Metal conductor electrical connector inner sheet and manufacturing method therefor

Abstract

The present invention relates to a metal conductor electrical connector inner sheet having a structure in which micro solder balls are dispersed and arranged on the surface of a base plate, and a manufacturing method therefor. In particular, the present invention relates to a metal conductor electrical connector inner sheet and a manufacturing method therefor, the metal conductor electrical connector inner sheet having a structure in which micro solder balls, which are inserted and fixed into micro holes of a base plate and protrude from the surface thereof, are spread flat by means of a compressive force according to the fastening between an upper terminal and a lower terminal of a metal conductor connector, so as to form a solder ball continuum, thereby increasing contact adhesion between terminals, remarkably reducing electrical contact resistance generated in an electrical connector, and suppressing a temperature rise due to heat generation of the electrical connector, and thus the metal conductor electrical connector inner sheet can be effectively applied to an electric vehicle battery system for preventing fire accidents.

Description

Metal conductor electrical connector inner sheet and method of manufacturing the same

[0001] The present invention relates to a metal conductor electrical connector inner sheet having a structure in which micro solder balls are dispersed on the surface of a base plate, and a method for manufacturing the same. More specifically, the invention relates to a metal conductor electrical connector inner sheet and a method for manufacturing the same, which can be effectively applied to an electric vehicle battery system for preventing fire accidents. This is achieved by increasing the degree of contact adhesion between terminals through a structure in which micro solder balls protruding from the upper and lower surfaces, inserted and fixed into micro holes of the base plate, spread flatly due to the compressive force resulting from the connection between the upper and lower terminals of the metal conductor connector to form a continuous solder ball structure, thereby significantly reducing the electrical contact resistance generated in the electrical connector and suppressing the temperature rise caused by heat generation in the electrical connector.

[0002]

[0003] The factors currently identified as causing frequent electric vehicle fire accidents include ① battery defects, ② battery management system (BMS) defects, ③ wiring or electrical connector defects, and ④ battery aging due to rapid charging. The aforementioned ③ wiring or electrical connector defects are caused by the high electrical contact resistance generated at the connectors. In particular, the electrical contact resistance of electrical connectors exhibits behavioral characteristics that deteriorate rapidly as the usage period increases. Since automobiles are typically used for a long period of time—typically over 10 years—it is essential to ensure stability not only in the initial stages but also in the mid-to-long term.

[0004]

[0005] Meanwhile, the Battery Disconnected Unit (BDU), installed between the DC-DC converter (a power conversion device) and the battery, has multiple electrical connectors installed inside the battery pack—one for high-voltage connection to high-voltage copper busbars and another for low-voltage connection to low-voltage copper busbars—to perform the function of cutting off and controlling the power; therefore, ensuring the stability of these electrical connectors has a significant impact on the overall safety of the battery.

[0006] It is warned that the optimal temperature range for lithium-ion batteries used in electric vehicles is approximately 15 to 35°C, and that performance drops significantly at temperatures above 40°C, and that temperatures above 60°C can lead to fire accidents. However, a study on the temperature rise behavior of electrical connectors installed around the battery pack revealed that the maximum temperature of the electrical connectors rose to 78°C [Cited source: Analysis of Temperature Characteristics of BDU (Battery Disconnected Unit) Using Electrical and Thermal Equivalent Circuits, Proceedings of the 2011 Summer Conference of the Korean Institute of Electrical Engineers], making it extremely urgent to find a corrective measure. According to the results of a study on the effects of poor contact in electrical connectors [Analysis of Voltage, Current, and Temperature Signal Characteristics When Poor Contact Occurs in Connectors, Journal of the Korean Society of Safety, Vol. 29, No. 2, 2014], when the electrical connector is installed normally, the temperature distribution of the connector is 26.4℃ to 36.5℃ for current values ​​of 1 to 4A, but when there is poor contact, it increases significantly to 49.5℃ to 180℃. Therefore, it is pointed out that if a short circuit occurs due to poor contact in the electrical connector, an arc flash phenomenon occurs in the electrical connector, and at this time, an overcurrent of tens of thousands of amperes (A) is induced, causing the temperature to rise to 20,000℃ and the volume to expand up to four times, inducing a discharge explosion accident that leads to a fire accident in an electric vehicle.

[0007] For this reason, defects in electrical connectors are identified as one of the major causes of battery fire accidents. The electrical connectors of electric vehicle batteries conduct current by connecting busbars together; they are structured to be connected by overlapping the terminals of metal conductors and then bolting them with a specified torque value. However, due to factors such as imprecise processing equipment and manufacturing processes, the surface conditions of currently commercialized metal conductors inherently possess defects such as surface roughness, waviness, and thickness variations. Consequently, when metal conductors are connected and brought into contact, the surface contact adhesion at the contact point becomes very poor, leading to a constant problem where electrical contact resistance increases rapidly during current flow. In other words, copper busbars, which are metal conductors for electrical connectors, have inherently poor surface flatness, and consequently, when forming an electrical connector, the actual contact area is reported to be only 5 to 10 percent of the apparent contact area. Furthermore, after forming a fixed contact on the copper busbar electrical connector terminal, a difference between the apparent contact area and the actual contact area, and a current concentration phenomenon in which current flows concentrated only at the contact area when current is applied, have been reported.

[0008] As such, Joule heat is generated due to electrical contact resistance in metal conductor electrical connectors with very poor surface contact adhesion. This leads to a temperature rise, which ultimately causes the internal temperature of the battery pack to increase. In particular, if the temperature exceeds the safe operating temperature range of the battery, which is vulnerable to temperature, it can lead to a fire and cause significant damage. Furthermore, in electric vehicles that operate for long periods, defects in the contact areas of the electrical connectors are further exacerbated by various corrosion phenomena, thereby increasing the likelihood of a fire.

[0009] To explain in more detail, as electrical connectors age, the contact points between metal conductors gradually corrode, causing the current path to rapidly decrease and consequently, the electrical contact resistance to increase rapidly. In particular, due to vehicle body vibrations during operation and various atmospheric corrosive environmental factors, oxide films are repeatedly formed and destroyed at the contact points between metal conductors, leading to widespread and rapid fretting corrosion. Consequently, the current path decreases rapidly, and the electrical contact resistance increases sharply. As a result, heat generation within the electrical connector intensifies, causing the internal temperature to rise rapidly. Furthermore, in electrical connectors with very high electrical contact resistance, a short-circuit accident may occur due to the interruption of current flow. In this case, an overcurrent of tens of thousands of amperes (A) is instantaneously induced, causing an arc flash phenomenon, which leads to a discharge explosion of the battery.

[0010] In particular, as electric connectors are constantly subjected to shear stress due to vibrations that occur constantly during operation, and as wear corrosion occurs due to exposure to various atmospheric corrosive environments, thorough countermeasures are required for electric connectors. Accordingly, the inventor has developed the "Metal Conductive Sheet for Improving Electrical Conductivity Performance in Metal Conductors" disclosed in Korean Patent Publication No. 10-2023-0126518. However, since the metal conductive sheet has a structure in which solder balls (12) are simply dispersed on the surface of a base plate (11), the solder balls may separate from or peel off the upper and lower terminals of the metal conductor of the electric connector due to shear stress caused by vibrations that occur constantly in the vehicle. This can cause a decrease in surface contact adhesion and lead to a rise in temperature, so there is a need to develop technology that can improve this. That is, in the case of a vehicle, since it is a moving body, it causes three-dimensional vibration of the components, and in this process, the solder ball (12) of the metal conductive sheet also moves irregularly left and right, and the process of the electrical connector metal conductor and the solder ball (12) sticking together and then separating is repeated, which causes poor contact and increases the possibility of a short circuit accident due to increased contact resistance, so it is necessary to develop technology that can improve this.

[0011]

[0012] Accordingly, the present invention aims to improve upon the problems of such conventional technology by providing a new type of metal conductor electrical connector inner sheet and a method for manufacturing the same, wherein micro-holes penetrating the upper and lower surfaces of a base plate are formed in a set pattern, and a structure is provided in which micro-solder balls are inserted and fixed into the micro-holes and protrude from the upper and lower surfaces, thereby 1) suppressing irregular horizontal movement of micro-solder balls caused by three-dimensional vibrations occurring in a moving body such as an electric vehicle, thereby preventing rapid temperature rise, excessive heat generation, and short-circuit accidents caused by contact failure, and 2) preventing separation or peeling of micro-solder balls through a structure in which a middle portion, which is a part of the micro-solder ball, is placed in the micro-hole penetrating the upper and lower surfaces of the base plate, a structure in which the base plate surrounds the middle portion, which is a part of the micro-solder ball, and a structure in which the fastening force of a fastening bolt / fastening nut connecting the metal conductor connector on the upper and lower sides of the base plate acts on the micro-solder balls and the base plate.

[0013]

[0014] The present invention aims to provide a new type of metal conductor electrical connector inner sheet and a method for manufacturing the same, which can be effectively applied to an electric vehicle battery system for preventing fire accidents by preventing the separation or peeling of micro solder balls in this manner, thereby ensuring that the micro solder balls perform their function for a long period while maintaining a high degree of contact adhesion between the terminals of the metal conductor connector, and thereby continuously maintaining a significant reduction in electrical contact resistance generated in the metal conductor connector, so that the temperature rise caused by heat generation in the metal conductor connector is continuously suppressed.

[0015]

[0016] That is, the present invention aims to provide a new type of metal conductor electrical connector inner sheet and a method for manufacturing the same, which prevents electric vehicle battery fire accidents by focusing on wiring or electrical connector defects among the factors causing electric vehicle fire accidents caused by batteries, and by providing a structure that can drastically reduce the high electrical contact resistance occurring in the electrical connector, thereby ensuring not only stable performance in the initial stage but also stability in the mid-to-long term.

[0017]

[0018] According to the features of the present invention for achieving the above-described purpose, the present invention comprises a base plate (100) which is disposed between electrically connected metal conductor connectors (1) and is made of a thin plate made of a conductive material, and has a plurality of micro holes (110) distributed in a set pattern; and micro solder balls (200) which are inserted into and dispersed in each micro hole (110) of the base plate (100), protrude from the upper and lower surfaces of the base plate (100), and are made of a conductive material.

[0019] A metal conductor electrical connector inner sheet is provided, characterized in that a middle portion, which is a part of each micro solder ball (200), is disposed in each of the micro holes (110) formed by penetrating the upper and lower surfaces of the base plate (100), and an upper portion, which is a part of each micro solder ball (200), protrudes upward from the upper surface of the base plate (100), while a lower portion, which is a part of each micro solder ball (200), protrudes downward from the lower surface of the base plate (100).

[0020]

[0021] In the metal conductor electrical connector inner sheet according to the present invention, the micro solder ball (200) is formed in a spherical shape so that 1) the upper portion protrudes upward from the upper surface of the base plate (100) in a hemispherical shape, and 2) the lower portion protrudes downward from the lower surface of the base plate (100) in a hemispherical shape.

[0022]

[0023] In the metal conductor electrical connector inner sheet according to the present invention, the base plate (100) has a thickness (H) of 10 to 1,000 μm, and the micro-holes (110) have a diameter (d) of tens to hundreds of μm, while the spacing between the micro-holes (110) has a length (D) of tens to hundreds of μm, and the micro-holes (110) are uniformly distributed on the base plate (100) with a space factor of 20 to 80%, forming multiple rows and multiple columns at equal intervals.

[0024] The micro solder ball (200) may be integrally bonded to the base plate (100) by an organic solvent or integrally bonded to the base plate (100) by heating.

[0025]

[0026] According to another feature of the present invention for achieving the above-described purpose, the present invention comprises: a base plate provision step in which a base plate (100) made of a thin plate made of a conductive material is provided; a base plate specification cutting step in which the base plate (100) is cut to match the connection area between the upper terminal and the lower terminal of a metal conductor connector (1); and a base plate hole dispersion formation step in which a plurality of micro holes (110) are dispersed and formed in a set pattern on the base plate (100), wherein each of the micro holes (110) is formed by penetrating the upper and lower surfaces of the base plate (100). A method for manufacturing a metal conductor electrical connector inner sheet is provided, comprising a micro solder ball dispersion formation step in which micro solder balls (200) made of a conductive material are dispersed and arranged in each micro hole (110) of the base plate (100), wherein a middle portion, which is a part of each micro solder ball (200), is arranged in each of the micro holes (110), and an upper portion, which is a part of each micro solder ball (200), is protruded upward from the upper surface of the base plate (100), and a lower portion, which is a part of each micro solder ball (200), is protruded downward from the lower surface of the base plate (100).

[0027]

[0028] In the method for manufacturing a metal conductor electrical connector inner sheet according to the present invention, the base plate hole dispersion formation step is formed such that the micro-holes (110) penetrate the upper and lower surfaces of the base plate (100) through micro laser processing of the base plate (100), and the micro-holes (110) of the same diameter are arranged in a grid pattern forming multiple rows and multiple columns with various hole spacings or various hole shape patterns.

[0029]

[0030] In the method for manufacturing a metal conductor electrical connector inner sheet according to the present invention, the micro solder ball dispersion formation step may be performed through: an organic solvent base plate surface coating step of applying an organic solvent to a micro hole (110) of the base plate (100); a micro solder ball base plate insertion step of inserting a micro solder ball (200) into the micro hole (110) to which the organic solvent has been applied; and a micro solder ball base plate bonding step in which the micro solder ball (200) is bonded to the base plate (100) inside the micro hole (110) by the organic solvent.

[0031] Alternatively, the micro solder ball dispersion formation step may be performed through: a micro solder ball base plate insertion step in which micro solder balls (200) are inserted into micro holes (110) of the base plate (100); a base plate heating step in which the base plate (100) into which the micro solder balls (200) are inserted is heated for a set time at a set temperature range; and a micro solder ball base plate bonding step in which the micro solder balls (200) and the base plate (100) become integrated as alloying is induced by a diffusion reaction between the metal components of the base plate (100) and the metal components of the micro solder balls (200) by heating.

[0032]

[0033] The method for manufacturing a metal conductor electrical connector inner sheet according to the present invention may further include: a silver paste surface coating step performed after the micro solder ball dispersion formation step, wherein a conductive resin silver paste (Ag paste) (300) is applied to the upper and lower surfaces of the base plate (100) on which the micro solder balls (200) are formed; and a drying step of drying the silver paste (300) applied to the surface of the base plate (100) in the atmosphere.

[0034]

[0035] According to the metal conductor electrical connector inner sheet and the method for manufacturing the same according to the present invention, 1) a structure is provided in which the middle portion of a micro solder ball is inserted and fixed into a micro hole penetrating the upper and lower surfaces of the base plate and protrudes from the upper and lower surfaces, thereby suppressing irregular horizontal movement of the micro solder ball caused by three-dimensional vibrations occurring in a moving body such as an electric vehicle, and preventing short-circuit accidents caused by contact failures, while 2) a structure in which the middle portion, which is a part of the micro solder ball, is placed in a micro hole penetrating the upper and lower surfaces of the base plate, a structure in which the base plate surrounds the middle portion, which is a part of the micro solder ball, and a structure in which the fastening force of the fastening bolt / fastening nut connecting the metal conductor connector on the upper and lower sides of the base plate acts on the micro solder ball and the base plate, thereby preventing separation or peeling of the micro solder ball, and accordingly, the effect of improving the stability and durability of the current path can be expected. In addition, since a continuous solder ball structure is formed without separation or peeling of micro solder balls, the contact tightness between terminals of the metal conductor connector can be continuously increased, so the metal conductor electrical connector inner sheet of the present invention is effectively applied to an electric vehicle battery system to continuously suppress the temperature rise caused by heat generation of the metal conductor connector and prevent fire accidents.

[0036] The metal conductor electrical connector inner sheet according to the present invention significantly increases the degree of contact between the terminals of the metal conductor connector. As the degree of contact between the terminals of the metal conductor connector increases, the current path through which current can travel is also significantly increased, thereby minimizing electrical contact resistance and suppressing heat generation and temperature rise in the metal conductor connector, so that the temperature safety of the electric vehicle battery can be expected to be maximized.

[0037]

[0038] FIG. 1 is an example diagram of the use of a metal conductor electrical connector inner sheet according to an embodiment of the present invention;

[0039] FIG. 2(a) is a drawing for showing the shape structure of a bait plate according to an embodiment of the present invention;

[0040] FIG. 2(b) is a drawing for showing the arrangement structure of micro solder balls according to an embodiment of the present invention;

[0041] FIG. 2(c) is a drawing for showing the silver paste surface coating structure of a metal conductor electrical connector inner sheet according to an embodiment of the present invention;

[0042] FIG. 3 is a perspective view of a metal conductor electrical connector inner sheet according to an embodiment of the present invention;

[0043] FIG. 4 is a drawing for showing a connection structure between metal conductors by a metal conductor electrical connector inner sheet according to an embodiment of the present invention;

[0044] FIG. 5 is a drawing for showing a structure for suppressing shear stress caused by compressive stress of micro solder balls provided in an inner sheet of a metal conductor electrical connector according to an embodiment of the present invention;

[0045] FIG. 6 (a) and (b) are block diagrams of the sequence of the method for manufacturing a metal conductor electrical connector inner sheet according to the present invention;

[0046] FIG. 7(a) is an exemplary diagram showing a base plate in which micro-holes are formed through it by micro laser processing in the base plate hole dispersion formation step according to an embodiment of the present invention;

[0047] FIG. 7(b) is an example diagram showing micro solder balls distributed on the base plate of FIG. 7(a);

[0048] FIG. 8 is a partial enlarged view of FIG. 7 (b);

[0049] FIG. 9 is a block diagram of the sequence of micro solder ball dispersion shape steps according to the first embodiment of the present invention;

[0050] FIG. 10 is a block diagram of the sequence of micro solder ball dispersion shape steps according to a second embodiment of the present invention;

[0051] FIG. 11 is a drawing illustrating a silver paste surface coating step according to an embodiment of the present invention.

[0052]

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Meanwhile, in the drawings and detailed description, the illustration and mention of configurations and operations that are easily understood by those skilled in the art have been simplified or omitted. In particular, in the drawings and detailed description, detailed descriptions and illustrations of specific technical configurations and operations of elements not directly related to the technical features of the present invention have been omitted, and only the technical configurations related to the present invention have been briefly illustrated or described.

[0054]

[0055] A metal conductor electrical connector inner sheet (10) according to an embodiment of the present invention is composed of a base plate (100) and a micro solder ball (200) as shown in FIGS. 1 to 3.

[0056]

[0057] As shown in FIG. 1, the base plate (100) is positioned between the upper terminal and the lower terminal of the metal conductor connector (1) and is made of a conductive material to electrically connect the metal conductor connector (1). The upper terminal and the lower terminal of the metal conductor connector (1) can be joined by fastening bolts (2) and fastening nuts (3). The number of fastening bolts (2) and fastening nuts (3) may vary depending on the size of the metal conductor connector (1), and the bolt hole diameter and number of bolt holes according to the electrical connector dimension specifications must be taken into account. Here, as shown in FIG. 3, the base plate (100) has a set number of bolt holes (120) through which the fastening bolts (2) that join the upper terminal and the lower terminal of the metal conductor connector (1) pass.

[0058] A base plate (100) of this type is made of a thin sheet made of a conductive material as shown in FIG. 2, and may be made of a copper plate or an aluminum plate having a thickness (H) of 10 to 1,000 μm. The base plate (100) according to an embodiment of the present invention uses a copper plate with a thickness of 200 μm (0.2 mm), but it is obvious that the dimensions and materials are not limited thereto. The copper plate and the aluminum plate may be made of a hard material or a soft material. In addition, the copper plate or the aluminum plate may be plated with tin, silver, etc.

[0059] As shown in FIG. 2(a), a plurality of micro-holes (110) are distributed in a set pattern on the base plate (100). The micro-holes (110) have a diameter (d) of tens to hundreds of μm, while the distance (edge ​​to edge) between the micro-holes (110) has a length (D) of tens to hundreds of μm. In the base plate (100) according to an embodiment of the present invention, the diameter of the micro-holes (110) is formed to be 550 μm (0.55 mm) and the distance between the micro-holes (110) is formed to be 550 μm (0.55 mm), but it is obvious that the dimensions are not limited thereto. In particular, as shown in FIG. 3, the micro-holes (110) according to an embodiment of the present invention are uniformly distributed on the base plate (100) at equal intervals, forming multiple rows and multiple columns, with a space factor of 20 to 80%. Here, the space factor refers to the area ratio of the micro-holes (110) to the base plate (100). That is, as the packing ratio increases, the number of micro holes (110) increases, and more micro solder balls (200) are placed on the base plate (100). The degree of contact adhesion in the metal conductor connector (1) is correlated with the packing ratio of the micro solder balls (200) which are the dispersing material; when the packing ratio is high, the proportion of the micro solder balls (200) which are the dispersing material increases, and thus the degree of contact adhesion in the metal conductor connector (1) increases.

[0060] Meanwhile, the micro-holes (110) may be formed in a circular shape, but are not limited thereto and can have various shapes. That is, they can have regular shape patterns such as squares and rhombuses, as well as various irregular shapes. In addition, micro-holes (110) of the same shape may be distributed on a single base plate (100), but micro-holes (110) of various sizes and shapes may also be mixed and distributed.

[0061] Here, the micro-hole (110) according to an embodiment of the present invention is formed in a shape that penetrates the upper and lower surfaces of the base plate (100) as in FIG. 2 (a). For this purpose, micro laser processing technology may be applied.

[0062]

[0063] Micro solder balls (200) are inserted into each micro hole (110) of the base plate (100) and distributed therein. They may be integrally bonded to the base plate (100) by an organic solvent or integrally bonded to the base plate (100) by heating. Such micro solder balls (200) protrude from the upper and lower surfaces of the base plate (100). They may protrude convexly in a hemispherical shape or in various other shapes. Micro solder balls (200) may have a diameter (d) of several tens to several hundred μm, the same size as the micro hole (110), and may be uniformly distributed on the base plate (100) in multiple rows and columns at equal intervals with a space factor of 20 to 80%. Such micro solder balls (200) may be made of a soft conductive material having a ball shape with a surface hardness of 10 to 60 Hv. Preferably, they may be tin-lead solder balls, tin-silver-copper solder balls, tin-bismuth solder balls, bismuth-silver-copper solder balls, etc., and all types of solder balls currently commercialized as alloys may be used as micro solder balls (200). In addition, micro solder balls (200) made of pure copper (Cu), copper alloys, pure silver (Ag), or silver alloys may also be used, although low deformation is expected due to high hardness characteristics. Such micro solder balls (200) serve as a current path between the upper and lower terminals of the metal conductor connector (1).

[0064] Here, the metal conductor electrical connector inner sheet (10) according to an embodiment of the present invention is configured such that the middle portion of a micro solder ball (200) is placed in a micro hole (110) penetrating the upper and lower surfaces of a base plate (100) as shown in FIG. 2 (b), and the upper portion and lower portion of the micro solder ball (200) protrude from the upper surface and lower surface of the base plate (100). Such a micro solder ball (200) is formed in a spherical shape such that 1) the upper portion protrudes upward from the upper surface of the base plate (100) in a hemispherical shape, while 2) the lower portion protrudes downward from the lower surface of the base plate (100) in a hemispherical shape.

[0065]

[0066] In the case of the metal conductor electric connector inner sheet according to the embodiment of the present invention configured as such, irregular horizontal movement of the micro solder balls (200) caused by three-dimensional vibrations occurring in a moving body such as an electric vehicle is suppressed, thereby preventing short-circuit accidents caused by the occurrence of contact failure areas. In addition, 1) when the base plate (100) receives a compressive force by the fastening elements (2)(3) connecting the metal conductor connector (1), 2) the upper portion of each micro solder ball (200) spreads flatly to the upper and lower surfaces of the base plate (100) due to malleability, forming a solder ball continuous body (200') as shown in FIG. 4, and the solder ball continuous body (200') serves as a current path between the upper and lower terminals of the metal conductor connector (1). And 3) a structure in which a middle portion, which is a part of the micro solder ball (200), is placed in a micro hole (110) penetrating the upper and lower surfaces of the base plate (100), a structure in which the base plate (100) surrounds the middle portion, which is a part of the micro solder ball (200), and a structure in which the fastening force of the fastening bolt / fastening nut that connects the metal conductor connector (1) on the upper and lower sides of the base plate (100) acts on the micro solder ball (200) and the base plate (100) prevents the micro solder ball (200) from being separated from or peeled off from the upper and lower terminals of the metal conductor connector (1).

[0067]

[0068] Meanwhile, in the metal conductor electrical connector inner sheet (10) according to an embodiment of the present invention, as shown in (c) of FIG. 2, a conductive resin silver paste (Ag paste) (300) is surface-coated on the upper and lower surfaces of a base plate (100) on which micro solder balls (200) are formed, thereby firmly fixing the micro solder balls (200) to the base plate (100).

[0069]

[0070] A method for manufacturing an inner sheet of a metal conductor electrical connector according to an embodiment of the present invention comprises, as shown in FIG. 6 (a), a step of providing a base plate, a step of cutting the base plate to a specific size, a step of forming dispersed holes in the base plate, and a step of forming dispersed micro solder balls.

[0071]

[0072] The base plate provision step is a step in which a base plate (100) made of a thin plate made of a conductive material is provided.

[0073]

[0074] *

[0075] The base plate standard cutting step is a step in which the base plate (100) is cut to match the connection area between the upper terminal and the lower terminal of the metal conductor connector (1).

[0076] Meanwhile, performance values ​​such as the allowable current capacity that can be conducted in the metal conductor connector (1) are standardized, and the allowable current capacity of the electrical connector according to the material is determined by the electrical contact resistance characteristics of the connector and is standardized. Therefore, if the electrical contact resistance in the connector is significantly reduced, the allowable current capacity of the copper busbar or aluminum busbar, which is the metal conductor connector (1), can be standardized to a high value. In this case, when manufacturing an electrical connector with the same allowable current capacity, a metal conductor of smaller dimensions than before can be used, so the manufacturing cost can be significantly reduced. Since the metal conductor electrical connector according to the embodiment of the present invention significantly reduces the electrical contact resistance, a metal conductor of smaller dimensions can be used, and the dimensions of the base plate (100) cut in the base plate standard cutting step can also be reduced.

[0077]

[0078] The base plate hole dispersion formation step is a step of dispersing and forming a plurality of micro holes (110) in a set pattern on a base plate (100). Here, the base plate hole dispersion formation step forms micro holes (110) using a laser processing process, a micro punching process, or an etching process, which is a surface treatment technology. In the base plate hole dispersion formation step according to an embodiment of the present invention, micro holes (110) of the same diameter are formed in a certain pattern as shown in FIG. 7 (a) through micro laser processing on the base plate (100). The micro holes (110) can be arranged in a grid pattern forming multiple rows and multiple columns at equal intervals. In particular, the base plate hole dispersion formation step according to an embodiment of the present invention causes the micro holes (110) to be formed by penetrating the upper and lower surfaces of the base plate (100) through micro laser processing on the base plate (100).

[0079]

[0080] The micro solder ball dispersion formation step is a step of dispersing micro solder balls (200) made of a conductive material into each micro hole (110) of a base plate (100), such that the micro solder balls (200) protrude from the upper and lower surfaces of the base plate (100). As shown in FIG. 7 (b) and FIG. 8, micro solder balls (200) of the same diameter can be formed in a certain pattern on the surface of the base plate (100). Additionally, the micro solder balls (200) can be arranged in a grid pattern forming multiple rows and multiple columns at equal intervals. In particular, the micro solder ball dispersion formation step according to an embodiment of the present invention places the middle portion of the micro solder balls (200) in the micro hole (110) penetrating the upper and lower surfaces of the base plate (100), and causes the upper and lower portions of the micro solder balls (200) to protrude from the upper and lower surfaces of the base plate (100).

[0081] Here, the micro solder ball dispersion formation step according to the first embodiment of the present invention is performed through the steps of coating the surface of an organic solvent base plate, introducing a micro solder ball base plate, and bonding a micro solder ball base plate, as shown in FIG. 9.

[0082] The step of applying an organic solvent to the surface of the base plate is a step of applying an organic solvent to the micro-holes (110) of the base plate (100), and a polymer paste which is an organic solvent having a boiling point of 300°C or higher may be applied. Here, as the organic solvent, a solvent comprising at least one of an ether structure, an ester structure, or a hydroxyl structure may be used.

[0083] The micro solder ball baseplate insertion step is a step of inserting micro solder balls (200) into micro holes (110) coated with an emulsion solvent.

[0084] The micro solder ball base plate bonding step is a step in which the micro solder ball (200) is bonded to the base plate (100) inside the micro hole (110) by an emulsion solvent.

[0085]

[0086] *

[0087] In contrast, the micro solder ball dispersion formation step according to the second embodiment of the present invention is performed through the micro solder ball base plate insertion step, base plate heating step, and micro solder ball base plate bonding step as shown in FIG. 10.

[0088] The micro solder ball base plate insertion step is a step of inserting micro solder balls (200) into micro holes (110) of the base plate (100).

[0089] The base plate heating step is a step of heating the base plate (100) into which micro solder balls (200) are introduced for a set time within a set temperature range. Such a base plate heating step can heat-treat the base plate (100) into which micro solder balls (200) are introduced for several minutes to tens of minutes at a temperature of 200 to 300°C. In order to prevent oxidation of the metallic components of the base plate (100) and micro solder balls (200), the base plate heating step needs to be performed under vacuum conditions.

[0090] The micro solder ball base plate bonding step is a step in which the micro solder ball (200) and the base plate (100) become integrated as alloying is induced by a diffusion reaction between the metal component of the base plate (100) and the metal component of the micro solder ball (200) by heating. That is, the micro solder ball (200) is fixed to the base plate (100) by alloying as the diffusion reaction between the atoms of the micro solder ball (200), which consists of alloy metal components of tin, copper, and silver, and the copper or aluminum material which is the metal component of the base plate (100) is promoted.

[0091]

[0092] Meanwhile, the method for manufacturing a metal conductor electrical connector inner sheet according to the present invention may perform a silver paste surface coating step and a drying step after the micro solder ball dispersion formation step as shown in FIG. 6 (b).

[0093] The silver paste surface application step is a step in which a conductive resin silver paste (Ag paste) (300) is applied to the upper and lower surfaces of a base plate (100) on which micro solder balls (200) are formed as in FIG. 11, and the drying step is a step of drying the silver paste (300) applied to the surface of the base plate (100) in the atmosphere.

[0094] Through this, the micro solder ball (200) is firmly fixed to the base plate (100).

[0095]

[0096] Although the metal conductor electrical connector inner sheet and the method for manufacturing the same according to the embodiment of the present invention as described above have been illustrated in accordance with the description and drawings, this is merely an example, and those skilled in the art will understand that various changes and modifications are possible within the scope of the technical spirit of the present invention.

Claims

1. A base plate (100) disposed between electrically connected metal conductor connectors (1), made of a thin plate made of a conductive material, and having a plurality of micro holes (110) distributed in a set pattern; The configuration comprises: micro solder balls (200) made of a conductive material, which are inserted into each micro hole (110) of the base plate (100), are integrally bonded with the base plate (100), are dispersedly arranged, protrude from the upper and lower surfaces of the base plate (100), and are formed. A metal conductor electrical connector inner sheet characterized by a structure in which a middle portion, which is a part of each micro solder ball (200), is disposed in each of the micro holes (110) formed by penetrating the upper and lower surfaces of the base plate (100), and an upper portion, which is a part of each micro solder ball (200), protrudes upward from the upper surface of the base plate (100), while a lower portion, which is a part of each micro solder ball (200), protrudes downward from the lower surface of the base plate (100).

2. In Paragraph 1, The above-described micro solder ball (200) is formed in a spherical shape and is characterized by 1) the upper portion protruding upward from the upper surface of the base plate (100) in a hemispherical shape, and 2) the lower portion protruding downward from the lower surface of the base plate (100) in a hemispherical shape, in a metal conductor electrical connector inner sheet.

3. In Paragraph 1, The base plate (100) has a thickness (H) of 10 to 1,000 μm, and the micro-holes (110) have a diameter (d) of tens to hundreds of μm, while the spacing between the micro-holes (110) has a length (D) of tens to hundreds of μm, and the micro-holes (110) are uniformly distributed on the base plate (100) with a space factor of 20 to 80%, forming multiple rows and multiple columns at equal intervals. A metal conductor electrical connector inner sheet characterized in that the micro solder ball (200) is integrally bonded to the base plate (100) by an organic solvent or integrally bonded to the base plate (100) by heating.

4. A base plate provision step in which a base plate (100) made of a thin plate made of a conductive material is provided; A base plate specification cutting step in which the base plate (100) is cut to match the connection area between the upper terminal and the lower terminal of the metal conductor connector (1); A base plate hole dispersion formation step in which a plurality of micro holes (110) are dispersed and formed in a set pattern on the base plate (100), wherein each of the micro holes (110) is formed by penetrating the upper and lower surfaces of the base plate (100); A method for manufacturing a metal conductor electrical connector inner sheet, characterized by comprising: a micro solder ball dispersion formation step in which micro solder balls (200) made of a conductive material are dispersed and arranged in each micro hole (110) of the base plate (100), wherein the micro solder balls (200) are integrally bonded with the base plate (100), wherein a middle portion, which is a part of each micro solder ball (200), is arranged in each micro hole (110), and an upper portion, which is a part of each micro solder ball (200), is protruded upward from the upper surface of the base plate (100), and a lower portion, which is a part of each micro solder ball (200), is protruded downward from the lower surface of the base plate (100).

5. In Paragraph 4, A method for manufacturing a metal conductor electrical connector inner sheet, wherein the above-described base plate hole dispersion formation step is characterized by forming the micro-holes (110) through the upper and lower surfaces of the base plate (100) by micro laser processing of the base plate (100), and wherein the micro-holes (110) of the same diameter are arranged in a grid pattern forming multiple rows and multiple columns with various hole spacings or various hole shape patterns.

6. In Paragraph 4, The above micro solder ball dispersion formation step is, 1) an organic solvent base plate surface application step of applying an organic solvent to a micro hole (110) of the base plate (100); a micro solder ball base plate insertion step of inserting a micro solder ball (200) into the micro hole (110) to which the emulsion solvent has been applied; and a micro solder ball base plate bonding step in which the micro solder ball (200) is bonded to the base plate (100) inside the micro hole (110) by the emulsion solvent; are configured to include, 2) A micro solder ball base plate insertion step of inserting a micro solder ball (200) into a micro hole (110) of the base plate (100); a base plate heating step of heating the base plate (100) into which the micro solder ball (200) has been inserted for a set time within a set temperature range; and a micro solder ball base plate bonding step in which the micro solder ball (200) and the base plate (100) become integrated as alloying is induced by a diffusion reaction between the metal component of the base plate (100) and the metal component of the micro solder ball (200) by heating; the method of manufacturing a metal conductor electrical connector inner sheet is characterized by comprising the above-mentioned configuration.

7. In Paragraph 4, A silver paste surface coating step performed after the above micro solder ball dispersion formation step, wherein a conductive resin silver paste (Ag paste) (300) is surface coated on the upper and lower surfaces of the base plate (100) on which the micro solder balls (200) are formed; A method for manufacturing a metal conductor electrical connector inner sheet, further comprising a drying step of drying the silver paste (300) applied to the surface of the base plate (100) in the atmosphere.

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