Substrate, laminated structure, and method for manufacturing 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

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

Background Art

[0002] In mounting a chip 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substrate using solder or the like, or methods of pouring an insulating material after joining electrode portions, are no longer applicable.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 a 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 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 active state by cleaning for a long time, and the active 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] An object of the present invention is to solve the above problems and to provide a substrate and a laminated structure capable of maintaining a surface active state even in the atmosphere and enabling mounting of narrow electrode pitches. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides: A substrate capable of having a laminated structure in which substrates are polymerically bonded to each other, An electrode portion formed on a surface of a substrate; an insulating material filled in a surface area of the base material other than the electrode portion on the surface of the base material; a self-assembled film formed on the electrode exposed surface formed by the electrode portion and the insulating material. 、 The self-assembled film enables polymerization bonding with the self-assembled film on the exposed electrode surface of the counterpart substrate by having a functional group at the surface tip including a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group, while enabling electrical conduction between the electrode of the counterpart substrate and the electrode portion. A substrate is provided.

[0008] This configuration allows the surface activation state to be maintained even in the atmosphere by the self-assembled film, making it possible to mount electrodes with a narrow pitch. In addition, a laminated structure in which the vinyl group, hydroxy group, acrylic group, epoxy group, amino group, or isocyanate group of the self-assembled film is polymerized to maintain a strong bonding state can be realized.

[0011] In order to solve the above problems, Polymerization A bonded laminate structure, a first electrode portion formed on a surface of a first base material; a first insulating material filled in a surface region of the first base material other than the first electrode portion on the surface of the first base material; and a first self-assembled film formed on an electrode exposed surface formed by the first electrode portion and the first insulating material, a second electrode portion formed on a surface of a second base material, a second insulating material filled in a surface region of the second base material other than the second electrode portion on the surface of the second base material, and a second self-assembled film formed on an electrode exposed surface formed by the second electrode portion and the second insulating material, the second self-assembled film on the second substrate facing each other; At least a part of the first electrode portion and at least a part of the second electrode portion are aligned and stacked. and The first self-assembled film and the second self-assembled film enable polymerization bonding between the self-assembled films on the exposed electrode surfaces in the first electrode portion and the second electrode portion by having a functional group at the surface tip including a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group, while the first electrode portion and the second electrode portion are electrically conductive. The present invention provides a laminated structure characterized by the above.

[0012] With this configuration, electrical conduction can be achieved between the first electrode portion and the second electrode portion facing each other through the first self-assembled film and the second self-assembled film, and a laminated structure in which electrical conduction through the first insulating material or the second insulating material is not achieved can be realized. In addition, a laminated structure in which the vinyl group, hydroxy group, acrylic group, epoxy group, amino group, or isocyanate group of the self-assembled film is polymerized to maintain a strong bonding state can be realized.

[0015] Also, in order to solve the above problems, a method for manufacturing a laminated structure having a self-assembled film, a first substrate including an electrode portion formed on a substrate surface, an insulating material filled in a substrate surface region other than the electrode portion on the substrate surface, and a self-assembled film formed on an electrode exposed surface formed by the electrode portion and the insulating material, and a self-assembled film of a second substrate are opposed to each other, and an alignment step of aligning at least a part of the electrode portion in the first substrate and at least a part of the electrode portion in the second substrate in the air, and a bonding step of bonding the aligned first substrate and the second substrate in the air. 、 In the bonding step, the self-assembled films on the first substrate and the second substrate enable polymerization bonding between the self-assembled films on the exposed electrode surfaces in the first substrate and the second substrate by having a functional group at the surface tip including a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group, The electrode portions on the first substrate and the second substrate after bonding are capable of electrical conduction. There is provided a method for manufacturing a laminated structure, characterized by the above.

[0016] With this configuration, it is possible to bond substrates that can maintain a surface active state even in the air, and a laminated structure capable of fine chip mounting can be realized. In addition, a laminated structure in which the vinyl group, hydroxy group, acrylic group, epoxy group, amino group, or isocyanate group on the first substrate and the vinyl group, hydroxy group, acrylic group, epoxy group, amino group, or isocyanate group on the second substrate are polymerized by heating or ultraviolet irradiation to maintain a strong bonding state can be realized.

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 air and enable fine chip mounting.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode 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 the substrate 10 in Example 1, electrode portions 3 such as bumps are formed on the circuit pattern 2 on the surface of the base material 1 so as to be electrically conductive. Further, the surface region of the base material 1 other than the electrode portions 3 on the surface of the base material 1 is filled with an insulating material 4. And the electrode exposed surfaces formed by the electrode portions 3 and the insulating material 4 are configured to be substantially flush. The base material 1 in Example 1 is a chip made of silicon, but is not necessarily limited thereto and can be appropriately changed. For example, it may be a glass substrate, a ceramic substrate, a glass epoxy substrate, or a wafer substrate. Also, the electrode portion 3 is formed of copper, but this may also be another material. For example, gold, silver, etc. can be adopted. The thickness of the electrode portion 3 may be arbitrary, but in Example 1, it is about 1 μm. Also, the pitch of the electrode portions 3 is 10 μm or less at the narrowest. The insulating material 4 is composed of SiO2 in Example 1, but is not particularly limited and may be any insulator.

[0023] In addition, a self-assembled monolayer 5 is formed on the entire surface of the electrode exposed surface formed by the base material 1 of the electrode portion 3 and the insulating material 4. The self-assembled monolayer 5 is composed of a film of metal alkoxide containing a silane coupling agent, and is also called a SAM film (Self-Assembled Monolayer). It is extremely thin at the molecular level (on the order of nm) and can transmit light to visually recognize the electrode portion 3. Further, the tip portion (the portion on the opposite side of the electrode portion 3 and the insulating material 4) contains a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group (see Fig. 3(b)). As will be described later, when forming a laminated structure between the substrates 10, these can polymerize to achieve a strong bond.

[0024] Conventionally, even if the chip surface is activated by plasma cleaning in a vacuum chamber, the activated state cannot be maintained when returned to the atmosphere. Therefore, direct mounting such as hybrid bonding has been difficult. The substrate 10 in Example 1 has the self-assembled monolayer 5 on its surface, so that the surface active state can be maintained even in the atmosphere. Thus, bonding between the electrode portions 3 and bonding between the insulating materials 4 in the atmosphere can be performed with a conventional mounting machine. In addition, since the surface is covered with the self-assembled monolayer 5, the peeling resistance against strongly penetrating substances such as acidic substances, alkaline substances, or surfactants is strong. Furthermore, since the thickness of the self-assembled monolayer 5 is on the order of nm, current flows only between the opposing electrode portions 3 in the laminated structure described later. Even when the pitch of the electrode portion 3 is 10 μm or less, current does not leak to adjacent electrodes, and mounting with a narrow electrode pitch can be realized.

[0025] (Method for manufacturing a substrate) The method for manufacturing the substrate in Example 1 of the present invention will be described with reference to Figs. 2 and 3. Fig. 2 is a diagram for explaining the method for manufacturing the substrate in Example 1 of the present invention. Fig. 3 is a diagram for explaining the self-assembled monolayer of the substrate in Example 1 of the present invention.

[0026] First, an electrode portion forming step of forming an electrode portion 3 on the circuit pattern 2 of the base material 1 is performed. The electrode portion 3 may be formed by film deposition in a vacuum, or may be formed by plating or printing, and can be formed by any method. Next, an insulating material filling step of filling an insulating material in a region other than the electrode portion 3 on the surface of the base material 1 is performed. Any filling method can be adopted.

[0027] Next, a self-assembled film forming step is performed. Before this self-assembled film forming step, surface polishing (for example, CMP method, etc.) and a cleaning step are performed on the surface formed by the electrode portion 3 and the insulating material 4, thereby forming an electrode exposed surface. And in the self-assembled film forming step, first, the base material 1 on which the electrode portion 3 and the insulating material 4 are formed is placed in a vacuum chamber C, and the surface (electrode exposed surface) is plasma-cleaned by irradiating plasma in a vacuum (see Fig. 2(a)). Next, an evaporation source for imparting a hydrophilic group is supplied into the vacuum chamber C, and the surfaces (electrode exposed surfaces) of the electrode portion 3 and the insulating material 4 on the base material 1 are modified by the plasma atmosphere formed by plasma generation to perform a surface hydrophilization mode of hydrophilizing (see Fig. 2(b)). Next, in the same vacuum chamber C, an evaporation source for promoting the hydrolysis of the precursor material of the self-assembled film is supplied to the base material 1 whose surface has been hydrophilized, and a self-assembly mode of forming a SAM film on the hydrophilized surface (electrode exposed surface) is performed (see Fig. 2(c)).

[0028] At this time, the Y site of the precursor material of the self-assembled film contains a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group as a functional group at the tip. As will be described later, when forming a laminated structure of the substrates 10, these vinyl groups, hydroxy groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups can polymerize with each other to realize a strong bond. Note that the above-mentioned vinyl group, hydroxy group, acrylic group, epoxy group, amino group, or isocyanate group is not a functional group in the middle part of the self-assembled film.

[0029] Next, hydrolysis with water vapor is carried out in the same vacuum chamber C (see Fig. 2(d)). As a result, in the self-assembled mode of Fig. 2(e), the molecular arrangement as shown in Fig. 3(a) becomes the molecular arrangement after dehydration and condensation as shown in Fig. 3(b), and a structure that can extend long from the surface and is difficult to fall down can be obtained. Note that the example of Fig. 3 shows the case where the terminal of the self-assembled film 5 has an acrylic group.

[0030] Through the above electrode portion formation step, insulating material formation step, and self-assembled film formation step, the substrate 10 can be obtained. The substrate 10 on which the self-assembled film 5 is formed can maintain an active state without surface inactivation even in the atmosphere, and chip bonding can be carried out in the atmosphere.

[0031] As described above, in Example 1, the electrode portion formed on the substrate surface and the insulating material filled in the surface region of the substrate other than the electrode portion on the surface of the substrate, the self-assembled film formed on the electrode exposed surface formed by the electrode portion and the insulating material, by the substrate provided with the self-assembled film is formed, the surface active state can be maintained even in the atmosphere, and fine chip mounting can be enabled.

Example

[0032] (Laminated structure) Example 2 of the present invention is different from Example 1 in that it relates to a laminated structure in which substrates are joined together. The laminated structure in Example 2 will be described with reference to Figs. 4 and 5. Fig. 4 is a diagram for explaining the laminated structure in Example 2 of the present invention. Fig. 5 is a diagram for explaining the manufacturing method of the laminated structure in Example 2 of the present invention.

[0033] The laminated structure 100 in Example 2 has, with respect to the first self-assembled film 5 in the first substrate 10 which has the first electrode portion 3 formed on the surface of the first substrate 1, the 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 the 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 electrode portion 3' formed on the surface of the second substrate 1', the 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 the second self-assembled film 5' formed on the electrode exposed surface formed by the second electrode portion 3' and the second insulating material 4', and the second self-assembled film 5' in the second substrate 1' is joined facing each other.

[0034] At this time, the first electrode portion 3 and the second electrode portion 3' are opposed to each other, aligned, and joined. Therefore, electrical conduction is possible between the first electrode portion 3 and the second electrode portion 3' through the first self-assembled film 5 and the second self-assembled film 5' on the nm order. However, it is not necessary for all of the first electrode portions 3 and the second electrode portions 3' to be aligned, and a laminated structure in which at least a part of a plurality of the first electrode portions 3 and at least a part of a plurality of the second electrode portions 3' are opposed to each other, aligned, and joined according to the convenience of the electronic circuit may be used.

[0035] In the laminated structure 100 of FIG. 4, since the distance between the tip of the opposing first electrode portion 3 and the tip of the second electrode portion 3' is on the nm order which is the length of the first self-assembled film 5 and the second self-assembled film 5', electricity can easily conduct. On the other hand, since the distance between each electrode portion is about 10 μm, there is no risk of current leakage, and an electrical circuit can be configured normally.

[0036] (Manufacturing method of laminated structure) The manufacturing method of the laminated structure will be described with reference to FIG. 5. FIG. 5 is a diagram for explaining the manufacturing method of the laminated structure in Example 2 of the present invention.

[0037] First, in a known mounting machine, the first self-assembled film 5 on the first substrate 10 is opposed to the second self-assembled film 5' on the second substrate 10'. Then, after the first substrate 10 and the second substrate 10' are moved in parallel, an alignment process is carried out in the atmosphere to perform two-dimensional alignment of at least a part of the electrode portion 3 on the first substrate 10 and at least a part of the electrode portion 3' on the second substrate 10'.

[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 films as thin as the order of nm, the positions of the underlying electrode portion 3 and the electrode portion 3' can be visually recognized. Then, while confirming the alignment marks with the camera of the mounting machine, the positions of the electrode portion 3 and the electrode portion 3' can be confirmed and alignment can be performed by a known method.

[0039] After the alignment process is completed, a bonding process is carried out to bond the first substrate 10 and the second substrate 10' in the atmosphere. The mounting machine eliminates the distance in the height direction between the first substrate 10 and the second substrate 10' and brings them into contact. Then, it is heated to about 50°C to 500°C. The heating time varies depending on the electrode portion material, but it may be about several minutes to several tens of minutes.

[0040] Note that in Example 2, heating was performed in the bonding process, but it is not necessarily limited to this and can be appropriately changed. For example, after mounting, ultraviolet rays may be irradiated.

[0041] Thus, in Example 2, it is a laminated structure in which the substrates are bonded to each other, the first electrode portion formed on the surface of the first base material, the first insulating material filled in the surface region of the first base material other than the first electrode portion on the surface of the first base material, and the first self-assembled film formed on the electrode exposed surface formed by the first electrode portion and the first insulating material, with respect to the first self-assembled film in the first 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 on the surface of the second substrate, and a second self-assembled film formed on the electrode exposed surface formed by the second electrode portion and the second insulating material, the second self-assembled film in the second substrate having is opposed, By a laminated structure characterized in that at least a part of the first electrode portion and at least a part of the second electrode portion are aligned and laminated, between the second electrode portion facing the first electrode portion through the first self-assembled film and the second self-assembled film, electrical conduction is achieved, and a laminated structure in which electrical conduction through the first insulating material or the second insulating material is not achieved can be realized.

[0042] Further, it is a method for manufacturing a laminated structure having a self-assembled film, A first substrate including 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, and a self-assembled film formed on the electrode exposed surface formed by the electrode portion and the insulating material, and a self-assembled film of a second substrate are opposed to each other, and an alignment step of aligning at least a part of the electrode portion in the first substrate and at least a part of the electrode portion in the second substrate in the air, A bonding step of bonding the aligned first substrate and the second substrate in the air, by a method for manufacturing a laminated structure characterized by including this, it is possible to bond substrates that can maintain a surface active state even in the air, and a laminated structure enabling fine chip mounting can be obtained.

Industrial Applicability

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

Explanation of Signs

[0044] 1: Substrate 2: Circuit pattern 3: Electrode portion 4: Insulating material 5: Self-assembled film 10: Substrate 1´: Substrate 2´: Circuit pattern 3´: Electrode portion 4´: Insulating material 5': Self-assembled membrane 10': Substrate 100: Stacked structure C: Chamber

Claims

1. A substrate capable of having a laminated structure in which substrates are polymerically bonded to each other, a plurality of electrode portions formed on the surface of a base material, an insulating material filled in the surface region of the base material between the electrode portions on the surface of the base material, and a self-assembled film formed on the entire surface of the electrode exposed surface formed by the electrode portion and the insulating material, wherein the self-assembled film has a functional group at the surface tip including a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group, enabling polymerization bonding with the self-assembled film on the counterpart substrate. On the other hand, the electrode portion is capable of electrical conduction between the electrode portions facing each other on the counterpart substrate through the self-assembled film, and between the adjacent electrode portions, there is no electrical conduction through the self-assembled film. The substrate is characterized by this.

2. A laminated structure in which substrates are polymerically bonded to each other, a plurality of first electrode portions formed on the surface of a first base material, a first insulating material filled in the surface region of the first base material between the first electrode portions on the surface of the first base material, and a first self-assembled film formed on the entire surface of the electrode exposed surface formed by the first electrode portion and the first insulating material. With respect to the first self-assembled film in the first substrate having these, a plurality of second electrode portions formed on the surface of a second base material, a second insulating material filled in the surface region of the second base material between the second electrode portions on the surface of the second base material, and a second self-assembled film formed on the entire surface of the electrode exposed surface formed by the second electrode portion and the second insulating material. The second self-assembled film in the second substrate having these faces each other, at least a part of the first electrode portion and at least a part of the second electrode portion are aligned and laminated, the first self-assembled film and the second self-assembled film have a functional group at the surface tip including a vinyl group, a hydroxy group, an acrylic group, an epoxy group, an amino group, or an isocyanate group, so that the self-assembled films are polymerically bonded to each other. On the other hand, the first electrode portion and the second electrode portion facing each other through the first self-assembled film and the second self-assembled film are electrically conductive, and between the adjacent first electrode portions and between the adjacent second electrode portions, there is no electrical conduction through the first self-assembled film and the second self-assembled film. The laminated structure is characterized by this.

3. A method for manufacturing a laminated structure having a self-assembled film, A first substrate including a plurality of electrode portions formed on a substrate surface, an insulating material filled in a substrate surface region between the electrode portions on the substrate surface, and a self-assembled monolayer formed on the entire electrode exposed surface formed by the electrode portions and the insulating material, and an alignment step of aligning at least a part of the electrode portions in the first substrate and at least a part of the electrode portions in the second substrate in the air by opposing the self-assembled monolayers of the first substrate and the second substrate. A bonding step of bonding the aligned first substrate and second substrate in the air. In the bonding step, the self-assembled monolayers on the first substrate and the second substrate enable polymerization bonding between the self-assembled monolayers on the first substrate and the second substrate because the functional groups at the surface tips of the self-assembled monolayers on the first substrate and the second substrate include vinyl groups, hydroxy groups, acrylic groups, epoxy groups, amino groups, or isocyanate groups. A method for manufacturing a laminated structure, characterized in that the electrode portions on the first substrate and the second substrate facing each other through the self-assembled monolayers on the first substrate and the second substrate after bonding are electrically conductive, and the adjacent electrode portions on the first substrate and the second substrate are not electrically conductive through the self-assembled monolayers on the first substrate and the second substrate.

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

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