Printed circuit board

Abstract

A printed circuit board according to one embodiment of the present invention comprises: a substrate portion having first and second insulating layers formed on both sides and a circuit layer formed between the first and second insulating layers; an electrical component mounted in an exposed area where the circuit layer is exposed by removing a portion of the first insulating layer; and a component reinforcement portion attached to the second insulating layer of the exposed area and supporting the electrical component. The component reinforcement portion comprises a component reinforcement plate bonded to the second insulating layer of the exposed area, a component adhesive layer formed between the second insulating layer and the component reinforcement plate, and a discharge path for discharging bubbles within the component adhesive layer. The substrate portion further comprises a pattern fuse portion formed in such a way that a portion of the circuit layer can function as a fuse. The pattern fuse portion is characterized by including a melting portion that melts faster than other parts of the circuit layer at a current above a certain level, thereby preventing lifting of the electrical component and improving the reliability and durability of the product.

Description

Technology Field

[0001] The present invention relates to a printed circuit board, and more specifically, to a printed circuit board in which an internal circuit is printed and electrically connected to other components to complete a circuit. Background Technology

[0002] A printed circuit board is a circuit board with patterned internal circuits printed on it, designed to fix and connect multiple electronic components in a standardized manner; by mechanically and electrically combining multiple circuits, it enables the miniaturization and lightweighting of electrical products.

[0003] Printed circuit boards offer the advantages of stabilized circuit characteristics, no risk of wiring errors, and low production costs. Due to these various benefits, printed circuit boards are used in diverse fields and have become essential core components in all electronic devices. In particular, the use of flexible printed circuit boards is increasing in recent years to align with the trend toward miniaturization and lightweighting.

[0004] Electrical components such as connectors and terminals are mounted on one side of such printed circuit boards and connected to each circuit; in order to prevent damage to the printed circuit board, particularly flexible printed circuit boards, a reinforcing plate is attached to the other side using adhesive. However, when soldering is performed to electrically connect the electrical components to each circuit, there was a problem in that the temperature rises due to soldering, causing air bubbles in the adhesive to expand, significantly reducing the stability of the electrical connection with the components and resulting in defects due to reduced flatness.

[0005] Therefore, there is a growing demand for lighter printed circuit boards that allow for the stable installation of various electronic components. The problem to be solved

[0006] The embodiments of the present invention are devised to solve the above-mentioned problems and aim to provide a lightweight printed circuit board with improved product reliability and productivity. means of solving the problem

[0007] To solve the above problem, the present invention provides a printed circuit board comprising: a substrate portion having first and second insulating layers formed on both sides and a circuit layer formed between the first and second insulating layers; an electrical component mounted in an exposed area where the circuit layer is exposed by removing a portion of the first insulating layer; and a component reinforcement portion attached to the second insulating layer of the exposed area and supporting the electrical component; wherein the component reinforcement portion includes a component reinforcement plate bonded to the second insulating layer of the exposed area, a component adhesive layer formed between the second insulating layer and the component reinforcement plate, and a discharge path for discharging bubbles within the component adhesive layer; wherein the substrate portion further includes a pattern fuse portion formed in such a way that a portion of the circuit layer can function as a fuse, and the pattern fuse portion includes a melting portion that melts faster than other parts of the circuit layer at a current above a certain level.

[0008] The above electrical component preferably has a connection portion formed that is electrically contacted by soldering with the circuit layer exposed in the above exposed area, and the discharge path is preferably formed corresponding to the location of the connection portion.

[0009] It is effective for the above discharge path to be formed as an air tunnel in which the component adhesive layer is removed from the location of the connection part to one end of the exposed area.

[0010] It is preferable that the above discharge path be formed as an air hole penetrating the component reinforcing plate and the component adhesive layer at the location of the connection part.

[0011] It is effective for the above discharge path to be formed as a horizontal discharge path formed by removing the component adhesive layer at the location of the connection part, and a vertical discharge path formed by penetrating the component reinforcing plate so as to communicate with the horizontal discharge path.

[0012] In the above-mentioned exposed area, a fixed circuit is formed in which the above-mentioned electrical component is fixed by soldering, and the above-mentioned discharge path is additionally formed corresponding to the position of the above-mentioned fixed circuit.

[0013] The pattern fuse section preferably further includes connection pads formed at both ends of the melting section.

[0014] It is effective for the width of the above connection pad to be wider than the width of the above molten part.

[0015] At least one of the first insulating layer and the second insulating layer on which the connection pad is formed may not be formed, so the connection pad may be exposed to the outside.

[0016] It is effective to apply a protective coating solution to the upper side of the above connection pad.

[0017] It is preferable that the above pattern fuse part further includes an interference prevention part in which the circuit layer is removed, and which surrounds the melting part.

[0018] The above pattern fuse section is effective in further including a concentrated melting section in which at least one of the first insulating layer and the second insulating layer in at least a portion of the melting section is open.

[0019] It is preferable to apply a protective coating liquid to the open surface of the above concentrated melting part.

[0020] The pattern fuse portion is formed as a closed curve surrounding the pattern fuse portion, and it is effective to further include an overflow prevention portion formed by protruding from at least one of the first insulating layer and the second insulating layer.

[0021] The above pattern fuse section may be implemented by including a connecting wire connected to one end of the melting section; and a connection pad formed by connecting the connecting wire.

[0022] It further includes a fuse reinforcement member formed on one side of the pattern fuse member and supporting the pattern fuse member; wherein the fuse reinforcement member includes a fuse adhesive layer attached to at least one of the first and second insulating layers of the pattern fuse member; and a fuse reinforcement plate attached to the fuse adhesive layer.

[0023] It is effective to form the above fuse adhesive layer in the remaining portion excluding the location corresponding to the melted portion, thereby forming a void portion at the location corresponding to the melted portion.

[0024] It is preferable that the above-mentioned fuse reinforcement member further includes a fuse reinforcement member fixing hole formed by penetrating the above-mentioned fuse reinforcement member. Effects of the invention

[0025] According to the means for solving the problem of the present invention as described above, various effects including the following can be expected. However, the present invention is not required to exhibit all of the following effects to be valid.

[0026] The printed circuit board of the present invention has a discharge channel formed to discharge air bubbles within the adhesive layer corresponding to an exposed area where electronic components are mounted, thereby preventing the electronic components from lifting and providing a more stable electrical connection with the circuit layer.

[0027] In addition, it prevents the flatness of the circuit board from deteriorating due to the lifting of electrical components, thereby significantly reducing the defect rate, while also ensuring the fixing strength of the components to improve durability against continuous vibrations caused by vehicle operation.

[0028] In addition, in the discharge path of another embodiment, a discharge path penetrating the reinforcing plate is formed so that air bubbles generated in the adhesive layer are immediately removed in the stacking direction, thereby maximizing the above-mentioned effect.

[0029] In addition, by providing a pattern fuse section, the present invention can realize a lighter printed circuit board compared to using a conventional chip fuse.

[0030] In addition, there is an advantage in that defects in the pattern fuse section can be tested in advance during the manufacturing stage through the connection pad.

[0031] In addition, by providing an interference prevention section, a concentrated melting section, and an overflow prevention section, the reliability of the melting characteristics of the melting section can be increased. Brief explanation of the drawing

[0032] FIG. 1 is a schematic diagram of a printed circuit board of a first embodiment of the present invention. FIG. 2 is an exploded perspective view of part A of FIG. 1. FIG. 3(a) is a plan view of the reinforcement section of part A in FIG. 1. FIG. 3(b) is a cross-sectional view along the III-III direction of section A in FIG. 1. FIG. 4(a) is a plan view of a reinforcement section illustrating a modified example of an exhaust path. FIG. 4(b) is an exploded perspective view of FIG. 4(a). FIG. 5(a) is a plan view of a reinforcement showing another modified example of the discharge path of FIG. 1. FIG. 5(b) is an exploded perspective view of FIG. 5(a). FIG. 6(a) is a cross-sectional view in the direction VIa-VIa of FIG. 4(a) with electrical components mounted. FIG. 6(b) is a cross-sectional view in the direction VIb-VIb of FIG. 5(a) with electrical components mounted. FIG. 7 is an enlarged view of the pattern fuse section of FIG. 1. FIG. 8 is a cross-sectional view along the cutting line VIII-VIII of FIG. 7. FIG. 9 is a cross-sectional view along the cutting line IX-IX of FIG. 7. FIG. 10 is a plan view illustrating a modified example of the connection pad of FIG. 7. FIGS. 11 to 14 illustrate a pattern fuse portion of a printed circuit board of a second embodiment, wherein FIG. 11 is a plan view of the pattern fuse section. FIG. 12 is a bottom view of FIG. 8 FIG. 13 is a cross-sectional view along the cutting line XIII-XIII of FIG. 11. FIG. 14 is a plan view of the adhesive layer of FIG. 11. Specific details for implementing the invention

[0033] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. However, in order not to obscure the essence of the present invention, descriptions of known functions or configurations are omitted.

[0034] Additionally, for the sake of convenience of explanation, the direction in which the printed circuit board is extended is defined as the extension direction, the direction in which the insulating layer and the circuit layer are laminated is defined as the lamination direction, the direction in which the connector is mounted is defined as the upper side of the lamination direction, and the direction in which the reinforcement is formed is defined as the lower side of the lamination direction.

[0035] FIG. 1 is a schematic diagram of a printed circuit board according to a first embodiment of the present invention, FIG. 2 is an exploded perspective view of part A of FIG. 1, FIG. 3(a) is a plan view of the reinforcing part of part A of FIG. 1, FIG. 3(b) is a cross-sectional view in the direction III-III of part A of FIG. 1, FIG. 4(a) is a plan view of the reinforcing part illustrating a modified example of the discharge path, FIG. 4(b) is an exploded perspective view of FIG. 4(a), FIG. 5(a) is a plan view of the reinforcing part illustrating another modified example of the discharge path of FIG. 1, FIG. 5(b) is an exploded perspective view of FIG. 5(a), FIG. 6(a) is a cross-sectional view in the direction VIa-VIa of FIG. 4(a) with electrical components mounted thereon, FIG. 6(b) is a cross-sectional view in the direction VIb-VIb of FIG. 5(a) with electrical components mounted thereon, FIG. 7 is an enlarged view of the pattern fuse section of FIG. 1, FIG. 8 is a cross-sectional view along the cutting line VIII-VIII of FIG. 7, FIG. 9 is a cross-sectional view along the cutting line IX-IX of FIG. 7, and FIG. 10 is a plan view showing a modified example of the connection pad of FIG. 7.

[0036] Referring to these drawings, a printed circuit board (10) of one embodiment of the present invention comprises a substrate portion (100) having first and second insulating layers (101, 102) formed on both sides and a circuit layer (103) formed between the first and second insulating layers (101, 102), an electrical component (200) mounted in an exposed area (131) where the circuit layer (103) is exposed by removing a portion of the first insulating layer (101), and a component reinforcement portion (300) formed on one side of the exposed area (131) to support the electrical component (200).

[0037] A substrate portion (100) comprises a circuit layer (103) in which an internal circuit is formed as a pattern, a first insulating layer (101) is laminated on the upper side of the stacking direction of the circuit layer (103), and a second insulating layer (102) is laminated on the lower side of the stacking direction of the circuit layer (103) to electrically connect the external components and the circuit layer (103) to complete a plurality of circuits. At this time, the first and second insulating layers (101, 102) support the thinly formed circuit layer (103) to prevent the internal circuit from being damaged, such as by a disconnection, and protect the circuit layer (103) by preventing phenomena such as short circuits with other surrounding components. Accordingly, the circuit layer (103) has a plurality of internal circuits formed as a pattern, and the first and second insulating layers (101, 102) are formed to cover the entire internal circuit on both sides of the stacking direction so that all circuit layers (103) are not exposed to the outside.

[0038] In the above description, each component configured in the thickness direction of the substrate portion (100) has been described. Below, each component arranged in a planar shape will be described in more detail, classified according to the shape or function of the substrate portion (100).

[0039] The substrate portion (100) includes a body portion (110) formed vertically by the aforementioned first and second insulating layers (101, 102) and circuit layer (103), a component mounting portion (130) in which the aforementioned electrical component (200) is mounted according to function in the horizontal direction, and a pattern fuse portion (150) formed in a shape such that a part of the circuit layer (103) can function as a fuse.

[0040] The pattern fuse section (150) includes a melting section (151) that melts faster than other parts of the circuit layer (103) at a certain current or higher, connection pads (152) formed at both ends of the melting section (151), an interference prevention section (153) that surrounds the melting section (151) and has the circuit layer (103) removed, a concentrated melting section (154) in which at least one of the first insulating layer (101) and the second insulating layer (102) is open in at least a portion of the melting section (151), and an overflow prevention section (155) formed as a closed curve surrounding the pattern fuse section (150) and protruding from at least one of the first insulating layer (101) and the second insulating layer (102).

[0041] The pattern fuse section (150) may consist of a single melting section (151), but as shown in FIG. 7, a plurality of melting sections (151) may be formed in a cluster. The interference prevention section (153) and the overflow prevention section (155) are formed in a shape that surrounds the entire plurality of melting sections (151).

[0042] The molten portion (151) is formed to be smaller than the cross-sectional area of ​​other circuit wiring (104) of the circuit layer (103), so that when a certain current or more flows, it is fused before other circuit wiring (104). In addition, as shown in FIG. 7, the molten portion (151) is formed with a thin line width to increase resistance and is formed in a zigzag shape to increase length. Multiple such molten portions (151) may be formed. By forming the pattern fuse portion (150) as described above, there is an advantage that not only can the weight be reduced compared to a chip fuse, but the manufacturing cost can also be reduced.

[0043] The connection pad (152) is formed with a size wider than the width of the melting section (151) and is formed at each end of the melting section (151). The connection pad (152) is necessary for testing the performance of the pattern fuse and is used to test the resistance of the melting section (151) during or after the process. Therefore, the connection pad (152) can be exposed only during the testing phase in the manufacturing process to prevent continuous exposure or unnecessary contamination. That is, at least one of the first insulating layer (101) and the second insulating layer (102) on which the connection pad (152) is formed is not formed so that the connection pad (152) is exposed to the outside, or as shown in FIG. 8, a protective coating liquid (157) is applied to the upper side of the connection pad (152) after testing so that the connection pad (152) is not exposed after manufacturing. Alternatively, the connection pad (152) may be prevented from being exposed by testing with only one of the first and second insulating layers (101, 102) formed, and then heat-fusing the remaining insulating layer. Since the shape of the connection pad (152) is a test point for resistance measurement, it can be formed in various shapes such as square, circle, or polygon as needed.

[0044] Additionally, as illustrated in FIG. 10, the connection pad (152) may be formed separately rather than directly at both ends of the melting section (151). That is, the pattern fuse section (150) may include a connecting wire (1156) connected to one end of the melting section (151) and a connection pad (1152) formed by connecting the connecting wire (156). The connection pad (1152) is formed at a location away from the melting section (151), and by the connecting wire (156) connecting the melting section (151) and the connection pad (1152), the connection pad (152), which occupies a large area, can be positioned outward, thereby increasing the freedom of design.

[0045] The interference prevention section (153) is the circuit layer (103) of the area surrounding the molten section (151), that is, the area where the conductive conductor is removed. By removing the conductive conductor from the area surrounding the molten section (151) in this way, the electrical characteristics of the pattern fuse can be maintained at a constant level. Since the electrical characteristics change due to the influence of heat dispersion when there is a conductor in the molten section (151), the interference prevention section (153) prevents such changes.

[0046] The concentrated melting section (154) is a portion in which at least one of the first and second insulating layers (101, 102) of a certain area of ​​the melting section (151), in the present invention, the central area, is opened. By being opened in this way, the melting characteristics of the melting section (151) are prevented from being altered by the first and second insulating layers (101, 102). In addition, to protect the open portion, a protective coating liquid (157) may be applied to the open surface of the concentrated melting section (154).

[0047] The overflow prevention part (155) is formed to protrude upward on either side of the first and second insulating layers (101, 102), that is, on the side where the protective coating liquid (156) is applied, so as to surround the pattern fuse part (150). The manufacturing method is such that it is formed to protrude upward on the first and second insulating layers (101, 102) by a method such as silk screen printing. The overflow prevention part (155) prevents the protective coating liquid (157) applied to the upper side of the concentrated melting part (154) or the connection pad (152) from overflowing to other parts of the circuit board. Alternatively, when a coating liquid is applied to the upper surface of the pattern fuse part (150) to ensure the performance of the pattern fuse part (150), it provides a guideline for the coating area, prevents coating in unnecessary areas, reduces the amount of coating liquid required, and makes it easier to recognize and determine defects in the event of an overflow of the coating liquid.

[0048] As described above, one embodiment of the present invention is provided with a pattern fuse section, thereby reducing the overall weight compared to when a chip fuse is used.

[0049] In addition, there is an advantage in that defects in the pattern fuse section can be tested in advance during the manufacturing stage through the connection pad.

[0050] In addition, by providing an interference prevention section, a concentrated melting section, and an overflow prevention section, the reliability of the melting characteristics of the melting section can be increased.

[0051] The component mounting portion (130) includes an exposed area (131) formed by removing a portion of the first insulating layer (101) of the body portion (110), an exposed circuit (132) located in the exposed area (131) and in which the circuit layer (103) is directly electrically connected to the electrical component (200), and a fixed circuit (133) formed in the circuit layer (103) for fixing the electrical component (200) and exposed by the exposed area (131).

[0052] Here, the exposed circuit (132) is formed of copper foil and extends in an extended direction so that a part of the internal circuit of the body part (110) is exposed and is electrically connected to the electrical component (200), but the fixed circuit (133) is formed of a circuit layer (103) in the form of copper foil and is not connected to the internal circuit, so it is used only for fixing the electrical component (200).

[0053] Accordingly, the exposed area (131) is formed in correspondence with the size of the mounted electrical component (200), and as needed, an area where the exposed circuit (132) is exposed and an area where the fixed circuit (133) is exposed can be formed separately. Preferably, a plurality of exposed areas (131) are formed so that each exposed circuit (132) and fixed circuit (133) are partitioned and exposed, thereby minimizing the exposure of parts other than those connected to the electrical component (200) and ensuring the stability of the circuit layer (103).

[0054] In summary, the printed circuit board (10) of the present invention forms an exposed area (131) in which the circuit layer (103) is exposed on the first insulating layer (101) laminated on one side of the circuit layer (103), so as to be directly connected to an electrical component (200) and easily form multiple circuits with an external device.

[0055] The electrical component (200) is extended on one side of the printed circuit board (10) and is directly electrically connected to the exposed circuit (131) to relay the connection between the external device and the circuit layer (103), and means a connector, a sensor, an element, etc. that measures the state of the connected device.

[0056] To this end, the electrical component (200) is formed with a component body (210), a connection part (220) exposed on one side of the component body (210) and electrically connected to each of the exposed circuits (132) by soldering, and a fixing part (230) fixed to the fixed circuit (133) by soldering.

[0057] At this time, the connecting portion (220) is formed in multiple numbers to be connected to each of the multiple circuits forming the circuit layer (103), thereby forming multiple circuits that serve as pathways for electrical signals, and the fixing portion (230) is configured to be exposed on the outside of the electrical component (200) and simply connected to the fixing circuit (133), so that even when connected to the fixing circuit (133) by soldering, no circuit is formed.

[0058] The component reinforcement part (300) is attached to the second insulating layer (102) corresponding to the position of the exposed area (131) to support the electrical component (200) and prevent damage such as tearing of the flexible printed circuit board (10) due to the mounting of the electrical component (200).

[0059] The above component reinforcement section (300) is characterized by being formed of a component reinforcement plate (310) installed on the second insulating layer (102) of the above exposed area (131), a component adhesive layer (320) formed between the second insulating layer (102) and the component reinforcement plate (310), and a discharge channel (330) for discharging bubbles within the component adhesive layer (320). The component reinforcement section (300) supports the mounted electrical component (200) and simultaneously prevents deformation that may occur in the printed circuit board (10) during soldering, thereby significantly improving product reliability and durability.

[0060] The component reinforcement plate (310) has a hard physical property to stably support electrical components (200) having a weight greater than a certain amount, such as connectors, even when mounted, and it is desirable to have a width that can accommodate all of the multiple exposed areas (131) to support the entire surface area of ​​the electrical components (200). Plate fixing holes (311) are formed through the component reinforcement plate (310). The plate fixing holes (311) are formed by penetrating the component adhesive layer (320) and the substrate part (100). The plate fixing holes (311) are formed in the number and locations required to fix the printed circuit board (10). Bosses formed on the mating part to which the printed circuit board (10) is fixed are inserted into the plate fixing holes (311) and fused, thereby fixing the plate.

[0061] The component adhesive layer (320) is formed between the second insulating layer (102) and the component reinforcing plate (310) and serves to fix the component reinforcing plate (310) to the second insulating layer (102). The component adhesive layer (320) is formed from a material of double-sided tape having a certain thickness, and release paper is attached to both sides before attachment, and the release paper is removed before attachment. The component adhesive layer (320) is formed by a discharge channel (330) penetrating it to discharge air bubbles within the component adhesive layer (320).

[0062] At this time, as the electrical component (200) is mounted by soldering with the component reinforcement plate (310) attached, the temperature of the exposed area (131) rises, and accordingly, the bubbles in the component adhesive layer (320) expand, causing lifting to occur in the mounted portion of the electrical component (200).

[0063] Generally, a reflow soldering process is used in which solder paste (20) is printed in advance on the exposed area (131) of a printed circuit board (10), and then external heat is supplied to remelt the solder paste (20) to bond electrical components (200). The heat supplied at this time has a temperature of approximately 250°C, and in this case, the bubbles in the component adhesive layer (320) expand in volume by about 2 times.

[0064] The discharge path (330) is a passage for discharging expanded bubbles within the component adhesive layer (320), and is formed corresponding to the location of the connection part (220) where the connection part (220) of the electrical component (200) and the circuit layer (103) are joined by soldering, and communicates with the outside to discharge bubbles to the outside along the discharge path (330).

[0065] Specifically, the discharge path (330) of the first embodiment is formed as an air tunnel (331) that extends from the component adhesive layer (320) at the location of the connection part (220) and the fixing part (230) to one end of the component adhesive layer (320). When the temperature rises due to soldering, bubbles within the component adhesive layer (320) expand and merge with other surrounding bubbles, causing their size to gradually increase. At this time, the expanded bubbles move to the discharge path (330), where the relative pressure is low because no pressure is generated by the component reinforcing plate (310), and are discharged to the outside through the discharge path (330) to prevent lifting from occurring in the mounting part of the electrical component (200).

[0066] Additionally, since the discharge passage (330) is formed by removing the component adhesive layer (320) and thus reducing the adhesive area, it is preferable that the discharge passage (330) be formed by a plurality of air tunnels (331) connected to the end portion closest to the connection portion (220) and the fixing portion (230). In the case of the discharge passage (330) connected to the connection portion (220), it is preferable to form it in the central part of the connection portion (220) to secure a contact area while simultaneously discharging the air bubbles expanding from the surroundings, taking into account that the expanded air bubbles merge with the surrounding air bubbles.

[0067] FIG. 4(a) is a side view of a reinforcing part illustrating a modified example of a discharge path, and FIG. 4(b) is an exploded perspective view of FIG. 4(a).

[0068] As shown in FIG. 4, the discharge path (1330) of the modified example is formed with a first air hole (1331) that simultaneously penetrates the component reinforcing plate (310) and the component adhesive layer (320) corresponding to the position of the connecting part (220), and a second air hole (1332) that simultaneously penetrates the component reinforcing plate (310) and the component adhesive layer (320) corresponding to the position of the fixing part (230), thereby discharging the expanding bubbles in the stacking direction.

[0069] At this time, for processability and removal of surrounding bubbles, it is preferable that the first and second air holes (1331, 1332) be formed in communication with each other, and in another embodiment, the discharge path (1330) is formed by simultaneously penetrating the component reinforcing plate (310) and the component adhesive layer (320), thereby minimizing the length of the path through which bubbles are discharged, allowing for faster bubble discharge.

[0070] As illustrated in FIG. 5, the discharge path (2330) of another variant is formed by removing the component adhesive layer (320) corresponding to the positions of the connecting part (220) and the fixing part (230) to form a horizontal discharge path (2331), and by penetrating the component reinforcing plate (310) in the thickness direction so as to communicate with one side of the horizontal discharge path (2331) to form a vertical discharge path (2332).

[0071] More specifically, the horizontal discharge path (2331) is formed by starting from the location of the connection part (220) and the fixing part (230) and extending a predetermined length to one side, and the vertical discharge path (2332) is formed to correspond to the location of the connection part (220) and the fixing part (230) and to communicate with the horizontal discharge path (2331), so that bubbles are rapidly discharged in the axial direction in the part where soldering is performed, and at the same time, the horizontal discharge path (2331) is formed to have a certain length so that the movement path of expanded bubbles around the connection part (220) and the fixing part (230) is reduced, thereby enabling smooth discharge.

[0072] In summary, the discharge path (330) of the printed circuit board (10) of the present invention can be formed in various embodiments capable of discharging expanded bubbles within the component adhesive layer (320). In this case, the discharge path (330) of the embodiment of FIGS. 1 to 3 is formed to have a certain length so that the component reinforcing plate (310) can support the entire exposed area (131) to maintain support force, and also so that bubbles around the connection part (220) and the fixing part (230) are smoothly discharged. However, as the bubbles are discharged while moving along the air tunnel (331), rapid discharge is difficult compared to the discharge path (330) formed in the axial direction.

[0073] In addition, the discharge path (1330) of the modified example of FIG. 4 is formed with first and second air holes (1331, 1332) that connect both the connecting part (220) and the fixing part (230), thereby greatly reducing the support area of ​​the component reinforcing plate (310), but allowing for smooth discharge of expansion bubbles around the connecting part (220) and the fixing part (230), and the entire discharge path (1330) is formed open in the axial direction so that bubbles are discharged quickly.

[0074] In addition, the discharge path (2330) of another variant of FIG. 5 is formed by removing the component adhesive layer (320) at the location of the connection part (220) and the fixing part (230) to form a horizontal discharge path (2331) and a vertical discharge path (2332) that communicates with the horizontal discharge path (2331) at the location of the connection part (220) and the fixing part (230), thereby minimizing the reduction of the support area, while simultaneously forming a vertical discharge path (2332) that is axially open at the location of the connection part (220) and the fixing part (230) where soldering is directly performed, so that bubbles are quickly discharged.

[0075] At this time, the horizontal discharge channel (2331) is formed to extend a predetermined length to one side from the location of the connection part (220) and the fixing part (230) so that air bubbles in the surrounding area where soldering is directly performed are also smoothly discharged.

[0076] In other words, the discharge paths (330, 1330, 2330) of different embodiments have the same purpose, function, and effect, but the support area of ​​the component reinforcement plate (310) and the bubble discharge path are different, so the most suitable example can be selected by considering the type of electrical component (200) to be mounted, the size of the printed circuit board (10), the installation location, etc.

[0077] Accordingly, the printed circuit board (10) of the present invention is provided with a discharge channel (330) for discharging bubbles within the component adhesive layer (320) that expands during the process of mounting the electrical component (200), thereby ensuring electrical connection stability between the electrical component (200) and the circuit layer (103), and stably fixing the component reinforcement part (300), so as to improve the reliability and durability of the product.

[0078] Furthermore, it prevents defects from occurring as the flatness of the printed circuit board (10) is reduced due to bubbles, and also solves problems such as reduced tensile strength and reduced electrical connection stability with the electrical component (200), thereby improving the reliability of the external device connected to the printed circuit board (10).

[0079] FIGS. 11 to 14 illustrate a pattern fuse portion of a printed circuit board of a second embodiment, where FIG. 11 is a plan view of the pattern fuse portion, FIG. 12 is a bottom view of FIG. 8, FIG. 13 is a cross-sectional view along the cutting line XIII-XIII of FIG. 11, and FIG. 14 is a plan view of the adhesive layer of FIG. 11.

[0080] The printed circuit board of the second embodiment is identical to the first embodiment in its configuration, except for the pattern fuse section. Therefore, only the pattern fuse section and the distinguishing configuration will be described.

[0081] The printed circuit board of the second embodiment is characterized by further including a fuse reinforcement part (400) formed on one side of the pattern fuse part (150) and supporting the pattern fuse part (150).

[0082] The fuse reinforcement section (400) includes a fuse adhesive layer (420) attached to at least one of the first and second insulating layers (101, 102) of the pattern fuse section (150), and a fuse reinforcement plate (410) attached to the fuse adhesive layer (420).

[0083] The fuse adhesive layer (420) is formed in the remaining portion excluding the position corresponding to the melting portion (151), thereby forming a void portion (425) at the position corresponding to the melting portion (151). That is, as shown in FIG. 11, the fuse adhesive layer (420) includes a square ring-shaped fuse adhesive layer body (421) that surrounds the void portion (425).

[0084] The fuse reinforcement plate (410) is formed of the same material as the component reinforcement plate (310).

[0085] The above fuse reinforcement part (400) includes a fuse reinforcement part fixing hole (430) formed by penetrating the fuse reinforcement part (400). That is, the fixing hole (430) is formed by penetrating the pattern fuse part (150), the fuse adhesive layer (420), and the fuse reinforcement plate (410). The fixing hole (430) is formed in the number and location required to fix the pattern fuse part (150). The pattern fuse part (150) is fixed by inserting a boss, etc. formed on the mating part to which it is fixed into the fixing hole (430) and fusing it.

[0086] As described above, the printed circuit board of the second embodiment is provided with a fuse reinforcement part (400) in the pattern fuse part (150), thereby maintaining the flatness of the pattern fuse and allowing it to be firmly fixed to the mating object. In addition, by providing a void part (421), changes in melting characteristics and current conduction characteristics that may occur when a fuse adhesive layer (420) is attached to the molten part (151) can be prevented. In particular, when the molten part (151) melts, the fuse adhesive layer (420) can be prevented from carbonizing due to the high temperature and affecting other circuits.

[0087] Although preferred embodiments of the present invention have been described illustratively above, the scope of the present invention is not limited to such specific embodiments, and any modifications that are appropriately possible within the scope described in the claims fall within the scope of protection of the present invention. Explanation of the symbols

[0088] 100: Substrate part 101: First insulating layer 102: Second insulating layer 103: Circuit layer 131: Exposure area 132: Fixed circuit 150: Pattern fuse section 151: Melting section 152: Connection pad 154: Concentrated melting section 156: Connection Wiring 200: Electrical Components 220: Connection part 2331: Horizontal discharge path 2332: Vertical discharge passage 300: Component reinforcement section 310: Component reinforcement plate 320: Component adhesive layer 330, 1330, 2330: Discharge path 400: Fuse reinforcement section 420: Fuse adhesive layer

Claims

Claim 1 A substrate portion (100) having first and second insulating layers (101, 102) formed on both sides and a circuit layer (103) formed between the first and second insulating layers (101, 102); and an electrical component (200) mounted in an exposed area (131) where the circuit layer is exposed by removing a portion of the first insulating layer (101); and a component reinforcement part (300) attached to the second insulating layer (102) of the exposed area (131) and supporting the electrical component (200); wherein the component reinforcement part (300) includes a component reinforcement plate (310) bonded to the second insulating layer (102) of the exposed area (131), a component adhesive layer (320) formed between the second insulating layer (102) and the component reinforcement plate (310), and an exhaust passage (330, 1330, 2330) for discharging bubbles within the component adhesive layer (320); the substrate part (100) further includes a pattern fuse part (150) formed in a shape such that a part of the circuit layer (103) can function as a fuse, and the pattern fuse part (150) melts faster than other parts of the circuit layer (103) at a current above a certain level. A printed circuit board characterized by comprising: a melting portion (151); and an overflow prevention portion (155) formed as a closed curve surrounding the pattern fuse portion (150) and protruding from at least one of the first insulating layer (101) and the second insulating layer (102). Claim 2 A printed circuit board according to claim 1, wherein the electrical component (200) has a connection portion (220) formed therein that is electrically contacted by soldering with the circuit layer (103) exposed in the exposure area (131), and the discharge path (330, 1330, 2330) is formed corresponding to the position of the connection portion (220). Claim 3 A printed circuit board according to claim 2, wherein the discharge path (330, 1330, 2330) is formed as an air tunnel (331) in which the component adhesive layer (320) is removed from the location of the connection part (220) to one end of the exposed area (131). Claim 4 A printed circuit board according to claim 2, wherein the discharge passage (330, 1330, 2330) is formed as an air hole (1331, 1332) that penetrates the component reinforcing plate (310) and the component adhesive layer (320) at the location of the connection part (220). Claim 5 A printed circuit board according to claim 2, wherein the discharge path (330, 1330, 2330) is formed by a horizontal discharge path (2331) formed by removing the component adhesive layer (320) at the location of the connection part, and a vertical discharge path (2332) formed by penetrating the component reinforcing plate (310) so as to be in communication with the horizontal discharge path (2331). Claim 6 A printed circuit board characterized in that, in any one of claims 3 to 5, a fixed circuit (132) is formed in the exposed area (131) such that the electrical component (200) is fixed by soldering, and the discharge path (330, 1330, 2330) is additionally formed corresponding to the position of the fixed circuit (132). Claim 7 A printed circuit board characterized in that, in any one of claims 1 to 5, the pattern fuse portion (150) further comprises connection pads (152) formed at both ends of the melting portion (151). Claim 8 A printed circuit board according to claim 7, characterized in that the width of the connection pad (152) is wider than the width of the melting portion (151). Claim 9 A printed circuit board according to claim 8, characterized in that at least one of the first insulating layer (101) and the second insulating layer (102) on which the connection pad (152) is formed is not formed, so that the connection pad (152) is exposed to the outside. Claim 10 A printed circuit board according to claim 9, characterized in that a protective coating liquid is applied to the upper side of the connection pad (152). Claim 11 A printed circuit board according to claim 7, wherein the pattern fuse portion (150) further comprises an interference prevention portion (153) in which the circuit layer (103) is removed, and which surrounds the melting portion (151). Claim 12 A printed circuit board according to claim 7, wherein the pattern fuse portion (150) further comprises a concentrated melting portion (154) in which at least one of the first insulating layer (101) and the second insulating layer (102) of at least a portion of the melting portion (151) is open. Claim 13 A printed circuit board according to claim 12, characterized in that a protective coating liquid is applied to the open surface of the concentrated melting portion (154). Claim 14 delete Claim 15 A printed circuit board according to any one of claims 1 to 5, wherein the pattern fuse portion (150) comprises: a connecting wire (1156) connected to one end of the melting portion (151); and a connection pad (1152) formed by connecting the connecting wire (1156). Claim 16 A printed circuit board according to any one of claims 1 to 5, further comprising: a fuse reinforcement member (400) formed on one side of the pattern fuse member (150) and supporting the pattern fuse member (150); wherein the fuse reinforcement member (400) comprises: a fuse adhesive layer (420) attached to at least one side of the first and second insulating layers (101, 102) of the pattern fuse member (150); and a fuse reinforcement plate (410) attached to the fuse adhesive layer (420). Claim 17 A printed circuit board according to claim 16, wherein the fuse adhesive layer (420) is formed in the remaining portion excluding the position corresponding to the melting portion (151), and a void portion (425) is formed at the position corresponding to the melting portion (151). Claim 18 A printed circuit board according to claim 16, wherein the fuse reinforcement part (400) further comprises a fuse reinforcement part fixing hole (430) formed by penetrating the fuse reinforcement part (400).

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