TW202420905A - Method for producing heat dissipation circuit board - Google Patents

Abstract

A method for producing heat dissipation circuit board is provided. The method for producing heat dissipation circuit board includes a preparation step, an aligning target hole forming step, a thru-hole forming step, a plating step, and an outer layer exposure step. The preparation step is implemented by providing an inner circuit board structure. The inner circuit board structure has two opposite wide surfaces, each of the wide surfaces defines a central area and a periphery area surrounding the central area. The aligning target hole forming step is implemented by forming a plurality of aligning target holes on the periphery area of the inner circuit board structure. The thru-hole forming step is implemented by forming a plurality of thru-holes on the central area of the inner circuit board structure in a mechanical drilling manner. The plating step is implemented by forming a plurality of copper columns in the thru-holes in a plating manner. The outer layer exposure step is implemented by performing an outer layer exposure operation to the inner circuit board structure to form a heat dissipation circuit board.

Description

Manufacturing method of heat dissipation circuit board

The present invention relates to a method for manufacturing a circuit board, and in particular to a method for manufacturing a heat dissipation circuit board.

In the existing manufacturing method of the circuit board, two wide sides of the inner circuit board structure are generally processed by laser to form a plurality of through holes. Therefore, the inner circuit board structure is turned over during the processing, thereby making the processing process more complicated.

Therefore, how to simplify the existing circuit board manufacturing method to overcome the above-mentioned defects has become one of the important issues that the industry wants to solve.

The technical problem to be solved by the present invention is to provide a method for manufacturing a heat dissipation circuit board in view of the shortcomings of the prior art. The manufacturing process is relatively simple, and the heat dissipation circuit board finally formed can have excellent heat dissipation effect and reliability.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a method for manufacturing a heat dissipation circuit board, which includes: implementing a pre-step, which includes: providing an inner circuit board structure, the inner circuit board structure has two wide sides opposite to each other, each of the wide sides defines a middle area and a surrounding area surrounding the middle area; implementing a positioning target hole forming step, which includes: A plurality of alignment target holes are formed in the surrounding area of the inner circuit board structure; a through-hole forming step is performed, which includes: forming a plurality of through-holes in the middle area of the inner circuit board structure by mechanical drilling; a plating step is performed, which includes: forming a plurality of copper pillars in the plurality of through-holes by plating; and an outer layer exposure step is performed, which includes: performing outer layer exposure on the inner circuit board structure to form a heat dissipation circuit board.

Preferably, in the alignment target hole forming step, four alignment target holes are formed, and the four alignment target holes are formed at four corners of the inner layer circuit board structure.

Preferably, the diameter of each of the through holes is between 0.15 mm and 0.25 mm.

Preferably, in the through-hole step, mechanical drilling is performed only from one of the wide sides to form a plurality of through-holes without flipping the inner circuit board structure.

Preferably, in the through-hole forming step, the number of the through-holes is between 20 and 40. The through-holes are arranged in a matrix, and the distance between any two adjacent through-holes is between 0.15 mm and 0.25 mm.

Preferably, in the electroplating step, a plurality of the copper pillars are formed in the plurality of the through holes by periodic pulse electroplating.

Preferably, in the electroplating step, the frequency of the periodic pulse electroplating is between 3:1 and 6:1.

Preferably, after the through hole forming step and before the electroplating step, the manufacturing method of the heat sink circuit board further includes a blind groove forming step, wherein the surrounding area of the inner layer circuit board structure is lasered to form at least one blind groove. In the electroplating step, a copper layer is formed in the blind groove by electroplating.

Preferably, in the blind groove forming step, the blind groove is formed in the surrounding area by using a laser having an energy between 8 mJ and 10 mJ and a pulse width between 4 μs and 8 μs.

Preferably, the length of the blind groove is between 4 mm and 6 mm, and the width of the blind groove is between 0.05 mm and 0.1 mm. The thickness of the copper layer is between 22 μm and 28 μm.

One of the beneficial effects of the present invention is that the manufacturing method of the heat dissipation circuit board provided by the present invention can simplify the processing process of the manufacturing method of the heat dissipation circuit board through the technical solutions of "implementing a through hole forming step, which includes: forming a plurality of through holes in the middle area of the inner layer circuit board structure by mechanical drilling" and "implementing a plating step, which includes: forming a plurality of copper pillars in the plurality of through holes by electroplating". The heat dissipation circuit board finally formed can have excellent heat dissipation effect and reliability.

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 used for reference and description and are not used to limit the present invention.

The following is a specific embodiment to illustrate the implementation of the "method for manufacturing a heat dissipation circuit board" disclosed in the present invention. The technical personnel in this field can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without deviating from the concept of the present invention. In addition, the drawings of the present invention are only for simple schematic illustrations and are not depicted according to actual sizes. Please note in advance. The following implementation will further explain the relevant technical content of the present invention in detail, but the disclosed content is not used to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", etc. 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 mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used in this document may include any one or more combinations of the related listed items depending on the actual situation.

[First embodiment]

Referring to Figures 1 to 5, Figure 1 is a flow chart of the method for manufacturing a heat dissipation circuit board of the first embodiment of the present invention, Figure 2 is a schematic diagram of the pre-step of the method for manufacturing a heat dissipation circuit board of the first embodiment of the present invention, Figure 3 is a schematic diagram of the alignment target hole forming step of the method for manufacturing a heat dissipation circuit board of the first embodiment of the present invention, Figure 4 is a schematic diagram of the through hole forming step of the method for manufacturing a heat dissipation circuit board of the first embodiment of the present invention, and Figure 5 is a schematic diagram of the electroplating step of the method for manufacturing a heat dissipation circuit board of the first embodiment of the present invention.

The first embodiment of the present invention provides a method for manufacturing a heat dissipating circuit board. The heat dissipating circuit board 100 manufactured by the heat dissipating circuit board manufacturing method can have an excellent heat dissipation effect. The heat dissipating circuit board manufacturing method includes a pre-step S110, a positioning target hole forming step S120, a through hole forming step S130, a plating step S140 and an outer layer exposure step S150.

In the preceding step S110, an inner circuit board structure 1 is provided. The inner circuit board structure 1 has two opposite wide sides 11. Each of the wide sides 11 defines a middle area 11a and a surrounding area 11b surrounding the middle area 11a.

In the alignment target hole forming step S120, a plurality of alignment target holes 2 are formed in the peripheral area 11b of the inner circuit board structure 1. In the alignment target hole forming step S120 of the present embodiment, four alignment target holes 2 are formed, and the four alignment target holes 2 are formed at four corners of the inner circuit board structure 1. In addition, the plurality of alignment target holes 2 may be formed by mechanical drilling or laser, but the plurality of alignment target holes 2 may also be formed by other methods, and the present invention is not limited thereto.

It is worth mentioning that the number and position of the alignment target holes 2 can be changed according to the needs. For example, in other embodiments not shown in the present invention, the number of the alignment target holes 2 can be two, and the two alignment target holes 2 can be formed in two non-adjacent corners of the inner circuit board structure 1.

In the through hole forming step S130, a plurality of through holes 3 are formed in the middle region 11a of the inner circuit board structure 1 by mechanical drilling. Furthermore, in the through hole forming step S130, the inner circuit board structure 1 may be mechanically drilled according to the positions of the plurality of alignment target holes.

In this embodiment, the diameter of each through hole 3 is between 0.15 mm and 0.25 mm, and more preferably, the diameter of each through hole 3 is between 0.18 mm and 0.22 mm, but the present invention is not limited thereto. It is worth mentioning that if the diameter of the through hole 3 is higher than the upper limit (such as 0.25 mm), the through hole 3 may not be fully filled in the subsequent electroplating step S140. On the contrary, if the diameter of the through hole 3 is lower than the lower limit (such as 0.15 mm), the heat sink circuit board 100 finally formed may have a problem of poor reliability.

Furthermore, in the through hole forming step S130 of the present embodiment, the plurality of through holes 3 are formed by mechanically drilling only from one of the wide side surfaces 11 without flipping the inner layer circuit board structure 1. In addition, in the through hole forming step S130, it may be limited to exclude the use of a laser method to form the through holes 3. In other words, the through holes 3 formed by a laser method are not suitable for comparison with the through holes 3 formed by mechanical drilling in the present case.

In the existing manufacturing method of the circuit board, two wide sides of the inner circuit board structure are generally processed by laser to form a plurality of through holes. Therefore, the inner circuit board structure is turned over during the processing, thereby making the processing process more complicated.

In contrast, the plurality of through holes 3 in the present embodiment are formed without turning over the inner layer circuit board structure 1, so the processing process is relatively simple. In addition, since the through holes 3 in the present invention are formed by mechanical drilling, compared with through holes formed by laser in the manufacturing method of general circuit boards, the through holes 3 in the present case can have a larger diameter, thereby increasing the reliability and reliability of the heat dissipation circuit board 100 finally formed.

In addition, in the through hole forming step S130 of the present embodiment, the number of the through holes 3 is between 20 and 40, the through holes 3 are arranged in a matrix, and the distance D between any two adjacent through holes 3 is between 0.15 mm and 0.25 mm. It is worth mentioning that the arrangement and number of the through holes 3 can be changed according to actual needs, and the present invention does not limit the arrangement and number of the through holes 3.

In the electroplating step S140, a plurality of copper pillars 4 are formed in the plurality of through holes 3 by electroplating. In the electroplating step S140 of the present embodiment, the plurality of copper pillars 4 are formed in the plurality of through holes 3 by periodic pulse electroplating, and the frequency of the periodic pulse electroplating is between 3:1 and 6:1. Specifically, the periodic pulse electroplating is to periodically connect and disconnect the electroplating circuit so that the copper pillars 4 are denser and have a lower porosity, especially when the inner wall of the through hole 3 is uneven.

In the outer layer exposure step S150 , the inner layer circuit board structure 1 is exposed to an outer layer to form the heat dissipation circuit board 100 .

[Second embodiment]

Please refer to Figures 6 to 8, Figure 6 is a flow chart of the manufacturing method of the heat dissipation circuit board of the second embodiment of the present invention, Figure 7 is a schematic diagram of the blind groove forming step of the manufacturing method of the heat dissipation circuit board of the second embodiment of the present invention, and Figure 8 is a schematic diagram of the electroplating step of the manufacturing method of the heat dissipation circuit board of the second embodiment of the present invention.

This embodiment is similar to the first embodiment described above, so the similarities between the two embodiments will not be described in detail, and the differences between the two embodiments are roughly described as follows:

In this embodiment, after the through hole forming step S130 and before the electroplating step S140, the manufacturing method of the heat dissipation circuit board further includes a blind groove forming step S131, laser irradiation is performed on the surrounding area 11b of the inner layer circuit board structure 1 to form at least one blind groove 5, and in the electroplating step S140, electroplating is further performed to form a copper layer 6 in the blind groove 5. In addition, in the electroplating step S140 of the above embodiment, the copper layer 6 can be formed on the wide side surface 11.

In the blind groove forming step S131 of the present embodiment, the blind groove 5 is formed in the surrounding area 11b by a laser having an energy between 8 mJ and 10 mJ and a pulse width between 4 μs and 8 μs. However, the energy and pulse width of the laser used to form the blind groove 5 can be changed according to actual needs, and the present invention is not limited thereto. In the present embodiment, the length of the blind groove 5 is between 4 mm and 6 mm, the width of the blind groove 5 is between 0.05 mm and 0.1 mm, and the depth of the blind groove 5 is between 25 mm and 75 mm, but the present invention is not limited thereto. Preferably, the depth of the blind groove 5 is between 35 mm and 65 mm, and more preferably, the depth of the blind groove 5 is between 45 mm and 55 mm.

That is to say, the blind groove 5 in this embodiment is generally in the shape of a strip. However, the present invention does not limit the shape of the blind groove 5. For example, in other embodiments not shown in the present invention, the blind groove 5 can be in an L-shape or a V-shape.

In this embodiment, the thickness of the copper layer 6 is preferably between 22 microns and 28 microns, so that the copper layer 6 can provide an excellent heat dissipation effect when combined with the blind slot 5. More preferably, the thickness of the copper layer 6 is preferably between 24 microns and 26 microns. Specifically, since the copper layer 6 is formed in the blind slot 5 along the side wall of the blind slot 5, the surface area of the copper layer 6 in the present invention is relatively large compared to a circuit board without a blind slot or a circuit board with only a blind hole, thereby providing an excellent heat dissipation effect.

[Third Embodiment]

Please refer to Figures 9 to 11, Figure 9 is a flow chart of the manufacturing method of the heat dissipation circuit board of the third embodiment of the present invention, Figure 10 is a schematic diagram of the blind hole step of the manufacturing method of the heat dissipation circuit board of the third embodiment of the present invention, and Figure 11 is a schematic diagram of the electroplating step of the manufacturing method of the heat dissipation circuit board of the third embodiment of the present invention.

This embodiment is similar to the first embodiment described above, so the similarities between the two embodiments will not be described in detail, and the differences between the two embodiments are roughly described as follows:

In this embodiment, after the blind groove forming step S131 and before the electroplating step S140, the manufacturing method of the heat sink circuit board further includes a blind hole forming step S132, in which the surrounding area 11b of the inner layer circuit board structure 1 is lasered to form at least one blind hole 7. In addition, in the electroplating step S130 of this embodiment, the copper layer 6 is also formed in the blind hole 7 by electroplating.

In this embodiment, the diameter of the blind hole 7 is approximately between 0.05 mm and 0.1 mm, and the depth of the blind hole 7 is between 25 mm and 75 mm, but the present invention is not limited thereto. Preferably, the depth of the blind hole 7 is between 35 mm and 65 mm, and more preferably, the depth of the blind hole 7 is between 45 mm and 55 mm.

In the blind hole forming step S132, the blind hole 7 is formed in the surrounding area 11b by using a laser with an energy between 12 mJ and 15 mJ and a pulse width between 8 μs and 15 μs. It is worth mentioning that the energy and pulse width of the laser used in the blind hole forming step S132 are respectively greater than the energy and pulse width of the laser used in the blind groove forming step S131, because the blind groove 5 in this embodiment can be formed by overlapping the blind hole 7.

In addition, in the blind groove forming step S131, the blind groove 5 may be formed by only a single laser, and in the blind hole forming step S132, the blind hole 7 may be formed by three lasers. Among the three lasers used to form the blind hole 7, the first laser is used to open a window in the surrounding area 11b, and the remaining two lasers are used to modify the position of the window to form the blind hole 7.

In this embodiment, the blind hole 7 is formed in the surrounding area 11b through the blind hole forming step S132 to further improve the heat dissipation effect. Specifically, the surrounding area 11b may have a part of the area that is too small to form the blind groove 5. In this case, the blind hole 7 can be formed in the above part of the area through the blind hole forming step S132 to avoid poor heat dissipation due to the inability to form the blind groove 5.

[Heat dissipation circuit board]

The present invention also provides a heat dissipation circuit board 100, and the heat dissipation circuit board 100 can be formed by the above heat dissipation circuit board manufacturing method. It is worth mentioning that the heat dissipation circuit board 100 can also be formed by other methods, and the present invention is not limited thereto.

The heat dissipation circuit board 100 includes an inner circuit board structure 1, a plurality of alignment target holes 2, a plurality of through holes 3, and a plurality of copper pillars 4. In addition, the heat dissipation circuit board 100 may further include an outer layer (not shown), which may be formed on the inner circuit board structure 1 by outer layer exposure, but the heat dissipation circuit board 100 is not limited to include the outer layer.

The inner circuit board structure 1 has two opposite wide sides 11, and each of the wide sides 11 defines a middle area 11a and a surrounding area 11b surrounding the middle area 11a.

In this embodiment, the heat dissipation circuit board 100 includes four alignment target holes 2 , and the four alignment target holes 2 are formed at four corners of the inner circuit board structure 1 .

The plurality of through holes 3 are mechanically drilled in the middle region 11a of the inner circuit board structure 1. In the present embodiment, the diameter of each through hole 3 is between 0.15 mm and 0.25 mm, and more preferably, the diameter of each through hole 3 is between 0.18 mm and 0.22 mm, but the present invention is not limited thereto.

In addition, in this embodiment, the number of the plurality of through holes 3 is between 20 and 40, the plurality of through holes 3 are arranged in a matrix, and the distance between any two adjacent through holes 3 is between 0.15 mm and 0.25 mm. The plurality of copper pillars 4 are formed in the plurality of through holes 3 by electroplating.

[Beneficial Effects of the Embodiments]

One of the beneficial effects of the present invention is that the manufacturing method of the heat dissipation circuit board provided by the present invention can simplify the processing process of the manufacturing method of the heat dissipation circuit board through the technical solutions of "implementing a through hole forming step, which includes: forming a plurality of through holes in the middle area of the inner layer circuit board structure by mechanical drilling" and "implementing a plating step, which includes: forming a plurality of copper pillars in the plurality of through holes by electroplating". The heat dissipation circuit board finally formed can have excellent heat dissipation effect and reliability.

Furthermore, in the electroplating step, a plurality of the copper pillars are formed in the plurality of the through holes by periodic pulse electroplating, so that the formed copper pillars are denser and have a lower porosity.

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

100: Heat dissipation circuit board 1: Inner circuit board structure 11: Wide side 11a: Middle area 11b: Peripheral area 2: Alignment target hole 3: Through hole 4: Copper pillar 5: Blind groove 6: Copper layer 7: Blind hole D: Distance S110: Pre-step S120: Alignment target hole formation step S130: Through hole formation step S131: Blind groove formation step S132: Blind hole formation step S140: Electroplating step S150: Outer layer exposure step

FIG. 1 is a flow chart of a method for manufacturing a heat dissipation circuit board according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of the pre-step of the manufacturing method of the heat dissipation circuit board of the first embodiment of the present invention.

FIG. 3 is a schematic diagram of a step of forming a positioning target hole in a method for manufacturing a heat dissipation circuit board according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram of a through-hole forming step of a method for manufacturing a heat dissipation circuit board according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram of the electroplating step of the method for manufacturing the heat dissipation circuit board of the first embodiment of the present invention.

FIG6 is a flow chart of a method for manufacturing a heat dissipation circuit board according to a second embodiment of the present invention.

FIG. 7 is a schematic diagram of a blind groove forming step of a method for manufacturing a heat dissipation circuit board according to a second embodiment of the present invention.

FIG. 8 is a schematic diagram of the electroplating step of the manufacturing method of the heat dissipation circuit board of the second embodiment of the present invention.

FIG. 9 is a flow chart of a method for manufacturing a heat dissipation circuit board according to a third embodiment of the present invention.

FIG. 10 is a schematic diagram of a blind hole step of a method for manufacturing a heat dissipation circuit board according to a third embodiment of the present invention.

FIG. 11 is a schematic diagram of the electroplating step of the method for manufacturing a heat dissipation circuit board according to the third embodiment of the present invention.

S110: Preliminary steps

S120: Alignment target hole formation step

S130: Through hole formation step

S140: Electroplating step

S150: External layer exposure step

Claims (10)

A method for manufacturing a heat dissipation circuit board, comprising: Implementing a pre-step, comprising: providing an inner circuit board structure, the inner circuit board structure having two opposite wide sides, each of the wide sides defining a middle area and a surrounding area surrounding the middle area; Implementing a positioning target hole forming step, comprising: forming a plurality of positioning target holes in the surrounding area of the inner circuit board structure; Implementing a through hole forming step, comprising: forming a plurality of through holes in the middle area of the inner circuit board structure by mechanical drilling; Implementing an electroplating step, comprising: forming a plurality of copper pillars in the plurality of through holes by electroplating; and Implement an outer layer exposure step, which includes: performing outer layer exposure on the inner layer circuit board structure to form a heat dissipation circuit board. The manufacturing method of the heat dissipation circuit board as described in claim 1, wherein in the alignment target hole forming step, four alignment target holes are formed, and the four alignment target holes are formed at four corners of the inner layer circuit board structure. A method for manufacturing a heat sink circuit board as described in claim 1, wherein the diameter of each of the through holes is between 0.15 mm and 0.25 mm. The manufacturing method of the heat dissipation circuit board as described in claim 1, wherein, in the through-hole step, a plurality of through-holes are formed by mechanically drilling only from one of the wide sides without flipping the inner layer circuit board structure. A method for manufacturing a heat dissipation circuit board as described in claim 1, wherein, in the through-hole forming step, the number of the plurality of through-holes is between 20 and 40; wherein the plurality of through-holes are arranged in a matrix, and the distance between any two adjacent through-holes is between 0.15 mm and 0.25 mm. The manufacturing method of the heat dissipation circuit board as described in claim 1, wherein, in the electroplating step, a plurality of the copper pillars are formed in the plurality of the through holes by periodic pulse electroplating. A method for manufacturing a heat sink circuit board as described in claim 6, wherein, in the electroplating step, the frequency of the periodic pulse electroplating is between 3:1 and 6:1. The method for manufacturing a heat sink circuit board as described in claim 1, wherein, after the through hole forming step and before the electroplating step, the method for manufacturing a heat sink circuit board further includes a blind groove forming step, wherein the surrounding area of the inner layer circuit board structure is lasered to form at least one blind groove; wherein, in the electroplating step, a copper layer is also formed in the blind groove by electroplating. A method for manufacturing a heat dissipation circuit board as described in claim 8, wherein, in the blind groove forming step, the blind groove is formed in the surrounding area by using a laser with an energy between 8 mJ and 10 mJ and a pulse width between 4 μs and 8 μs. A method for manufacturing a heat dissipation circuit board as described in claim 8, wherein the length of the blind groove is between 4 mm and 6 mm, and the width of the blind groove is between 0.05 mm and 0.1 mm; wherein the thickness of the copper layer is between 22 μm and 28 μm.

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