KR-20260064485-A - Metal Conductor Electric Connector Inner Sheet and Manufacturing Mehtod thereof

Abstract

The present invention provides 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. In particular, the present invention provides a metal conductor electrical connector inner sheet and a method for manufacturing the same that can be effectively applied to an electric vehicle battery system for preventing fire accidents, as the electrical contact resistance generated in the electrical connector is significantly reduced and the temperature rise caused by heat generation in the electrical connector is suppressed, by increasing the degree of contact adhesion between terminals through a structure in which micro solder balls protruding from the surface and 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 suppressing the temperature rise caused by heat generation in the electrical connector.

Inventors

• 김병걸

Assignees

• 김병걸

Dates

Publication Date

20260507

Application Date

20250724

Claims (1)

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; A metal conductor electrical connector inner sheet characterized by including micro solder balls (200) made of a conductive material, which are inserted into and dispersed in each micro hole (110) of the base plate (100) and protrude from the upper and lower surfaces of the base plate (100).

Description

Metal Conductor Electric Connector Inner Sheet and Manufacturing Method thereof 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. 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. Meanwhile, the BDU (Battery disconnected unit), which is installed between the DC-DC converter (a power conversion device) and the battery, has multiple high-voltage connection electrical connectors connected to high-voltage copper busbars and low-voltage connection electrical connectors connected to low-voltage copper busbars installed inside the battery pack as shown in FIG. 12 to perform the function of cutting off and controlling power, so ensuring the stability of the electrical connectors has a significant impact on the safety of the entire battery. 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. 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. That is, copper busbars, which are