Individually processed adhesive film, method for manufacturing connected structure, and connected structure

Abstract

To provide an individually processed adhesive film, a method for manufacturing a connected structure, and the connected structure that can improve adhesive strength to a substrate on which components are mounted.SOLUTION: An individually processed adhesive film is made up of a substrate on which components are mounted, and individual pieces each having an opening that surrounds the component are arranged in the longitudinal direction of a base film. In addition, in a method for manufacturing the connected structure, a terminal of a first electronic component and a terminal of a second electronic component are connected to the substrate on which the components are mounted using a piece having an opening surrounding the component. Therefore, the adhesive strength can be improved.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present technology relates to an individualized adhesive film in which individual pieces are arranged in the longitudinal direction of a base film, a method for manufacturing a connection structure, and a connection structure. [Background technology]

[0002] In recent years, adhesive films such as anisotropic conductive films (ACF), conductive films, and non-conductive films (NCF) have been processed into individual pieces, and the long films in which the individual pieces are arranged in the longitudinal direction of the base film are wound onto reels and shipped (see, for example, Patent Document 1).

[0003] However, as shown in FIG. 8 , in the case of a substrate 100 on which a component 101 is mounted, while it is possible to place an ACF 103 on a terminal row 102 while avoiding the component, full lamination over the entire substrate surface is not possible, which raises concerns about unstable temporary fixation to the component connected to the substrate and reduced adhesive strength of the resulting connection structure. Furthermore, as shown in FIG. 9 , if an adhesive film provided over the entire surface of a release substrate while avoiding the component is fully laminated over the entire substrate in accordance with the substrate layout, ACFs 1031 to 1034 must be laminated, for example, four times, resulting in increased labor costs. Furthermore, when the ACFs are laminated in multiple steps, the lamination error (e.g., ±50 μm) plus the ACF shape error (e.g., ±50 μm on one side) becomes large, making it difficult to laminate the ACFs with minimal error. Even if full lamination is possible, there is a concern that productivity will be significantly reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 066411 Summary of the Invention [Problem to be solved by the invention]

[0005] The present technology has been proposed in consideration of the current situation, and provides an individualized adhesive film, a method for manufacturing a connection structure, and a connection structure that can improve the adhesive strength of a substrate on which components are mounted. [Means for solving the problem]

[0006] The individualized adhesive film according to the present technology is formed by arranging individual pieces, each having an opening surrounding a component, in the longitudinal direction of a base film relative to a substrate on which the component is mounted.

[0007] The manufacturing method of a connection structure according to the present technology connects a terminal of a substrate on which a component is mounted to a terminal of an electronic component via an individual piece having a through portion surrounding the component.

[0008] The connection structure according to the present technology comprises a substrate on which components are mounted and an electronic component, and terminals of the substrate and terminals of the electronic component are connected using individual pieces of adhesive film having openings surrounding the periphery of the component. [Effects of the Invention]

[0009] According to the present technology, adhesive strength can be improved by using an individual piece having an opening surrounding the periphery of the component. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a first example of an adhesive film for individual processing. [Figure 2] FIG. 2 is a diagram showing a second example of an adhesive film for individual processing. [Figure 3] FIG. 3 is a diagram for explaining an example of the design of the opening. [Figure 4] FIG. 4 is a diagram showing an example of the shape of an individual piece having an opening surrounding the periphery of a component with respect to a board on which the component is mounted. [Figure 5] FIG. 5 is a diagram showing a first modified example of the individual processing adhesive film. [Figure 6] FIG. 6 is a diagram showing a second modified example of the individual processing adhesive film. [Figure 7] FIG. 7(A) shows a board on which components are mounted, and FIG. 7(B) shows a state in which an individual piece is attached to the board on which components are mounted. [Figure 8] FIG. 8 is a diagram showing a conventional method for attaching an ACF. [Figure 9] FIG. 9 is a diagram showing a conventional method of attaching an ACF in the case of full lamination. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings. 1. Individually processed adhesive film 2.Method for manufacturing the connection structure

[0012] <1. Individually processed adhesive film> The individual piece processing adhesive film according to this embodiment is formed by placing individual pieces, each having an opening surrounding the component, in the longitudinal direction of the base film relative to the substrate on which the component is mounted. This allows full lamination (with almost no gap between the adhesive film piece and the contact surface of the component) over the entire surface of the substrate or in required areas, avoiding the component, thereby stabilizing temporary fixation of the component to be connected to the substrate and improving the adhesive strength of the connection structure.

[0013] Fig. 1 is a diagram showing a first example of a singulated adhesive film, and Fig. 2 is a diagram showing a second example of a singulated adhesive film. As shown in Figs. 1 and 2, singulated adhesive film 10 has a long base film 11 and adhesive film pieces 20 arranged in the longitudinal direction of base film 11. The lower limit of the pitch (distance between pieces) of the pieces arranged in the longitudinal direction of base film 11 is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more, and the upper limit of the pitch of the pieces is preferably 10 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less.

[0014] Each piece 20 has an opening surrounding the component with respect to the board on which the component is mounted. The opening may be an exposed portion 21 where the base film 11 is exposed by half-cutting the base film 11, as shown in Fig. 1, or a void portion 22 where the base film 11 is not present by fully cutting the base film 11, as shown in Fig. 2.

[0015] 3 is a diagram illustrating an example of the design of the opening. The lower limit of the minimum distance D from the edge of the opening to the chip is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more, and the upper limit of the minimum distance D from the edge of the opening to the chip is preferably 100 mm or less, more preferably 20 mm or less, and even more preferably 10 mm or less.

[0016] The lower limit of the area S2 of the opening is preferably 0.01 mm 2 More than 0.04mm, preferably 0.04mm 2 More preferably, 0.09 mm 2 The upper limit of the area S2 of the opening is preferably 400 mm 2 Less than or equal to 225mm, preferably 2 Less than 100 mm, more preferably 2The lower limit of the ratio of the area S2 of the opening to the area S1 of the individual piece (S1:S2) is preferably 40,000:1 or more, more preferably 10,000:1 or more, and even more preferably 4,000:9 or more, and the upper limit of S1:S2 is preferably 400:392.04 or less, more preferably 16:9 or less, and even more preferably 4:1 or less.

[0017] The individual piece processing adhesive film 10 preferably has an edge region made of the base film 11 at the edge in the width direction. The width direction length W of the edge region made of the base film 11 is preferably 100 μm or more, more preferably 500 μm or more, and even more preferably 1000 μm or more. The presence of such an edge region reduces the likelihood of adhesive overflow, which is likely to occur when the film is long. This is because the adhesive is less likely to reach the edge of the base film, making so-called blocking less likely to occur, improving practical convenience. As will be described later, when the individual pieces are separated from the edge of the base film, blocking is less likely to occur, which also contributes to productivity.

[0018] The individualized adhesive film 10 may be formed by consecutively arranging the individual pieces 20 in unit areas in the longitudinal direction and winding them on a reel. Here, a "unit area" refers to a predetermined length in the longitudinal direction of the substrate, e.g., a rectangular area, and may be considered to be an area consisting of a center line between the individual pieces and a center line between adjacent pieces, or an area where one individual piece is sandwiched between the center lines. This adhesive film is peeled and separated from the substrate film. In this technology, the individualized adhesive film does not have a corresponding support, but is composed only of a layer of adhesive (although a cover film of approximately the same width as the substrate may be laminated thereon).

[0019] The base film 11 is a support film that supports the multiple pieces. Examples of the base film 11 include PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), and PTFE (Polytetrafluoroethylene). In addition, the base film 11 is preferably one in which at least the surface on the side facing the pieces is subjected to release treatment, for example, with a silicone resin.

[0020] The thickness of the base film 11 is not particularly limited. From the viewpoint of peeling, the lower limit of the thickness of the base film 11 is preferably 10 μm or more, more preferably 25 μm or more, and even more preferably 38 μm or more. The upper limit of the thickness of the base film is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 75 μm or less, and may be 50 μm or less, because if the base film is too thick, there is a concern that excessive pressure will be applied to the adhesive film. Furthermore, when a cover film is provided on an individual piece of adhesive film, the thickness of the cover film is also in the same range, but it is preferable that the cover film be thinner than the base film.

[0021] The width of the base film 11 is also not particularly limited. From the viewpoint of winding, the lower limit of the width of the base film 11 is preferably 1 mm or more, more preferably 2 mm or more, and even more preferably 4 mm or more. The upper limit of the width of the base film 11 is preferably 500 mm or less, more preferably 250 mm or less, and even more preferably 120 mm or less, because if the width is too large, it may be difficult to carry or handle.

[0022] The adhesive film is not particularly limited, and examples thereof include anisotropic conductive films (ACF), conductive films in which conductive particles are contained in an adhesive, adhesive films (NCF: non-conductive films), solder-containing films containing solder particles, etc. The binder of the adhesive film may be either thermosetting or thermoplastic.

[0023] When conductive particles such as metal particles, resin-core metal-coated particles, or solder particles are contained, the individual pieces may have regions containing conductive particles and regions not containing conductive particles. The individual pieces may also be configured with two or more layers, such as a layer containing conductive particles or solder particles and a layer not containing conductive particles, a layer containing conductive particles, or a layer not containing conductive particles. The binder of the adhesive film may be thermosetting or thermoplastic. The adhesive film may be a single layer or may be laminated with multiple layers.

[0024] The thickness of the individual pieces is not particularly limited, and if the individual pieces are too thin, the substrate is more likely to be damaged during processing, so the lower limit of the thickness of the individual pieces is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 4 μm or more.If the individual pieces are too thick, it becomes difficult to remove the window frame portion during processing, so the upper limit of the thickness of the individual pieces is preferably 50 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less.

[0025] The thickness of the individual pieces can be measured using a known micrometer or digital thickness gauge (e.g., minimum display of 0.0001 mm). However, when conductive particles are contained, if the thickness of the individual pieces is thinner than the particle diameter of the conductive particles, a contact-type thickness measuring device is not suitable, and it is preferable to use a laser displacement meter (e.g., a spectral interference displacement type). Here, the thickness of the individual pieces refers to the thickness of the binder resin layer only and does not include the particle diameter of the conductive particles.

[0026] [Variation 1] 4 is a diagram showing example shapes of pieces having openings surrounding the periphery of the component relative to the board on which the component is mounted. The shape of the opening may be, for example, a rectangle like piece 31, a circle like piece 32, a triangle like piece 33, a heart like piece 34, or an octagon like piece 35. The lower limit of the size (dimension) of the opening is preferably 100 μm or more.

[0027] The shape of the openings may be such that adhesive film portions and void portions alternate, as in piece 36. In this case, the minimum width of the adhesive film portion is preferably 100 μm or more. The number of openings may be two or more, as in piece 37. When the openings are large, as in piece 38, the minimum width of the adhesive film portion is preferably 100 μm or more. The width of the openings is preferably 100 μm or more, as in piece 39, and there may be multiple openings. The openings may penetrate the base film, but when adhesive film portions and void portions alternate as in piece 36, it is preferable that the adhesive film portions do not penetrate the base film to prevent them from falling apart.

[0028] Furthermore, the individual pieces may have other shapes in addition to the openings surrounding the periphery of the component. For example, as described in JP 2020-198422 A, they may have shapes such as a U-shape with two horizontal sides and one vertical side, a J-shape, an L-shape, a U-shape, or a C-shape. Furthermore, when conductive particles are contained, the conductive particles may be embedded in an insulating resin, as described in Japanese Patent No. 6187665 A. Furthermore, the conductive particles may be arranged randomly or regularly, and it is preferable that the conductive particles are aligned in the film thickness direction. Furthermore, when solder particles are contained, as described in Japanese Patent No. 6898413, it is preferable to blend a thermoplastic resin that is solid at room temperature and has a melt flow rate of 10 g / 10 min or more measured at a temperature of 190°C and a load of 2.16 kg, and to have a thickness that is 50% to 300% of the average particle size of the solder particles. As described in Japanese Patent No. 7032367, it is preferable that the minimum melt viscosity of the adhesive film is less than 100 Pa·s. The binder of the adhesive film may be thermosetting or thermoplastic. It may also be a single layer or a multi-layer laminate.

[0029] [Variation 2] Fig. 5 is a diagram showing a first modified example of the adhesive film for singulation processing, and Fig. 6 is a diagram showing a second modified example of the adhesive film for singulation processing. As shown in Figs. 5 and 6, the adhesive film for singulation processing 40 may have openings at predetermined intervals in the longitudinal direction of the adhesive film 41. This allows the base film to be half-cut to form individual pieces when the adhesive film for singulation processing is used.

[0030] The opening may be an exposed portion 42 where the base film is exposed by half-cutting the base film, as shown in Fig. 5, or a void portion 43 where the base film is not present by full-cutting the base film, as shown in Fig. 6. The base film may have a half-cut formed when the individual adhesive film is produced.

[0031] The aforementioned individualized adhesive film allows for full lamination of the entire substrate, avoiding the components, on a board on which the components are mounted. This allows for stable temporary fixation of the components to the board and improved adhesive strength of the connection structure. Using only an adhesive film applied to the entire substrate would increase costs due to the need for a wider variety of film widths depending on the layout of the connection components, the need for multiple film application directions, and the complexity of the connection equipment and the process of applying the film to the board. This technology improves productivity by pre-processing openings for components (boards) with uneven connection surfaces, which would otherwise be subject to poor productivity if the adhesive film were applied all over the surface (i.e., solid application). This technology also allows for environmentally friendly use, such as by pre-processing openings for components (boards) with uneven connection surfaces. This technology also allows for the adhesive film with openings to be reused for other purposes (e.g., by storing it at the supplier for management purposes and reducing unnecessary resin material).

[0032] Furthermore, by providing openings in the adhesive film pieces, it is possible to provide pieces with shapes that are closer to the customer's design, and the pieces can be bonded more stably and without requiring additional labor. Furthermore, since the pieces can be installed so as to avoid the component parts, they can be crimped with the components installed, allowing for more freedom in designing the manufacturing process for the connection structure and improving the degree of freedom.

[0033] <2. Method for manufacturing connection structure> The method for manufacturing a connection structure according to the present embodiment uses a piece having an opening surrounding the periphery of a component mounted on a substrate to connect the terminal of the substrate to the terminal of the electronic component. The connection between the terminal of the substrate and the terminal of the electronic component can be performed in accordance with the description of JP 2020-198422 A.

[0034] FIG. 7(A) shows a substrate on which components are mounted, and FIG. 7(B) is a diagram showing a state in which individual pieces are attached to the substrate on which the components are mounted. As shown in FIG. 7(A), a substrate 50 has a component 51 mounted thereon, and is provided with a terminal row 52 around the component 51. Examples of the substrate 50 include a ceramic substrate, a rigid substrate, a flexible substrate (FPC: Flexible Printed Circuits), a glass substrate, a plastic substrate, and a resin multilayer substrate, and examples of the component 51 include an image sensor, an IC (Integrated Circuit) module, and an IC chip. In functional modules such as camera modules, ceramic substrates are sometimes used because of their excellent electrical insulation and thermal insulation properties. Ceramic substrates are used for miniaturization (for example, to a size of 1 cm). 2 It has advantages such as excellent dimensional stability at high temperatures (see below).

[0035] Next, as shown in Figure 7(B), the opening is aligned with the component 51 and the piece 53 is attached. For example, a bonding device is used to press from the base film side and attach the piece to the substrate 50 on the stage. This positions the component 51 in the opening and allows the component 51 to be surrounded by the adhesive film of the piece 53. The piece-processed adhesive film onto which the piece has been transferred is then rolled up, leaving only the base film.

[0036] Next, the terminal row 52 of the substrate 50 and the terminal of the electronic component are connected via the individual pieces 53. For example, a crimping tool is used to press the substrate and the terminal row of the electronic component via a buffer material. The individual pieces are then cured by heating, irradiating with light, or the like, depending on the curing type of the adhesive film on the individual pieces. This allows a connection structure to be obtained. Examples of electronic components include ceramic substrates, rigid substrates, flexible substrates (FPCs: Flexible Printed Circuits), glass substrates, plastic substrates, and resin multilayer substrates.

[0037] According to this method of manufacturing a connection structure, full lamination can be performed on the entire surface of the substrate while avoiding the components, thereby stabilizing temporary fixation to the components connected to the substrate and improving the adhesive strength of the connection structure.

[0038] The present technology also encompasses the connection structure obtained in this manner. That is, the connection structure according to the present embodiment includes a substrate on which components are mounted and an electronic component, and is configured such that terminals of the substrate and terminals of the electronic component are connected using individual pieces of adhesive film having openings that surround the periphery of the component. [Explanation of symbols]

[0039] 10 Individual piece processed adhesive film, 11 Base film, 20 Individual piece, 21 Exposed portion, 22 Gap portion, 31-39 Individual piece, 40 Individual piece processed adhesive film, 41 Base film, 42 Exposed portion, 43 Gap portion, 50 Board, 51 Component, 52 Terminal row, 53 Individual piece, 100 Board, 101 Component, 102 Terminal row, 103 ACF, 1031-1034 ACF

Claims

1. An individual piece processed adhesive film in which an individual piece of adhesive film having an opening surrounding a component is arranged in the longitudinal direction of a base film relative to a substrate on which the component is mounted.

2. 2. The adhesive film for individualization according to claim 1, wherein the opening is an exposed portion where the base film is exposed.

3. 2. The adhesive film for individualization according to claim 1, wherein the opening is a void where the base film is not present.

4. 4. The adhesive film for individualization according to claim 1, wherein the long film is wound around a reel.

5. An individual piece processed adhesive film described in any one of claims 1 to 4, wherein the adhesive film contains conductive particles.

6. A method for manufacturing a connection structure in which a terminal of a substrate on which a component is mounted is connected to a terminal of an electronic component using a piece of adhesive film having an opening that surrounds the periphery of the component.

7. A method for manufacturing a connection structure as described in claim 6, wherein the adhesive film contains conductive particles.

8. A connection structure comprising a substrate on which components are mounted, and an electronic component, the terminals of the substrate being connected to the terminals of the electronic component using an individual piece of adhesive film having an opening surrounding the periphery of the component.

9. A connection structure as described in claim 8, wherein the adhesive film contains conductive particles.

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