JP-7854644-B2 - Force sensor module

Inventors

• 田名網 克周
• 林 美由希
• 金森 義明
• 岡谷 泰佑

Assignees

• 新東工業株式会社
• 国立大学法人東北大学

Dates

Publication Date

20260507

Application Date

20220331

Claims (3)

1. A first substrate having light-transmitting properties, A metasurface pattern provided on the first main surface of the first substrate, A second substrate provided so as to face the first substrate, the second substrate including a second main surface facing the first main surface, A reflective layer provided on the second main surface, A spacer layer made of a conductive material is provided on the first main surface, A bonding layer that joins the second main surface and the spacer layer, The spacer layer is connected to a ground wire , The spacer layer is made of indium titanium tin, The bonding layer is made of silicon. A force sensor module characterized by the following features.
2. The ground wiring is connected to the spacer layer via an anisotropic conductive film. The force sensor module according to feature 1 .
3. It is translucent and further comprises a protective layer that covers the metasurface pattern. The force sensor module according to claim 1 or 2.

Description

This invention relates to a force sensor module. A force sensor module is known that comprises a metasurface pattern provided on a first substrate made of glass, a reflective layer provided on a second substrate facing the metasurface pattern, and a spacer that defines the distance between the first and second substrates (for example, Patent Document 1). In such a force sensor module, light is incident on the metasurface pattern, and information regarding the distance between the metasurface pattern and the reflective layer is obtained using the light transmitted through the metasurface pattern and reflected by the reflective layer. Since this distance is determined according to the magnitude of the force acting on the second substrate, the force sensor module can detect the magnitude of the force acting on the second substrate using an optical method. Japanese Patent Publication No. 2020-94973 This is a schematic diagram of a force sensor system including a force sensor module according to one embodiment of the present invention. Figure 1 includes a cross-sectional view of the force sensor module.(a) and (b) are plan views of the first and second substrates that constitute the force sensor module shown in Figure 1, respectively. A force sensor module 10 and a force sensor system 1 equipped with the force sensor module 10, according to one embodiment of the present invention, will be described with reference to Figure 1. The force sensor module 10 will also be described with reference to Figure 2. Figure 1 is a schematic diagram of the force sensor system 1 including the force sensor module 10. Figure 1 includes a cross-sectional view of the force sensor module 10. Figures 2(a) and 2(b) are plan views of the first substrate 11 and the second substrate 12 constituting the force sensor module 10, respectively. [Configuration of the force sensor module] As shown in Figure 1, the force sensor module 10 comprises a first substrate 11, a second substrate 12, a spacer layer 13, a metasurface pattern 14, a protective layer 15, a reflective layer 16, a hard coat layer 17, a bonding layer 18, an anisotropic conductive film 21, and ground wiring 22. The force sensor module 10 detects a point load F when it is applied to the second substrate 12 of the first substrate 11. <First substrate> The first substrate 11 is a translucent plate-like member. In this embodiment, alkali-free glass is used as the material constituting the first substrate 11. Because alkali-free glass does not contain alkaline components, its surface is less susceptible to corrosion by chemicals and water, and it has excellent electrical insulation properties. However, the material constituting the first substrate 11 can be any solid material that is translucent in the wavelength band of light L1, as described later, and can be appropriately selected from materials available on the market. Other examples of materials constituting the first substrate 11 include quartz and polycarbonate resin. As will be described later, in this embodiment, the wavelength band of light L1 is set to 1400 nm or more and 1600 nm or less. In this embodiment, the shape of the first substrate 11 when viewed from above (see Figure 2(a)) is a square with sides of 4 cm. Also, in this embodiment, the thickness of the first substrate 11 is 500 μm. The shape and thickness of the first substrate 11 are not limited to the above example and can be determined as appropriate. A preferred thickness of the first substrate 11 is 500 μm or more and 2000 μm or less. The first substrate 11 includes a pair of opposing main surfaces, namely main surface 111 and main surface 112. In the configuration shown in Figure 1, the first substrate 11 is arranged such that main surface 111 is on the upper side and main surface 112 is on the lower side. Main surface 111 is an example of a first main surface. Furthermore, the force sensor module 10 applies a point load F to the second substrate 12 as described above. The force sensor module 10 then detects the point load F by utilizing the deflection of the second substrate 12 caused by the point load F. Therefore, it is preferable that the first substrate 11 is configured such that it does not deflect when the point load F is applied to the second substrate 12, or deflects only to an extent that is negligible compared to the deflection of the second substrate 12. (Metasurface pattern) As shown in Figures 1 and 2(a), a metasurface pattern 14 is provided on the main surface 111 of the first substrate 11. In Figure 2(a), the metasurface pattern 14 is covered by a protective layer 15 and is therefore shown with a dashed line. The metasurface pattern 14 consists of multiple (25 in Figure 2(a)) periodically arranged subpatterns 141. In this embodiment, the subpatterns 141 are arranged in a 5x5 matrix. However, Figure 2(a) is a schematic diagram for easier understanding of the subpatterns 141. The actual metasurface pattern 14 is composed of many more subpatterns