CONDUCTOR BONDING METHOD

Abstract

Provided is a conductor bonding method capable of simply and easily performing a conductor bonding operation by placing conductive particle patterns and a conductive particle fixing material directly on lead terminals of an electronic device, the conductor bonding method includes 1) placing a first conductive particle fixing material 110 on lead terminals 2 of a display panel 1 (S100), 2) forming conductive particle patterns by placing conductive particles 120 in a dense state only on regions, in an upper surface of the first conductive particle fixing material 110, corresponding to the regions where the lead terminals 2 are formed in the display panel 1 (S200), 3) aligning a conductor 3 on the lead terminals 2 of the display panel 1, on which the first conductive particle fixing material and the conductive particle patterns are formed in step 1) and step 2) (S100-S200) (S300), and 4) bonding the aligned conductor 3 to the lead terminals 2 by applying heat or pressure (S400).

Claims

1. A conductor bonding method comprising: 1) placing a first conductive particle fixing material 110 on lead terminals 2 of a display panel 1 (S100); 2) forming conductive particle patterns by placing conductive particles 120 in a dense state only on regions, in an upper surface of the first conductive particle fixing material 110, corresponding to the regions where the lead terminals 2 are formed in the display panel 1 (S200); 3) aligning a conductor 3 on the lead terminals 2 of the display panel 1, on which the first conductive particle fixing material and the conductive particle patterns are formed in step 1) and step 2) (S100-S200) (S300); and 4) bonding the aligned conductor 3 to the lead terminals 2 by applying heat or pressure (S400).

2. The conductor bonding method of claim 1, further comprising, after performing step 2) (S200), placing a second conductive particle fixing material 130 that fixes the conductive particle patterns, on the conductive particle pattern (S500).

3. The conductor bonding method of claim 2, wherein each of the first conductive particle fixing material 110 and the second conductive particle fixing material 130 is one selected from a non-conductive film, a non-conductive tape, and a non-conductive liquid.

4. The conductor bonding method of claim 1, wherein the conductive particles 120 each have a diameter of 10 .Math.m or less and include metal particles or polymer particles plated with metal.

5. The conductor bonding method of claim 2, wherein a protective film 140 is further coated on the second conductive particle fixing material 130 or the conductive particle pattern, and before performing step 3) (S300), isolating of the protective film is further performed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIGS. 1 and 2 are diagrams showing arrangement state of conductive particles in an anisotropic conductive film (ACF) according to the related art.

[0024] FIGS. 3 and 4 are diagrams showing processes of a first step (S100) in a conductor bonding method according to the present disclosure.

[0025] FIGS. 5 and 6 are diagrams showing processes of a second step (S200) in a conductor bonding method according to the present disclosure.

[0026] FIG. 7 is a diagram showing processes of a third step (S300) in a conductor bonding method according to the present disclosure.

[0027] FIG. 8 is a diagram showing a process in which a protective film is further coated in the third step (S300) of the conductor bonding method according to the present disclosure.

[0028] FIG. 9 is a diagram showing a process in which a protective film is isolated in the third step (S300) of the conductor bonding method according to the present disclosure.

[0029] FIG. 10 is a diagram showing processes of a fourth step (S400) in a conductor bonding method according to the present disclosure.

[0030] FIGS. 11 and 12 are partially cross-sectional views showing a structure in a bonded state.

[0031] FIG. 13 is a plan view showing a lead terminal and a conductor structure in a bonded state.

[0032] FIG. 14 is a flowchart illustrating a conductor bonding method according to the present disclosure.

[0033] FIGS. 15 and 16 are diagrams showing arrangement states of conductive particles in an ACF according to an embodiment of the present disclosure.

BEST MODE

[0034] Provided is a conductor bonding method capable of simply and easily performing a conductor bonding operation by placing conductive particle patterns and a conductive particle fixing material directly on lead terminals of an electronic device, the conductor bonding method includes 1) placing a first conductive particle fixing material 110 on lead terminals 2 of a display panel 1 (S100), 2) forming conductive particle patterns by placing conductive particles 120 in a dense state only on regions, in an upper surface of the first conductive particle fixing material 110, corresponding to the regions where the lead terminals 2 are formed in the display panel 1 (S200), 3) aligning a conductor 3 on the lead terminals 2 of the display panel 1, on which the first conductive particle fixing material and the conductive particle patterns are formed in step 1) and step 2) (S100-S200) (S300), and 4) bonding the aligned conductor 3 to the lead terminals 2 by applying heat or pressure (S400).

MODE

[0035] Hereinafter, one or more embodiments will be described in detail with reference to accompanying drawings.

<Embodiment 1>

[0036] In the embodiment, the electronic device may include various electronic devices such as a display apparatus, a display panel, etc. A conductor bonding method according to the embodiment starts with step S100 in which a first conductive particle fixing material is placed, as shown in FIG. 14. In detail, in this operation (S100), as shown in FIGS. 3 and 4, a first conductive particle fixing material 110 is thinly placed on lead terminals 2 of a display panel 1. The first conductive particle fixing material 110 includes a material that may attach and fix first conductive particles 120 that will be described later on the lead terminals 2. For example, the first conductive particle fixing material 110 may include one selected from a non-conductive film, a non-conductive tape, and a non-conductive liquid.

[0037] In the embodiment, the first conductive particle fixing material 110 may be placed in a manner of entirely covering the plurality of lead terminals 2 or in a manner of separately covering each of the lead terminals 2, as shown in FIG. 3.

[0038] Next, as shown in FIG. 14, an operation of forming a conductive particle pattern (S200) is performed. In this operation (S200), as specifically shown in FIGS. 5 and 6, on an upper surface of the first conductive particle fixing material 110, the conductive particles 120 are placed only on regions corresponding to the regions, where the lead terminals 2 of the electronic device are formed, to be dense to form the conductive particle pattern. That is, the conductive particle pattern is formed by arranging the conductive particles 120 in a dense state to be a pattern matching the shape of the lead terminals 2.

[0039] In addition, in the embodiment, ‘arranged in a dense state’ denotes that the conductive particles 120 are arranged while coming into contact with one another without forming a separation space or while being as close to one another as possible. Therefore, in the conductive particle pattern according to the embodiment, the conductive particles may be arranged without having an empty space other than a gap that is inevitably formed when the conductive particles are in close contact with or adjacent to one another.

[0040] In detail, a ratio of an area in which the conductive particles are arranged with respect to a total area of one conductive particle pattern according to the embodiment is 60% or greater.

[0041] * Ratio of conductive particle arrangement (%) = area of conductive particle arrangement/entire pattern area × 100

[0042] When the ratio of the conductive area is high as 60% or greater, in a next operation of bonding a conductor 3 (S400), a large number of conductive particles 120 are arranged between the conductor 3 and the lead terminal 2, and the possibility of generating a connection failure is lowered. In addition, even in use after the bonding process, electric energization is carried out over a large area, and then, resistance is reduced and the possibility of generating defects such as heat generation during operation may be reduced. Meanwhile, the conductor 3 may include a conductor on an FPCB.

[0043] In addition, in the embodiment, as shown in FIG. 7, an operation of placing a second conductive particle fixing material 130 that fixes the conductive particle pattern on the conductive particles (S500) may be further performed after the process of forming the conductive particle pattern (S200).

[0044] When the conductor alignment process (S300) and the bonding process (S400) are immediately performed after the conductive particle pattern forming process (S200), the process of placing the second conductive particle fixing material 130 may not be necessary. However, when the electronic device is stored and the conductor alignment process (S300) and the bonding process (S400) are performed or is moved to another space and the conductor alignment process (S300) and the bonding process (S400) are performed after a considerable time amount has passed since the conductive particle pattern is formed, the second conductive particle fixing material 130 is placed once more for protecting and fixing the conductive particle pattern.

[0045] Moreover, as shown in FIG. 8, a protective film 140 may be further coated on the second conductive particle fixing material 130 or the conductive particle pattern, and the protective film 140 is isolated and removed before performing the conductor alignment process (S300) as shown in FIG. 9. Therefore, when the protective film 140 is coated, a protective film isolation process may be further performed before the conductor alignment process (S300).

[0046] Next, as shown in FIG. 14, the process of aligning the conductor 3 on the lead terminals 2 of the display panel 1, on which the first conductive particle fixing material 110 and the conductive particles 120 are formed is performed (S300). In this process S300, as shown in FIG. 12 in detail, positions of conductor patterns 4 having the same interval as that of the patterns of the lead terminals 2 and the conductive particle patterns are adjusted so that each interval between the conductor patterns 4 coincides with that of the patterns of the lead terminals 2 or the conductive particle patterns.

[0047] Next, as shown in FIG. 14, the operation of bonding the aligned conductor 3 onto the lead terminals 2 by applying heat or pressure is performed (S400). That is, as shown in FIGS. 10 and 11, the bonding is carried out in the manner of applying both the heat and pressure from upper and lower sides or applying one of the heat and pressure while the conductor patterns 4 and the lead terminals 2 are in close contact with each other. When the bonding is performed as described above, as shown in FIG. 11, the conductive particles 120 between the conductor patterns 4 and the lead terminals 2 allow the both to be electrically connected while coming into contact with the conductor patterns 4 and the lead terminals 2. Here, the conductive particles 120 are slightly pushed and deformed into elliptical shapes, and the first and second conductive particle fixing materials 110 and 120 are pushed to opposite sides to fill empty spaces.

<Embodiment 2>

[0048] An anisotropic conductive sheet 1000 according to the embodiment has a sheet shape as a whole and includes a sheet 1100 and the conductive particles 1200, as shown in FIG. 15. The sheet 1100 forms the overall exterior of the anisotropic conductive sheet 1000 according to the embodiment and includes a plastic resin. The sheet 1100 may be formed of a thermosetting epoxy resin or other resins.

[0049] The sheet is virtually divided into an area in which the conductive particles 1200 are arranged and an area in which the conductive particles 1200 are not arranged. Here, the area in which the conductive particles 1200 are arranged may be referred to as a conductive pattern 1300, and the other area may be referred to as a non-conductive pattern. In addition, the conductive pattern 1300 may be changed into various shapes, and the shape and size of the conductive pattern 1300 may be precisely the same as those of the electrode pattern formed on the substrate, on which the anisotropic conductive sheet 1000 is to be mounted.

[0050] In the conductive pattern 1300 set as above, the plurality of conductive particles 1200 are arranged in close contact with one another as shown in FIG. 15. Here, ‘arranged in close contact with one another’ denotes that the conductive particles 1200 are densely arranged while contacting each other without having a separation space. Therefore, in the anisotropic conductive sheet 1000 according to the embodiment, the conductive particles may be arranged without forming an empty space, other than a gap that is inevitably formed while the conductive particles are in close contact with one another, in the conductive pattern 1300.

[0051] In detail, in the anisotropic conductive sheet 1000 according to the embodiment, a ratio of an area in which the conductive particles are arranged with respect to the entire area in one conductive pattern may be 60% or greater.

[00001]$\begin{array}{l}\text{* Ration of conductive particle arrangement (\%) = area of conductive particle}\\ \text{arrangement/entire pattern area}\times \text{100}\end{array}$

[0052] When the conductive area ratio is high as 60% or greater, a large number of conductive particles 1200 are arranged between the electrode and the electrode pattern in the process of mounting electrodes and electrode patterns, and thus, a possibility of generating the connection failure may decrease. In addition, even in use after the mounting operation, the electricity is energized over a large area, and thus, the resistance is lowered and the possibility of generating defects such as heat generation during operation also decrease.

[0053] In addition, in the anisotropic conductive sheet 1000 according to the embodiment, the conductive particles 1200 may be only arranged in the virtual conductive pattern 1300, but some may be arranged out of the conductive pattern 1300.

[0054] Meanwhile, in the embodiment, the conductive particles 1200 may have a particle diameter of 10 .Math.m or less and may include metal particles or polymer particles plated with metal.

[0055] In addition, the anisotropic conductive sheet 1000 and 2000 according to the embodiment may further include a mark 1400 and 2400 as shown in FIGS. 15 and 16. The anisotropic conductive sheet 1000 and 2000 according to the embodiment includes the conductive patterns having the same shapes and sizes as those of the electrode patterns formed on the substrate on which the mounting operation is to be performed, and thus, the anisotropic conductive sheet 1000 and 2000 has to be accurately aligned with the substrate in the actual mounting operation.

[0056] Therefore, the mark 1400 and 2400 is indicated at an edge or corner of the sheet 1100 and 2100 to be used as a reference point in the aligning operation with the substrate.

INDUSTRIAL APPLICABILITY

[0057] According to the anisotropic conductive sheet of the present disclosure, the conductive particles are intensively arranged only in certain patterns and are not arranged in the other regions. Thus, the electric connection may be stably made within the certain patterns, and the electric short generation is fundamentally prevented due to the regions where the conductive particles are not arranged.

[0058] In particular, because the conductive particles are intensively arranged in the certain patterns according to the present disclosure, the occurrence of electric short may be prevented by utilizing the regions where the conductive particles are not arranged, without reducing the size of the conductive particles. Thus, handling of the conductive particles becomes easy during the manufacturing process of the anisotropic conductive sheet.