TWM622285U - Intelligent circuit board etching device - Google Patents

Abstract

An intelligent circuit board etching device is suitable for the manufacturing process of a circuit board, wherein the circuit board surface has a copper layer. The intelligent circuit board etching device includes: a copper thickness measuring device, which measures the thickness distribution of the copper layer on the surface of the circuit board; and a matrix wet etching machine, connected to a copper thickness measuring device, according to the thickness distribution of the copper layer, non-uniformly etch the copper layer, and make the thickness of the copper layer uniform.

Description

Intelligent circuit board etching device

The present invention relates to an intelligent circuit board manufacturing process, in particular to an intelligent circuit board manufacturing process that can improve the circuit yield rate of the circuit board.

Printed circuit boards are almost necessary components of all electronic products. Due to the requirements of light, thin and short electronic products, the line width reduction and precision requirements of printed circuit boards are also getting higher and higher. Please refer to FIG. 1 , which is a flowchart of a circuit board manufacturing process using a conventional subtractive method. In step S10, the circuit board is first fed, and then in step S12, a drilling step is performed on the circuit board, and a plurality of via holes are drilled on the circuit board for subsequent electrical conduction. In step S14, an electroless copper plating step is performed, and an electroless copper layer is plated on the surface of the circuit board and the surface of the via hole. In step S16, a copper electroplating step is performed, using the chemical copper layer as the seed layer, and an electroplating copper layer is plated by means of electroplating. Those with ordinary knowledge in this field should know that in circuit design, the circuit density of different areas on the circuit board is not the same, and the density of via holes is also different. The copper thickness is also different. Especially in order to fill the via hole with electroplated copper, the electroplated copper layer is usually thicker, which also causes the thickness non-uniformity to be more pronounced.

In step S18, a thin copper process is performed for the thicker electroplated copper layer as described above to reduce the thickness of the electroplated copper layer. Conventionally, wet etching is performed. Due to the isotropic nature of wet etching, the aforementioned The uneven state of copper thickness still cannot be improved. Next, in step S20, a lithography process is performed to transfer the patterned film to the electroplated copper layer. In step S22, an etching step is performed to remove the electroplated copper layer and the chemical copper layer exposed by the patterned film, so as to form a patterned circuit. As mentioned above, due to the uneven thickness of the electroplated copper, the thickness of the patterned circuit will be uneven, which will affect the circuit impedance and reduce the yield.

Please refer to FIG. 2 , which is a flow chart of a circuit board manufacturing process of a conventional additive method. In step S24, the circuit board is first fed, and then in step S26, a drilling step is performed on the circuit board, and a plurality of via holes are drilled on the circuit board for subsequent electrical conduction. In step S28, an electroless copper plating step is performed, and an electroless copper layer is plated on the surface of the circuit board and the surface of the via hole. Next, as in step S30, a lithography process is performed, the patterned film is transferred to the chemical copper layer, and the holes and the areas where the lines are to be formed are exposed. In step S32, a copper electroplating step is performed, using the chemical copper layer as the seed layer, and an electroplating copper layer is plated by means of electroplating. Those with ordinary knowledge in this field should know that in circuit design, the circuit density of different areas on the circuit board is not the same, and the density of via holes is also different. The copper thickness is also different. Especially in order to fill the via hole with electroplated copper, the electroplated copper layer is usually thicker, which also causes the thickness non-uniformity to be more pronounced. In step S34, a film stripping etching step is performed, the patterned film is peeled off, the chemical copper layer is etched and the electroplated copper layer is thinned to form a patterned circuit, which is also conventionally performed by wet etching. Similarly, due to the uneven thickness of the electroplated copper, the patterned circuit will have uneven thickness, which will affect the circuit impedance and reduce the yield.

In view of the above problems to be solved and the reasons, the present invention proposes an intelligent circuit board etching device, which is suitable for a circuit board manufacturing process, wherein the surface of the circuit board has a copper layer, and the intelligent circuit board etching device includes: a copper thickness A measuring device for measuring the thickness distribution of the copper layer on the surface of the circuit board; and a matrix wet etching machine, connected to the copper thickness measuring device, according to the thickness distribution of the copper layer, non-uniformly etching the copper layer, and making the thickness of the copper layer evenly.

According to an embodiment of the present invention, the matrix etching machine further includes: a controller; and a plurality of nozzles arranged in a matrix and connected to the controller respectively, wherein the controller can individually control the switch of each nozzle.

According to another embodiment of the present invention, it further includes a machine learning module connected to the controller.

According to yet another embodiment of the present invention, it further includes another copper thickness measuring device connected to the matrix wet etching machine to measure the thickness distribution of the copper layer after etching, and transmit the thickness distribution of the copper layer to the machine learning model Group.

According to yet another embodiment of the present invention, the copper thickness measuring device utilizes the introduction of eddy current to the copper layer, and measures the impedance of the copper layer to detect the thickness distribution of the copper layer.

According to another embodiment of the present invention, the copper thickness measuring device measures the thickness of the copper layer by optical means.

In order to facilitate the understanding of the embodiments, a number of technical details will be provided below. Of course, not all embodiments require these technical details. Meanwhile, some well-known structures or elements are only shown in the drawings in a schematic manner to appropriately simplify the contents of the drawings.

In order to make the description of the present disclosure more detailed and complete, the following provides an illustrative description of the implementation aspects and specific embodiments of the present invention; but this is not the only form of implementing or using the specific embodiments of the present invention. The features of various specific embodiments as well as method steps and sequences for constructing and operating these specific embodiments are encompassed in the detailed description. However, other embodiments may also be utilized to achieve the same or equivalent function and sequence of steps.

Please refer to FIG. 3 , which is a flow chart of an intelligent circuit board manufacturing process according to an embodiment of the present invention, and please refer to FIGS. 4A to 4H at the same time, which are drawn corresponding to FIG. 3 of an intelligent circuit board manufacturing process Cross-sectional schematic diagram of each step. The present embodiment takes the subtractive circuit board manufacturing process as an example, as shown in step S50 and FIG. 4A , to provide a circuit board 100 . Next, as shown in step S52 and FIG. 4B , a drilling step is performed on the circuit board 100 , and a plurality of via holes 102 are drilled on the circuit board 100 for subsequent electrical conduction. As shown in step S54 and FIG. 4C , an electroless copper plating step is performed, and an electroless copper layer 104 is plated on the surface of the circuit board 100 and the surface of the via hole 102 . As shown in step S56 and FIG. 4D , a copper electroplating step is performed, and the electroless copper layer 104 is used as the seed layer to connect the electrodes for electroplating, and an electroplated copper layer 106 is plated by electroplating. Due to different circuit designs, the circuit density in different areas on the circuit board is not the same, and the density of the via holes 102 in different areas is also different. Therefore, during the electroplating step, the current density in different areas is also different, resulting in different electroplating reaction rates. , the thickness of the formed copper electroplating 106 is also different in different regions. Generally, the thickness of the electroplated copper layer is thicker in the region with higher current density, and the thickness of the electroplated copper layer is thinner in the region with lower current density (not shown). At the same time, in order to fill the via hole 102 with the electroplated copper layer 106 to improve the conductivity of the via hole 102 , the thickness of the electroplated copper layer 106 should be sufficient, which also causes the aforementioned thickness difference to be more significant, that is, the difference in the thickness of the electroplated copper layer 106 The uniformity is particularly remarkable.

Next, in step S58, a copper thickness measurement step is performed to measure the thickness distribution of the electroplated copper layer 106 in FIG. 4D, for example, by introducing eddy current, measuring the impedance to detect the thickness of the electroplated copper layer, or optical methods can be used to measure the thickness of the electroplated copper layer. measurement, or measure the thickness of the electroplated copper layer by X-ray measurement. Those with ordinary knowledge in the art should know that any other method for measuring the thickness of the conductive layer can be applied to the present invention. Next, as shown in step S60 and FIG. 4E , an intelligent non-uniform thin copper process is performed to form a thin electroplated copper layer 106A. Please also refer to FIG. 5 , the novel intelligent non-uniform thin copper process is performed on a matrix wet etching machine (not shown). As shown in FIG. 5 , the matrix wet etching machine has a plurality of nozzles Nx,y arranged in a matrix. For example, as shown in the figure, it can be composed of multiple etchant transfer tubes Px (X=1~7) arranged at equal distances in the X direction, and each etchant transfer tube Px is equidistantly arranged with multiple etchant transfer tubes Px in the Y direction. Nozzles Nx,y (Y=1~7), thus forming a plurality of nozzles Nx,y arranged in a matrix. The nozzles Nx, y are used to spray the etching solution to the surface of the electroplated copper layer for wet etching. Each nozzle Nx,y can be an electrically controlled or digitally controlled nozzle, and is connected to a controller (not shown), and the controller can individually control the opening and closing of each nozzle. In an embodiment of the present invention, after the copper thickness measurement step, the thickness distribution of the electroplated copper layer on the circuit board 100 is known. In order to obtain a uniform copper electroplating layer in the thin copper process, the etching degree of the subsequent wet etching regions 100A and 100B should be lower, or the etching time should be shorter. As shown in FIG. 5 , when the circuit board 100 enters the matrix wet etching machine in the direction 122 for wet etching, the area 100A will pass through the nozzles Nx,y (X=1~7, Y=2,3), while the area 100B will pass through the nozzles Nx,y (X=1~7, Y=2,3). It will pass through the nozzle Nx,y (X=1~7, Y=5,6). Therefore, the controller closes part of the nozzles Nx,y (X=1~7, Y=2,3) during the period when the area 100A passes through the nozzles Nx,y (X=1~7, Y=2,3), for example, closes N3 , 2, N3, 3, N4, 2, N4, 3, the etching amount of the region 100A is reduced to 5/7 of the other regions. While the area 100B passes through the nozzles Nx,y (X=1~7, Y=5,6), part of the nozzles Nx,y (X=1~7, Y=5,6) are closed, such as N3,5, N3,6, N4,5, N4,6, N5,5, N5,6, the etching amount of the region 100B is reduced to 4/7 of the other regions. Through the above method, the novel intelligent non-uniform thin copper manufacturing process can make the etching solution contact the surface of the copper electroplating layer non-uniformly, so as to achieve the effect of non-uniform etching. Thereby, the thickness of the electroplated copper layer will be uniform, that is, the thickness of the electroplated copper layer in each region on the circuit board 100 is approximately the same. In addition, the controller can also be connected to a machine learning module, and another copper thickness measurement step can be configured after the matrix wet etching machine, and the thickness distribution of the electroplated copper layer after non-uniform etching can be fed back to the machine learning module, so that the Adjusting the control of the nozzle to achieve the effect of artificial intelligence non-uniform etching can also improve the precision and reliability of non-uniform etching.

It is worth mentioning that in practice, the circuit boards of the same batch have the same circuit design and the same distribution of vias, so the thickness distribution of the electroplated copper layer is roughly the same. Therefore, the control of the nozzle in the new intelligent non-uniform thin copper process should also be the same. As shown in FIG. 5 , a conventional circuit board will have a mark 120, such as a barcode or a two-dimensional barcode, to record the circuit board batch number or product batch number, or contain other related product or process information. As mentioned above, the thickness distribution of the electroplated copper layer of the same batch of circuit boards is also roughly the same. Therefore, in order to improve production efficiency, for circuit boards of the same batch number, it is only necessary to perform a copper thickness measurement step on one of the circuit boards. The result of measuring the thickness distribution of the electroplated copper layer can be used in other circuit boards of the same batch number. That is to say, for one of the circuit boards of the same batch number, before the intelligent non-uniform thin copper process, a copper thickness measurement step is performed to measure the thickness distribution of the electroplated copper layer. For other circuit boards of the same batch number, the intelligent non-uniform thin copper process is carried out based on the thickness distribution of the electroplated copper layer measured by the aforementioned measurement. In this way, the control of the nozzle can be adjusted correspondingly through the detection of the mark on the circuit board, so the non-uniform thin copper process of the present invention has the characteristics of intelligence.

Next, as shown in step S62 and FIG. 4F , a lithography process is performed to transfer a patterned film 108 to the thinned copper electroplating layer 106A. In an embodiment of the present invention, a photosensitive dry film is first attached to the thinned electroplated copper layer 106A, and then an exposure step, such as a yellow light process, is performed to irradiate the pattern of the circuit layout on the photosensitive dry film with yellow light. on the membrane. Then, a developing step is performed to peel off the unexposed photosensitive dry film to form the patterned film 108 . Next, as shown in step S64 and FIG. 4G , an etching step is performed to remove the thin electroplated copper layer 106A and the electroless copper layer 104 exposed by the patterned film 108 , and the circuit layout pattern is transferred to the thin electroplated copper layer through the patterned film 108 Layer 106A and chemical copper layer 104 to form patterned lines. At this time, the etching method is isotropic wet etching. Since the above-mentioned intelligent non-uniform thin copper process has made the thickness of the electroplated copper layer uniform, the thickness of the electroplated copper layer after this etching step is also uniform. As shown in FIG. 4H , the patterned film 108 is then peeled off, and the patterned circuit 110 is completed.

Please refer to FIG. 6 , which is a flow chart of a manufacturing process of an intelligent circuit board according to another embodiment of the present invention, and please refer to FIGS. 7A to 7H at the same time, which is a manufacturing process of an intelligent circuit board corresponding to FIG. 6 . Cross-sectional schematic diagram of each step. This embodiment takes a semi-additive process (SAP) as an example. Those with ordinary knowledge in this field should know that the new process can also be applied to a modified semi-additive process (Modified Semi-Additive Process). , mSAP). In step S70 and FIG. 7A , a circuit board 200 is provided. Next, as shown in step S72 and FIG. 7B , a drilling step is performed on the circuit board 200 , and a plurality of via holes 202 are drilled on the circuit board 200 for subsequent electrical conduction. As shown in step S74 and FIG. 7C , an electroless copper plating step is performed, and an electroless copper layer 204 is plated on the surface of the circuit board 200 and the surface of the via hole 202 .

Next, as shown in step S76 and FIG. 7D , a lithography process is performed to transfer a patterned film 206 onto the chemical copper layer 204 . In an embodiment of the present invention, a photosensitive dry film is attached to the surface of the circuit board 200 first, and then an exposure step, such as a yellow light process, is performed to irradiate the pattern of the circuit layout on the photosensitive dry film with yellow light. Then, a developing step is performed to peel off the unexposed and cured photosensitive dry film to form a patterned film 206 . At this time, the exposed part of the patterned film 206 is the area to be electroplated with copper. As shown in step S78 and FIG. 7E , a copper electroplating step is performed, using the chemical copper layer 204 as the seed layer to connect the electrodes for electroplating, and the exposed areas of the patterned film 206 (including the surface of the circuit board 200 and the via holes 202 ) are electroplated with electroplating. A copper electroplating layer 208 is plated by the method. Due to the difference in circuit design, the circuit density in different areas on the circuit board is not the same, and the density of the via holes 202 in different areas is also different. Therefore, during the electroplating step, the current density in different areas is also different, resulting in different electroplating reaction rates. , the thickness of the formed copper electroplating 208 is also different in different regions. Generally, the thickness of the electroplated copper layer is thicker in the region with higher current density, and the thickness of the electroplated copper layer is thinner in the region with lower current density (not shown). At the same time, in order to fill the via hole 202 with the electroplated copper layer 208 to improve the conductivity of the via hole 202, the thickness of the electroplated copper layer 208 should be sufficient, which also causes the aforementioned difference in thickness to be more significant, that is, the difference in the thickness of the electroplated copper layer 208 is greater. The uniformity is particularly remarkable.

Next, in step S80, a copper thickness measurement step is performed to measure the thickness distribution of the electroplated copper layer 208 in FIG. 7E, for example, by introducing eddy current, measuring the impedance to detect the thickness of the electroplated copper layer, or optical methods can be used to measure the thickness of the electroplated copper layer. measurement, or measure the thickness of the electroplated copper layer by X-ray measurement. Those with ordinary knowledge in the art should know that any other method for measuring the thickness of the conductive layer can be applied to the present invention. Next, as shown in step S82 and FIG. 7F , an intelligent non-uniform thin copper process is performed to form a thin electroplated copper layer 208A with a uniform thickness. The method and principle of this part are the same as step S60 in the previous embodiment and the description corresponding to FIG. 5 , and will not be repeated here. In step S84 and FIGS. 7G and 7H , a stripping etching step is performed. As shown in FIG. 7G , the patterned film 206 is stripped. Next, as shown in FIG. 7H , the chemical copper layer 204 originally covered by the patterned film 206 is etched and removed by wet etching, and the connection between the patterned circuits 210 is disconnected to avoid short circuits and form the pattern of the originally designed circuit layout pattern. chemical line 210. Of course, in this wet etching step, it is isotropic, so the electroplated copper layer 208A is also etched and thinned at the same time. However, in the aforementioned intelligent non-uniform copper thinning process, the thickness of the electroplated copper layer has been uniformized, so the thickness of the electroplated copper layer after this etching step is also uniform.

To sum up, the new intelligent circuit board manufacturing process of the present invention can effectively uniformize the thickness of the electroplated copper layer by using the intelligent non-uniform thin copper process, and can also improve the accuracy and reliability of the non-uniform thin copper process through machine learning. Spend. At the same time, the new intelligent circuit board manufacturing process can simplify the copper thickness measurement steps and increase the production capacity by identifying the lot number of the circuit board. More importantly, through the new intelligent circuit board manufacturing process, the uniformity of the thickness of the electroplated copper layer can improve the precision and yield of the circuit board.

The present invention is only disclosed by preferred embodiments herein. However, any person skilled in the art should understand that the above-mentioned embodiments are only used to describe the present invention, and are not intended to limit the scope of the claimed patent rights of the present invention. All changes or substitutions that are equal or equivalent to the above embodiments should be construed as being covered within the spirit or scope of the present invention. Therefore, the protection scope of this new model shall be defined by the following patent application scope.

S10~S22: Steps S24~S34: Steps S50~S64: Steps · S70~S84: Steps Px: Etching liquid transfer tube Nx,y: nozzle 100, 200: circuit board 100A, 100B: Area 120:mark 122: Directions 102, 202: Vias 104, 204: Electroless copper layer 106, 208: Electroplating copper layer 106A, 208A: Thin Electroplated Copper Layer 108, 206: Patterned Films 110, 210: Patterned Circuits

In order to make the above-mentioned and other objects, features, advantages and embodiments of the present invention more clearly understood, the accompanying drawings are described as follows: FIG. 1 is a flow chart of a circuit board manufacturing process using a conventional subtractive method. FIG. 2 is a flowchart of a circuit board manufacturing process using a conventional additive method. FIG. 3 is a flowchart of an intelligent circuit board manufacturing process according to an embodiment of the present invention. FIGS. 4A to 4H are cross-sectional schematic diagrams of each step of an intelligent circuit board manufacturing process corresponding to FIG. 3 . FIG. 5 is a schematic diagram of an intelligent non-uniform thin copper manufacturing process according to an embodiment of the present invention. FIG. 6 is a flowchart of an intelligent circuit board manufacturing process according to another embodiment of the present invention. 7A to 7H are cross-sectional schematic diagrams of each step of an intelligent circuit board manufacturing process corresponding to FIG. 6 .

Px: Etching liquid transfer tube

Nx,y: nozzle

100: circuit board

100A, 100B: Area

120:mark

122: Directions

Claims (6)

An intelligent circuit board etching device is suitable for the manufacturing process of a circuit board, wherein the surface of the circuit board has a copper layer, and the intelligent circuit board etching device comprises: a copper thickness measuring device for measuring the thickness distribution of the copper layer on the surface of the circuit board; and A matrix wet etching machine is connected to the copper thickness measuring device, and according to the thickness distribution of the copper layer, the copper layer is etched non-uniformly and the thickness of the copper layer is made uniform. The intelligent circuit board etching device as claimed in claim 1, wherein the matrix etching machine further comprises: a controller; and A plurality of nozzles are arranged in a matrix and are respectively connected to the controller, wherein the controller can individually control the opening and closing of each of the nozzles. The intelligent circuit board etching device as claimed in claim 2, further comprising a machine learning module connected to the controller. The intelligent circuit board etching device as claimed in claim 3, further comprising another copper thickness measuring device, connected to the matrix wet etching machine, to measure the thickness distribution of the copper layer after etching, and to measure the thickness of the copper layer The thickness distribution of is transmitted to the machine learning module. The intelligent circuit board etching device as claimed in claim 1, wherein the copper thickness measuring device utilizes introducing eddy current to the copper layer, and measures the impedance of the copper layer to detect the thickness distribution of the copper layer. The intelligent circuit board etching device as claimed in claim 1, wherein the copper thickness measuring device measures the thickness of the copper layer by optical means.

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