Substrate, laminated structure, and method for manufacturing a laminated structure

Abstract

To realize a substrate and a laminated structure that can maintain a surface active state even in the air and that allow fine chip mounting.SOLUTION: A substrate 10 includes an electrode portion 3 formed on the surface of a base material 1, an insulating material 4 filled in the base material 1 surface region other than the electrode part 3 on the surface of the base material 1, and a self-assembled film 5 formed on the electrode exposed surface formed by the electrode portion 3 and the insulating material 4. As a result, it is possible to bond substrates that can maintain a surface active state even in the air, and to realize a laminated structure that enables fine chip mounting.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , ,

[0001] The present invention relates to a substrate having a self-organized film, a laminated structure, and a method for manufacturing the laminated structure.

Background Art

[0002] In mounting chips on a printed circuit board, joining chips together, and in mounting, the pitch between circuit patterns or electrode portions has become narrow and has decreased to about 10 μm. Therefore, conventional methods of joining an electrode portion to a circuit pattern of a substrate using solder or the like, or methods of pouring an insulating material after joining electrode portions, are no longer applicable.

[0003] Patent Document 1 describes cleaning the bonding surface by plasma irradiation or the like in order to bond a chip and a substrate by direct bonding (also referred to as "hybrid bonding") in which the bonding surfaces of the chip and the substrate are made of an insulating material having a metal region and a dielectric region.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of the method described in Patent Document 1, after cleaning by plasma irradiation or the like, the bonding surface is exposed to a non-vacuum environment such as a mounting machine, so it is difficult to maintain the activated state by cleaning for a long time, and the activated state is impaired by oxidation or the like, and there is a problem that hybrid bonding may become difficult. Further, when attempting to perform mounting in a vacuum, there is a problem that the apparatus such as housing the mounting machine itself in a chamber becomes large-sized and costly.

[0006] The present invention aims to solve the above problems and realize a substrate and laminated structure that can maintain a surface-active state even in air and enable the mounting of narrow electrode pitches. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides an electrode portion formed on the surface of a substrate, An insulating material filled in the surface region of the substrate other than the electrode portion on the surface of the substrate, The present invention provides a substrate comprising the electrode portion and a self-assembled film formed on the electrode exposed surface formed by the insulating material.

[0008] This configuration allows the self-assembled film to maintain its surface-active state even in the atmosphere, enabling the mounting of narrow electrode pitches.

[0009] The substrate may have a self-assembled film in which the functional groups at the surface tip include vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups.

[0010] This configuration allows for bonding of electrode parts to each other and insulating materials to each other, and enables electrical conductivity between electrode parts via the self-assembled film.

[0011] Furthermore, in order to solve the above problems, the present invention provides a laminated structure in which substrates are joined together, A first self-assembled film on a first substrate having a first electrode portion formed on the surface of the first substrate, a first insulating material filled in the surface region of the first substrate other than the first electrode portion on the surface of the first substrate, and a first self-assembled film formed on the electrode exposed surface formed by the first electrode portion and the first insulating material, A second substrate having a second electrode portion formed on the surface of the second substrate, a second insulating material filled in the surface region of the second substrate other than the second electrode portion, and a second self-assembled film formed on the electrode exposed surface formed by the second electrode portion and the second insulating material, wherein the second self-assembled film in the second substrate faces each other, The present invention provides a laminated structure characterized in that at least a portion of the first electrode portion and at least a portion of the second electrode portion are aligned and stacked.

[0012] This configuration enables a laminated structure in which there is electrical conductivity between the first electrode portion and the second electrode portion facing it via the first self-assembled film and the second self-assembled film, but no electrical conductivity is achieved through the first or second insulating material.

[0013] The laminated structure may be configured such that the first self-assembled film and the second self-assembled film have functional groups at the surface tips that include vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups.

[0014] This configuration enables the realization of a laminated structure in which vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups of the self-assembled film on the first substrate polymerize with vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups of the self-assembled film on the second substrate, maintaining a strong bond.

[0015] Furthermore, in order to solve the above problems, the present invention provides a method for manufacturing a laminated structure having a self-assembled film, A first substrate comprising an electrode portion formed on the surface of the substrate, an insulating material filled in the substrate surface region other than the electrode portion on the substrate surface, and a self-assembled film formed on the electrode exposed surface formed by the electrode portion and the insulating material; and an alignment step of aligning at least a portion of the electrode portion on the first substrate with at least a portion of the electrode portion on the second substrate in air by facing the self-assembled films of the first and second substrates toward each other. The present invention provides a method for manufacturing a laminated structure, characterized by comprising a bonding step of joining the aligned first substrate and the second substrate in the atmosphere.

[0016] This configuration makes it possible to join substrates that can maintain a surface-active state even in the atmosphere, enabling the realization of a multilayer structure that allows for the attachment of fine chips.

[0017] A method for manufacturing a laminated structure, in the bonding step, heating or ultraviolet irradiation may be performed on the self-assembled films of the first substrate and the second substrate.

[0018] With this configuration, by heating or ultraviolet irradiation, vinyl groups, hydroxy groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups on the first substrate and vinyl groups, hydroxy groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups on the second substrate are polymerized to realize a laminated structure that maintains a strong bonding state.

Advantages of the Invention

[0019] According to the present invention, it is possible to realize a substrate and a laminated structure that can maintain a surface-active state even in the atmosphere and enable fine chip mounting.

Brief Description of the Drawings

[0020] [Figure 1] It is a diagram for explaining the substrate in Example 1 of the present invention. [Figure 2] It is a diagram for explaining the manufacturing method of the substrate in Example 1 of the present invention. [Figure 3] It is a diagram for explaining the self-assembled film of the substrate in Example 1 of the present invention. [Figure 4] It is a diagram for explaining the laminated structure in Example 2 of the present invention. [Figure 5] It is a diagram for explaining the manufacturing method of the laminated structure in Example 2 of the present invention.

Modes for Carrying Out the Invention

Examples

[0021] (Substrate) The configuration of the substrate in Example 1 of the present invention will be described with reference to FIG. 1. FIG. 1 is a diagram for explaining the substrate in Example 1 of the present invention.

[0022] In Example 1, the substrate 10 has electrode portions 3, such as bumps, formed on the surface of the base material 1 so as to be electrically conductive with the circuit pattern 2. Furthermore, the surface area of ​​the base material 1 other than the electrode portions 3 is filled with insulating material 4. The electrode exposed surface formed by the electrode portions 3 and the insulating material 4 is substantially flush. The base material 1 in Example 1 is a silicon chip, but is not necessarily limited to this and can be changed as appropriate. For example, it may be a glass substrate, ceramic substrate, glass epoxy substrate, or wafer substrate. The electrode portions 3 are formed of copper, but may also be made of other materials. For example, gold, silver, etc., can be used. The thickness of the electrode portions 3 can be arbitrary, but in Example 1 it is about 1 μm. The pitch of the electrode portions 3 is 10 μm or less in narrow places. The insulating material 4 in Example 1 is made of SiO2, but is not particularly limited and can be any insulator.

[0023] Furthermore, a self-assembled film 5 is formed over the entire electrode exposed surface of the electrode portion 3 and the insulating material 4 substrate 1. The self-assembled film 5 consists of a metal alkoxide film containing a silane coupling agent and is also called a SAM film (Self-Assembled Monolayer). It is extremely thin, with a molecular-level thickness (on the order of nm), and transmits light, allowing the electrode portion 3 to be seen. In addition, the tip portion (the portion opposite to the electrode portion 3 and insulating material 4) contains vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups (see Figure 3(b)). As will be described later, when forming a laminated structure of substrates 10, these groups polymerize to achieve a strong bond.

[0024] Conventionally, even if the chip surface was activated by plasma cleaning in a vacuum chamber, the activated state could not be maintained when returned to the atmosphere, making direct mounting such as hybrid bonding difficult. In Example 1, the substrate 10 has a self-assembled film 5 on its surface, so the surface activated state can be maintained even in the atmosphere, allowing bonding of electrode parts 3 and insulating materials 4 in the atmosphere to be performed with conventional mounting machines. Furthermore, because the surface is covered with the self-assembled film 5, it has strong resistance to peeling from acidic substances, alkaline substances, or highly penetrating substances such as surfactants. Moreover, since the thickness of the self-assembled film 5 is on the order of nm, current flows only between opposing electrode parts 3 in the stacked structure described later, and even if the pitch of the electrode parts 3 is 10 μm or less, current does not leak to adjacent electrodes, enabling mounting with a narrow electrode pitch.

[0025] (Manufacturing method for substrates) The method for manufacturing the substrate in Example 1 of the present invention will be described with reference to Figures 2 and 3. Figure 2 is a diagram illustrating the method for manufacturing the substrate in Example 1 of the present invention. Figure 3 is a diagram illustrating the self-assembled film of the substrate in Example 1 of the present invention.

[0026] First, an electrode portion formation step is performed to form electrode portions 3 on the circuit pattern 2 of the substrate 1. The electrode portions 3 may be formed by deposition in a vacuum, plating, printing, or any other method. Next, an insulating material filling step is performed to fill the areas on the surface of the substrate 1 other than the electrode portions 3 with insulating material. Any filling method can be used.

[0027] Next, a self-assembled film formation process is carried out. Prior to this self-assembled film formation process, the surface formed by the electrode portion 3 and the insulating material 4 is subjected to surface polishing (e.g., CMP method) and cleaning to form the electrode exposed surface. Then, in the self-assembled film formation process, first, the substrate 1 on which the electrode portion 3 and insulating material 4 are formed is placed in a vacuum chamber C, and the surface (electrode exposed surface) is plasma-cleaned by irradiating it with plasma in a vacuum (see Figure 2(a)). Next, an evaporation source that imparts hydrophilic groups is supplied to the vacuum chamber C, and a surface hydrophilization mode is performed in which the surface (electrode exposed surface) of the electrode portion 3 and insulating material 4 on the substrate 1 is modified and made hydrophilic by the plasma atmosphere formed by plasma generation (see Figure 2(b)). Next, in the same vacuum chamber C, an evaporation source that promotes the hydrolysis of the precursor material of the self-assembled film is supplied to the substrate 1 whose surface has been made hydrophilic, and a self-assembly mode is performed in which a SAM film is formed on the hydrophilic surface (electrode exposed surface) (see Figure 2(c)).

[0028] In this case, the Y portion of the precursor material of the self-assembled film contains a vinyl group, hydroxyl group, acrylic group, epoxy group, amino group, or isocyanate group as a functional group at its tip. As described later, when forming a laminated structure of substrates 10, these vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups polymerize with each other to achieve a strong bond. Note that the vinyl groups, hydroxyl groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups mentioned above are not functional groups in the middle of the self-assembled film.

[0029] Next, hydrolysis with water vapor is carried out in the same vacuum chamber C (see Figure 2(d)). As a result, the molecular arrangement in the self-assembly mode shown in Figure 2(e) becomes the molecular arrangement after dehydration and condensation shown in Figure 3(b), creating a structure that extends long from the surface and is resistant to collapsing. Note that the example in Figure 3 shows the case where the self-assembled film 5 has acrylic groups at its ends.

[0030] The substrate 10 can be formed through the electrode formation process, insulating material formation process, and self-assembled film formation process described above. The substrate 10 on which the self-assembled film 5 is formed can maintain an active state without its surface becoming inactive even in the atmosphere, and chip bonding can be performed in the atmosphere.

[0031] Thus, in Example 1, the electrode portion formed on the surface of the substrate and An insulating material filled in the surface region of the substrate other than the electrode portion on the surface of the substrate, A substrate comprising the electrode portion and a self-assembled film formed on the electrode exposed surface formed by the insulating material allows the self-assembled film to maintain its surface active state even in the atmosphere, enabling fine chip mounting. [Examples]

[0032] (Laminated structure) Embodiment 2 of the present invention differs from Embodiment 1 in that it relates to a laminated structure in which substrates are joined together. The laminated structure in Embodiment 2 will be described with reference to Figures 4 and 5. Figure 4 is a diagram illustrating the laminated structure in Embodiment 2 of the present invention. Figure 5 is a diagram illustrating the manufacturing method of the laminated structure in Embodiment 2 of the present invention.

[0033] In Example 2, the laminated structure 100 has a first self-assembled film 5 on a first substrate 10 which has a first electrode portion 3 formed on the surface of the first substrate 1, a first insulating material 4 filled in the surface region of the first substrate 1 other than the first electrode portion 3 on the surface of the first substrate 1, and a first self-assembled film 5 formed on the electrode exposed surface formed by the first electrode portion 3 and the first insulating material 4. The second self-assembled film 5 on a second substrate 10' which has a second electrode portion 3' formed on the surface of the second substrate 1', a second insulating material 4' filled in the surface region of the second substrate 1' other than the second electrode portion 3' on the surface of the second substrate 1', and a second self-assembled film 5' formed on the electrode exposed surface formed by the second electrode portion 3' and the second insulating material 4', which are joined opposite each other.

[0034] In this configuration, the first electrode portion 3 and the second electrode portion 3' are aligned and joined to each other. As a result, electrical conductivity is possible between the first electrode portion 3 and the second electrode portion 3' via the first self-assembled film 5 and the second self-assembled film 5', which are on the order of nanometers. However, it is not necessary for all of the first electrode portions 3 and the second electrode portions 3' to be aligned; a laminated structure in which at least some of the multiple first electrode portions 3 and at least some of the multiple second electrode portions 3' are aligned and joined to each other is sufficient, depending on the requirements of the electronic circuit.

[0035] In the laminated structure 100 shown in Figure 4, the distance between the tip of the opposing first electrode portion 3 and the tip of the second electrode portion 3' is on the order of nanometers, which is the length of the first self-assembled film 5 and the second self-assembled film 5', so electricity can easily conduct. In contrast, the distance between each electrode portion is about 10 μm, so there is no risk of current leakage, and an electrical circuit can be formed normally.

[0036] (Method of manufacturing a laminated structure) The method for manufacturing the laminated structure will be explained with reference to Figure 5. Figure 5 is a diagram illustrating the method for manufacturing the laminated structure in Example 2 of the present invention.

[0037] First, in a known mounting machine, the first self-assembled film 5 of the first substrate 10 and the second self-assembled film 5' of the second substrate 10' are placed facing each other. Then, after aligning the first substrate 10 and the second substrate 10' parallel to each other, an alignment process is performed in the atmosphere to align at least a portion of the electrode portions 3 on the first substrate 10 and at least a portion of the electrode portions 3' on the second substrate 10' in two dimensions.

[0038] At this time, since both the self-assembled film 5 on the first substrate 10 and the self-assembled film 5' on the second substrate 10' are thin films on the order of nanometers, the positions of the electrode portions 3 and 3' underneath can be visually confirmed. Then, while checking the alignment marks with the camera of the mounting machine, the positions of the electrode portions 3 and 3' can be confirmed and aligned using a known method.

[0039] Once the alignment process is complete, a bonding process is performed to join the first substrate 10 and the second substrate 10' in the atmosphere. The mounting machine is used to eliminate the height difference between the first substrate 10 and the second substrate 10' and bring them into contact. After that, they are heated to approximately 50°C to 500°C. The heating time varies depending on the electrode material, but a few minutes to several tens of minutes is sufficient.

[0040] In Example 2, heating was performed during the bonding process, but this is not necessarily the only option, and modifications can be made as appropriate. For example, ultraviolet light may be irradiated after mounting.

[0041] Thus, in Example 2, the substrates are joined together in a laminated structure, A first self-assembled film on a first substrate having a first electrode portion formed on the surface of the first substrate, a first insulating material filled in the surface region of the first substrate other than the first electrode portion on the surface of the first substrate, and a first self-assembled film formed on the electrode exposed surface formed by the first electrode portion and the first insulating material, A second substrate having a second electrode portion formed on the surface of the second substrate, a second insulating material filled in the surface region of the second substrate other than the second electrode portion, and a second self-assembled film formed on the electrode exposed surface formed by the second electrode portion and the second insulating material, wherein the second self-assembled film in the second substrate faces each other, A laminated structure is characterized in that at least a portion of the first electrode portion and at least a portion of the second electrode portion are aligned and laminated, thereby realizing a laminated structure in which there is electrical conductivity between the first electrode portion and the second electrode portion facing it via the first self-assembled film and the second self-assembled film, but there is no electrical conductivity via the first insulating material or the second insulating material.

[0042] Furthermore, a method for manufacturing a laminated structure having a self-assembled film, A first substrate comprising an electrode portion formed on the surface of the substrate, an insulating material filled in the substrate surface region other than the electrode portion on the substrate surface, and a self-assembled film formed on the electrode exposed surface formed by the electrode portion and the insulating material; and an alignment step of aligning at least a portion of the electrode portion on the first substrate with at least a portion of the electrode portion on the second substrate in air by facing the self-assembled films of the first and second substrates toward each other. A method for manufacturing a laminated structure, characterized by comprising a bonding step of joining the aligned first substrate and the second substrate in the atmosphere, makes it possible to bond substrates that can maintain a surface active state even in the atmosphere, and to create a laminated structure that enables fine chip mounting. [Industrial applicability]

[0043] The substrate, the laminated structure, and the method for manufacturing the laminated structure of the present invention can be widely used in fields involving the mounting of fine chips. [Explanation of Symbols]

[0044] 1, 1´ Base material 2, 2' Circuit Pattern 3, 3´ electrode part 4, 4' Insulating material 5, 5´ Self-assembled membrane 10, 10' circuit board 100 laminated structure C Chamber

Claims

1. A substrate capable of forming a laminated structure by polymerizing and bonding substrates together, Multiple electrode portions formed on the surface of the substrate, An insulating material filled in the surface region of the substrate between the electrode portions on the surface of the substrate, The electrode portion and a self-assembled film formed on the entire surface of the electrode exposed surface formed by the insulating material are provided. The substrate is characterized in that the self-assembled film enables polymerization bonding with the self-assembled film on the mating substrate, while the electrode portion is electrically conductive with opposing electrode portion on the mating substrate via the self-assembled film, but there is no electrical conductivity between adjacent electrode portions via the self-assembled film.

2. A laminated structure in which substrates are polymerized and bonded together, A first self-assembled film in a first substrate having a plurality of first electrode portions formed on the surface of the first substrate, a first insulating material filled in the first substrate surface region between the first electrode portions on the surface of the first substrate, and a first self-assembled film formed on the entire surface of the electrode exposed surface formed by the first electrode portions and the first insulating material, The second substrate has a plurality of second electrode portions formed on the surface of the second substrate, a second insulating material filled in the surface region of the second substrate between the second electrode portions on the surface of the second substrate, and a second self-assembled film formed on the entire surface of the electrode exposed surface formed by the second electrode portions and the second insulating material, and the second self-assembled film is facing each other. At least a portion of the first electrode portion and at least a portion of the second electrode portion are aligned and stacked, The laminated structure is characterized in that the first self-assembled film and the second self-assembled film are polymerized and bonded to each other, the first electrode portion and the second electrode portion facing each other via the first self-assembled film and the second self-assembled film are electrically conductive, and there is no electrical conductivity between adjacent first electrode portions and between adjacent second electrode portions via the first self-assembled film and the second self-assembled film.

3. A method for manufacturing a laminated structure having a self-assembled film, A first substrate comprising a plurality of electrode portions formed on the surface of the substrate, an insulating material filled in the substrate surface region between the electrode portions on the substrate surface, and a self-assembled film formed on the entire surface of the electrode exposed surface formed by the electrode portions and the insulating material; and an alignment step of aligning at least some of the electrode portions on the first substrate and at least some of the electrode portions on the second substrate in air by facing the self-assembled films of the first and second substrates toward each other. The process includes a bonding step of joining the aligned first substrate and the second substrate in the atmosphere, In the bonding process, the self-assembled films on the first and second substrates enable polymerization bonding between the self-assembled films on the first and second substrates. A method for manufacturing a laminated structure, characterized in that the electrode portions on the first substrate and the second substrate facing each other via the self-assembled film on the first substrate and the second substrate after bonding are electrically conductive, while adjacent electrode portions on the first substrate and the second substrate are not electrically conductive via the self-assembled film on the first substrate and the second substrate.

4. The method for manufacturing a laminated structure according to claim 3, characterized in that the bonding step involves heating or ultraviolet irradiation of the self-assembled films of the first substrate and the second substrate.

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