US-20260126399-A1 - SHAPE EVALUATION METHOD OF THERMALLY CONDUCTIVE ADHESIVE AND METHOD FOR MANUFACTURING BATTERY MODULES USING THE SAME

US20260126399A1US 20260126399 A1US20260126399 A1US 20260126399A1US-20260126399-A1

Abstract

The present disclosure provides a shape evaluation method of a thermally conductive adhesive, including collecting two-dimensional shape information of a measurement site of the thermally conductive adhesive distributed on a substrate, dividing the measurement site into two or more units, measuring heights of each unit to evaluate a thickness of the measurement site, and measuring shading of each unit to evaluate a discontinuity of the measurement site.

Inventors

Hyeon Su KIM
Su Min KWON
Jeong Been KIM

Assignees

SK ON CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251105
Priority Date: 20241106

Claims (17)

1 . A shape evaluation method of a thermally conductive adhesive, comprising: collecting two-dimensional shape information of a measurement site of the thermally conductive adhesive distributed on a substrate; dividing the measurement site into two or more units; measuring heights of each unit to evaluate a thickness of the measurement site; and measuring shading of each unit to evaluate a discontinuity of the measurement site.
2 . The shape evaluation method of claim 1 , wherein the measurement site is equally divided into two or more units.
3 . The shape evaluation method of claim 1 , wherein, in the collecting of the two-dimensional shape information, length and height information of the measurement site is collected using a direction in which the adhesive is distributed and a direction perpendicular to the distribution direction as an x-axis and a y-axis, respectively.
4 . The shape evaluation method of claim 3 , wherein the height information of the measurement site is calculated by correcting a height of a lowermost end portion of the measurement site as a reference value.
5 . The shape evaluation method of claim 1 , wherein the two-dimensional shape information is measured using a phase measurement method or a laser scanning technique.
6 . The shape evaluation method of claim 1 , wherein the evaluating of the thickness of the measurement site includes: calculating maximum values of the heights of each unit at 10th to 40th percentiles of a volume-weighted distribution of the measurement site; and calculating an average value of the maximum values of the heights of each unit.
7 . The shape evaluation method of claim 6 , wherein, in the evaluating of the thickness of the measurement site, when the average value differs from a predetermined height threshold value, the adhesive distribution is determined to be defective.
8 . The shape evaluation method of claim 1 , wherein the evaluating of the discontinuity of the measurement site includes: measuring a continuous length from one end of the measurement site to the other end based on a change in shading of each unit; and determining the adhesive distribution as a defect when the measured length differs from the predetermined length threshold value.
9 . The shape evaluation method of claim 8 , wherein the continuous length of the measurement site is a length from one end of the measurement site to a portion where the change in the shading differs from the predetermined threshold value for a total area of each unit.
10 . A method for manufacturing a battery module, comprising: distributing a thermally conductive adhesive on a battery module case; evaluating a shape of the thermally conductive adhesive that includes collecting two-dimensional shape information of a measurement site of the thermally conductive adhesive, dividing the measurement site into two or more units, measuring heights of each unit to evaluate a thickness of the measurement site, and measuring shading of each unit to evaluate a discontinuity of the measurement site; and assembling the battery module by coupling the battery module case and a battery cell stack that pass through the evaluation.
11 . The method of claim 10 , wherein the measurement site is equally divided into two or more units.
12 . The method of claim 10 , wherein, in the distributing of the thermally conductive adhesive, the thermally conductive adhesive is distributed at one or more positions selected from among between the battery module accommodated in the battery module case and the cell stack, between the battery cells, and one side of the battery cell stack.
13 . The method of claim 10 , wherein, in the collecting of the two-dimensional shape information, length and height information of the measurement site is collected using a direction in which the adhesive is distributed and a direction perpendicular to the distribution direction as an x-axis and a y-axis, respectively.
14 . The method of claim 10 , wherein the evaluating of the thickness of the measurement site includes: calculating maximum values of the heights of each unit at 10th to 40th percentiles of a volume-weighted distribution of the measurement site; and calculating an average value of the maximum values of the heights of each unit.
15 . The method of claim 14 , wherein, in the evaluating of the thickness of the measurement site, when the average value differs from a predetermined height threshold value, the adhesive distribution is determined to be defective.
16 . The method of claim 10 , wherein the evaluating of the discontinuity of the measurement site includes: measuring a continuous length from one end of the measurement site to the other end based on a change in shading of each unit; and determining the adhesive distribution as a defect when the measured length differs from the predetermined length threshold value.
17 . The method of claim 16 , wherein the continuous length of the measurement site is a length from one end of the measurement site to a portion where the change in the shading differs from the predetermined threshold value for a total area of each unit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S. C. § 119 to Korean Patent Application No. 10-2024-0155971, filed on Nov. 6, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The following disclosure relates to a shape evaluation method of a thermally conductive adhesive and a method for manufacturing a battery module using the same. BACKGROUND Secondary batteries may be charged and discharged, and thus, may be applied to various fields such as digital cameras, mobile phones, laptop computers, hybrid vehicles, and electric vehicles. Among these secondary batteries, many studies are being conducted on lithium secondary batteries having high energy density and discharge voltage. The lithium secondary battery is manufactured as a pouched type battery cell having flexibility or a prismatic battery cell or a cylindrical can type battery cell having rigidity. A plurality of battery cells are mounted on a module case in units of cell stacks in which the battery cells are stacked and electrically connected to each other, thereby constituting a battery system such as a battery module or a battery pack. The battery systems are installed and used in electric vehicles, etc. It is very important to secure the safety of such battery systems. In particular, when a flame is generated from a battery cell due to an abnormal phenomenon and spreads to other nearby battery cells, thermal runaway may occur, which may lead to additional fires or explosions. Therefore, a structure capable of preventing the spread of a flame generated inside a battery cell is required. In this case, when the thermally conductive adhesive is not applied uniformly, poor contact between the battery cell and the case may reduce the mechanical strength of the coupling, which may in turn reduce the durability of the battery module. In addition, when voids or delamination occur in the thermally conductive adhesive, heat is not adequately transferred to increase the temperature of the battery cell, thereby posing a risk of shortened battery cell lifespan. Therefore, there is a need to develop a method for evaluating whether a thermally conductive adhesive is properly applied to optimize the thermal performance of a battery module. SUMMARY An embodiment of the present disclosure is directed to providing a shape evaluation method of a thermally conductive adhesive capable of determining whether the thermally conductive adhesive is poorly distributed by inspecting whether the thermally conductive adhesive is normally distributed. Another embodiment of the present disclosure is directed to providing a shape evaluation method of a thermally conductive adhesive that is stable and effective in consideration of surface noise of the thermally conductive adhesive. According to one aspect of the present disclosure, the shape evaluation method of a thermally conductive adhesive having the above-described advantages may provide optimal process conditions in a battery module process, and furthermore, may be widely applied in green technology fields such as electric vehicles, battery charging stations, and solar and wind power generation using batteries. In one general aspect, a shape evaluation method of a thermally conductive adhesive includes: collecting two-dimensional shape information of a measurement site of the thermally conductive adhesive distributed on a substrate; dividing the measurement site into two or more units; measuring heights of each unit to evaluate a thickness of the measurement site; and measuring shading of each unit to evaluate a discontinuity of the measurement site. The measurement site may be equally divided into two or more units. In the collecting of the two-dimensional shape information, length and height information of the measurement site may be collected using a direction in which the adhesive is distributed and a direction perpendicular to the distribution direction as an x-axis and a y-axis, respectively. The height information of the measurement site may be calculated by correcting a height of a lowermost end portion of the measurement site as a reference value. The two-dimensional shape information may be measured using a phase measurement method or a laser scanning technique. The evaluating of the thickness of the measurement site may include: calculating maximum values of the heights of each unit at 10th to 40th percentiles of a volume-weighted distribution of the measurement site; and calculating an average value of the maximum values of the heights of each unit. In the evaluating of the thickness of the measurement site, when the average value differs from a predetermined height threshold value, the adhesive distribution may be determined to be defective. The evaluating of the discontinuity of the measurement site may include: measuring a continuous length from one end of the measurement site to the