TWI833428B - 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 manufacturing method of a circuit board, and in particular to a manufacturing method of a heat dissipating circuit board.

In the existing circuit board manufacturing method, the two wide sides of the inner circuit board structure are generally processed by laser to form multiple through holes. Therefore, the inner circuit board structure will be turned over during the processing process. , which makes the processing process more complicated.

Therefore, how to simplify the existing circuit board manufacturing methods to overcome the above-mentioned defects has become one of the important issues to be solved in this project.

The technical problem to be solved by the present invention is to provide a manufacturing method of a heat dissipation circuit board in view of the shortcomings of the existing technology. The processing 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 manufacturing method of a heat dissipation circuit board, which includes: implementing a pre-step, which includes: providing an inner layer circuit board structure, the inner layer The 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; a pair of A step of forming a target hole, which includes: forming a plurality of target holes in the surrounding area of the inner circuit board structure; and performing a step of forming a through hole, which includes: mechanically drilling the inner circuit A plurality of through holes are formed in the middle area of the board structure; an electroplating step is performed, which includes: forming a plurality of copper pillars in the plurality of through holes by electroplating; and an outer layer exposure step is performed, which includes: The inner circuit board structure is exposed to the outer layer 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 circuit board structure.

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

Preferably, in the through-hole step, a plurality of through-holes are formed by mechanical drilling from only one of the wide sides without turning over the inner circuit board structure.

Preferably, in the through hole forming step, the number of the plurality of through holes is between 20 and 40. A plurality of 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 copper pillars are formed in a plurality of the through holes by periodic pulse electroplating.

Preferably, in the electroplating step, the frequency of 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 dissipation circuit board further includes a blind groove forming step to conduct lightning on the surrounding area of the inner circuit board structure. shot to form at least one blind slot. In the electroplating step, a copper layer is also formed in the blind trench by electroplating.

Preferably, in the step of forming the blind groove, a laser with an energy between 8 millijoules and 10 millijoules and a pulse width between 4 microseconds and 8 microseconds is used to form the blind groove in the surrounding area. Describe the blind slot.

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 microns and 28 microns.

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 be achieved by "implementing a through-hole forming step, which includes: mechanically drilling the inner layer of the circuit board structure. The technical solution is to form a plurality of through holes in the middle area" and "implement an electroplating step, which includes: forming a plurality of copper pillars in a plurality of the through holes by electroplating" to simplify the processing process of the manufacturing method of the heat dissipation circuit board. , and enables the final heat dissipation circuit board to have excellent heat dissipation effect and reliability.

In order to further understand the features and technical content 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 illustration and are not used to limit the present invention.

100:Heat dissipation circuit board

1: Inner circuit board structure

11: wide side

11a: Middle area

11b: Surrounding area

2: Alignment target hole

3:Through hole

4: Copper pillar

5: Blind slot

6: Copper layer

7: Blind hole

D: distance

S110: Preliminary steps

S120: Alignment target hole formation step

S130: Through hole formation step

S131: Blind slot formation steps

S132: Blind hole formation step

S140: Electroplating steps

S150: Outer layer exposure step

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

FIG. 2 is a schematic diagram of the preliminary steps of the manufacturing method of the heat dissipation circuit board according to the first embodiment of the present invention.

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

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

FIG. 6 is a flow chart of a manufacturing method of a heat dissipation circuit board according to the second embodiment of the present invention.

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

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

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

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

The following is a specific example to illustrate the implementation of the "heat dissipation circuit board manufacturing method" disclosed in the present invention. Those skilled in the art 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 various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depictions based on actual dimensions, as is stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of the present invention.

It should be understood that although terms such as “first”, “second” and “third” may be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another component or one signal from another signal. In addition, the term "or" used in this article shall include any one or combination of more of the associated listed items depending on the actual situation.

[First Embodiment]

Referring to FIGS. 1 to 5 , FIG. 1 is a flow chart of a manufacturing method of a heat dissipation circuit board according to a first embodiment of the present invention. FIG. 2 is a flowchart of the preliminary steps of a manufacturing method of a heat dissipation circuit board according to the first embodiment of the present invention. Schematic diagram, FIG. 3 is a schematic diagram of the alignment target hole forming step of the manufacturing method of the heat dissipation circuit board according to the first embodiment of the present invention, and FIG. 4 is the through hole forming step of the manufacturing method of the heat dissipating circuit board according to the first embodiment of the present invention. 5 is a schematic diagram of the electroplating step of the manufacturing method of the heat dissipation circuit board according to the first embodiment of the present invention.

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

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

In the alignment target hole forming step S120, a plurality of alignment target holes 2 are formed in the surrounding area 11b of the inner circuit board structure 1. In the alignment target hole forming step S120 of this embodiment, four alignment target holes 2 are formed, and the four alignment target holes 2 are formed in the inner circuit board structure 1 of the four corners. In addition, the plurality of alignment target holes 2 may be formed by mechanical drilling or laser processing, 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 requirements. For example, in other embodiments not shown in the present invention, the number of the alignment target holes 2 may be two, and the two alignment target holes 2 may be formed on the inner circuit board. Two non-adjacent corners of Structure 1.

In the through hole forming step S130, mechanical drilling is used to drill holes in the inner circuit Said central area 11 a of the plate structure 1 forms a plurality of through holes 3 . 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 of the through holes 3 is between 0.15 mm and 0.25 mm. More preferably, the diameter of each of the through holes 3 is between 0.18 mm and 0.22 mm. However, in this embodiment The 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), there may be a problem that the through hole 3 cannot be filled in the subsequent electroplating step S140. On the contrary, If the diameter of the through hole 3 is lower than the lower limit (eg, 0.15 mm), the final heat dissipation circuit board 100 may have poor reliability.

Furthermore, in the through hole forming step S130 of this embodiment, without turning over the inner circuit board structure 1 , mechanical drilling is performed from only one of the wide sides 11 to form multiple holes. 3 through holes. In addition, in the through-hole forming step S130, it may be limited to exclude the use of laser to form the through-hole 3. In other words, the through hole 3 formed by laser is not suitable for comparison with the through hole 3 formed by mechanical drilling in this case.

In the existing circuit board manufacturing method, the two wide sides of the inner circuit board structure are generally processed by laser to form multiple through holes. Therefore, the inner circuit board structure will be turned over during the processing process. , which makes the processing process more complicated.

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

In addition, in the through hole forming step S130 of this embodiment, the number of the plurality of through holes 3 is between 20 and 40, and the plurality of the through holes 3 are arranged in a matrix, and any two of the through holes 3 are arranged in a matrix. adjacent The distance D between the 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 a plurality of the through holes 3 by electroplating. In the electroplating step S140 of this embodiment, a plurality of copper pillars 4 are formed in a plurality of through holes 3 by periodic pulse plating, and the frequency of periodic pulse plating is between 3:1 to 6:1. Specifically, periodic pulse plating is to periodically turn the plating circuit on and off, so that the copper pillars 4 are denser and have low porosity, especially if the inner side walls of the through holes 3 are uneven. case.

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

[Second Embodiment]

Please refer to FIGS. 6 to 8 . FIG. 6 is a flow chart of the manufacturing method of the heat dissipation circuit board according to the second embodiment of the present invention. FIG. 7 is the blind groove formation of the manufacturing method of the heat dissipation circuit board according to the second embodiment of the present invention. 8 is a schematic diagram of the electroplating step of the manufacturing method of the heat dissipation circuit board according to the second embodiment of the present invention.

This embodiment is similar to the above-mentioned first embodiment, so the similarities between the two embodiments will not be described in detail. The differences between the two embodiments are briefly described as follows: In this embodiment, in the through hole forming step After S130 and before the electroplating step S140, the manufacturing method of the heat dissipation circuit board also includes a blind groove forming step S131, which involves lasering the surrounding area 11b of the inner circuit board structure 1 to form at least one Blind trench 5 , and in the electroplating step S140 , a copper layer 6 is also formed in the blind trench 5 by electroplating. In addition, in the electroplating step S140 of the above embodiment, the copper layer 6 may be formed on the wide side 11 .

In the blind groove forming step S131 of this embodiment, the energy is between 8 mJ and The blind groove 5 is formed in the surrounding area 11b by a laser with a pulse width between 10 millijoules and a pulse width between 4 microseconds and 8 microseconds. 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 this 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 It 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. 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 elongated. 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 L-shaped or V-shaped.

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 excellent heat dissipation effect when matched with the blind groove 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 groove 5 along the side wall of the blind groove 5, compared with a circuit board without a blind groove or a circuit board with only blind holes, this The surface area of the copper layer 6 in the invention is relatively large, thereby providing excellent heat dissipation effect.

[Third Embodiment]

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

This embodiment is similar to the above-mentioned first embodiment, so the similarities between the two embodiments will not be described in detail. The differences between the two embodiments are roughly described as follows: In this embodiment, in the blind groove forming step After S131 and in the electroplating step Before S140, the manufacturing method of the heat dissipation circuit board also includes a blind hole forming step S132, in which laser is applied to the surrounding area 11b of the inner circuit board structure 1 to form at least one blind hole 7. In addition, in the electroplating step S140 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 invention is not limited thereto. Here it is. Preferably, the depth of the blind hole 7 is between 35 mm and 65 mm. 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 is formed in the surrounding area 11b using a laser with energy between 12 millijoules and 15 millijoules and a pulse width between 8 microseconds and 15 microseconds. 7. 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. The reason is that , the blind groove 5 in this embodiment may be formed by overlapping the blind holes 7 .

In addition, in the blind groove forming step S131, the blind groove 5 may be formed by only a single laser shot, and in the blind hole forming step S132, the blind groove 5 may be formed by three laser shots. Hole 7. 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, some areas of the surrounding area 11b may be too small to be conducive to forming the blind groove 5. In this case, the blind hole 7 can be formed in the above partial area through the blind hole forming step S132. , to avoid poor heat dissipation effect 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. 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 also include an outer layer (not shown). The outer layer may be formed on the inner circuit board structure 1 through 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 wide sides 11 opposite to each other. 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 area 11a of the inner circuit board structure 1 . In this embodiment, the diameter of each of the through holes 3 is between 0.15 mm and 0.25 mm. More preferably, the diameter of each of the through holes 3 is between 0.18 mm and 0.22 mm. However, in this embodiment The 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 the through holes 3 are arranged in a matrix, and any two adjacent through holes 3 are arranged in a matrix. The distance between 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 embodiment]

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 be achieved by "implementing a through-hole forming step, which includes: mechanically drilling the inner layer of the circuit board structure. The technical solution is to form a plurality of through holes in the middle area" and "implement an electroplating step, which includes: forming a plurality of copper pillars in a plurality of the through holes by electroplating" to simplify the processing process of the manufacturing method of the heat dissipation circuit board. , and enable the final heat dissipation circuit board to have excellent Heat dissipation effect and reliability.

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

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

S110: Preliminary steps

S120: Alignment target hole formation step

S130: Through hole formation step

S140: Electroplating steps

S150: Outer layer exposure step

Claims (9)

A manufacturing method of a heat dissipation circuit board, which includes: performing 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 There is a middle area and a surrounding area surrounding the middle area; performing an alignment target hole forming step, which includes: forming a plurality of alignment target holes in the surrounding area of the inner circuit board structure; implementing a through hole The forming step includes: forming a plurality of through holes in the middle area of the inner circuit board structure by mechanical drilling; wherein, in the through hole step, the inner circuit board is not turned over. In the case of the structure, mechanical drilling is performed from only one of the wide sides to form a plurality of through holes; an electroplating step is performed, which includes: forming a plurality of copper pillars in the plurality of through holes by electroplating ; and perform an outer layer exposure step, which includes: performing outer layer exposure on the inner circuit board structure to form a heat dissipation circuit board. The manufacturing method of a heat dissipation circuit board according to claim 1, wherein in the step of forming the alignment target holes, four alignment target holes are formed, and the four alignment target holes are formed in The four corners of the inner circuit board structure. The manufacturing method of a heat dissipation circuit board as claimed 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 a heat dissipation circuit board according to 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 the through-holes are 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. The manufacturing method of a heat dissipation circuit board according to claim 1, wherein in the electroplating step, a plurality of through holes are formed in a periodic pulse electroplating manner. the copper pillar. The manufacturing method of a heat dissipation circuit board as claimed in claim 5, wherein in the electroplating step, the frequency of periodic pulse electroplating is between 3:1 and 6:1. The manufacturing method of a heat dissipation circuit board according to claim 1, wherein after the through hole forming step and before the electroplating step, the manufacturing method of the heat dissipation circuit board further includes a blind groove forming step. The surrounding area of the inner circuit board structure is lasered to form at least one blind trench; wherein, in the electroplating step, a copper layer is also formed in the blind trench through electroplating. The manufacturing method of a heat dissipation circuit board according to claim 7, wherein in the blind groove forming step, the energy is between 8 millijoules and 10 millijoules and the pulse width is between 4 microseconds and 8 microseconds. The laser beam within seconds forms the blind groove in the surrounding area. The manufacturing method of a heat dissipation circuit board as claimed in claim 7, 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 microns and 28 microns.