Manufacturing method of flexible connecting device and flexible connecting device

Abstract

The invention provides a manufacturing method of a flexible connecting device and the flexible connecting device, the manufacturing method is used for manufacturing a device on a flexible thin film layer, and the manufacturing method comprises the following steps: bonding a first surface of the flexible thin film layer to the front surface of a first substrate; forming a first device layer on the second surface of the flexible thin film layer; separating the flexible thin film layer from the first substrate; the face, provided with the first device layer, of the flexible thin film layer is bonded to the back face of the first substrate, or the face, provided with the first device layer, of the flexible thin film layer is bonded to a second substrate; forming a second device layer on the first surface of the flexible thin film layer; and separating the first device layer from the first substrate, or separating the first device layer from the second substrate.

Description

Technical Field

[0001] The present disclosure relates to the technical field of circuit boards, and in particular to a method for manufacturing a flexible connecting device and the flexible connecting device. Background Art

[0002] Currently, the commonly used connection boards and COF (Chip On Film) technologies are mainly used in display driver IC packaging, and the terminals are used in full-screen smartphones, high-end monitors, narrow-framed large-size smart TVs, wearable electronic products, inkjet printers, high-end medical devices and other fields. It is expected to become the mainstream of the market under the continuous drive of products such as mobile phones, laptops, and LCD monitors. With the rapid development of AI technology, the requirements for product computing power are getting higher and higher, and the corresponding hardware requirements are becoming more and more refined. For example, the development of high-precision connection boards has higher requirements for high-pin count 3000+channel and high-end LED packaging, as well as higher requirements for line width and line spacing. High-precision connection boards need to have the function of connecting panels, carry more lines, and meet the requirements of product flexibility. Summary of the invention

[0003] The present disclosure provides a method for manufacturing a flexible connecting device and a flexible connecting device, so as to at least solve the above technical problems existing in the prior art.

[0004] According to a first aspect of the present disclosure, a method for manufacturing a flexible connection device is provided, which is used to manufacture the device on a flexible film layer, and the manufacturing method comprises:

[0005] Bonding the first surface of the flexible film layer to the front surface of a first substrate;

[0006] forming a first device layer on the second surface of the flexible film layer;

[0007] separating the flexible film layer from the first substrate;

[0008] Bonding the side of the flexible film layer having the first device layer to the reverse side of the first substrate, or bonding the side of the flexible film layer having the first device layer to a second substrate;

[0009] forming a second device layer on the first surface of the flexible film layer;

[0010] The first device layer is separated from the first substrate, or the first device layer is separated from the second substrate.

[0011] In one embodiment, the method further comprises:

[0012] Before forming the first device layer on the second surface of the flexible film layer, a plurality of first through holes are provided in the flexible film layer; or,

[0013] Before forming the second device layer on the first surface of the flexible film layer, a plurality of first through holes are provided in the flexible film layer; wherein the first through holes penetrate through the flexible film layer.

[0014] In one embodiment, the method further comprises:

[0015] A conductive material is filled in the through hole to connect the first device layer and the second device layer.

[0016] In one embodiment, the method further comprises:

[0017] After forming the first device layer, a planarization layer is coated on the first device layer.

[0018] In one embodiment, bonding the first surface of the flexible film layer to a front surface of a first substrate comprises:

[0019] bonding the first surface of the flexible film layer to the front surface of the first substrate through a first temporary bonding layer;

[0020] The step of bonding the side of the flexible film layer having the first device layer to the reverse side of the first substrate, or bonding the side of the flexible film layer having the first device layer to the second substrate, comprises:

[0021] The side of the flexible film layer having the first device layer is bonded to the reverse side of the first substrate through a second temporary bonding layer, or the side of the flexible film layer having the first device layer is bonded to a second substrate.

[0022] In one embodiment, the bonding force between the second temporary bonding layer and the reverse side of the first substrate or the second substrate is smaller than the bonding force between the first device layer and the flexible film layer.

[0023] In one embodiment, the method further comprises:

[0024] After forming the second device layer, forming an insulating layer covering the second device layer;

[0025] Disposing a plurality of second through holes in the insulating layer;

[0026] Filling the second through hole with a conductive material;

[0027] A third device layer is formed on the insulating layer.

[0028] According to a second aspect of the present disclosure, a method for manufacturing a flexible connection device is provided, which is used to manufacture the device on a flexible film layer, and the manufacturing method comprises:

[0029] Bonding the first surface of the flexible film layer to a first substrate;

[0030] forming a first device layer on the second surface of the flexible film layer;

[0031] separating the flexible film layer from the first substrate;

[0032] Bonding the side of the flexible film layer having the first device layer to the first substrate;

[0033] forming a second device layer on the first surface of the flexible film layer;

[0034] The first device layer is separated from the first substrate.

[0035] According to a third aspect of the present disclosure, there is provided a flexible connection device, the device comprising:

[0036] A flexible film layer, the flexible film layer comprising a first surface and a second surface arranged opposite to each other;

[0037] A first device layer, located on the second surface of the flexible film layer;

[0038] a second device layer, located on the first surface of the flexible film layer;

[0039] A plurality of first through holes penetrate the flexible film layer, wherein the first through holes are filled with a conductive material to connect the first device layer and the second device layer.

[0040] In one possible implementation, the device further comprises:

[0041] an insulating layer, covering the second device layer;

[0042] A third device layer, located on the insulating layer;

[0043] A plurality of second through holes are located in the insulating layer, wherein the second through holes are filled with a conductive material to connect the second device layer and the third device layer.

[0044] In one possible implementation manner, the first device layer and the second device layer each include a plurality of metal lines, and the spacing between adjacent metal lines ranges from 4 to 8 μm.

[0045] The manufacturing method of the flexible connecting device and the flexible connecting device disclosed in the present invention are achieved by first bonding the first surface of the flexible film layer to the front side of the first substrate, and then separating the flexible film layer from the first substrate after forming the first device layer, and bonding the side forming the first device layer to the back side of the first substrate or the second substrate. In this way, more circuits can be carried within the same area and the requirements for product flexibility can be met.

[0046] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0048] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0049] Figure 1 A flowchart of a method for manufacturing a flexible connection device provided in an embodiment of the present disclosure;

[0050] Figure 2a to Figure 2f A schematic diagram of a flexible connection device provided in an embodiment of the present disclosure during the manufacturing process;

[0051] Figure 3 A flow chart of another method for manufacturing a flexible connection device provided in an embodiment of the present disclosure;

[0052] Figure 4 A schematic diagram of the structure of a flexible connecting device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0053] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0054] The embodiment of the present disclosure provides a method for manufacturing a flexible connection device, which is used to manufacture a device on a flexible film layer. Figure 1 A flowchart of a method for manufacturing a flexible connection device provided in an embodiment of the present disclosure, see Figure 1, the method comprises the following steps:

[0055] Step 101: Bonding a first surface of a flexible film layer to a front surface of a first substrate;

[0056] Step 102: forming a first device layer on the second surface of the flexible film layer;

[0057] Step 103: separating the flexible film layer from the first substrate;

[0058] Step 104: bonding the side of the flexible film layer having the first device layer to the reverse side of the first substrate, or bonding the side of the flexible film layer having the first device layer to the second substrate;

[0059] Step 105: forming a second device layer on the first surface of the flexible film layer;

[0060] Step 106: Separating the first device layer from the first substrate, or separating the first device layer from the second substrate.

[0061] The manufacturing method of the flexible connection device provided in the embodiment of the present disclosure is further described in detail below in conjunction with specific embodiments. Figure 2a to Figure 2f A schematic diagram of a flexible connection device during the manufacturing process provided in an embodiment of the present disclosure.

[0062] First, see Figure 2a , perform step 101 to bond the first surface 301 of the flexible film layer 30 to the front surface 101 of a first substrate 10 .

[0063] The thickness of the flexible film layer 30 is 10-150 μm, and the material may be PI (polyimide) or PET (polyester resin).

[0064] The flexible film layer provides better mechanical flexibility, making the design more flexible and diverse. This flexibility helps to achieve a more compact design, especially in application scenarios that require bending or folding, such as wearable devices, flexible displays, etc.

[0065] The first substrate 10 may be a glass substrate. Since the glass substrate has good flatness, placing a flexible film on the glass substrate can make it easier to manufacture a device layer with a smaller line pitch.

[0066] In one embodiment, bonding the first surface 301 of the flexible film layer 30 to the front surface 101 of a first substrate 10 includes:

[0067] The first surface 301 of the flexible film layer 30 is bonded to the front surface 101 of the first substrate 10 through the first temporary bonding layer 21 .

[0068] The main material of the first temporary bonding layer 21 is a coupling agent or an adhesive.

[0069] Next, see Figure 2b A plurality of first through holes 41 are provided in the flexible film layer 30, wherein the first through holes 41 penetrate the flexible film layer 30. It is easier to punch holes in the flexible film layer than to punch holes in glass.

[0070] In some embodiments, Figure 2b As shown, the first through hole 41 is formed before forming the first device layer.

[0071] In some other embodiments, the first through hole 41 is formed after the first device layer is formed and before the second device layer is formed.

[0072] In one embodiment, the diameter of the first through hole is 1-3 μm.

[0073] Next, a conductive material is filled in the through hole 41 to connect the first device layer and the second device layer to be formed subsequently. The conductive material includes but is not limited to copper.

[0074] Next, see Figure 2c , perform step 102 to form a first device layer 41 on the second surface 302 of the flexible film layer 30. The first device layer 41 may be a metal circuit layer.

[0075] Specifically, metal is sputtered on the second surface 302 of the flexible film layer 30 to form a metal layer. The metal layer material can be at least one of aluminum, molybdenum, silver, chromium, nickel, titanium and copper, or a superposition of several of them, with a thickness of 200 to 3000nm; a circuit is made on the metal layer, using a TFT yellow light process, sputtering metal, exposing, developing, etching, stripping, and processing to form a plurality of metal circuits, and the spacing between adjacent metal circuits ranges from 4 to 8μm.

[0076] Next, after the first device layer 51 is formed, a planarization layer (not shown) is coated on the first device layer 51 .

[0077] In order to avoid the unevenness of the flexible film layer after the first device layer is bonded to the reverse side of the first substrate or the second substrate, a flat layer (glue layer) is coated after the first device layer is formed, so that the entire second surface formed with the first device layer and the flat layer is flat, so that after the second surface of the flexible film is bonded to the reverse side of the first substrate or the second substrate, there is no gap (bubble) between the second surface and the reverse side of the first substrate or the second substrate, so as to prevent the formation of the subsequent second device layer from being affected by the existence of bubbles. The thickness of the flat layer is greater than the thickness of the first device layer; or, after the glue layer is coated on the reverse side of the first substrate or the second substrate, it is bonded to the side of the flexible film layer with the first device layer.

[0078] Next, step 103 is performed to separate the flexible film layer 30 from the first substrate 10 .

[0079] Specifically, the flexible film layer 30 may be separated from the first substrate 10 by LLO (Laser Lift-Off) or MLO (Mechanical Lift-Off).

[0080] Next, see Figure 2d , perform step 104 to bond the side of the flexible film layer 30 having the first device layer 51 to the reverse side 102 of the first substrate 10 .

[0081] In another embodiment, the side of the flexible film layer 30 having the first device layer 51 may be bonded to a second substrate (not shown).

[0082] In the disclosed embodiment, because the front side of the first substrate has been bonded to the first surface of the flexible film layer, there will be residual contaminants. If it continues to be bonded to the first device layer, it will contaminate the device and affect the device performance. Therefore, the side of the flexible film layer that forms the first device layer is bonded to the back side of the first substrate or the second substrate. In this way, repeated bonding with the front side of the first substrate is avoided, pollution is reduced, and device performance is improved. At the same time, more circuits can be carried in the same area, and the demand for product flexibility can be met.

[0083] In one embodiment, bonding one side of the flexible film layer 30 having the first device layer 51 to the reverse side 102 of the first substrate 10, or bonding one side of the flexible film layer 30 having the first device layer 51 to the second substrate, includes:

[0084] The side of the flexible film layer 30 having the first device layer 51 is bonded to the reverse side 102 of the first substrate 10 through the second temporary bonding layer 22 , or the side of the flexible film layer 30 having the first device layer 51 is bonded to the second substrate.

[0085] The main material of the second temporary bonding layer 22 is a coupling agent or an adhesive.

[0086] In one embodiment, the bonding force between the second temporary bonding layer and the reverse side of the first substrate or the second substrate is smaller than the bonding force between the first device layer and the flexible film layer.

[0087] In this way, during subsequent separation, the first device layer will not be separated from the flexible film layer, thereby preventing the first device layer from being damaged.

[0088] In one embodiment, the bonding force between the first device layer and the flexible film layer is in the range of 5-20 N / cm.

[0089] Next, see Figure 2e , perform step 105 to form a second device layer 52 on the first surface 301 of the flexible film layer 30 .

[0090] The process of forming the second device layer 52 is the same as the process of forming the first device layer 51 , and will not be described again here.

[0091] Next, see Figure 2f , after forming the second device layer 52, forming an insulating layer 60 covering the second device layer 52;

[0092] A plurality of second through holes 42 are provided in the insulating layer 60;

[0093] Filling the second through hole 42 with a conductive material;

[0094] The third device layer 53 is formed on the insulating layer 60 .

[0095] In one embodiment, the material of the insulating layer 60 includes but is not limited to PSPI (Photosensitive Polyimide), SiO2, SiN x or OC.

[0096] The second through hole 42 has a diameter of 1-3 μm and is used to connect the second device layer 52 and the third device layer 53 .

[0097] The process of forming the third device layer 53 is the same as the process of forming the first device layer 51 , and will not be described again here.

[0098] It should be explained that, although the flexible connection device in this embodiment has three device layers, it is not limited to three device layers, and the number of device layers can be determined according to actual needs. For example, the first surface of the flexible connection device can be made into M device layers, and the second surface can be made into N device layers (where M≥1, N≥1), and each device layer is insulated and separated by an insulating layer, and the electrical connection between each device layer is achieved through the through hole on the flexible film layer or the opening provided on the insulating layer.

[0099] Next, step 106 is performed to separate the first device layer 51 from the first substrate 10 , or to separate the first device layer 51 from the second substrate.

[0100] Specifically, the first device layer 51 may be separated from the first substrate 10 by LLO or MLO, or the first device layer 51 may be separated from the second substrate.

[0101] In this embodiment, the multi-layer device layer is attached to the flexible film layer, which enables the placement of multi-layer circuits in a limited space. This can not only improve the assembly density, but also improve the wiring density, thereby significantly reducing the size and weight of the electronic product, which is in line with the current development trend of lighter and smaller electronic products.

[0102] The disclosed embodiment also provides another method for manufacturing a flexible connection device, which is used to manufacture a device on a flexible film layer. Figure 3 A flowchart of a method for manufacturing a flexible connection device according to another embodiment of the present disclosure. Figure 3 As shown, the method comprises the following steps:

[0103] Step 301: bonding a first surface of a flexible film layer to a first substrate;

[0104] Step 302: forming a first device layer on the second surface of the flexible film layer;

[0105] Step 303: separating the flexible film layer from the first substrate;

[0106] Step 304: bonding the side of the flexible film layer having the first device layer to the first substrate;

[0107] Step 305: forming a second device layer on the first surface of the flexible film layer;

[0108] Step 306: Separate the first device layer from the first substrate.

[0109] Figure 3 The examples shown are Figure 1 Compared with the embodiment shown, the difference is Figure 3 In the embodiment, the first surface of the flexible film layer and the side of the flexible film layer having the first device layer are bonded to the same surface of the first substrate, and Figure 1 In the method, the first surface of the flexible film layer is bonded to the front surface of the first substrate, and the side of the flexible film layer having the first device layer is bonded to the back surface of the first substrate or the second substrate.

[0110] In addition to the above differences, Figure 3 The other steps in the embodiment shown are Figure 1 The steps in the embodiment are the same, see Figure 1 The description in the illustrated embodiment will not be repeated here.

[0111] The embodiment of the present disclosure also provides a flexible connection device, Figure 4 A schematic diagram of the structure of a flexible connection device provided in an embodiment of the present disclosure, such as Figure 4 As shown, the device includes:

[0112] A flexible film layer 30, the flexible film layer 30 comprises a first surface 301 and a second surface 302 arranged opposite to each other;

[0113] The first device layer 51 is located on the second surface 302 of the flexible film layer 30;

[0114] The second device layer 52 is located on the first surface 301 of the flexible film layer 30;

[0115] A plurality of first through holes 41 penetrate the flexible film layer 30 , wherein the first through holes 41 are filled with a conductive material to connect the first device layer 51 and the second device layer 52 .

[0116] In one embodiment, the thickness of the flexible film layer 30 is 10-150 μm, and the material is PI (polyimide) or PET (polyester resin).

[0117] The material of the first device layer 51 and the second device layer 52 can be at least one of aluminum, molybdenum, silver, chromium, nickel, titanium and copper, or a combination of several of them.

[0118] The first device layer 51 and the second device layer 52 each include a plurality of metal circuits, and the spacing between adjacent metal circuits ranges from 4 to 8 μm.

[0119] The aperture of the first through hole 41 is 1-3 μm; the conductive material includes but is not limited to copper.

[0120] In one embodiment, the device further comprises:

[0121] an insulating layer 60 covering the second device layer 52;

[0122] A third device layer 53, located on the insulating layer 60;

[0123] A plurality of second through holes 42 are located in the insulating layer 60 , wherein the second through holes 42 are filled with a conductive material to connect the second device layer 52 and the third device layer 53 .

[0124] In one embodiment, the material of the insulating layer 60 includes but is not limited to PSPI, SiO2, SiN x or OC.

[0125] The third device layer 53 includes a plurality of metal circuits, and the spacing between adjacent metal circuits ranges from 4 to 8 μm.

[0126] In addition, in one embodiment, the chip can be bonded and welded on the metal circuit of the first device layer or the second device layer. First, an ACF (Anisotropic Conductive Film) machine is used to stick the ACF to the welding position, and then a bonding machine is used to weld the chip to the metal circuit.

[0127] This embodiment also discloses a flexible connection device, which can be connected to a PCB board on one side of a first surface and connected to a chip or other semiconductor devices on one side of a second surface.

[0128] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0129] In addition, the terms "first", "second", "front", "back", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", etc. may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0130] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for manufacturing a flexible connection device, used for manufacturing a device on a flexible film layer, characterized in that: The production method comprises: Bonding the first surface of the flexible film layer to the front surface of a first substrate; forming a first device layer on the second surface of the flexible film layer; separating the flexible film layer from the first substrate; Bonding the side of the flexible film layer having the first device layer to the reverse side of the first substrate, or bonding the side of the flexible film layer having the first device layer to a second substrate; forming a second device layer on the first surface of the flexible film layer; The first device layer is separated from the first substrate, or the first device layer is separated from the second substrate.

2. The method according to claim 1, characterized in that: The method further comprises: Before forming the first device layer on the second surface of the flexible film layer, a plurality of first through holes are provided in the flexible film layer; or, Before forming the second device layer on the first surface of the flexible film layer, a plurality of first through holes are provided in the flexible film layer; wherein the first through holes penetrate through the flexible film layer.

3. The method according to claim 2, characterized in that The method further comprises: A conductive material is filled in the through hole to connect the first device layer and the second device layer.

4. The method according to claim 1, characterized in that: The method further comprises: After forming the first device layer, a planarization layer is coated on the first device layer.

5. The method according to claim 1, characterized in that The step of bonding the first surface of the flexible film layer to the front surface of a first substrate comprises: bonding the first surface of the flexible film layer to the front surface of the first substrate through a first temporary bonding layer; The step of bonding the side of the flexible film layer having the first device layer to the reverse side of the first substrate, or bonding the side of the flexible film layer having the first device layer to the second substrate, comprises: The side of the flexible film layer having the first device layer is bonded to the reverse side of the first substrate through a second temporary bonding layer, or the side of the flexible film layer having the first device layer is bonded to a second substrate.

6. The method according to claim 5, characterized in that The bonding force between the second temporary bonding layer and the reverse side of the first substrate or the second substrate is smaller than the bonding force between the first device layer and the flexible film layer.

7. The method according to claim 1, characterized in that The method further comprises: After forming the second device layer, forming an insulating layer covering the second device layer; Disposing a plurality of second through holes in the insulating layer; Filling the second through hole with a conductive material; A third device layer is formed on the insulating layer.

8. A method for manufacturing a flexible connection device, used for manufacturing a device on a flexible film layer, characterized in that: The production method comprises: Bonding the first surface of the flexible film layer to a first substrate; forming a first device layer on the second surface of the flexible film layer; separating the flexible film layer from the first substrate; Bonding the side of the flexible film layer having the first device layer to the first substrate; forming a second device layer on the first surface of the flexible film layer; The first device layer is separated from the first substrate.

9. A flexible connection device, characterized in that: The device comprises: A flexible film layer, the flexible film layer comprising a first surface and a second surface arranged opposite to each other; A first device layer, located on the second surface of the flexible film layer; a second device layer, located on the first surface of the flexible film layer; A plurality of first through holes penetrate the flexible film layer, wherein the first through holes are filled with a conductive material to connect the first device layer and the second device layer.

10. The device according to claim 9, characterized in that The device further comprises: an insulating layer, covering the second device layer; A third device layer, located on the insulating layer; A plurality of second through holes are located in the insulating layer, wherein the second through holes are filled with a conductive material to connect the second device layer and the third device layer.

11. The device according to claim 9, characterized in that The first device layer and the second device layer both include a plurality of metal circuits, and the spacing between adjacent metal circuits ranges from 4 to 8 μm.

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