KR20220087049A - Circuit board and mehod of manufacturing thereof - Google Patents

Abstract

A circuit board according to an embodiment includes an insulating layer including a first region and a second region; a circuit pattern including a 1-1 circuit pattern disposed in the first region of the insulating layer and a 1-2 circuit pattern disposed in the second region of the insulating layer; and a solder resist disposed in the first region and the second region of the insulating layer, wherein a height of the solder resist in the first region is lower than a height of the 1-1 circuit pattern, and the second region The height of the solder resist is higher than the height of the 1-2 circuit pattern, and the 1-1 circuit pattern includes a first portion covered by the solder resist in the first region, and the first A second portion other than the portion is included, and the height of the second portion satisfies a range of 3 μm to 9 μm.

Description

Circuit board and manufacturing method thereof

The embodiment relates to a circuit board, and more particularly, to a circuit board capable of supporting a circuit pattern disposed on the outermost side of the circuit board using a solder resist, and a method of manufacturing the same.

As miniaturization, weight reduction, and integration of electronic components are accelerated, the line width of circuits is being miniaturized. In particular, as design rules of semiconductor chips are integrated on a nanometer scale, a circuit line width of a package substrate or circuit board on which a semiconductor chip is mounted has been reduced to several micrometers or less.

In order to increase the degree of circuit integration of the circuit board (that is, in order to refine the circuit line width), various methods have been proposed. For example, in order to prevent loss of circuit line width in the etching step to form a pattern after copper plating, a semi-additive process (SAP) method and a modified semi-additive process (MSAP) ) have been proposed

Then, in order to implement a finer circuit pattern, an embedded trace substrate (ETS) method in which a copper foil is embedded in an insulating layer is used in the art. Since the ETS method manufactures a copper foil circuit by embedding it in the insulating layer instead of protruding it on the surface of the insulating layer, there is no circuit loss due to the nickname, so it is advantageous to fine-tune the circuit pitch.

Meanwhile, efforts are being made to develop an improved 5 ^th generation (5G) communication system or a pre-5G communication system to meet the wireless data traffic demand. Here, the 5G communication system uses a high frequency (mmWave) band (eg, 6 GHz, 28 GHz, 35 GHz) or higher frequencies to achieve a high data rate.

And, in order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the propagation distance of radio waves, in the 5G communication system, beamforming, massive MIMO, array antenna, etc. Integration technologies are being developed. Considering that it can consist of hundreds of active antennas in these frequency bands, the antenna system becomes relatively large.

Since these antennas and AP modules are patterned or mounted on a circuit board, low loss of the circuit board is very important. This means that several substrates constituting an active antenna system, for example, an antenna substrate, an antenna feeding substrate, a transceiver substrate, and a baseband substrate, should be integrated into one compact unit. it means.

And, the circuit board applied to the 5G communication system as described above is manufactured in the trend of lightness, thinness and miniaturization, and accordingly, the circuit pattern is gradually becoming finer.

However, the circuit board including the conventional fine circuit pattern has a structure in which the outermost circuit pattern protrudes above the insulating layer, and thus the outermost circuit pattern easily collapses due to various factors. .

In the embodiment, a circuit board having a new structure and a method for manufacturing the same are provided.

In addition, the embodiment provides a circuit board capable of improving reliability by providing a structure including a solder resist capable of supporting a circuit pattern disposed on the outermost side, and a method of manufacturing the same.

In addition, the embodiment provides a circuit board including a solder resist capable of supporting a circuit pattern disposed on an SR exposed region among circuit patterns disposed on the outermost side, and a method of manufacturing the same.

In addition, the embodiment provides a circuit board capable of minimizing deformation of a circuit pattern disposed on the outermost side and a method of manufacturing the same.

Technical tasks to be achieved in the proposed embodiment are not limited to the technical tasks mentioned above, and other technical tasks not mentioned are clear to those of ordinary skill in the art to which the proposed embodiment belongs from the description below. can be understood clearly.

A circuit board according to an embodiment includes an insulating layer including a first region and a second region; a circuit pattern including a 1-1 circuit pattern disposed in the first region of the insulating layer and a 1-2 circuit pattern disposed in the second region of the insulating layer; and a solder resist disposed in the first region and the second region of the insulating layer, wherein a height of the solder resist in the first region is lower than a height of the 1-1 circuit pattern, and the second region The height of the solder resist is higher than the height of the 1-2 circuit pattern, and the 1-1 circuit pattern includes a first portion covered by the solder resist in the first region, and the first A second portion other than the portion is included, and the height of the second portion satisfies a range of 3 μm to 9 μm.

In addition, the total height of the 1-1 circuit pattern is 12 μm or more.

In addition, the 1-1 circuit pattern includes a trace and a pad.

In addition, the height of the solder resist in the second region satisfies 110% to 400% of the 1-2 circuit pattern.

In addition, the copper concentration of the surface of the second portion of the 1-1 circuit pattern is 90 wt% or more.

In addition, the upper surface of the solder resist includes a first upper surface in the first region and a second upper surface in the second region, and a surface roughness (Ra) of the first upper surface is a surface of the second upper surface. It is different from roughness (Ra).

In addition, the upper surface of the solder resist includes an interface between the first upper surface and the second upper surface, and the surface roughness (Ra) of the interface is the surface roughness (Ra) of the first upper surface and the surface of the second upper surface. It is different from roughness (Ra).

In addition, the surface roughness (Ra) of the first upper surface of the solder resist is greater than the surface roughness (Ra) of the second upper surface, and the surface roughness (Ra) of the interface is greater than the surface roughness (Ra) of the first upper surface. small, and greater than the surface roughness Ra of the second upper surface.

In addition, the insulating layer includes a plurality of insulating layers, and the circuit pattern is disposed to protrude from an upper surface of an uppermost insulating layer among the plurality of insulating layers.

In addition, a primer layer is disposed between the uppermost insulating layer and the circuit pattern, and between the uppermost insulating layer and the solder resist.

Meanwhile, in the method of manufacturing a circuit board according to the embodiment, an inner-layer substrate is manufactured, an uppermost insulating layer is formed on the inner-layer substrate, and a 1-1 circuit pattern is formed on the first and second regions of the uppermost insulating layer. and 1-2 circuit patterns are respectively formed, and on the uppermost insulating layer, a solder resist layer covering the 1-1 circuit pattern and the 1-2 circuit pattern is formed, and the solder resist layer is partially and forming solder resists having different heights in the first region and the second region by exposing and developing, wherein a height of the solder resist in the first region is lower than a height of the 1-1 circuit pattern; , a height of the solder resist in the second region is higher than a height of the 1-2 circuit pattern, and the 1-1 circuit pattern is a first portion covered by the solder resist in the first region and a second part other than the first part, wherein the total height of the 1-1 circuit pattern is 12 µm or more, and forming the solder resist, the height of the second part is 3 µm to 9 µm and partially exposing and developing the solder resist layer to satisfy the range of .

In addition, the height of the solder resist in the second region satisfies 110% to 400% of the 1-2 circuit pattern.

In addition, the copper concentration of the surface of the second portion of the 1-1 circuit pattern is 90 wt% or more.

In addition, the upper surface of the solder resist includes a first upper surface in the first region, a second upper surface in the second region, and an interface between the first upper surface and the second upper surface, and the solder resist The surface roughness Ra of the first upper surface is greater than the surface roughness Ra of the second upper surface of It is larger than the surface roughness (Ra) of the upper surface.

The circuit board in this embodiment includes an outer layer circuit pattern disposed on the outermost side. In this case, the outer layer circuit pattern includes a 2-1 outer layer circuit pattern disposed in the first area of the solder resist and a 2-2 outer layer circuit pattern disposed in the second area of the solder resist. At this time, the 2-2 outer layer circuit pattern can be supported by being surrounded by the solder resist, but the 2-1 outer layer circuit pattern does not have a support layer that can support it, so it can easily collapse due to various factors. have

Accordingly, in the embodiment, the second-first outer layer circuit pattern can be supported by using the solder resist. Accordingly, in the embodiment, problems such as collapsing or abrasion of the protruding outer layer circuit pattern can be solved by miniaturization of the outer layer circuit pattern, and thus product reliability can be improved. In particular, in the embodiment, it is possible to solve problems such as collapsing or abrasion of the outer layer circuit pattern in the first region, and thus product reliability can be improved.

In addition, in the embodiment, in forming the first region of the solder resist, it is removed using an exposure and development method rather than a sand blast method or a plasma method. In this case, when the solder resist is removed by sandblasting or plasma method, the outer layer circuit pattern may be deformed, and in some cases, the outer layer circuit pattern may have a triangular cross-section. In addition, when the cross section of the outer layer circuit pattern has a triangular shape, the adhesive member cannot be stably disposed on the outer layer circuit pattern, and thus reliability problems may occur. In contrast, in the embodiment, the solder resist may be removed without deformation of the outer layer circuit pattern, and thus reliability may be improved.

In addition, in the embodiment, the height of the second portion of the 2-1 outer layer circuit pattern (eg, the difference between the height of the first region of the solder resist and the height of the 2-1 outer layer circuit pattern) is 3 µm to 9 µm It should have a value between μm. Accordingly, in the embodiment, a reliability problem that may occur because the second portion of the 2-1 outer layer circuit pattern is not completely exposed, or the height of the second portion of the 2-1 outer layer circuit pattern is too large It is possible to solve problems such as pattern deformation or pattern collapse that may occur depending on

In addition, the circuit board in the embodiment can be applied to a 5G communication system, thereby minimizing transmission loss at high frequencies to further improve reliability. Specifically, the circuit board in the embodiment can be used at a high frequency and can reduce propagation loss.

1 is a diagram illustrating a circuit board according to a first comparative example.
2 is a diagram illustrating a circuit board of a second comparative example.
3 is a diagram illustrating a circuit board according to an embodiment.
FIG. 4A is an enlarged view of an outermost region of the circuit board of FIG. 3 .
4B is a diagram specifically illustrating the circuit pattern of FIG. 4A.
5A to 5E are views illustrating reliability evaluation results according to a height of a second portion of an outer layer circuit pattern according to an embodiment.
6 is a plan view illustrating a circuit board including a protective layer according to an embodiment.
7 is a view showing an outer layer circuit pattern according to a comparative example.
8 to 14 are views showing the manufacturing method of the circuit board shown in FIG. 2 in order of process.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "part" for components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have distinct meanings or roles by themselves. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical idea disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

Terms including an ordinal number such as 1st, 2nd, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “comprises” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Prior to the description of the present embodiment, a comparative example compared with the present embodiment will be described.

1 is a diagram illustrating a circuit board according to a first comparative example. Specifically, FIG. 1 is a view showing a circuit board manufactured by the SAP method.

Referring to FIG. 1 , as in (a), the circuit board according to the comparative example may be manufactured by the SAP method.

Specifically, the circuit board of the comparative example includes an insulating layer 10 , a circuit pattern 20 , and a protective layer 30 . In this case, the circuit pattern 20 is disposed on the upper and lower surfaces of the insulating layer 10 , respectively.

In this case, at least one of the circuit patterns 20 disposed on the surface of the insulating layer 10 may be a microcircuit pattern.

1 shows that the circuit pattern 20 disposed on the upper surface of the insulating layer 10 is a fine circuit pattern. The microcircuit pattern includes a trace 21 which is a signal transmission wiring line and a pad 22 for chip mounting.

At this time, since the supporting layer using solder resist is formed for the purpose of protecting the fine circuit pattern in the embodiment, the structure in the region where the fine circuit pattern is formed in the comparative example will be described.

The upper region of the insulating layer 10 in the comparative example includes a first region in which the protective layer 30 is disposed, and a second region that is an open region in which the protective layer 30 is not disposed.

Accordingly, some of the circuit patterns 20 disposed on the upper surface of the insulating layer 10 are covered by the passivation layer 30 , and the remaining part is exposed to the outside without being covered by the passivation layer 30 .

In this case, as described above, in the second region that is the open region of the protective layer 30 , the trace 21 and the pad 22 corresponding to the microcircuit pattern are disposed. For example, at least one of the trace 21 and the pad 22 has a width in a range of 10 μm to 15 μm, and a spacing in a range of 10 μm to 15 μm.

Here, when the circuit pattern formed in the open region of the protective layer 30 is a general pattern (a pattern having a width exceeding 15 μm) rather than a fine circuit pattern, a reliability problem in the open region may not occur. .

However, as shown in (b) of FIG. 1 , as the circuit pattern is gradually made finer, the width and spacing of the trace 21 and the pad 22 which are the outermost fine circuit pattern are gradually decreasing. Accordingly, when the microcircuit pattern protruding above the surface of the insulating layer 10 is disposed in the second area that is the open area of the protective layer 30, the reliability problem that the microcircuit pattern easily collapses due to an external impact Occurs.

For example, as shown in part B of FIG. 1(b), the trace 21 corresponding to the outermost microcircuit pattern has a property that is weak to external impact, and thus it is easily collapsed or swept by various factors. Reliability issues arise.

On the other hand, recently, a microcircuit pattern disposed in an open area of the protective layer is formed while having a structure buried in the insulating layer by using the ETS method.

2 is a diagram illustrating a circuit board of a second comparative example. Specifically, FIG. 2 is a view showing a circuit board manufactured by the ETS method.

Referring to FIG. 2 , the circuit board includes an insulating layer 10A, a circuit pattern 20A, and a protective layer 30A.

The circuit pattern 20A is disposed on the upper and lower surfaces of the insulating layer 10A, respectively.

At this time, at least one of the circuit patterns 20A disposed on the surface of the insulating layer 10A includes a fine circuit pattern.

Here, when the circuit pattern is formed by the ETS method, the first circuit pattern formed has a structure buried in the insulating layer 10A. Accordingly, when the initially formed circuit pattern is formed as a micro circuit pattern, the micro circuit pattern may have a structure in which the micro circuit pattern is buried in the insulating layer 10A even in the comparative example.

That is, the circuit board manufactured by the ETS method includes a fine circuit pattern having a structure buried in the surface of the insulating layer 10A. That is, the microcircuit pattern includes a trace 21A, which is a signal transmission wiring line, and a pad 22A for mounting a chip or the like.

And, in the case of the circuit board manufactured by the ETS method as described above, since the microcircuit pattern has a structure buried in the insulating layer, the microcircuit pattern can be protected from external impact.

At this time, there is no major problem in manufacturing the circuit board by the ETS method for the substrate having a two-layer structure (based on the number of layers of the circuit pattern) as in FIG. 2 . However, when a circuit board having 8 or more layers, particularly 10 or more layers, is manufactured by the ETS method, a lead time for manufacturing the circuit board takes at least 2 months or more, and thus there is a problem in that productivity is lowered.

In addition, in order to manufacture the microcircuit pattern of the buried structure by the ETS method, the microcircuit pattern must be formed first in the manufacturing process of the multilayer circuit board. In addition, in order to be applied to an AP module of recent high integration/high specification, etc., circuit boards of 8 to 10 layers are required. At this time, in the process of forming the microcircuit pattern first during the ETS process and performing the subsequent multilayer lamination process, damage is applied to the microcircuit pattern due to thermal stress, etc. There are problems that are difficult to implement.

In addition, when the circuit board is manufactured by the ETS method, an ETS core layer is separately required. In this case, when the circuit board is manufactured by the ETS method, an additional process for finally removing the ETS core layer is required.

In addition, in the case of manufacturing a circuit board by the ETS method, there is a problem in that the yield due to the cumulative tolerance is lowered due to the cumulative tolerance when the layers are laminated more than a certain number of times, and the product cost accordingly increases. As this progresses, there is a problem in that pattern damage due to stress increases.

In addition, as 5G technology develops in recent years, interest in circuit boards that can reflect this is increasing. At this time, in order to apply the 5G technology, the circuit board must have a high multi-layer structure, and accordingly, the circuit pattern must be miniaturized. However, although it is possible to form a fine pattern in the comparative example, there is a problem in that it cannot be stably protected.

Accordingly, the embodiment is to provide a circuit board having a new structure capable of solving the reliability problem of a microcircuit pattern disposed on the outermost side and a control method thereof.

3 is a view showing a circuit board according to an embodiment, FIG. 4A is an enlarged view of an outermost region of the circuit board of FIG. 3, and FIG. 4B is a view showing the circuit pattern of FIG. 4A in detail.

Prior to the description of FIGS. 3, 4A, and 4B , the circuit board according to the embodiment may have a multi-layered structure. Preferably, the circuit board according to the embodiment may have a structure of 10 or more layers based on the number of layers of the circuit pattern. However, the embodiment is not limited thereto. That is, the circuit board according to the embodiment may have a number of layers less than 10, and alternatively may have a number of layers greater than 10 layers.

However, the circuit board of the embodiment is for solving the problem of the ETS method of the second comparative example. At this time, the ETS method in the second comparative example has many problems in manufacturing a circuit board of 8 or more layers. .

3 , 4A and 4B , the circuit board 100 includes an insulating layer 110 . Preferably, the circuit board 100 may include first to ninth insulating layers 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 to implement a 10-layer circuit pattern structure. can

At this time, among the insulating layers 110 , the first insulating layer 111 , the second insulating layer 112 , the third insulating layer 113 , the fourth insulating layer 114 , the fifth insulating layer 115 , The sixth insulating layer 116 and the seventh insulating layer 117 may be internal insulating layers disposed inside in the laminated insulating layer structure, and the eighth insulating layer 118 may be an uppermost insulating layer disposed on the inner insulating layer. (first outermost insulating layer), and the ninth insulating layer 119 may be a lowermost insulating layer (second outermost insulating layer) disposed under the inner insulating layer.

The first insulating layer 111 may be a core insulating layer disposed at the center in the stacked structure of the insulating layer 110 . The second insulating layer 112 , the fourth insulating layer 114 , the sixth insulating layer 116 , and the eighth insulating layer 118 may be upper insulating layers sequentially disposed on the first insulating layer 111 . have. In addition, the third insulating layer 113 , the fifth insulating layer 115 , the seventh insulating layer 117 , and the ninth insulating layer 119 are lower insulating layers sequentially disposed under the first insulating layer 111 . It can be a layer.

The insulating layer 110 is a substrate on which an electric circuit capable of changing wiring is formed, and may include all of a printed circuit board and an insulating substrate made of an insulating material capable of forming circuit patterns on a surface thereof.

For example, at least one of the insulating layers 110 may be rigid or flexible. For example, at least one of the insulating layer 110 may include glass or plastic. In detail, at least one of the insulating layers 110 includes chemically strengthened/semi-tempered glass such as soda lime glass or aluminosilicate glass, or polyimide (PI), polyethylene terephthalate ( Reinforced or soft plastics such as polyethylene terephthalate, PET), propylene glycol (PPG), and polycarbonate (PC) may be included, or sapphire may be included.

In addition, at least one of the insulating layers 110 may include an optical isotropic film. For example, at least one of the insulating layer 110 includes cyclic olefin copolymer (COC), cyclic olefin polymer (COP), optical isotropic polycarbonate (PC), or optical isotropic polymethyl methacrylate (PMMA). can do.

Also, at least one of the insulating layers 110 may be bent while having a partially curved surface. That is, at least one of the insulating layers 110 may be partially curved and partially flat. In detail, at least one of the insulating layers 110 may have a curved end with a curved end, or may have a surface including a random curvature and may be bent or bent.

Also, at least one of the insulating layers 110 may be a flexible substrate having a flexible characteristic. Also, at least one of the insulating layers 110 may be a curved or bent substrate. At this time, at least one of the insulating layers 110 may represent the electrical wiring connecting the circuit parts based on the circuit design as a wiring diagram, and the electrical conductor may be reproduced on the insulating material. In addition, at least one of the insulating layers 110 may form a wiring for mounting electrical components and circuitly connecting them, and may mechanically fix components other than the electrical connection function of the components.

The insulating layer 110 as described above may be divided into a first region R1 and a second region R2 based on a region in which a solder resist 160 to be described later is disposed. The first region R1 and the second region R2 will be described later with reference to the solder resist.

A circuit pattern may be disposed on the surface of the insulating layer 110 .

That is, circuit patterns may be disposed on respective surfaces of the first to ninth insulating layers 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , and 119 constituting the insulating layer 110 .

Here, the circuit pattern may include the inner layer circuit pattern 120 and the outer layer circuit patterns 130 and 140 . The inner circuit pattern 120 is an inner circuit pattern disposed inside the insulating layer 110 in the laminated structure of the circuit board, and the outer circuit patterns 130 and 140 are the insulating layer 110 in the laminated structure of the circuit board. It may be a circuit pattern disposed on the outermost side of the .

The inner layer circuit pattern 120 includes a first circuit pattern 121 , a second circuit pattern 122 , a third circuit pattern 123 , a fourth circuit pattern 124 , a fifth circuit pattern 125 , and a sixth circuit. It may include a pattern 126 and a seventh circuit pattern 127 .

The first circuit pattern 121 may be disposed on the upper surface of the first insulating layer 111 , and thus may be covered by the second insulating layer 112 . The second circuit pattern 122 may be disposed on the lower surface of the first insulating layer 111 , and thus may be covered by the third insulating layer 113 . The third circuit pattern 123 may be disposed on the upper surface of the second insulating layer 112 , and thus may be covered by the fourth insulating layer 114 . The fourth circuit pattern 124 may be disposed on the lower surface of the third insulating layer 113 , and thus may be covered by the fifth insulating layer 115 . The fifth circuit pattern 125 may be disposed on the upper surface of the fourth insulating layer 114 , and thus may be covered by the sixth insulating layer 116 . The sixth circuit pattern 126 may be disposed on the lower surface of the fifth insulating layer 115 , and thus may be covered by the seventh insulating layer 117 . The seventh circuit pattern 127 may be disposed on the upper surface of the sixth insulating layer 116 , and thus may be covered by the eighth insulating layer 118 . The eighth circuit pattern 128 may be disposed on the lower surface of the seventh insulating layer 117 , and thus may be covered by the ninth insulating layer.

The outer circuit pattern may be disposed on the surface of the outermost insulating layer disposed on the outermost side of the insulating layer 110 . Preferably, the outer circuit pattern may include the first outer circuit pattern 130 disposed on the lower surface of the ninth insulating layer 119 disposed at the lowermost portion of the insulating layer 110 .

In addition, the outer circuit pattern may include the second outer circuit pattern 140 disposed on the upper surface of the eighth insulating layer 118 disposed on the uppermost portion of the insulating layer 110 .

In this case, at least one of the first outer layer circuit pattern 130 and the second outer layer circuit pattern 140 may be formed to protrude from the surface of the insulating layer. Preferably, the first outer layer circuit pattern 130 may be formed to protrude below the lower surface of the ninth insulating layer 119 . In addition, the second outer layer circuit pattern 140 may be formed to protrude above the upper surface of the eighth insulating layer 118 . That is, the circuit board in the embodiment is manufactured by the SAP method, and accordingly, the circuit patterns disposed on the outermost side may all protrude from the surface of the insulating layer.

That is, the upper surface of the first outer layer circuit pattern 130 may be positioned on the same plane as the lower surface of the ninth insulating layer 119 . In addition, the lower surface of the second outer layer circuit pattern 140 may be positioned on the same plane as the upper surface of the primer layer 150 disposed on the upper surface of the eighth insulating layer 180 .

In other words, the primer layer 150 may be disposed between the eighth insulating layer 180 and the second outer layer circuit pattern 140 .

That is, the second outer layer circuit pattern 140 may include a fine circuit pattern. Preferably, the second outer layer circuit pattern 140 may be a fine circuit pattern having a line width of 10 μm or less and an interval between the patterns of 10 μm or less. Accordingly, when the second outer circuit pattern 140 is directly disposed on the eighth insulating layer 118 , a contact area between the eighth insulating layer 118 and the second outer circuit pattern 140 . Due to this small size, a problem may occur that the second outer layer circuit pattern 150 is separated from the eighth insulating layer 118 .

Therefore, in the embodiment, the primer layer 150 is disposed between the second outer layer circuit pattern 140 and the eighth insulating layer 118 . The primer layer 150 may improve adhesion between the second outer circuit pattern 140 and the eighth insulating layer 118 . The primer layer 150 may be disposed to completely cover the upper surface of the eighth insulating layer 118 . In addition, the second outer layer circuit pattern 140 may be partially disposed on the primer layer 150 . Accordingly, the upper surface of the primer layer 150 in the embodiment may include a first portion in contact with the second outer layer circuit pattern 140 and a second portion in contact with the lower surface of the solder resist 160 to be described later. can That is, the primer layer 150 improves the bonding strength between the eighth insulating layer 118 and the second outer circuit pattern 140 when the second outer layer circuit pattern 140 is formed by the SAP process. can play a role. Such a primer layer 150 may include a polyurethane-based resin, an acrylic resin, or a silicone-based resin, but is not limited thereto.

Meanwhile, in FIG. 3 , the primer layer is not disposed between the ninth insulating layer 119 and the first outer circuit pattern 130 , but the primer layer is formed between the ninth insulating layer 119 and the first outer layer circuit pattern 130 . It may also be disposed between the first outer layer circuit patterns 130 . However, the first outer layer circuit pattern 130 may not be a micro circuit pattern. And, in this case, the primer layer between the ninth insulating layer 119 and the first outer layer circuit pattern 130 may be selectively omitted.

Consequently, when the microcircuit pattern is disposed on the inner layer, the primer layer may be omitted as the microcircuit pattern of the inner layer is covered by at least one of the insulating layers 110 . On the other hand, in the embodiment, when the microcircuit pattern is disposed on the outermost layer, since there is no insulating layer covering the microcircuit pattern, the primer layer 150 is used to improve bonding strength between the microcircuit pattern and the insulating layer. to place the

Hereinafter, it will be described that the second outer layer circuit pattern 140 is formed as a fine circuit pattern. However, the embodiment is not limited thereto, and the first outer layer circuit pattern 130 may also be formed of a fine circuit pattern. It will be apparent that the structure for improving reliability can also be applied to the first outer layer circuit pattern 130 .

The inner layer circuit pattern 120 , the first outer layer circuit pattern 130 , and the second outer layer circuit pattern 140 are wirings that transmit electrical signals, and may be formed of a metal material having high electrical conductivity. To this end, the inner circuit pattern 120 , the first outer circuit pattern 130 , and the second outer circuit pattern 140 are gold (Au), silver (Ag), platinum (Pt), titanium (Ti), and tin. It may be formed of at least one metal material selected from (Sn), copper (Cu), and zinc (Zn). In addition, the inner circuit pattern 120, the first outer circuit pattern 130, and the second outer circuit pattern 140 have excellent bonding strength of gold (Au), silver (Ag), platinum (Pt), titanium (Ti), It may be formed of a paste or solder paste including at least one metal material selected from tin (Sn), copper (Cu), and zinc (Zn). Preferably, the inner circuit pattern 120 , the first outer circuit pattern 130 , and the second outer circuit pattern 140 may be formed of copper (Cu), which has high electrical conductivity and is relatively inexpensive.

At least one of the inner circuit pattern 120, the first outer circuit pattern 130, and the second outer circuit pattern 140 is a conventional circuit board manufacturing process, an additive process, a subtractive process ( Subtractive Process), Modified Semi Additive Process (MSAP), and Semi Additive Process (SAP) methods are available, and detailed descriptions thereof will be omitted here.

Preferably, the first outer layer circuit pattern 130 and the second outer layer circuit pattern 140 are the outermost circuit patterns disposed on the outermost side of the circuit board, and accordingly, they are to be formed by the SAP (Semi Additive Process) method. will be able

Meanwhile, a via V may be disposed in the insulating layer 110 . The vias V are disposed in each insulating layer, and thus may serve to electrically connect circuit patterns disposed in different layers to each other.

A first via V1 may be disposed in the first insulating layer 111 . The first via V1 electrically connects the first circuit pattern 121 disposed on the upper surface of the first insulating layer 111 and the second circuit pattern 122 disposed on the lower surface of the first insulating layer 111 . can be connected to

A second via V2 may be disposed in the second insulating layer 112 . The second via V2 electrically connects the first circuit pattern 121 disposed on the upper surface of the first insulating layer 111 and the third circuit pattern 123 disposed on the upper surface of the second insulating layer 112 . can be connected to

A third via V3 may be disposed in the third insulating layer 113 . The third via V3 electrically connects the second circuit pattern 122 disposed on the lower surface of the first insulating layer 111 and the fourth circuit pattern 124 disposed on the lower surface of the third insulating layer 113 . can be connected to

A fourth via V4 may be disposed in the fourth insulating layer 114 . The fourth via V4 electrically connects the third circuit pattern 123 disposed on the upper surface of the second insulating layer 111 and the fifth circuit pattern 125 disposed on the upper surface of the fourth insulating layer 114 . can be connected to

A fifth via V5 may be disposed in the fifth insulating layer 115 . The fifth via V5 electrically connects the fourth circuit pattern 124 disposed on the lower surface of the third insulating layer 113 and the sixth circuit pattern 126 disposed on the lower surface of the fifth insulating layer 115 . can be connected to

A sixth via V6 may be disposed in the sixth insulating layer 116 . The sixth via V6 electrically connects the fifth circuit pattern 125 disposed on the upper surface of the fourth insulating layer 114 and the seventh circuit pattern 127 disposed on the upper surface of the sixth insulating layer 116 . can be connected to

A seventh via V7 may be disposed in the seventh insulating layer 117 . The seventh via V7 electrically connects the sixth circuit pattern 126 disposed on the lower surface of the fifth insulating layer 115 and the eighth circuit pattern 128 disposed on the lower surface of the seventh insulating layer 117 . can be connected to

An eighth via V1 may be disposed in the eighth insulating layer 118 . The eighth via V8 electrically connects the seventh circuit pattern 127 disposed on the upper surface of the sixth insulating layer 116 and the second outer circuit pattern 140 disposed on the upper surface of the primer layer 150 . can be connected

A ninth via V9 may be disposed in the ninth insulating layer 119 . The ninth via V9 connects the eighth circuit pattern 128 disposed on the lower surface of the seventh insulating layer 117 and the first outer circuit pattern 130 disposed on the lower surface of the ninth insulating layer 119 . It can be electrically connected.

The via V as described above may be formed by filling the inside of the via hole formed in each insulating layer with a metal material.

The via hole may be formed by any one of machining methods, including mechanical, laser, and chemical machining. When the via hole is formed by machining, methods such as milling, drilling, and routing can be used, and when formed by laser processing, UV or CO ₂ laser method is used. In the case of being formed by chemical processing, the insulating layer 110 may be opened using chemicals including aminosilane, ketones, and the like.

On the other hand, the processing by the laser is a cutting method that takes a desired shape by concentrating optical energy on the surface to melt and evaporate a part of the material. Complex formation by a computer program can be easily processed. Even difficult composite materials can be machined.

In addition, the processing by the laser can have a cutting diameter of at least 0.005 mm, and has a wide advantage in a range of possible thicknesses.

As the laser processing drill, it is preferable to use a YAG (Yttrium Aluminum Garnet) laser, a CO ₂ laser, or an ultraviolet (UV) laser. The YAG laser is a laser that can process both the copper foil layer and the insulating layer, and the CO ₂ laser is a laser that can process only the insulating layer.

When the via hole is formed, the first to ninth vias V1 , V2 , V3 , V4 , V5 , V6 , V7 , V8 , and V9 may be formed by filling the interior of the via hole with a conductive material. The metal material forming the first to ninth vias V1, V2, V3, V4, V5, V6, V7, V8, and V9 is copper (Cu), silver (Ag), tin (Sn), or gold (Au). ), may be any one material selected from nickel (Ni) and palladium (Pd), and the conductive material filling is electroless plating, electrolytic plating, screen printing (Screen Printing), sputtering (Sputtering), evaporation (Evaporation) ), inkjetting and dispensing, or a combination thereof.

Meanwhile, a protective layer may be disposed on the outermost side of the circuit board 100 . Preferably, the first protective layer 160 may be disposed on the eighth insulating layer 118 (preferably, on the primer layer 150 ). Also, a second passivation layer 175 may be disposed under the ninth insulating layer 119 .

The first passivation layer 160 and the second passivation layer 175 may be formed of at least one layer using any one or more of Solder Resist (SR), oxide, and Au. Preferably, the first passivation layer 160 and the second passivation layer 175 may be solder resist.

Meanwhile, a first protective layer 160 is disposed on the primer layer 150 . The first protective layer 160 may serve to protect the surface of the second outer circuit pattern 140 while supporting the second outer circuit pattern 140 disposed on the primer layer 150 . .

That is, the first protective layer 160 may partially overlap the second outer layer circuit pattern 140 disposed on the primer layer 150 . An area of the first passivation layer 160 may be smaller than an area of the eighth insulating layer 118 . An area of the first protective layer 160 may be smaller than an area of the primer layer 150 . The first protective layer 160 is partially or entirely disposed on the primer layer 150 and the second outer layer circuit pattern 140 , and thus an open region exposing the surface of the second outer layer circuit pattern 140 . may include

The first passivation layer 160 may include an open region or a first region R1 having a groove-like shape. In the first region R1 , the surface of the second external circuit pattern 140 is formed through the first protective layer 160 among the upper regions of the primer layer 150 and the second external circuit pattern 140 . It may mean an exposed area.

That is, the circuit board includes a first region R1 and a second region R2. The first region R1 is an open region in which the surface of the second outer layer circuit pattern 140 must be exposed through the first protective layer 160 , and the second region R2 is the first protective layer 160 . It may be a buried region in which the surface of the second outer layer circuit pattern 140 is covered by the .

That is, the first region R1 may be a non-arranged region of the first protective layer 160 in which the second outer layer circuit pattern 140 is electrically connected to a component such as a chip. Accordingly, the second outer layer circuit pattern 140 disposed on the first region R1 may be exposed to the outside in a state in which a protective layer protecting the second outer layer circuit pattern 140 does not exist.

In addition, the second outer layer circuit pattern 140 disposed in the first region R1 as described above may have reliability problems such as collapsing or rubbing due to various factors. Moreover, the second outer layer circuit pattern 140 is a fine circuit pattern, and thus may have a line width of 10 μm or less and an interval of 10 μm or less. Accordingly, the second outer layer circuit pattern 140 disposed on the first region R1 may have reliability problems such as easily collapsing or rubbing even with various small external impacts.

Accordingly, in the embodiment, in order to improve the reliability of the second outer layer circuit pattern 140 disposed on the first region R1, a coating agent is also applied on the primer layer 150 corresponding to the first region R1. 1 A protective layer 160 is disposed.

That is, the first protective layer 160 may be disposed on the upper surface of the primer layer 150 in a region where the second outer layer circuit pattern 140 is not disposed. For example, the first protective layers 160 and 170 are disposed on the top surface of the primer layer 150 , and thus are disposed between the second outer layer circuit patterns 140 on the first region R1 . can

In this case, the second outer layer circuit pattern 140 includes a 2-1 th outer layer circuit pattern 140a formed in the first region R1 and a 2-2 th outer layer circuit pattern 140a formed in the second region R2 ( 140b).

The top surface of the primer layer 150 includes a first top surface corresponding to the first region R1 and a second top surface corresponding to the second region R2 .

At this time, as shown in FIGS. 3, 4A and 4B , the first passivation layer 160 does not separate the first region R1 and the second region R2 and is on the primer layer 150 . It may be disposed entirely, and may be disposed in a region between the 2-1 th outer layer circuit patterns 140a and a region between the 2-2 th outer layer circuit patterns 140b, respectively.

Accordingly, the first passivation layer 160 includes a first portion disposed in the first region R1 and a second portion disposed in the second region R2 .

In this case, the first passivation layer 160 may have different heights for each area.

For example, the first passivation layer 160 may include a first portion disposed in the first region R1 and a second portion disposed in the second region R2 . In this case, the first portion of the first passivation layer 160 may be referred to as a first region of the first passivation layer 160 , and the second portion of the first passivation layer 160 is the first passivation layer It can also be referred to as the second region of (160). Hereinafter, a first portion of the first passivation layer 160 will be referred to as a 'first region' and a second portion of the first passivation layer 160 will be referred to as a 'second region'.

At this time, in the first region R1 , the surface of the second outer layer circuit pattern 140 should be exposed to the outside, and in the second region R2 , the surface of the second outer layer circuit pattern 140 is covered with a protective layer should go

Accordingly, an upper surface of the first portion of the first passivation layer 160 disposed in the first region R1 may be lower than an upper surface of the second outer layer circuit pattern 140 . Preferably, the height or thickness of the first portion of the first passivation layer 160 may be smaller than the height or thickness of the second outer layer circuit pattern 140 .

Also, a top surface of the second portion of the first passivation layer 160 disposed in the second region R2 may be positioned higher than a top surface of the second outer layer circuit pattern 140 . Preferably, the height or thickness of the second portion of the first protective layer 160 may be greater than the height or thickness of the second outer layer circuit pattern 140 .

Accordingly, the surface of the 2-1 th outer layer circuit pattern 140a disposed in the first region R1 may be exposed to the outside due to the low height of the first protective layer 160 . In addition, the 2-2 second outer layer circuit pattern 140b disposed in the second region R2 may be buried in the first passivation layer 160 .

Hereinafter, the first protective layer 160 will be described in detail.

The first protective layer 160 may be disposed on the primer layer 150 . The first protective layer 160 is a solder resist.

The first protective layer 160 may be disposed between the second outer layer circuit patterns 140 on the primer layer 150 . That is, the second outer layer circuit patterns 140 are spaced apart from each other at a predetermined interval on the primer layer 150 , and accordingly, the first protective layer 160 is formed on the second top surface of the primer layer 150 . The outer layer circuit pattern 140 may be disposed on an area not disposed thereon.

Hereinafter, the first protective layer 160 will be described as a solder resist 160 .

The solder resist 160 may be disposed on an area of the upper surface of the primer layer 150 where the second outer layer circuit pattern 140 is not disposed.

Accordingly, the lower surface of the solder resist 160 may directly contact the upper surface of the primer layer 150 . Also, the solder resist 160 may have a structure in direct contact with the second outer layer circuit pattern 140 . For example, a side surface of the first portion of the solder resist 160 may directly contact a side surface of the second outer layer circuit pattern 140 . For example, the second portion of the solder resist 160 may be disposed to surround the side surface and the top surface of the second outer layer circuit pattern 140 .

In this case, the solder resist 160 may have different heights for each area.

That is, the solder resist 160 includes a first portion disposed in the first region R1 and a second portion disposed in the second region R2 .

In this case, the height of the first portion of the solder resist 160 may be smaller than the height of the second outer layer circuit pattern 140 . Preferably, a top surface of the first portion of the solder resist 160 may be positioned lower than a top surface of the second outer layer circuit pattern 140 . Accordingly, a portion of the side surface of the second outer layer circuit pattern 140 disposed in the first region R1 may contact the first portion of the first solder resist 160 , and the remaining portion may be exposed.

Here, the first portion of the solder resist 160 may be formed to surround the 2-1 th outer layer circuit pattern 140a disposed in the first region R1 . Accordingly, the first portion of the solder resist 160 may serve to prevent collapsing or rubbing of the second-first outer circuit pattern 140a disposed in the first region R1 .

The solder resist 160 may use a photo solder resist film. The solder resist 160 may have a structure in which a resin and a filler are mixed.

In addition, the second portion of the solder resist 160 may be disposed to cover the second-second outer layer circuit pattern 140b disposed in the second region R2 .

The first portion of the solder resist 160 may have a first height. In addition, the second portion of the solder resist 160 may have a second height greater than the first height. In this case, the first height is smaller than the height of the second outer layer circuit pattern 140 , and the second height is greater than the height of the second outer layer circuit pattern 140 .

Accordingly, the upper surface of the first portion of the solder resist 160 having the first height may be positioned lower than the upper surface of the second outer layer circuit pattern 140 , and The upper surface of the second portion may be positioned higher than the upper surface of the second outer layer circuit pattern 140 .

Here, the reason why the solder resist 160 has a different height for each region is that only the first region R1 of the solder resist 160 is selectively exposed and developed as the solder resist 160 is exposed and developed. This can be achieved by removing

Meanwhile, the solder resist 160 may include a filler such as BaSO ₄ , SiO ₂ , and Talc, and the content thereof may be 20 wt% to 35 wt%.

In this case, when the solder resist 160 includes a filler having a content of less than 20 wt %, the second outer layer circuit pattern 140 may not be stably protected by the solder resist 160 . In addition, if the content of the filler included in the solder resist 160 is greater than 35% by weight, the filler is on the surface of the second outer layer circuit pattern 140 when the first portion of the solder resist 160 is formed. can remain In addition, a reliability problem of the second outer layer circuit pattern 140 may occur due to the remaining filler, or an additional process of removing the remaining filler must be performed.

As described above, in the embodiment, by forming a solder resist layer on the uppermost insulating layer and selectively removing the solder resist layer in the first region R1 accordingly, solder having different heights for each region A resist 160 may be formed.

Accordingly, the solder resist 160 may have a lower height than the 2-1 th outer layer circuit pattern 140a in the first region R1 and expose the surface of the 2-1 th outer layer circuit pattern 140a, , to cover the second-second outer layer circuit pattern 140b in the second region R2 .

Meanwhile, the second outer layer circuit pattern 140 may include traces 141 and pads 142 according to functions. The pad 142 may be an area in which an adhesive member (not shown) is disposed for connection with an electronic component such as a chip. Also, the trace 141 may be a wiring line connecting different pads. Here, the pad 142 generally has a larger width than that of the trace, and thus the pad 142 may have a characteristic strong against external impact. However, the traces 141 are disposed to have a width and a spacing corresponding to the fine circuit pattern as described above, and thus may have a weak characteristic against external impact. Accordingly, the solder resist 160 stably stabilizes the 2-1 th outer layer circuit pattern 140a disposed in the first region R1, and more specifically, the trace 141 of the 2-1 th outer layer circuit pattern 140a. can play a supporting role.

That is, the second outer layer circuit pattern 140 may include a 2-1 th outer layer circuit pattern 140a disposed in the first region R1 of the solder resist 160 . In addition, the 2-1 th outer layer circuit pattern 140a may include a trace 141 and a pad 142 . Also, the second outer layer circuit pattern 140 may include a 2-2 second outer layer circuit pattern 140b disposed in the second region R2 of the solder resist 160 .

Meanwhile, as shown in FIG. 4A , the second outer layer circuit pattern 140 may have a first height H1 and may be disposed on the primer layer 150 . In addition, the solder resist 160 may have a different height for each area and may be disposed on the first solder resist 160 . The solder resist 160 may include a first portion disposed in the first region R1 and a second portion disposed in the second region R2 .

At this time, the upper surface 161 of the first part of the solder resist 160 , the upper surface 162 of the second part, and the boundary side surface 163 between the first part and the second part have different surface roughness. can

That is, the surface roughness Ra of the first upper surface 161 of the solder resist 160 , the surface roughness Ra of the second upper surface 162 , and the surface roughness Ra of the boundary side 163 are different from each other. can

The first upper surface 161 is a surface thinned by a developer after exposure and development processes are performed. And, the second upper surface 162 is a surface hardened by exposure. In addition, the boundary side 163 is a surface that has been swollen and removed by the developer.

Accordingly, the surface roughness Ra of the first upper surface 161 may be 1.0 μm or more. Also, the surface roughness Ra of the second upper surface 162 may be in a range of 0.01 μm to 0.1 μm. In addition, the surface roughness Ra of the boundary side 163 may be in a range of 0.1 to 0.5 μm.

As described above, in the embodiment, the surface roughness Ra of each of the first upper surface 161 , the second upper surface 162 , and the boundary side 163 of the solder resist 160 may be different from each other.

The first portion of the solder resist 160 may have a second height H2 and be disposed on the primer layer 150 . In addition, the second portion of the solder resist 160 may have a third height H3 and be disposed on the primer layer 150 .

In this case, the second height H2 is smaller than the first height H1 . Preferably, the first portion of the solder resist 160 may be disposed on the primer layer 150 while having a height smaller than that of the second-first outer layer circuit pattern 140a. In this case, the difference between the first height H1 and the second height H2 may correspond to the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a. That is, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a may correspond to the difference value H1 -H2 between the first height H1 and the second height H2. . The height of the second portion 140a - 2 of the 2-1 outer layer circuit pattern 140a may affect the reliability of the circuit board. When the height of the second portion 140a - 2 of the 2-1 th outer circuit pattern 140a is greater than the reference range, the upper surface of the second portion 140a - 2 of the 2-1 th outer circuit pattern 140a There is a problem in that the solder resist 160 remains. In addition, when the height of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is smaller than the existing range, the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a ) is deformed (eg, a triangle). Accordingly, in the embodiment, the solder resist 160 is formed so that the height of the second portion 140a-2 of the second-first outer layer circuit pattern 140a is within the reference range.

Here, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is the same as the total height H1 of the 2-1 th outer layer circuit pattern 140a and the solder resist 160 . It may be defined as a ratio of the height H2 of the first part. However, in this case, as the overall height H1 of the 2-1 th outer layer circuit pattern 140a increases, the height range of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a increases. will decrease. Accordingly, in the embodiment, the height range of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is set regardless of the height H1 of the 2-1 th outer layer circuit pattern 140a. and to allow the first portion of the solder resist 160 to be formed within this range.

In an embodiment, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a may have a value between 3 μm and 9 μm. In this case, it is preferable that the height H1 of the second-first outer layer circuit pattern 140a in the embodiment is 12 μm or more. When the height H1 of the 2-1 outer layer circuit pattern 140a is less than 12 μm, it may be difficult to implement a normal circuit pattern. In addition, when the height H1 of the 2-1 outer layer circuit pattern 140a is less than 12 μm, signal transmission performance may be deteriorated. Accordingly, in the embodiment, in the condition that the height H1 of the 2-1 th outer layer circuit pattern 140a is 12 μm or more, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is Make it possible to have a value between 3 μm and 9 μm.

For example, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is 3 , regardless of the total height H1 of the 2-1 th outer layer circuit pattern 140a. Make it possible to have a value between μm and 9 μm.

When the height of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is less than 3 μm, the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is There is a problem in that residual resin of the solder resist 160 remains on the surface. For example, when the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is less than 3 μm, copper (Cu) on the upper surface of the second portion 140a - 2 . There is a problem that the concentration appears to be 90% by weight or less. That is, when the copper (Cu) concentration on the surface of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is 90 wt% or less, the reliability of the 2-1 th outer layer circuit pattern 140a There is a problem with this decreasing.

In addition, when the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is greater than 9 μm, the 2-1 th outer layer circuit pattern is formed by the first portion of the solder resist 160 . (140a) may not be stably supported. In addition, when the height of the second portion 140a-2 of the 2-1 outer layer circuit pattern 140a is greater than 9 μm, in the pretreatment process for the subsequent surface treatment, the second portion 140a-2 There are problems that can cause deformation.

That is, in general, a surface treatment process is performed on the surface of the circuit pattern exposed in the first region R1 of the solder resist 160 . For example, a surface treatment process is performed on the second portion 140a - 2 of the 2-1 outer layer circuit pattern 140a. The surface treatment process may be any one of an organic solderability preservative (OSP) process and an ENEPIG (gold plating) process. And, in the pretreatment process for the surface treatment, the pretreatment of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is performed. For example, in the pretreatment process for the surface treatment, a nickname of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is made.

At this time, when the height of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is greater than 9 μm, in the pretreatment process for the surface treatment, the 2-1 th outer layer circuit pattern 140a ) of the second portion 140a - 2 may be deformed.

Meanwhile, the third height H3 may be greater than the first height H1 and the second height H2 . Preferably, the third height H3 may be 110% to 400% of the first height H1. For example, when the third height H4 is smaller than 110% of the first height H1, the second second outer layer circuit pattern ( 140b) may not be reliably protected. For example, when the third height H3 is greater than 400% of the first height H1, the overall thickness of the circuit board may increase.

Hereinafter, reliability evaluation results according to the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a will be described.

5A to 5E are views illustrating reliability evaluation results according to a height of a second portion of an outer layer circuit pattern according to an embodiment.

FIG. 5A (a) is a cross-sectional view when the height of the second portion 140a-2 of the second-first outer layer circuit pattern 140a is 7 μm, and (b) is the second portion 140a- 2) is a diagram showing the results of Energy Dispersive X-ray Spectroscopy (EDS) of the surface.

As described above, when the height of the second part 140a-2 is 7 μm, the EDS analysis results of the surface of the second part 140a-2 are shown in Table 1 below.

ingredient weight% C 6.51 Cu 93.49

As described above, when the height of the second part 140a-2 is 7 μm, it can be confirmed that the concentration of Cu on the surface of the second part 140a-2 is 93.49% by weight.

(a) of FIG. 5B is a cross-sectional view when the height of the second portion 140a-2 of the second-first outer layer circuit pattern 140a is 3 μm, and (b) is the second portion 140a- 2) is a diagram showing the results of Energy Dispersive X-ray Spectroscopy (EDS) of the surface.

As described above, when the height of the second part 140a-2 is 3 μm, the results of EDS analysis on the surface of the second part 140a-2 are shown in Table 2 below.

ingredient weight% C 6.19 Cu 93.81

As described above, when the height of the second portion 140a-2 is 3 μm as described above, it can be confirmed that the concentration of Cu on the surface of the second portion 140a-2 is 93.81 wt%.

FIG. 5C (a) is a cross-sectional view when the height of the second portion 140a-2 of the second-first outer layer circuit pattern 140a is 1 μm, and (b) is the second portion 140a- 2) is a diagram showing the results of Energy Dispersive X-ray Spectroscopy (EDS) of the surface.

As described above, when the height of the second part 140a-2 is 1 μm, the results of EDS analysis on the surface of the second part 140a-2 are shown in Table 3 below.

ingredient weight% C 17.65 Cu 82.35

As described above, when the height of the second part 140a-2 is less than 3㎛ 1㎛, the concentration of Cu on the surface of the second part 140a-2 is 82.35% by weight. could check That is, as the height of the second portion 140a - 2 became smaller than 3 μm, it was confirmed that the concentration of Cu on the surface of the second portion 140a - 2 rapidly decreased.

(a) of FIG. 5D is a cross-sectional view when the height of the second portion 140a-2 of the second-first outer layer circuit pattern 140a is -2 μm, and (b) is the second portion 140a according to the second portion 140a-2. -2) is a diagram showing the results of Energy Dispersive X-ray Spectroscopy (EDS) of the surface. That is, FIG. 5D shows the reliability evaluation result under the condition that the solder resist 160 is higher than that of the 2-1 th outer layer circuit pattern 140a.

As described above, when the height of the second part 140a-2 is -2 μm, the results of EDS analysis on the surface of the second part 140a-2 are shown in Table 4 below.

ingredient weight% C 17.65 Cu 79.90

As described above, when the height of the second part 140a-2 was -2 μm, it was confirmed that the concentration of Cu on the surface of the second part 140a-2 was 79.90 wt%. .

(a) of FIG. 5E is a cross-sectional view when the height of the second portion 140a-2 of the second-first outer layer circuit pattern 140a is 9 μm, and (b) is the second-first outer layer circuit pattern 140a. (140a) is a cross-sectional view when the height of the second part 140a-2 is 12 μm, (c) is the height of the second part 140a-2 of the 2-1 outer layer circuit pattern 140a It is a cross-sectional view in the case of 10 micrometers.

As described above, after the 2-1 th outer layer circuit pattern 140a is formed, a surface treatment process of the 2-1 th outer layer circuit pattern 140a is performed. At this time, in the surface treatment process of the 2-1 th outer layer circuit pattern 140a, a process of nicknamed a part of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a as a pretreatment process thereof necessarily going on. In this case, as described above, when the height of the second part 140a-2 was 9 μm, it was confirmed that there was no deformation of the second part 140a-2 even after the pretreatment process was performed. On the other hand, when the height of the second part 140a - 2 is 10 µm or 12 µm, which is greater than 9 µm, in the pretreatment process of the surface treatment process, the second part 140a - 2 is severely deformed. could check

6 is a plan view illustrating a circuit board including a protective layer according to an embodiment.

A protective layer including the solder resist 160 according to the embodiment will be described with reference to FIG. 6 . Here, the solder resist 160 may be a protective layer that protects the surface of the 2-2nd outer layer circuit pattern 140b in the second region R2, and the 2-1th outer layer circuit in the first region R1. It may be a support layer supporting the pattern 140a.

In this case, in the comparative example, the circuit pattern is disposed on the insulating layer having a protruding structure. In addition, the circuit pattern may be independently disposed on the insulating layer without being supported by another supporting layer. Accordingly, in the region corresponding to the fine pattern in the comparative example, collapse or abrasion of the circuit pattern occurs.

This may occur in the circuit pattern of the outermost layer in the circuit board including the circuit pattern manufactured by the SAP method.

Alternatively, in the embodiment, the primer layer 150 is disposed on the eighth insulating layer 118 , and the second outer layer circuit pattern 140 is disposed on the primer layer 150 .

In addition, a solder resist 160 serving as a support layer and a protective layer disposed around the second outer layer circuit pattern 140 is disposed on the primer layer 150 .

In this case, the solder resist 160 may be disposed in the first region R1 and the second region R2 . The solder resist 160 may support the 2-1 outer layer circuit pattern 140a disposed on the outermost layer of the circuit board 100 , and in particular, the second outer layer circuit pattern disposed in the first region R1 . By supporting the trace 141 and the pad 142 of 140a, the 2-1 th outer layer circuit pattern 140a may be protected from external impact.

7 is a view showing an outer layer circuit pattern according to a comparative example.

Meanwhile, in forming the passivation layer, various methods may be used to remove a portion of the passivation layer in the first region R1 . For example, a portion of the protective layer may be removed by a physical method or a chemical method. For example, the protective layer may be removed by a method such as plasma or sand blasting.

However, as in FIG. 7 , when the protective layer is physically or chemically removed, the circuit pattern is also removed in the process of removing the protective layer, so that the circuit pattern is deformed. For example, the circuit pattern may have a triangular cross-section as a part of the circuit pattern is removed together in the process of removing the protective layer. In addition, when the upper portion of the circuit pattern has a triangular shape, an adhesive member such as a solder ball cannot be stably seated on the circuit pattern, and thus a reliability problem may occur. In addition, in order to remove the protective layer by the physical or chemical method, expensive equipment is required, and thus manufacturing cost may increase.

Hereinafter, a method of manufacturing a circuit board according to an embodiment will be described.

8 to 12 are views showing the manufacturing method of the circuit board shown in FIG. 2 in order of process.

Referring to FIG. 8 , the embodiment may preferentially proceed with the process of manufacturing the inner layer substrate 100 - 1 for manufacturing the inner portion of the circuit board 100 .

A process of manufacturing the inner layer substrate 100 - 1 will be briefly described.

The inner layer substrate 100 - 1 may include one insulating layer, or alternatively, a plurality of insulating layers.

In FIG. 8 , the inner substrate 100 - 1 is illustrated as having a seven-layered insulating layer structure, but is not limited thereto. For example, the inner-layer substrate 100 - 1 may include fewer than seven insulating layers, or alternatively, more than seven insulating layers.

The inner layer substrate 100 - 1 may include the remaining insulating layers except for the insulating layer disposed on the outermost layer of the circuit board 100 . For example, the inner layer substrate 100 - 1 may include an insulating layer disposed on the uppermost portion of the circuit board 100 and other insulating layers excluding the insulating layer disposed on the bottommost portion of the circuit board 100 .

Briefly describing the process of manufacturing the inner layer substrate 100 - 1 , the first insulating layer 111 is firstly prepared.

Then, when the first insulating layer 111 is prepared, a first via V1 is formed in the first insulating layer 111 , and the first vias V1 are formed on the upper and lower surfaces of the first insulating layer 111 , respectively. A circuit pattern 121 and a second circuit pattern 122 are formed.

Thereafter, a second insulating layer 112 is formed on the first insulating layer 111 , and a third insulating layer 113 is formed under the first insulating layer 111 .

Next, a second via V2 is formed in the second insulating layer 112 , and a third circuit pattern 123 is formed on the upper surface of the second insulating layer 112 . In addition, a third via V3 is formed in the third insulating layer 113 , and a fourth circuit pattern 124 is formed under the lower surface of the third insulating layer 113 .

Thereafter, a fourth insulating layer 114 is formed on the second insulating layer 112 , and a fifth insulating layer 115 is formed under the third insulating layer 113 .

Next, a fourth via V4 is formed in the fourth insulating layer 114 , and a fifth circuit pattern 125 is formed on the upper surface of the fourth insulating layer 114 . In addition, a fifth via V5 is formed in the fifth insulating layer 115 , and a sixth circuit pattern 126 is formed under the lower surface of the fifth insulating layer 115 .

Thereafter, a sixth insulating layer 116 is formed on the fourth insulating layer 114 , and a seventh insulating layer 117 is formed under the fifth insulating layer 115 .

Next, a sixth via V6 is formed in the sixth insulating layer 116 , and a seventh circuit pattern 127 is formed on the upper surface of the sixth insulating layer 116 . In addition, a seventh via V7 is formed in the seventh insulating layer 117 , and an eighth circuit pattern 128 is formed under the lower surface of the seventh insulating layer 117 .

Since the process of manufacturing the inner layer substrate 100 - 1 is a known technique in the art to which the present invention pertains, a detailed description thereof will be omitted.

Referring to FIG. 9 , when the inner layer substrate 100 - 1 is manufactured, an eighth insulating layer 118 corresponding to the first outermost insulating layer is formed on the upper surface of the inner layer substrate 100 - 1 . In addition, a ninth insulating layer 119 corresponding to the second outermost insulating layer is formed under the lower surface of the inner layer substrate 100 - 1 .

At this time, when the eighth insulating layer 118 and the ninth insulating layer 119 are laminated, a primer layer 150 is formed on the upper surface of the eighth insulating layer 118 and the lower surface of the ninth insulating layer 119, respectively. is disposed, and a metal layer 155 may be disposed on the primer layer 150 . The metal layer 155 may serve to planarize the eighth insulating layer 118 and the ninth insulating layer 119 to have uniform heights. For example, the metal layer 155 may be disposed to improve the stacking reliability of the eighth insulating layer 118 and the ninth insulating layer 119 .

The primer layer 150 includes the eighth insulating layer 118 and the ninth insulating layer 119, respectively, and the first outer circuit pattern 130 and the second outer circuit pattern 140 to be respectively disposed on the upper and lower portions thereof. It can play a role in increasing the bonding force between them. That is, when the first outer layer circuit pattern 130 and the second outer layer circuit pattern 140 are disposed without the primer layer 150 , the eighth insulating layer 118 and the second outer layer circuit pattern 140 . The bonding force between them is low, so they can be separated from each other.

Meanwhile, although FIG. 9 illustrates that the primer layer 150 is disposed on the upper surface of the eighth insulating layer 118 and the lower surface of the ninth insulating layer 119 , respectively, the present invention is not limited thereto. For example, the primer layer 150 may be selectively disposed on the surface of the insulating layer on which the microcircuit pattern is to be disposed. That is, when only the first outer layer circuit pattern 130 is a micro circuit pattern, the primer layer 150 may be disposed only on the lower surface of the ninth insulating layer 119 . In addition, when only the second outer layer circuit pattern 140 is a micro circuit pattern, the primer layer 150 may be disposed only on the upper surface of the eighth insulating layer 118 . In addition, when the first outer circuit pattern 130 and the second outer circuit pattern 140 are both fine circuit patterns, the primer layer 150 is formed on the upper surface of the eighth insulating layer 118 and the ninth insulating layer. (119) can be all arranged on the lower surface.

Referring to FIG. 10 , when the eighth insulating layer 118 and the ninth insulating layer 119 are disposed, a via hole VH is formed in the eighth insulating layer 118 and the ninth insulating layer 119, respectively. to form In this case, the via hole VH may be formed not only in the eighth insulating layer 118 and the ninth insulating layer 119 , but also in the primer layer 150 and the metal layer 155 , respectively.

Next, referring to FIG. 11 , when the via hole VH is formed, an etching process of removing the metal layer 155 disposed on the primer layer 150 may be performed. For example, after the via hole VH is formed, a flash etching process may be performed to remove the metal layer 155 , and thus a process for exposing the surface of the primer layer 150 may be performed.

Next, referring to FIG. 12 , a via V forming process for filling the via hole VH may be performed, and thus the second outer layer circuit pattern 140 is formed on the upper surface of the eighth insulating layer 118 . and the first outer layer circuit pattern 130 may be formed on the lower surface of the ninth insulating layer 119 . In this case, in the embodiment, the first outer layer circuit pattern 130 is illustrated as a general circuit pattern rather than a fine circuit pattern. However, the present invention is not limited thereto, and the first outer layer circuit pattern 130 together with the second outer layer circuit pattern may be a fine circuit pattern. Accordingly, when the first outer circuit pattern 130 is a general circuit pattern, the primer layer 150 between the ninth insulating layer 119 and the first outer circuit pattern 130 may be omitted.

A second outer layer circuit pattern 140 is disposed on the upper surface of the eighth insulating layer 118 . In this case, the second outer layer circuit pattern 140 disposed on the upper surface of the eighth insulating layer 118 is the 2-1 outer layer circuit pattern 140a disposed in the open region R1 of the first protective layer 160 . and a 2-2 second outer layer circuit pattern 140b disposed in the arrangement region R2 of the first passivation layer 160 . In addition, each of the 2-1 th outer layer circuit pattern 140a and the 2-2 th outer layer circuit pattern 140b may correspond to a trace 141 that is a wiring line for signal transmission and an end of the trace 141 . and may include a pad 142 that is an area to which the component is to be attached.

Next, referring to FIG. 13 , a solder resist layer is disposed on the primer layer 150 to cover the second outer layer circuit pattern 140 . The solder resist layer formed at this time may be disposed in both the first region R1 and the second region R2 , and may be formed to have a height greater than that of the second outer layer circuit pattern 140 .

After the solder resist layer is formed, the solder resist layer may be exposed and developed to form the solder resist 160 having a different height for each area. Preferably, in an embodiment, the process of exposing the second region R2 of the solder resist layer to light and thus developing the first region R1 of the solder resist layer may be performed.

To this end, UV exposure is performed by masking only a desired area on the solder resist layer, and thereafter, in the unexposed area, tetramethylammonium hydroxide (TMAH) or trimethyl-2-hydroxyethylammonium hydroxide (choline), etc. The solder resist 160 may be formed by dipping the contained organic alkaline compound to perform a process of adjusting the height of the solder resist layer.

And, referring to FIG. 14 , as the above process is performed, the solder resist 160 may have a height lower than that of the second outer layer circuit pattern 140 in the first region R1 . For example, the solder resist 160 may expose the surface of the 2-1 th outer layer circuit pattern 140a disposed in the first region R1 . In addition, the solder resist 160 may be formed to cover the second-second outer layer circuit pattern 140b in the second region R2 .

In an embodiment, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a may have a value between 3 μm and 9 μm. In this case, it is preferable that the height H1 of the second-first outer layer circuit pattern 140a in the embodiment is 12 μm or more. When the height H1 of the 2-1 outer layer circuit pattern 140a is less than 12 μm, it may be difficult to implement a normal circuit pattern. Also, when the height H1 of the 2-1 outer layer circuit pattern 140a is less than 12 μm, signal transmission performance may be deteriorated. Accordingly, in the embodiment, in the condition that the height H1 of the 2-1 th outer layer circuit pattern 140a is 12 μm or more, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is Make it possible to have a value between 3 μm and 9 μm.

For example, the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is 3 , regardless of the total height H1 of the 2-1 th outer layer circuit pattern 140a. Make it possible to have a value between μm and 9 μm.

When the height of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is less than 3 μm, the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is There is a problem in that residual resin of the solder resist 160 remains on the surface. For example, when the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is less than 3 μm, copper (Cu) on the upper surface of the second portion 140a - 2 . There is a problem that the concentration appears to be 90% by weight or less. That is, when the copper (Cu) concentration on the surface of the second portion 140a-2 of the 2-1 th outer layer circuit pattern 140a is 90 wt% or less, the reliability of the 2-1 th outer layer circuit pattern 140a There is a problem with this decreasing.

In addition, when the height of the second portion 140a - 2 of the 2-1 th outer layer circuit pattern 140a is greater than 9 μm, the 2-1 th outer layer circuit pattern is formed by the first portion of the solder resist 160 . (140a) may not be stably supported. In addition, when the height of the second portion 140a-2 of the 2-1 outer layer circuit pattern 140a is greater than 9 μm, in the pretreatment process for the subsequent surface treatment, the second portion 140a-2 There are problems that can cause deformation

The circuit board in this embodiment includes an outer layer circuit pattern disposed on the outermost side. In this case, the outer layer circuit pattern includes a 2-1 outer layer circuit pattern disposed in the first area of the solder resist and a 2-2 outer layer circuit pattern disposed in the second area of the solder resist. At this time, the 2-2 outer layer circuit pattern can be supported by being surrounded by the solder resist, but the 2-1 outer layer circuit pattern does not have a support layer that can support it, so it can easily collapse due to various factors. have

Accordingly, in the embodiment, the second-first outer layer circuit pattern can be supported by using the solder resist. Accordingly, in the embodiment, problems such as collapsing or abrasion of the protruding outer layer circuit pattern can be solved by miniaturization of the outer layer circuit pattern, and thus product reliability can be improved. In particular, in the embodiment, it is possible to solve problems such as collapsing or abrasion of the outer layer circuit pattern in the first region, and thus product reliability can be improved.

In addition, in the embodiment, in forming the first region of the solder resist, it is removed using an exposure and development method rather than a sand blast method or a plasma method. In this case, when the solder resist is removed by sandblasting or plasma method, the outer layer circuit pattern may be deformed, and in some cases, the outer layer circuit pattern may have a triangular cross-section. In addition, when the cross section of the outer layer circuit pattern has a triangular shape, the adhesive member cannot be stably disposed on the outer layer circuit pattern, and thus reliability problems may occur. In contrast, in the embodiment, the solder resist may be removed without deformation of the outer layer circuit pattern, and thus reliability may be improved.

In addition, in the embodiment, the height of the second portion of the 2-1 outer layer circuit pattern (eg, the difference between the height of the first region of the solder resist and the height of the 2-1 outer layer circuit pattern) is 3 µm to 9 µm It should have a value between μm. Accordingly, in the embodiment, a reliability problem that may occur because the second portion of the 2-1 outer layer circuit pattern is not completely exposed, or the height of the second portion of the 2-1 outer layer circuit pattern is too large It is possible to solve problems such as pattern deformation or pattern collapse that may occur depending on

In addition, the circuit board in the embodiment can be applied to a 5G communication system, thereby minimizing transmission loss at high frequencies to further improve reliability. Specifically, the circuit board in the embodiment can be used at a high frequency and can reduce propagation loss.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

In the above, the embodiment has been mainly described, but this is only an example and does not limit the embodiment, and those of ordinary skill in the art to which the embodiment belongs are provided with several examples not illustrated above within the range that does not deviate from the essential characteristics of the embodiment. It can be seen that the transformation and application of branches are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And the differences related to these modifications and applications should be interpreted as being included in the scope of the embodiments set forth in the appended claims.

Claims (14)

an insulating layer including a first region and a second region;
a circuit pattern including a 1-1 circuit pattern disposed in the first region of the insulating layer and a 1-2 circuit pattern disposed in the second region of the insulating layer; and
a solder resist disposed on the first region and the second region of the insulating layer;
A height of the solder resist in the first region is lower than a height of the 1-1 circuit pattern,
A height of the solder resist in the second region is higher than a height of the first and second circuit patterns,
The 1-1 circuit pattern includes a first portion covered by the solder resist in the first region, and a second portion other than the first portion,
The height of the second part satisfies the range of 3 μm to 9 μm,
circuit board. According to claim 1,
The total height of the first 1-1 circuit pattern is 12 μm or more,
circuit board. 3. The method of claim 2,
The 1-1 circuit pattern includes a trace and a pad,
circuit board. 3. The method of claim 2,
The height of the solder resist in the second region satisfies 110% to 400% of the 1-2 circuit pattern,
circuit board. According to claim 1,
The copper concentration of the surface of the second part of the 1-1 circuit pattern is 90% by weight or more,
circuit board. According to claim 1,
The top surface of the solder resist,
a first upper surface in the first area and a second upper surface in the second area;
The surface roughness (Ra) of the first upper surface is different from the surface roughness (Ra) of the second upper surface,
circuit board. 7. The method of claim 6,
The upper surface of the solder resist includes an interface between the first upper surface and the second upper surface,
The surface roughness (Ra) of the interface is different from the surface roughness (Ra) of the first upper surface and the surface roughness (Ra) of the second upper surface,
circuit board. 8. The method of claim 7,
The surface roughness (Ra) of the first upper surface of the solder resist is greater than the surface roughness (Ra) of the second upper surface,
The surface roughness (Ra) of the interface is smaller than the surface roughness (Ra) of the first upper surface, and is larger than the surface roughness (Ra) of the second upper surface,
circuit board. According to claim 1,
The insulating layer includes a plurality of insulating layers,
The circuit pattern is
disposed to protrude on the upper surface of the uppermost insulating layer among the plurality of insulating layers,
circuit board. 10. The method of claim 9,
a primer layer disposed between the uppermost insulating layer and the circuit pattern and between the uppermost insulating layer and the solder resist,
circuit board. manufacturing an inner layer substrate,
forming an uppermost insulating layer on the inner layer substrate;
Forming a 1-1 circuit pattern and a 1-2 circuit pattern on the first region and the second region of the uppermost insulating layer, respectively;
forming a solder resist layer covering the 1-1 circuit pattern and the 1-2 circuit pattern on the uppermost insulating layer;
partially exposing and developing the solder resist layer to form solder resists having different heights in the first region and the second region;
A height of the solder resist in the first region is lower than a height of the 1-1 circuit pattern,
A height of the solder resist in the second region is higher than a height of the first and second circuit patterns,
The 1-1 circuit pattern includes a first portion covered by the solder resist in the first region, and a second portion other than the first portion,
The total height of the 1-1 circuit pattern is 12 μm or more,
Forming the solder resist,
and partially exposing and developing the solder resist layer so that the height of the second portion satisfies a range of 3 μm to 9 μm,
A method for manufacturing a circuit board. 12. The method of claim 11,
The height of the solder resist in the second region satisfies 110% to 400% of the 1-2 circuit pattern,
A method for manufacturing a circuit board. 12. The method of claim 11,
The copper concentration of the surface of the second part of the 1-1 circuit pattern is 90% by weight or more,
A method for manufacturing a circuit board. 12. The method of claim 11,
The top surface of the solder resist,
a first upper surface in the first region, a second upper surface in the second region, and a boundary surface between the first upper surface and the second upper surface;
The surface roughness (Ra) of the first upper surface of the solder resist is greater than the surface roughness (Ra) of the second upper surface,
The surface roughness (Ra) of the interface is smaller than the surface roughness (Ra) of the first upper surface, and is larger than the surface roughness (Ra) of the second upper surface,
A method for manufacturing a circuit board.

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