KR20230153955A - Circuit board with insulation reinforcement structure - Google Patents

Abstract

A circuit board according to an embodiment of the present invention includes a base film, a metal pattern disposed on one side of the base film and including an edge, an adhesive layer covering the metal pattern and the base film, a protective film covering the adhesive layer, and the metal. It includes an insulating reinforcement material filled in a corner portion that meets the base film at least in part of the border of the pattern.

Description

Circuit board with insulation reinforcement structure}

The present invention relates to circuit boards. More specifically, it relates to a circuit board in which the metal pattern on the circuit board has vulnerable parts that are prone to short circuit, corrosion, and deformation.

A circuit board includes metal wires that electrically interconnect circuit elements such as semiconductors/condensers/resistors. These circuit boards are widely used in various industrial fields.

Metal wiring is formed on a circuit board, and to protect the metal wiring, an adhesive layer is formed on the upper surface and then covered with a protective film.

However, because part of the metal wiring must be connected to a certain terminal, the protective film does not cover all parts of the metal wiring. That is, the protective film includes an opening to expose a portion of the metal pattern, such as a metal wire or a metal terminal, and the protective film with the opening is attached to the substrate so that a portion of the metal pattern is exposed to the upper surface of the substrate.

Chemicals are used in the post-processing of the substrate on which the protective film is formed. During this process, chemicals may flow in through the openings, causing metal patterns to be short-circuited, corroded, or deformed. Alternatively, defects may occur due to weakened adhesion between the metal patterns and the protective film.

One object of the present invention is to prevent short circuits that may occur during post-processing of circuit boards.

One object of the present invention is to prevent corrosion or discoloration that may occur during post-processing of a circuit board.

One object of the present invention is to prevent adhesion defects that may occur in post-processing of circuit boards.

The problem of the present invention is not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below.

A circuit board according to an embodiment of the present invention includes a base film, a metal pattern disposed on one side of the base film and including an edge, an adhesive layer covering the metal pattern and the base film, a protective film covering the adhesive layer, and the metal. It includes an insulating reinforcement material filled in a corner portion that meets the base film at at least a portion of the edge of the pattern, and each of the adhesive layer and the protective film includes a portion of the metal pattern and a portion of the base film adjacent to the portion of the metal pattern. It may include an opening exposing the.

In one embodiment, at least a portion of the insulating reinforcement may overlap the metal pattern in a planar direction.

In one embodiment, all of the insulating reinforcement may not overlap the area where the opening is disposed in the planar direction.

In one embodiment, a second insulating reinforcement connected to the insulating reinforcement may be disposed between the metal pattern and the adhesive layer.

In one embodiment, the insulating reinforcement material may be formed including at least one selected from the group consisting of polyester (PE), epoxy resin, acrylic resin, silicone resin, and fluorine resin.

According to the circuit board according to an embodiment of the present invention, metal patterns including openings may be exposed. Accordingly, the exposed terminal contact portion is connected to a predetermined terminal so that the circuit board can perform a specific function. At the same time, parts of the metal pattern that are not in contact with the terminal, including the metal pattern covered with the protective film, can be protected. Accordingly, the durability of the circuit board can be improved and its useful life can be improved.

The reinforcing material has insulating properties, so electrical connections between circuits or dissimilar circuits that were not intended by the manufacturer of the circuit board may not occur.

Since the passage through which chemicals can move along the pores is limited, the movement of chemicals can be controlled.

If the insulating reinforcement material is placed in the above position, inappropriate chemical reactions may not occur and disconnection of the circuit may not occur. In addition, defects in the circuit board can be prevented and defects in characteristics may not occur when assembling a set. Additionally, corrosion or discoloration of metal patterns caused by chemicals can be prevented. In addition, it is possible to prevent a decrease in adhesion due to bubbles or lifting phenomenon occurring between the metal pattern and the protective film due to chemicals.

Accordingly, characteristic defects can be prevented in advance, thereby improving the quality and reliability of the circuit board.

The insulating reinforcement may be formed continuously to intersect the electrode pattern. Accordingly, convenience and economic efficiency can be improved in the printing process of the insulating reinforcement material.

1 is a plan view of a circuit board according to an embodiment of the present invention.
2 and 3 are plan views of a circuit board according to an embodiment of the present invention.
4, 5, and 6 are cross-sectional views of a circuit board according to an embodiment of the present invention.

The meaning of terms described in this specification should be understood as follows.

Singular expressions should be understood to include plural expressions unless the context clearly defines otherwise, and terms such as “first” and “second” are used to distinguish one element from another element. The scope of rights should not be limited by these terms.

Terms such as “include,” “have,” or “equipped” do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. It must be understood.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, “at least one of the first, second, and third items” means each of the first, second, or third items, as well as two of the first, second, and third items. It means a combination of all items that can be presented from more than one.

The term “at least a portion” should be interpreted as being able to refer to all parts, from the minimum to the maximum, of an object.

The term “on” means not only the case where a certain component is formed directly on top of another component, but also the case where a third component is interposed between these components.

The term “pattern” does not necessarily mean a case in which a shape is arranged repeatedly, but may also mean any arbitrary shape that is not repetitive. For example, a metal pattern refers not only to repetitive parts of metal, but also to all shapes in which metal is drawn.

Hereinafter, a circuit board and its manufacturing method according to an embodiment of the present invention will be described in detail with reference to the attached drawings. In adding reference numerals to components in each drawing, identical components may have the same reference numerals as much as possible even if they are shown in different drawings.

Additionally, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

1A and 1B are plan views of a circuit board according to an embodiment of the present invention. In Figure 1b, the protective film 150 is omitted.

Referring to the coordinate system of FIG. 1A, the direction looking at arbitrary planes parallel to the xy plane is the plane direction of the circuit board according to one embodiment.

Referring to FIGS. 1A and 1B , a circuit board according to an embodiment of the present invention may include a base film 100 and a metal pattern 110 disposed on one surface of the base film 100 .

The base film 100 is not particularly limited, but includes polyimide (PI), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and urethane ( Urethane), and fluorine-based compounds.

The circuit board may include an adhesive layer 140 covering the metal pattern 110 and the base film 100, and a protective film 150 covering the adhesive layer 140. The adhesive layer 140 may be formed on one side of the protective film 150. The protective film 150 may be attached to the metal pattern 110 by the adhesive layer 140. Accordingly, the adhesion between the protective film 150 and the base film 100 can be improved.

The adhesive layer 140 may cover an area on the base film 100 where the metal pattern 110 is disposed and an area where the metal pattern 110 is not disposed.

The type of adhesive layer 140 is not limited as long as it can attach the protective film 150 and the base film 100. Preferably, the adhesive layer 140 may be formed including at least one selected from the group consisting of epoxy resin and acrylic resin.

In the circuit board according to one embodiment, the adhesive layer 140 may be in a semi-cured state. When in an appropriately cured state, the adhesion between the protective film 150 and the base film 100 is improved, and the fixing effect of the protective film 150 can be improved.

Since the metal pattern 110 is wrapped by the protective film 150, the metal pattern 110 is not exposed to chemicals and/or chemicals used in the circuit board manufacturing process, post-processing process, or set assembly process. You can. Accordingly, physical/chemical damage to the circuit board can be prevented.

The protective film 150 is not particularly limited thereto, but includes polyimide (PI), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and urethane. It may be formed including at least one selected from the group consisting of (Urethane) and fluorine-based compounds.

The metal pattern 110 may include a portion (hereinafter, abbreviated as “terminal contact portion”) where at least a portion thereof is disposed.

The terminal contact portion may be a portion of the circuit board that contacts or is connected to a predetermined terminal. The predetermined terminal is not limited thereto, but may be various components such as a semiconductor, condenser, resistor, or circuit board.

In one embodiment, the circuit board may include a region (hereinafter abbreviated as “opening region”) including terminal contact portions.

The size of the opening area may be larger than the terminal contact area. The size of the opening area may be substantially the same as the size of the desired terminal to be in contact with the terminal contact portion.

The circuit board may include an opening 160 formed by removing both the adhesive layer 140 and the protective film 150 on the opening area.

The shape of the opening 160 may be substantially the same as the opening area.

The adhesive layer 140 and the protective film 150 may include openings corresponding to the opening areas. A portion of the metal pattern 110 and a portion of the base film 100 adjacent thereto may be exposed through the opening.

In more detail, when the opening 160 is viewed from a planar direction, the terminal contact portion may be revealed or exposed. The exposed terminal contact portion is connected to a predetermined terminal so that the circuit board can perform a specific function. At the same time, parts of the metal pattern that are not in contact with the terminal, including the metal pattern 110 covered with a protective film, can be protected. Accordingly, the durability of the circuit board can be improved and its useful life can be improved.

The adhesive layer 140 and the protective film 150 may cover the metal patterns 110, 115, and 125. Accordingly, when one side of the circuit board is viewed in a planar direction, the remaining metal pattern portions 115 and 125 may not be exposed except for the metal pattern 110 exposed by the opening. Unexposed metal patterns 115 and 125 are not shown in FIG. 1 .

2 and 3 are plan views of a circuit board according to an embodiment of the present invention. In FIG. 2, for convenience of explanation, the remaining base film area excluding the adhesive layer 140, the protective film 150, and a portion of the base film 100 (e.g., a portion of the base film adjacent to a portion of the metal pattern exposed in the opening) ) has been omitted.

The shapes of the metal patterns 110, 115, and 125 are not particularly limited. As described above, a pattern may not necessarily mean a case in which a certain shape is repeatedly arranged. For example, the metal pattern may be a pattern in which one end formed in a 'T' shape and the other end formed in an 'O' shape are connected to each other. Alternatively, it may have a form that includes one end and the other end extending in a random direction therefrom and has the shape of a circle at any point in the extending direction. Alternatively, it may be substantially the same as an unfolded wristwatch including a watch strap. Alternatively, it may only have an 'O' shape or a polygonal shape. Alternatively, it may be any pattern shape including the above shapes.

The metal patterns 110, 115, and 125 may include the terminal contact portion described above.

The metal patterns 110, 115, and 125 may include first metal patterns 110 and 115 including the terminal contact portion 110 exposed by the opening. The metal pattern may include a second metal pattern 125 disposed to be spaced apart from the first metal patterns 110 and 115 .

The first metal patterns 110 and 115 and the second metal patterns 125 may be heterogeneous circuits. Heterogeneous circuits may mean that the magnitude of the current flowing or applied voltage to the corresponding circuit is of a different type.

Alternatively, a heterogeneous circuit may mean that the types of metals that make up the circuit are different. For different types of circuits, if an unsuitable chemical comes into contact with each circuit (for example, when a chemical suitable for a first circuit comes into contact with a second circuit), the chemical properties of each circuit may change. You can. As a result, a circuit short may occur or the circuit board may not function properly. Alternatively, chemicals may cause corrosion or discoloration of metal patterns. Alternatively, chemicals may cause bubbles or lifting between the metal pattern and the protective film, reducing adhesion.

Therefore, when any chemical treatment is performed on the first metal patterns 110 and 115, it is necessary to ensure that the chemical treatment is not applied to the second metal pattern 125.

In some embodiments, the circuit board may include insulating reinforcement (130, 135).

The insulating reinforcements 130 and 135 have insulating properties because they are in contact with at least a portion (eg, edges) of the metal patterns 110 and 115. If it is conductive, electrical connections between circuits or heterogeneous circuits may occur that were not intended by the manufacturer of the circuit board. Accordingly, the insulating reinforcement materials 130 and 135 may not include a conductive material.

The insulating reinforcements 130 and 135 may be formed of an insulating material. For example, but not limited thereto, the insulation reinforcement materials 130 and 135 may be made of polyester-based resins, epoxy-based resins, acrylic-based resins, or silicone-based resins. It may be formed by including at least one selected from the group consisting of (silicone-based resins) and fluorine-based resins.

The circuit board according to one embodiment may include only the first insulating reinforcement 130 that does not overlap the metal patterns 110 and 115 in the planar direction (see FIG. 3). In this case, the amount of insulating reinforcement used is reduced, so a circuit board with improved reliability can be manufactured at a low cost.

The insulating reinforcements 130 and 135 may include a first insulating reinforcement 130 that does not overlap the metal patterns 110 and 115 in the planar direction, and a second insulating reinforcement 135 that overlaps the metal patterns 110 and 115 in the planar direction.

By including the second insulating reinforcement 135, the insulating reinforcement may be formed on at least a portion of the edges of the metal patterns 110 and 115. This prevents inappropriate chemicals from being directed to non-target circuits and reduces circuit breakage.

The insulating reinforcements 130 and 135 may be formed to correspond to at least a portion of the edges of the metal patterns 110 and 115.

The insulating reinforcements 130 and 135 may be formed on the metal patterns 110 and 115 using an inkjet, printing, or dispenser method. In one embodiment, the insulating reinforcement material, like the first insulating reinforcement material 130, may be printed to substantially correspond to the edges of the metal patterns 110 and 115.

However, when printing in a manner that covers the metal patterns 110 and 115, when forming an insulating reinforcement on the metal patterns 110 and 115, including the second insulating reinforcement 135 (see FIG. 2), the insulating reinforcement is applied at once. It has the advantage of being convenient because it can be printed.

In one embodiment, the insulating reinforcements 130 and 135 may not overlap the opening area in the planar direction. The opening may expose components within the circuit board that may need to be treated with chemicals. When the insulating reinforcements 130 and 135 and the opening area overlap each other, the structure that should be exposed is obscured by the insulating reinforcements, and desirable chemical treatment may not be performed.

The insulating reinforcements 130 and 135 can be printed at an appropriate location in consideration of the position of the opening 160 through which chemicals can enter and the voids that may occur when the protective film 150 with the adhesive layer 140 is attached. there is.

For example, when a gap is formed corresponding to the edges of the electrode patterns 110 and 115, this may serve as a passage through which chemicals flowing into the opening 160 can move. Therefore, any point inside the passage can be appropriately selected and the insulating reinforcement materials 130 and 135 can be printed based on this. Accordingly, the path through which chemicals can move along the pores is limited, so the movement of chemicals can be controlled.

In one embodiment, the insulating reinforcements 130 and 135 may have a shape substantially the same as the edge shape of the metal patterns 110 and 115. However, it is not limited to this and can be printed in any form as long as it is in a form that can block the flow of incoming chemicals.

For example, the insulating reinforcements 130 and 135 may have a 'U' shape or a 'horseshoe' shape that surrounds the opening 160 and is open on one side, or may have an upside-down shape of these shapes. Alternatively, it may have a polygonal shape formed by intersecting the longitudinal direction of the metal patterns 110 and 115.

FIG. 4 is a cross-sectional view showing a portion of the circuit board taken along line A-A' in FIG. 2A.

Referring to FIG. 4 , in a longitudinal cross-section of a circuit board according to one embodiment, the second insulating reinforcement 135 may be disposed between the metal pattern 115 and the adhesive layer 140. The second insulating reinforcing material 135 is connected to the first insulating reinforcing material 130 and may function as a single insulating reinforcing material.

Additionally, the circuit board including the second insulating reinforcement 135 may be formed continuously so that the insulating reinforcement 135 intersects the electrode patterns 110 and 115. Accordingly, convenience and economic efficiency can be improved in the printing process of the insulating reinforcement materials 130 and 135.

While the adhesive layer 140 and the protective film 150 cover the metal patterns 110 and 115, voids may occur.

The gap may be a space formed by the insulating reinforcement 130 in FIG. 4 and surrounded by the edges of the metal patterns 110 and 115, one side of the base film 100, and the adhesive layer 140. The adhesive layer 140 may be in a semi-cured state.

Specifically, the viscosity and/or thickness of the adhesive layer 140 may not be high enough to fill the side portions of the metal patterns 110 and 115.

There may be a height difference between a portion where the metal patterns 110 and 115 exist and a portion where the metal patterns 110 and 115 do not exist. In the process of applying the protective film 150 including the adhesive layer 140, the adhesive layer 140 is not filled up to the corner portion 120 between the edges of the metal patterns 110 and 115 and the base film 100 due to the step. Otherwise, voids may occur.

In some embodiments, since the opening 160 is a part where the adhesive layer 140 and the protective film 150 are removed, a gap 170 is formed on the edges of the metal patterns 110 and 115 that overlap the opening 160 in the planar direction. ) may not occur. Accordingly, the insulating reinforcements 130 and 135 may not need to be arranged to overlap the opening 160 in the planar direction.

The edges of the metal patterns 110 and 115 may be both sides or both edges of the metal patterns 110 and 115.

On one side of the base film 1000, a corner portion 120 or an edge may be formed between the edge and the base film 100 due to the height of the metal patterns 110 and 115.

The corner portion 120 may be located on the lower side of the air gap. The corner portion 120 may be a portion where at least a portion of the edge meets the base film 100.

The void formed due to unfilling of the adhesive layer 140 may be adjacent to the opening area where the opening 160 is formed. “Adjacent” may mean close enough to block the flow of chemicals introduced through the opening 160 through the pores formed along the edges of the metal patterns 110 and 115. .

FIG. 5 is a cross-sectional view showing a portion of the circuit board taken along line B-B' in FIG. 2.

Referring to FIG. 5 , the circuit board to which the adhesive layer 140 and the protective film 150 are attached may include a portion where voids are formed and a portion where voids are not formed. In FIG. 5 , an air gap may refer to a space where the insulating reinforcement material 130 is disposed.

If the height difference between the metal patterns 110 and 115 and the base film 100 is not affected, a gap may not be created. In this case, the adhesive layer 140 may be in contact with the base film 100.

For example, if the area where the adhesive layer 140 covers the base film 100 is sufficiently far away from the area where the electrode patterns 110, 115, and 125 are formed, the adhesive layer 140 and the base film 100 are substantially in contact with each other. Voids may not appear.

The thickness T1 of the adhesive layer 140 may be sufficiently increased to prevent voids from occurring. For example, the thickness T1 of the adhesive layer 140 may be 60% or more and less than 200% of the thickness T2 of the metal patterns 110 and 115. In this case, the amount of insulating reinforcement materials 130 and 135 used may be reduced because the volume of the generated void is reduced. Accordingly, there is an economic advantage.

Figure 6 is a cross-sectional view showing a portion of the circuit board cut along line C-C' in Figure 2.

Referring to FIG. 6, edge portions of the electrode patterns 110 and 115 are shown. The edges of the electrode patterns 110 and 115 where the insulating reinforcement 130 is not disposed appear in the C' side direction. As described above, a gap 170 is shown at the edge of the electrode pattern, and an opening 160 is shown when looking further toward C'.

After the protective film 150 is attached, post-processing may be performed on the circuit board. Post-processing may include, for example, a pretreatment process and/or a plating process. Chemicals may be used in post-processing. Chemicals may cause an appropriate chemical reaction in the first metal patterns 110 and 115 through the opening 160.

Since a gap 170 is formed along the edge, the chemicals can flow into the circuit board along the edge. In this case, the chemical may move to the second metal pattern 125, which is a heterogeneous circuit, and initiate a chemical reaction that is not appropriate for the second metal pattern 125.

The insulating reinforcement material 130 may fill at least a portion of the void 170 formed between at least a portion of the edge of the metal pattern 160 and the base film 100 . Alternatively, the insulating reinforcement 135 may be connected to the insulating reinforcement 130 and disposed between the electrode 115 and the adhesive layer 140.

In this case, the flow and/or movement of chemicals flowing along the edge may be blocked by the insulating reinforcement material 130.

The filled insulating reinforcement 130 may be in an ink state. The “ink state” may mean a state having a viscosity that sufficiently fills the corner portion 120 so that chemicals flowing through the opening 160 do not penetrate or penetrate.

If the insulating reinforcement 130 is disposed at the above position, an inappropriate chemical reaction may not occur and a disconnection of the circuit may not occur. In addition, defects in the circuit board can be prevented and defects in characteristics may not occur when assembling a set. Accordingly, characteristic defects can be prevented in advance, thereby improving the quality and reliability of the circuit board.

Since the circuit board includes the insulating reinforcing material 130, the volume of the air gap 170 has the advantage of being larger than when the insulating reinforcing material 130 is not included. In other words, the thickness of the adhesive layer 140 used may not need to be sufficiently increased.

According to some embodiments, the total thickness of the adhesive layer 140 and the protective film 150 may be greater or less than the thickness of the metal pattern 110. The circuit board according to one embodiment has the advantage of improving the reliability of the board by preventing disconnection of the circuit even when the total thickness is less than the thickness of the metal pattern 110.

According to one embodiment, the thickness T1 of the adhesive layer 140 may be 5% or more and less than 200% of the thickness T2 of the metal patterns 110 and 115. For example, the thickness T1 of the adhesive layer 140 may be 5% or more and less than 100%, or 5% or more and less than 80% of the thickness T2 of the metal patterns 110 and 115. As the adhesive layer can be formed thinly according to the needs of design characteristics, the design needs of the circuit board can be met and ultimately the manufacturing cost of the board can be reduced. Additionally, circuit boards can be manufactured economically and environmentally friendly.

Additionally, according to one embodiment, even when the protective film 150 needs to be formed thinly depending on the purpose of the circuit board, disconnection of the circuit may not occur or a defect in the board itself may occur.

In the method of manufacturing a circuit board according to an embodiment of the present invention, metal patterns 110 and 115 are formed on the base film 100 and at least a portion of the edges of the metal patterns 110 and 115 and the base film 100 are formed. A process of printing the insulating reinforcement materials 130 and 135 on the meeting corner portions 120 may be performed. The protective film 150, which includes an opening and has an adhesive layer 140, is attached to the base film 100.

Although embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: base film
110, 115: first metal pattern
120: corner part
125: second metal pattern
130, 135: Insulating reinforcement
140: Adhesive layer
150: protective film
160: opening
170: void

Claims (5)

base film;
a metal pattern disposed on one side of the base film and including an edge;
an adhesive layer covering the metal pattern and the base film;
A protective film covering the adhesive layer; and
At least a portion of the edge of the metal pattern includes an insulating reinforcement material filled in a corner portion that meets the base film,
Each of the adhesive layer and the protective film,
A circuit board comprising an opening exposing a portion of the metal pattern and a portion of the base film adjacent to the portion of the metal pattern.
According to claim 1,
A circuit board, wherein at least a portion of the insulating reinforcement material overlaps the metal pattern in a planar direction.
According to clause 2,
The circuit board, wherein the insulating reinforcement does not overlap in a planar direction with the area where the opening is disposed.
According to claim 1,
A circuit board, wherein a second insulating reinforcing material connected to the insulating reinforcing material is disposed between the metal pattern and the adhesive layer.
According to claim 1,
The circuit board wherein the insulating reinforcement material includes at least one selected from the group consisting of polyester (PE), epoxy resin, acrylic resin, silicone resin, and fluorine resin.

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