Heat seal connector and method for manufacturing the same

Abstract

To provide a heat seal connector excellent in followability to a three-dimensional curved surface structure, and a method for manufacturing the same.SOLUTION: A heat seal connector 1 includes: a base material 11; a conductive pattern 12 arranged on at least one main surface 11a thereof; an insulation pattern 13 arranged so as to fill a space between the conductive patterns 12; and an anisotropic conductive adhesive layer 14 arranged on at least a portion in contact with an electrode terminal of an electric circuit board in the conductive patterns 12 on the conductive pattern 12 or the insulation pattern 13. The base material 11 is made of a silicone sheet. A maximum height h1 of the insulation pattern 13 is higher than a maximum height h2 of the conductive pattern 12. At least one main surface 11a of the base material 11 is covered with the conductive pattern 12 or the insulation pattern 13. The insulation pattern 13 has a portion 13A in which a height h11 of the insulation pattern 13 is lower than the maximum height h2 of the conductive pattern 12 between the conductive pattern 12 and the insulation pattern 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat seal connector and a method for producing the same. [Background technology]

[0002] Conventionally, heat seal connectors have been used to connect displays such as liquid crystal displays (LCDs), electroluminescent displays (ELs), light emitting diodes (LEDs), electrochromic displays (ECDs), and plasma displays (PDPs) to rigid printed circuit boards (PCBs) or flexible printed circuit boards (FPCs), or to connect PCBs or FPCs together.

[0003] A known heat seal connector has a configuration in which a desired conductive pattern is formed on an insulating flexible base film using a conductive paste, and an anisotropic conductive adhesive layer is provided on top of the pattern, the anisotropic conductive adhesive layer being made by dispersing conductive fine particles in an insulating adhesive (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 55-38073 [Patent Document 2] Special Publication No. 58-56996 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, there is a demand for connectors that can be integrated with housings that require high design quality, or modules that can follow three-dimensional curved structures such as the surfaces of living bodies or robots. However, when conventional technology is used, there is a limit to the flexibility of the connector due to the rigidity of the connector's base material, and the connector is not able to adequately follow three-dimensional curved structures.

[0006] Silicone can be used as a base material that can ensure flexibility and heat resistance during compression bonding. However, silicone has the following problems (1) to (3). (1) Due to differences in hardness and elasticity with the conductive material used in the electrodes, the interfacial adhesion decreases when stress is applied. (2) The silicone surface of the exposed part of the substrate between the electrodes has low adhesion, so if left as is, it will not bond sufficiently to the non-silicone anisotropic conductive film, resulting in a decrease in peel strength and the possibility of moisture penetrating the poorly adhered parts and causing migration, making it necessary to carry out a treatment to activate the surface. In this case, it is necessary to carry out the bonding during a period in which the effectiveness of the surface treatment can be maintained, which creates the issue of reduced freedom of design and process. (3) As a countermeasure against migration, a method has been proposed in which the conductive metal layer is coated with a material that does not cause migration, but applying this method impairs flexibility. (4) A method has been proposed in which the spaces between conductive patterns are filled with insulating patterns formed to approximately the same height. However, because the conductive patterns and insulating patterns have the same height, there is a limit to the deterioration of insulation between the conductive patterns.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide a heat seal connector that is excellent in conformity to three-dimensional curved structures, and a method for manufacturing the same. [Means for solving the problem]

[0008] The present invention includes the following aspects. [1] A substrate, A conductive pattern disposed on at least one main surface of the substrate; an insulating pattern disposed on at least one main surface of the base material so as to fill spaces between the conductive patterns; an anisotropic conductive adhesive layer disposed on the conductive pattern and the insulating pattern, at least on a portion of the conductive pattern that contacts an electrode terminal of an electric circuit board; The substrate is made of a silicone sheet, a maximum height of the insulating pattern based on at least one main surface of the base material is greater than a maximum height of the conductive pattern based on at least one main surface of the base material; At least one main surface of the base material is covered with the conductive pattern or the insulating pattern, A heat seal connector, wherein the insulating pattern has a portion between the conductive pattern and the insulating pattern where the height of the insulating pattern based on at least one main surface of the base material is lower than the maximum height of the conductive pattern based on at least one main surface of the base material. [2] A surface modification step of modifying at least one main surface of the substrate; a conductive pattern forming step of forming a conductive pattern on at least one main surface of the base material by printing using a conductive paste; an insulating pattern forming step of forming an insulating pattern on at least one main surface of the base material using an insulating resin agent by printing so as to fill in spaces between the conductive patterns; an anisotropic conductive adhesive layer forming step of forming an anisotropic conductive adhesive layer on the conductive pattern and the insulating pattern, at least on a portion of the conductive pattern that contacts an electrode terminal of an electric circuit board, using an anisotropic conductive adhesive; In the insulating pattern forming step, a maximum height of the insulating pattern based on at least one main surface of the base material is made higher than a maximum height of the conductive pattern based on at least one main surface of the base material; A method for manufacturing a heat seal connector, wherein in the insulating pattern forming process, a portion is formed in the insulating pattern between the conductive patterns, where the height of the insulating pattern based on at least one main surface of the base material is lower than the maximum height of the conductive pattern based on at least one main surface of the base material. [3] The method for producing a heat seal connector described in [2], wherein the surface modification process is selected from ultraviolet irradiation, corona discharge, plasma treatment, ozone treatment, and high-voltage discharge treatment. Effect of the Invention

[0009] According to the present invention, it is possible to provide a heat seal connector that is excellent in conformity to three-dimensional curved structures and a method for producing the same. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing an embodiment of a heat seal connector according to the present invention. [Diagram 2] 1 is a schematic cross-sectional view showing a state in which a conductive pattern of a heat seal connector according to the present invention is bonded to an electrode terminal of an electric circuit board. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] BEST MODE FOR CARRYING OUT THE DISCLOSURE Hereinafter, an embodiment of a heat seal connector according to the present invention will be described in detail with reference to Figs. In addition, in each drawing used in the following description, for the sake of convenience, characteristic parts may be shown enlarged in order to make the features easier to understand, and the dimensional ratios may differ from the actual ones. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto, and may be appropriately changed and implemented within the scope that does not change the gist of the present invention.

[0012] <Heat seal connector> The heat seal connector of the present invention comprises a substrate, a conductive pattern arranged on at least one main surface of the substrate, an insulating pattern arranged on at least one main surface of the substrate so as to fill spaces between the conductive patterns, and an anisotropic conductive adhesive layer arranged on the conductive pattern and the insulating pattern, at least on a portion of the conductive pattern that contacts an electrode terminal of an electric circuit board. In the present invention, the electric circuit board is a board made of an insulator, an electric circuit (wiring) formed on the surface or inside of the board, and an electrode terminal formed on the electric circuit. In the present invention, the electric circuit board may be called a circuit board. In addition to the electric circuit board, the circuit board may have electronic components such as a capacitor. Hereinafter, the embodiments of the heat seal connector of the present invention will be described in detail one by one.

[0013] FIG. 1 is a schematic cross-sectional view showing an embodiment of a heat seal connector according to the present invention. As shown in FIG. 1, the heat seal connector 1 of this embodiment includes a substrate 11, a conductive pattern 12, an insulating pattern 13, and an anisotropic conductive adhesive layer .

[0014] 1, conductive pattern 12 is disposed on one main surface 11a of substrate 11. Insulating pattern 13 is disposed on one main surface 11a of substrate 11 so as to fill spaces between conductive patterns 11. Anisotropic conductive adhesive layer 14 is disposed on conductive pattern 12 and insulating pattern 13, at least on a portion of conductive pattern 12 that contacts an electrode terminal of an electric circuit board.

[0015] The substrate 11 functions as a base material for maintaining the strength and shape of the heat seal connector 1 . As the substrate 11, for example, a film made of a silicone sheet or the like can be used.

[0016] The thickness of the substrate 11 is not particularly limited, but is preferably 10 μm or more and 200 μm or less, and more preferably 25 μm or more and 100 μm or less, in terms of average thickness. If the average thickness of the substrate 11 is equal to or more than the lower limit of the above range, heat can be uniformly transferred during heat sealing. If the average thickness of the substrate 11 is equal to or less than the upper limit of the above range, thermal conductivity is improved, and quick heating and cooling are possible during the heat sealing process. The average thickness of the substrate 11 described in this specification is the average value of thicknesses measured at any 10 points on the substrate 11.

[0017] One of the principal surfaces 11a of the substrate 11 is preferably surface-modified by ultraviolet irradiation. By surface-modifying one of the principal surfaces 11a of the substrate 11 by ultraviolet irradiation, the molecular bonds constituting the silicone of the substrate 11 are broken, resulting in good wettability. As a result, the adhesive force (bonding force) between the silicone of the substrate 11 and the conductive paste forming the conductive pattern 12 is increased.

[0018] The conductive pattern 12 is disposed on one main surface 11 a of the base material 11 . The conductive pattern 12 can be formed by printing a conductive paste on one main surface 11a of the base material 11. The conductive substance contained in the conductive paste is a conductive polymer. As the conductive polymer, a polythiophene-based conductive polymer is preferable, and from the viewpoint of improving transparency, conductivity, and heat resistance, PEDOT-PSS (poly(3,4-ethylenedioxythiophene-polystyrene sulfonic acid) is more preferable. In addition, the conductive paste may contain, as a conductive substance, indium-doped tin oxide (ITO), etc.), conductive nanowires (silver nanowires, gold nanowires, carbon nanotubes, etc.), metal particles (silver particles, copper particles, gold particles, etc.), conductive metal oxide particles (ITO particles, etc.), carbon (carbon black, graphite, etc.), etc. It is preferable that the conductive paste contains a known binder resin that binds these conductive substances together.

[0019] The height of the conductive pattern 12 (height based on one main surface 11a of the substrate 11) is not particularly limited, but is preferably, for example, 5 μm or more and 20 μm or less in average height, and more preferably 8 μm or more and 15 μm or less. If the average height of the conductive pattern 12 is equal to or more than the lower limit of the above range, the resistance value is lowered and efficient electrical transmission is possible. Also, if the average height of the conductive pattern 12 is equal to or less than the upper limit of the above range, the conductive pattern 12 becomes thinner, which is expected to improve design freedom and reduce weight.

[0020] The insulating pattern 13 prevents the conductive fine particles contained in the conductive pattern 12 from flowing out and causing a decrease in insulation between the conductive patterns 12 when the heat seal connector 1 is heat sealed. The insulating pattern 13 is disposed on one main surface 11 a of the base material 11 so as to fill the spaces between the conductive patterns 12 . The insulating pattern 13 can be formed on one main surface 11a of the base material 11 by printing an insulating resin agent so as to fill in the spaces between the conductive patterns 12.

[0021] Examples of insulating resin agents include photosensitive resins such as ultraviolet curing resins and electron beam curing resins, or chemically cured resins such as electron beam curing resins, epoxy, urethane, melamine, etc. Among these, ultraviolet curing resins have a process advantage in that after application, ultraviolet light is irradiated from the substrate 11 side to cure the resin filling the spaces between the conductive patterns 12, and the uncured resin on the conductive patterns 12 can be removed with a solvent.

[0022] The thickness of the insulating pattern 13 is not particularly limited, but is preferably 15 μm to 50 μm, more preferably 20 μm to 40 μm, in average thickness, for example. If the average thickness of the insulating pattern 13 is equal to or greater than the lower limit of the above range, high insulation properties can be obtained. If the average thickness of the insulating pattern 13 is equal to or less than the upper limit of the above range, the insulating pattern 13 becomes thinner, and improved design freedom and weight reduction can be expected.

[0023] A maximum height h1 of the insulating pattern 13 taken from one main surface 11a of the base material 11 as a reference is greater than a maximum height h2 of the conductive pattern 12 taken from one main surface 11a of the base material 11 as a reference. Here, the maximum height h1 of the insulating pattern 13 is determined by measurement using a non-contact method with a laser thickness gauge. Similarly, the maximum height h2 of the conductive pattern 12 is determined by measurement using a non-contact method with a laser thickness gauge.

[0024] One of the main surfaces 11a of the substrate 11 is covered with a conductive pattern 12 or an insulating pattern 13. The ratio of the area covered with the conductive pattern 12 or the insulating pattern 13 to the total area of ​​the main surface 11a is preferably 50% to 100%, more preferably 70% to 100%, and even more preferably 90% to 100%. When the ratio of the area is equal to or greater than the lower limit, there is an advantage that the reliability of the connection is improved. When the ratio of the area is equal to or less than the upper limit, there is an advantage that the thickness is reduced, which can be expected to improve the freedom of design and reduce weight.

[0025] The insulating pattern 13 is disposed between the conductive pattern 12 and the insulating pattern 13, and has a height h of the insulating pattern 13 based on one main surface 11a of the base material 11. 21 However, the conductive pattern 12 has a portion 13A that is lower than the maximum height h2 of the conductive pattern 12 based on one main surface 11a of the base material 11. The ratio of the lower area where the lower portion 13A is formed to the total area of ​​the insulating pattern 13 is preferably 10% to 80%, more preferably 20% to 70%, and even more preferably 30% to 60%. If the ratio of the lower area is equal to or greater than the lower limit, there is an advantage that the reliability of the connection is improved. If the ratio of the lower area is equal to or less than the upper limit, there is an advantage that the insulating pattern 13 becomes thinner, which can be expected to improve the freedom of design and reduce weight.

[0026] The anisotropic conductive adhesive layer 14 is for adhering (joining) the heat seal connector 1 to the electrode terminal of the electric circuit board. The anisotropic conductive adhesive layer 14 is formed from an anisotropic conductive adhesive, and is disposed on the conductive pattern 12 and the insulating pattern 13, at least on the portion of the conductive pattern 12 that contacts the electrode terminal of the electric circuit board.

[0027] As the anisotropic conductive adhesive, for example, one containing an adhesive component 15 having a melt viscosity lower than that of the insulating resin agent forming the insulating pattern 13, and conductive fine particles 16 dispersed in the adhesive component 15 can be used.

[0028] The thickness of the anisotropic conductive adhesive layer 14 is not particularly limited, but is preferably 10 μm or more and 25 μm or less, and more preferably 15 μm or more and 20 μm or less, in average thickness, for example. If the average thickness of the anisotropic conductive adhesive layer 14 is equal to or more than the lower limit of the above range, the reliability of the connection is improved. Also, if the average thickness of the anisotropic conductive adhesive layer 14 is equal to or less than the upper limit of the above range, it has advantageous characteristics as a thin product.

[0029] A method of using the heat seal connector 1 of this embodiment will be described with reference to FIG. An electric circuit board 100 having electrode terminals 120 formed on one main surface 110a of a substrate 110 with the same pitch as the connection terminals of the conductive pattern 12 of the heat seal connector 1 of this embodiment is superimposed, and the connection terminals and electrode terminals 120 are placed opposite each other and heat sealed.

[0030] In the heat seal connector 1 of this embodiment, the maximum height h1 of the insulating pattern 13 based on one main surface 11a of the substrate 11 is higher than the maximum height h2 of the conductive pattern 12 based on one main surface 11a of the substrate 11. Therefore, when the electric circuit board 100 is placed on the heat seal connector 1 of this embodiment as described above and the connection terminal and the electrode terminal 120 are heat sealed facing each other, the insulating pattern 13 can block the conductive material contained in the conductive pattern 12 and prevent the conductive material from flowing out to the outside. As a result, the insulation between the conductive patterns 12 is not impaired. Therefore, the heat seal connector 1 of this embodiment maintains a predetermined insulation property and conductivity even when attached to a three-dimensional curved structure, and has excellent conformability to the three-dimensional curved structure.

[0031] In the heat seal connector 1 of this embodiment, one main surface 11a of the base material 11 is covered with the conductive pattern 12 or the insulating pattern 13. Therefore, when the electric circuit board 100 is placed on the heat seal connector 1 of this embodiment as described above and the connection terminal and the electrode terminal 120 are heat sealed facing each other, it is possible to prevent the electrode terminal from coming into contact with one main surface 11a of the base material 11 and reducing the conductivity.

[0032] In the heat seal connector 1 of this embodiment, the insulating pattern 13 is disposed between the conductive pattern 12 and the insulating pattern 13, and has a height h of the insulating pattern 13 based on one main surface 11a of the base material 11. 21 However, the conductive pattern 12 has a portion 13A that is lower than the maximum height h2 of the conductive pattern 12 based on one main surface 11a of the substrate 11. Therefore, when the electric circuit board 100 is placed on the heat seal connector 1 of this embodiment as described above and the connection terminal and the electrode terminal 120 are heat sealed with each other, the conductive material that flows out from the conductive pattern 12 is contained in the portion 13A, and the conductive material can be prevented from flowing out to the outside. As a result, the insulation between the conductive patterns 12 is not impaired. Therefore, the heat seal connector 1 of this embodiment maintains a predetermined insulation property and conductivity even when attached to a three-dimensional curved structure, and has excellent conformability to the three-dimensional curved structure.

[0033] A method for producing the heat seal connector 1 of this embodiment will be described below. FIG. 2 is a schematic cross-sectional view showing a state in which the conductive pattern of the heat seal connector according to the present invention is bonded to an electrode terminal of an electric circuit board. The method for producing the heat seal connector 1 shown in FIG. 1 is not particularly limited, and may be, for example, a method including the following steps (a) to (d). Step (a): Surface modification step: At least one of the main surfaces 11a of the substrate 11 is irradiated with ultraviolet light, thereby modifying the surface of at least one of the main surfaces 11a of the substrate 11. Step (b): Conductive pattern forming step: On at least one main surface 11a of the base material 11, the conductive pattern 12 is formed by printing using a conductive paste. Step (c): Insulating pattern forming step: On at least one main surface 11a of the base material 11, an insulating pattern 13 is formed from an insulating resin agent by printing so as to fill in the spaces between the conductive patterns 12. Step (d): Anisotropic conductive adhesive layer forming step: on the conductive pattern 12 and the insulating pattern 13, an anisotropic conductive adhesive layer 14 is formed using an anisotropic conductive adhesive on at least the portion of the conductive pattern 12 that contacts the electrode terminal of the electric circuit board.

[0034] In step (a), for example, the method for performing surface treatment on one main surface 11a of the substrate 11 is selected from ultraviolet irradiation, corona discharge, plasma treatment, ozone treatment, and high-voltage discharge treatment.

[0035] In the step (b), the conductive paste can be printed by a known printing method such as screen printing, gravure printing, etc. By using these printing methods, a desired conductive pattern can be formed.

[0036] In step (c), the insulating resin agent can be printed on at least one of the main surfaces 11a of the substrate 11 so as to fill the spaces between the conductive patterns 12 by using a printing method such as screen printing, inkjet printing, or a dispenser. Here, a method capable of printing the insulating resin agent while avoiding the conductive patterns 12 is preferred. Among these printing methods, a printing method in which the maximum height h1 of the insulating pattern 13 based on at least one of the main surfaces 11a of the substrate 11 is made higher than the maximum height h2 of the conductive patterns 12 based on at least one of the main surfaces 11a of the substrate 11, and the height h2 of the insulating pattern 13 based on at least one of the main surfaces 11a of the substrate 11 is made lower than the maximum height h3 of the conductive patterns 12 based on at least one of the main surfaces 11a of the substrate 11, and the insulating pattern 13 between the conductive patterns 12 is made lower than the maximum height h1 of the insulating pattern 13 based on at least one of the main surfaces 11a of the substrate 11. 21 However, in order to form portion 13A of insulating pattern 13 that is lower than the maximum height h2 of conductive pattern 12 based on at least one of the main surfaces 11a of substrate 11, screen printing is preferred in order to adjust the applied thickness of the insulating resin agent to a constant value.

[0037] In the step (d), the anisotropic conductive adhesive layer 14 can be formed by the anisotropic conductive adhesive, for example, by a known printing method or coating method.

[0038] According to the manufacturing method of the heat seal connector 1 of this embodiment, in step (c), the maximum height h1 of the insulating pattern 13 based on at least one of the main surfaces 11a of the base material 11 is made higher than the maximum height h2 of the conductive pattern 12 based on at least one of the main surfaces 11a of the base material 11. Therefore, when the electric circuit board 100 is placed on the heat seal connector 1 of this embodiment as described above and the connection terminal and the electrode terminal 120 are heat-sealed facing each other, the insulating pattern 13 can block the conductive material contained in the conductive pattern 12 and suppress the conductive material from flowing out to the outside. As a result, the insulation between the conductive patterns 12 is not impaired. Therefore, the heat seal connector 1 of this embodiment maintains a predetermined insulation property and conductivity even when attached to a three-dimensional curved structure, and has excellent conformability to the three-dimensional curved structure.

[0039] According to the method for producing the heat seal connector 1 of this embodiment, in step (c), the insulating pattern 13 between the conductive patterns 12 is provided with a height h of the insulating pattern 13 based on at least one of the main surfaces 11a of the base material 11. 21 However, the insulating pattern 13 forms a portion 13A that is lower than the maximum height h2 of the conductive pattern 12 based on at least one of the main surfaces 11a of the substrate 11. Therefore, when the electric circuit board 100 is placed on the heat seal connector 1 of this embodiment as described above and the connection terminal and the electrode terminal 120 are heat sealed in opposition to each other, the conductive material that has flowed out from the conductive pattern 12 is contained in the portion 13A, and the conductive material can be prevented from flowing out to the outside. As a result, the insulation between the conductive patterns 12 is not impaired. Therefore, the heat seal connector 1 of this embodiment maintains a predetermined insulation property and conductivity even when attached to a three-dimensional curved structure, and is excellent in conformity to the three-dimensional curved structure. [Explanation of symbols]

[0040] 1 Heat seal connector 11 Base material 12 Conductive Pattern 13 Insulation Pattern 14 Anisotropic conductive adhesive layer 15 Resin components 16 Conductive particles 100 Electrical circuit board 110 Substrate 120 Electrode terminal

Claims

1. A substrate; A conductive pattern disposed on at least one main surface of the substrate; an insulating pattern disposed on at least one main surface of the base material so as to fill spaces between the conductive patterns; an anisotropic conductive adhesive layer disposed on the conductive pattern and the insulating pattern, at least on a portion of the conductive pattern that contacts an electrode terminal of an electric circuit board; The substrate is made of a silicone sheet, a maximum height of the insulating pattern based on at least one main surface of the base material is greater than a maximum height of the conductive pattern based on at least one main surface of the base material; At least one main surface of the base material is covered with the conductive pattern or the insulating pattern, A heat seal connector, wherein the insulating pattern has a portion between the conductive pattern and the insulating pattern, where the height of the insulating pattern based on at least one main surface of the base material is lower than the maximum height of the conductive pattern based on at least one main surface of the base material.

2. A surface modification step of modifying at least one main surface of the substrate; a conductive pattern forming step of forming a conductive pattern on at least one main surface of the base material by printing using a conductive paste; an insulating pattern forming step of forming an insulating pattern by printing an insulating resin agent on at least one main surface of the base material so as to fill spaces between the conductive patterns; an anisotropic conductive adhesive layer forming step of forming an anisotropic conductive adhesive layer on the conductive pattern and the insulating pattern, at least on a portion of the conductive pattern that contacts an electrode terminal of an electric circuit board, using an anisotropic conductive adhesive; In the insulating pattern forming step, a maximum height of the insulating pattern based on at least one main surface of the base material is made higher than a maximum height of the conductive pattern based on at least one main surface of the base material; A method for manufacturing a heat seal connector, wherein in the insulating pattern forming process, a portion is formed in the insulating pattern between the conductive patterns, where the height of the insulating pattern based on at least one main surface of the base material is lower than the maximum height of the conductive pattern based on at least one main surface of the base material.

3. The method for producing a heat seal connector according to claim 2, wherein the surface modification step is selected from ultraviolet irradiation, corona discharge, plasma treatment, ozone treatment, and high voltage discharge treatment.

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