the end face of the resin filler material is a roughened surface formed by grinding.

[0014] One embodiment of this utility model discloses a circuit board structure, the circuit board structure comprising: a substrate having a plurality of drill holes; and

[0015] Multiple resin filler materials are used to fill multiple drilled holes in a substrate; wherein each drilled hole has an aspect ratio between 20 and 40; wherein the end face of each resin filler material is not recessed from the surface of the substrate.

[0016] In summary, the circuit board structure disclosed in this embodiment of the present invention can improve the yield of the circuit board structure by setting that "the end face of the resin filling material is not recessed into the surface of the substrate".

[0017] To further understand the features and technical content of this utility model, please refer to the following detailed description and drawings of this utility model. However, these descriptions and drawings are only used to illustrate this utility model and are not intended to limit the scope of protection of this utility model in any way. Attached Figure Description

[0018] Figure 1 shows the resin plugging method for the circuit board according to Embodiment 1 of this utility model.

[0019] Figure 2 is a schematic diagram of the substrate and shielding sheet of Embodiment 1 of this utility model.

[0020] Figure 3 is a schematic diagram of the shielding sheet with an opening in Embodiment 1 of this utility model.

[0021] Figure 4 is a schematic diagram of the shielding sheet attached to the mesh plate in Embodiment 1 of this utility model.

[0022] Figure 5 is a schematic diagram of the removal of part of the wire mesh in Embodiment 1 of this utility model.

[0023] Figure 6 is a schematic diagram of the plugging steps in Embodiment 1 of this utility model.

[0024] Figure 7 is a schematic diagram of the resin filler material in Embodiment 1 of this utility model.

[0025] Figure 8 is a schematic diagram of the circuit board structure of Embodiment 2 of this utility model.

[0026] Figure 9 is a schematic diagram of the circuit board structure of Embodiment 3 of this utility model.

[0027] Figure 10 is a schematic diagram of the circuit board structure of Embodiment 4 of this utility model. Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of the "circuit board structure" disclosed in this utility model. Those skilled in the art can understand the advantages and effects of this utility model from the content disclosed in this specification. This utility model 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 utility model. Furthermore, the accompanying drawings of this utility model are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this utility model in detail, but the disclosed content is not intended to limit the scope of protection of this utility model.

[0029] 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 in this document should, depending on the context, include any combination of one or more related listed items.

[0030] [Example 1]

[0031] Please refer to Figures 1 to 7, which illustrate Embodiment 1 of this utility model. This embodiment discloses a resin via-filling method for a circuit board, used to fabricate a circuit board structure 100a. The resin via-filling method can be applied to a substrate 1, and a masking sheet 200 replaces the screen printing mesh 301 to perform resin via-filling on the substrate 1, thereby increasing the amount of ink applied during resin via-filling and preventing depressions after the resin ink cures.

[0032] For ease of understanding, in this embodiment, the resin plugging method is illustrated using a screen printing machine (not shown in the figure). The resin ink is filled into the drilled holes 11 of the substrate 1 by the screen printing machine equipped with a screen plate 300. However, the present invention is not limited to this.

[0033] Specifically, the resin plugging method for circuit boards includes steps S101, S102, S103, S104, S105, S106, and S107. It must be noted that the order of the steps and the actual operation method described in this embodiment can be adjusted according to needs and are not limited to those described in this embodiment.

[0034] Step S101 is a preliminary step, which includes providing a substrate 1 and a shielding sheet 200. The substrate 1 has drilled holes 11 formed on it.

[0035] It should be noted beforehand that in this embodiment, the number of drill holes 11 is described as one, but this utility model is not limited thereto. For example, in other embodiments of this utility model not shown, the number of drill holes 11 can be adjusted according to actual product requirements (as shown in Figure 10, the number of drill holes 11 on the substrate 1 can also be three).

[0036] As shown in Figure 2, the substrate 1 has a substrate thickness T, and the drill hole 11 of the substrate 1 has a drill hole diameter A1 and a drill hole depth D. The substrate thickness T is between 3.2 mm and 6.0 mm, the drill hole diameter A1 is between 6 mils and 30 mils, and the drill hole depth D is between 3.2 mm and 6.0 mm. In this embodiment, the substrate thickness T and the drill hole depth D are equal, but this is not a limitation of the present invention; for example, in other embodiments not shown in the present invention, the substrate thickness T may also be greater than the drill hole depth D.

[0037] Furthermore, the drilled hole 11 has an aspect ratio between 20 and 40, and more preferably between 25 and 30. Specifically, the drilled hole diameter A1 and the drilled hole depth D can affect the aspect ratio, and with the demands of technology, the aspect ratio is becoming increasingly higher. The aspect ratio is the ratio of the drilled hole depth D to the drilled hole diameter A1 of the substrate 1. In other embodiments not shown in this invention, the drilled hole 11 may be, for example, a through hole, and the aspect ratio may be defined as the ratio of the substrate thickness T to the drilled hole diameter A1.

[0038] It is worth mentioning that the masking sheet 200 is used to limit the ink application area of ​​the resin ink to prevent the resin ink from spreading to locations other than the drilled hole 11. In this embodiment, the masking sheet 200 is at least one of a film or an aluminum sheet, but the present invention is not limited thereto.

[0039] Furthermore, the film is preferably made of an insulating prepreg (PP) composed of glass fiber material and epoxy resin.

[0040] Step S102 is an opening step, which includes: forming an opening 201 on the shielding sheet 200.

[0041] In this embodiment, the opening step S102 can be performed on the shielding sheet 200 by drilling, laser cutting or mechanical punching, but the present invention is not limited thereto.

[0042] As shown in Figure 3, holes are drilled in the shielding sheet 200 to form openings 201, and the positions of the openings 201 correspond to the positions of the drilled holes 11 on the substrate 1. Furthermore, the number of openings 201 also corresponds to the number of drilled holes 11. For example, when the substrate 1 has three drilled holes 11, three openings 201 will also be formed in corresponding positions on the shielding sheet 200.

[0043] It is worth mentioning that the opening 201 of the shielding plate 200 is defined with an opening diameter A2, and the opening diameter A2 is between 16 mils and 40 mils, preferably between 22 mils and 40 mils. The difference between the drill hole diameter A1 and the opening diameter A2 is between 6 mils and 10 mils, and the opening diameter A2 of the opening 201 is larger than the drill hole diameter A1 of the drill hole 11.

[0044] Step S103 is the screen attaching step, which includes attaching the masking sheet 200 to the wire mesh 301 of the screen plate 300.

[0045] As shown in Figure 4, a masking sheet 200 with an opening 201 is aligned and attached to one surface of the wire mesh 301 of the screen plate 300. The masking sheet 200 is attached to approximately the center of the wire mesh 301, and the total area of ​​the masking sheet 200 is smaller than the total area of ​​the wire mesh 301 to facilitate the subsequent removal of the wire mesh.

[0046] Step S104 is a removal step, which includes: removing the portion of the screen 301 corresponding to the masking sheet 200 so that the masking sheet 200 is exposed from the screen 301.

[0047] Specifically, as shown in Figure 5, the portion of the screen 301 corresponding to the masking sheet 200 is removed from the other side of the screen 301 where the masking sheet 200 is not attached, using a cutting tool or laser, so that the masking sheet 200 is exposed from the screen 301.

[0048] It is worth mentioning that the area removed by the wire mesh 301 is smaller than the total area of ​​the masking sheet 200, so that the remaining part of the wire mesh 301 can support and fix the masking sheet 200 on the mesh plate 300.

[0049] Step S105 is the hole-filling step, which includes: placing a mesh plate 300 with a masking sheet 200 attached on the substrate 1, and filling the drilled hole 11 of the substrate 1 with resin ink through the opening 201 of the masking sheet 200.

[0050] For example, as shown in FIG6, the substrate 1 is placed on a screen printing machine, and the screen 300 with the masking sheet 200 attached is aligned with the substrate 1 so that the opening 201 of the masking sheet 200 can be aligned with the drill hole 11 of the substrate 1 to perform the hole plugging step S105.

[0051] For ease of explanation, in this embodiment, the screen printing machine uses a squeegee to perform the hole-filling step S105, but this invention is not limited to this. For example, in other embodiments of this invention, other tools may be used to perform the hole-filling step S105.

[0052] Furthermore, during the screen printing machine's hole-filling step S105, pressure is applied to the screen 300 by a squeegee to press the resin ink into one surface of the masking sheet 200, and the resin ink is further filled into the corresponding drill hole 11 below the opening 201 through the opening 201 of the masking sheet 200.

[0053] In this embodiment, the resin ink is a curable resin insulating material, such as epoxy resin or other materials suitable for performing the plugging step S105, but the present invention is not limited thereto.

[0054] Step S106 is a curing step, which includes curing resin ink to form resin filling material 2 in the drilled holes 11 of the substrate 1, thereby forming a circuit board structure 100a.

[0055] Specifically, after the hole-filling step S105, the substrate 1 is sent into a heating device (not shown in the figure) for curing treatment at a predetermined time and a predetermined temperature, so that the resin ink filled in the hole 11 undergoes a cross-linking reaction and hardens to form a resin filling material 2, which is fixed inside the hole 11 (as shown in Figure 7).

[0056] As shown in Figure 6, after the curing step S106, one end of the resin filler material 2 protrudes from the surface 12 of the substrate 1 where the drilled hole 11 is formed. That is, the resin filler material 2 does not form any depressions.

[0057] Step S107 is a grinding step, which includes grinding to remove the portion of the resin filler material 2 protruding from the substrate 1, thereby reducing the protrusion height H between the end face 21 of the resin filler material 2 and the substrate 1. After the grinding step, the protrusion height H is between 10 micrometers and 60 micrometers, but this invention is not limited thereto.

[0058] In this embodiment, the grinding step may be to use ceramic grinding to grind the portion of the resin filler material 2 that protrudes from the substrate 1 to ensure the surface flatness of the resin filler material 2 (as shown in Figure 8).

[0059] Based on the above, by replacing the screen 301 with a masking sheet 200 having an opening 201 and using it in conjunction with the stencil 300, resin ink can pass through the opening 201 of the masking sheet 200 to fill the holes 11 of the substrate 1 in the via filling step S105. This effectively avoids the problem of insufficient ink application caused by the overlap of the nodes of the screen 301 and the holes 11 of the substrate 1. Accordingly, when forming the circuit board structure 100a subsequently, it is possible to avoid the formation of depressions on the surface of the resin filling material 2, thereby improving the yield of the circuit board structure 100a.

[0060] [Example 2]

[0061] Please refer to Figure 8, which shows a second embodiment of this utility model. This embodiment of the utility model provides a circuit board structure 100a, which is manufactured by the aforementioned resin plugging method for circuit boards.

[0062] In this embodiment, the circuit board structure 100a includes a substrate 1 and a resin filler material 2 filling the drill holes 11 in the substrate 1. The substrate 1 has drill holes 11 formed therein, and the end face 21 of the resin filler material 2 is not recessed from the surface 12 of the substrate 1.

[0063] It should be noted beforehand that in this embodiment, the number of drill holes 11 is described as one, but this utility model is not limited thereto. For example, in other embodiments of this utility model, the number of drill holes 11 can be adjusted according to actual product requirements.

[0064] As shown in Figure 8, the substrate 1 has a substrate thickness T, and the drill hole 11 of the substrate 1 has a drill hole diameter A1 and a drill hole depth D. The substrate thickness T is between 3.2 mm and 6.0 mm, the drill hole diameter A1 is between 6 mils and 30 mils, and the drill hole depth D is between 3.2 mm and 6.0 mm. Further, the drill hole 11 has an aspect ratio between 20 and 40, and more preferably between 25 and 30. In this embodiment, the substrate thickness T and the drill hole depth D are equal, but this is not a limitation of the present invention; for example, in other embodiments not shown in the present invention, the substrate thickness T may also be greater than the drill hole depth D.

[0065] It is worth mentioning that one end of the resin filler material 2 protrudes from the surface 12 of the substrate 1 where the drilled hole 11 is formed, and the protrusion height H between the end face 21 of the resin filler material 2 and the substrate 1 is between 10 micrometers and 60 micrometers, but the present invention is not limited thereto.

[0066] Furthermore, in this embodiment, the end face 21 of the resin filler 2 is a rough surface formed by grinding. Specifically, to facilitate subsequent processing, the end face 21 of the resin filler 2 is formed by ceramic grinding, or the protrusion height H of the resin filler 2 is made to meet the preset requirements through grinding.

[0067] [Example 3]

[0068] Please refer to Figure 9, which illustrates Embodiment 3 of this utility model. This embodiment provides a circuit board structure 100b. Since this embodiment is similar to Embodiment 2 described above, the similarities between the two embodiments will not be repeated. The differences between this embodiment and Embodiment 2 are roughly explained as follows:

[0069] In this embodiment, one end of the resin filler material 2 is cut flush with the surface 12 of the substrate 1 where the drilled hole 11 is formed.

[0070] Specifically, after the grinding step S107, the end face 21 of the resin filler 2 is flush with the surface 12 of the substrate 1 where the drilled hole 11 is formed; that is, the protrusion height of the resin filler 2 is 0.

[0071] [Example 4]

[0072] Please refer to Figure 10, which illustrates Embodiment 4 of this utility model. This embodiment provides a circuit board structure 100c. Since this embodiment is similar to Embodiment 2 described above, the similarities between the two embodiments will not be repeated. The differences between this embodiment and Embodiment 2 are roughly explained as follows:

[0073] In this embodiment, the substrate 1 has three drilled holes 11, and each drilled hole 11 is filled with a resin filler material 2.

[0074] [Technical Effects of the Embodiments of this Utility Model]

[0075] In summary, the circuit board structure disclosed in this embodiment of the present invention can improve the yield of the circuit board structure by setting that "the end face of the resin filling material is not recessed into the surface of the substrate".

[0076] The above-disclosed content is only a preferred and feasible embodiment of the present utility model, and is not intended to limit the patent scope of the present utility model. Therefore, all equivalent technical changes made based on the contents of the present utility model specification and drawings are included in the patent scope of the present utility model.

Claims

1. A circuit board structure, characterized in that, The circuit board structure includes: a substrate having drilled holes; and a resin filler material filling the drilled holes in the substrate; wherein the drilled holes have an aspect ratio between 20 and 40; and wherein the end face of the resin filler material is not recessed from the surface of the substrate.

2. The circuit board structure according to claim 1, characterized in that, The drill hole in the substrate is defined with a drill hole diameter, and the drill hole diameter is between 6 mils and 30 mils.

3. The circuit board structure according to claim 1, characterized in that, The drill hole in the substrate is defined with a drill depth, and the drill depth is between 3.2 and 6.0 mm.

4. The circuit board structure according to claim 1, characterized in that, The thickness of the substrate is between 3.2 mm and 6.0 mm.

5. The circuit board structure according to claim 1, characterized in that, The aspect ratio is between 25 and 30.

6. The circuit board structure according to claim 1, characterized in that, One end of the resin filler material is cut flush with the surface of the substrate where the drilled hole is formed.

7. The circuit board structure according to claim 1, characterized in that, One end of the resin filler material protrudes from the surface of the substrate where the drilled hole is formed.

8. The circuit board structure according to claim 6, characterized in that, The protrusion height between the end face of the resin filler and the substrate is between 10 micrometers and 60 micrometers.

9. The circuit board structure according to claim 1, characterized in that, The end face of the resin filler material is a rough surface formed by grinding.

10. A circuit board structure, characterized in that, The circuit board structure includes: a substrate having a plurality of drilled holes; and a plurality of resin filler materials filling the plurality of drilled holes in the substrate; wherein each drilled hole has an aspect ratio between 20 and 40; and wherein the end face of each resin filler material is not recessed from the surface of the substrate.

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