Cavity substrate and method for manufacturing cavity substrate

Abstract

To shorten a processing time for processing a cavity and reduce processing costs.SOLUTION: A cavity substrate 100 includes a first substrate 10, a second substrate 20 stacked on the first substrate 10 and having a cavity 30, and a semiconductor element 40 mounted in the cavity 30. The cavity 30 is opened by moving a bit 60 in the thickness direction of the second substrate 20 using an NC processing machine.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cavity substrate and a method for manufacturing a cavity substrate. [Background technology]

[0002] For example, a wiring board having a cavity in which a semiconductor element is mounted is known (see, for example, Patent Document 1). The cavity is formed by cutting out the substrate using, for example, a router (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-267274 [Patent Document 2] Japanese Patent Application Publication No. 09-08837 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when forming a cavity using a router processing machine as in the conventional technology, the small diameter bit must be moved in a direction along the processing surface of the substrate, which requires a long movement distance of the small diameter bit. As a result, the conventional technology requires a long processing time and is unable to reduce processing costs.

[0005] An object of the present invention is to provide a cavity substrate and a method for manufacturing the cavity substrate that can shorten the processing time for processing a cavity and reduce processing costs. [Means for solving the problem]

[0006] The cavity substrate of the present disclosure comprises a first substrate, a second substrate stacked on the first substrate and having a cavity, and a semiconductor element mounted in the cavity, and the cavity is opened by moving a bit in the thickness direction of the second substrate using an NC machining machine. [Effects of the Invention]

[0007] The present disclosure can provide a cavity substrate and a method for manufacturing a cavity substrate that can shorten the processing time for processing a cavity and reduce processing costs. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view showing a sensor module according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the sensor module according to the embodiment. [Figure 3] FIG. 10 is a plan view showing a cavity substrate according to a comparative example. [Figure 4] 5A to 5C are process diagrams showing steps of a method for manufacturing a sensor module according to an embodiment. [Figure 5] FIG. 2 is a plan view showing a cavity substrate before being divided into individual pieces. [Figure 6] FIG. 10 is a plan view showing a second substrate according to a first modified example. [Figure 7] FIG. 10 is a plan view showing a second substrate according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a cavity substrate and a method for manufacturing the cavity substrate according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant description may be omitted.

[0010] [Sensor module 100 according to the embodiment] Fig. 1 is a plan view showing a sensor module 100 according to an embodiment. Fig. 2 is a cross-sectional view of the sensor module 100 according to an embodiment. In each drawing, an X-axis direction, a Y-axis direction, and a Z-axis direction that are orthogonal to each other are shown. The X-axis direction, the Y-axis direction, and the Z-axis direction do not have to be orthogonal to each other. The X-axis direction, the Y-axis direction, and the Z-axis direction may be any direction.

[0011] 1 and 2, the sensor module 100 includes a first substrate 10, a second substrate 20, and a semiconductor sensor element 40. The sensor module 100 is an example of a cavity substrate.

[0012] [First substrate 10] The first substrate 10 may be a wiring substrate having wiring formed on its upper surface 10a. The thickness direction of the first substrate 10 is along the Z-axis direction.

[0013] [Second substrate 20] The second substrate 20 has an upper surface 20a and a lower surface 20b that face each other in the thickness direction. The thickness direction of the second substrate 20 is along the Z-axis direction. The second substrate 20 is stacked on the upper surface 10a of the first substrate 10 in the Z-axis direction. The upper surface 10a of the first substrate 10 and the lower surface 20b of the second substrate 20 are bonded together. The first substrate 10 and the second substrate 20 are, for example, glued together.

[0014] [Cavity 30] A cavity 30 is formed in the second substrate 20, penetrating the second substrate 20 in the thickness direction. The cavity 30 has a circular outer shape when viewed in the thickness direction. A sidewall 31 forming the cavity 30 also has a circular shape when viewed in the thickness direction.

[0015] The cavity 30 is opened by moving a bit 60 in the thickness direction of the second substrate 20 using an NC machining machine. The cavity 30 is formed in the second substrate 20 before it is joined to the first substrate 10. The inner diameter ID30 of the cavity 30 may be equal to or greater than one time the chip diagonal dimension. The "chip diagonal dimension" is the length of the diagonal of the semiconductor chip that is the semiconductor sensor element 40.

[0016] [Semiconductor sensor element 40] The semiconductor sensor element 40 may be, for example, a semiconductor pressure sensor element. The semiconductor sensor element 40 is not limited to a semiconductor pressure sensor element. The semiconductor sensor element 40 may be, for example, a gas sensor, a temperature sensor, a humidity sensor, or any other sensor element. The semiconductor sensor element 40 may have a MEMS (Micro Electro Mechanical Systems) sensor chip and a glass substrate. The semiconductor sensor element 40 is an example of a semiconductor element.

[0017] The semiconductor sensor element 40 is mounted in the cavity 30. The semiconductor sensor element 40 is mounted on the upper surface 10a of the first substrate 10 exposed in the cavity 30. The semiconductor sensor element 40 is adhered to the upper surface 10a of the first substrate 10 using an adhesive resin (adhesive). The adhesive resin may be, for example, a die bond resin such as a silicone resin.

[0018] The semiconductor sensor element 40 is wire-bonded to the first substrate 10. The semiconductor sensor element 40 is connected to a wire-bonding pad formed on the first substrate 10 via a bonding wire 50.

[0019] [Problems with the prior art] Next, problems with the conventional technology will be described. FIG. 3 is a plan view showing a cavity substrate 2 according to a comparative example. A rectangular cavity 3 is formed in the cavity substrate 2. The cavity 3 has a rectangular shape, similar to the cavity substrate 2. In the conventional technology, the cavity 3 is formed using a router processing machine and a small-diameter bit 6. In FIG. 3, the outer diameter of the small-diameter bit 6 is indicated by a dashed line. The cavity 3 is formed by moving the small-diameter bit 6 in the X-axis and Y-axis directions. In the conventional technology, machining is performed by moving the small-diameter bit 6, so the movement distance of the small-diameter bit 6 is long. As a result, the conventional technology requires a long machining time, making it difficult to reduce machining costs.

[0020] [Operation and effect of the sensor module 100 according to the embodiment] The sensor module 100 according to the embodiment includes a first substrate 10, a second substrate 20 stacked on the first substrate 10 and having a cavity 30, and a semiconductor sensor element (semiconductor element) 40 mounted in the cavity 30. The cavity 30 is opened by moving a bit 60 in the thickness direction of the second substrate 20 using an NC processing machine.

[0021] In such a sensor module 100, the second substrate 20 can be cut and the cavity 30 can be formed by moving the bit 60 in the thickness direction of the second substrate 20 using an NC processing machine. With the sensor module 100, it is only necessary to move the bit 60 in the Z-axis direction, and it is not necessary to move the bit 60 in the X-axis and Y-axis directions as in the conventional technology. Therefore, with the sensor module 100, it is possible to shorten the processing time and reduce the processing cost.

[0022] [Method of manufacturing the sensor module 100 according to the embodiment] Next, an example of a method for manufacturing the sensor module 100 according to the embodiment will be described. FIG. 4 is a process chart showing the steps of the method for manufacturing the sensor module according to the embodiment. The method for manufacturing the sensor module 100 includes a step (S11) of processing a cavity 30 in the second substrate 20, a step (S12) of bonding the first substrate 10 and the second substrate 20 together, a step (S13) of mounting a semiconductor sensor element 40 in the cavity 30, and a step (S14) of singulating the sensor module 100. The method for manufacturing the sensor module 100 may include other steps. Furthermore, the order of the steps in the method for manufacturing the sensor module 100 may be reversed, or the steps may be performed simultaneously.

[0023] In the step (S11) of machining the cavity 30 in the second substrate 20, a bit 60 is moved in the thickness direction of the second substrate 20 using an NC machining machine to machine the cavity 30 in the second substrate 20. In the step (S11) of machining the cavity 30, the rotating bit 60 is moved in the Z-axis direction using the NC machining machine to form the cavity 30. Here, a tape-like adhesive is attached to the lower surface 20b of the second substrate 20. In this state, the cavity 30 is machined by the bit 60.

[0024] In the step (S12) of bonding the first substrate 10 and the second substrate 20, the first substrate 10 and the second substrate 20 are bonded in the thickness direction. The adhesive may be thermally cured by pressing the first substrate 10 and the second substrate 20 in the thickness direction.

[0025] In the step (S13) of mounting the semiconductor sensor element 40 in the cavity 30, the semiconductor sensor element 40 is placed at a predetermined position in the cavity 30, and the semiconductor sensor element 40 is mounted on the first substrate 10. In this step, the semiconductor sensor element 40 and the wiring of the first substrate 10 are wire-bonded.

[0026] 5 is a plan view showing the cavity substrate before being singulated. In the step (S14) of singulating the sensor modules 100, the first substrate 10 and the second substrate 20 are cut by, for example, dicing, to singulate the sensor modules 100.

[0027] [Second Substrate 20B According to First Modification] FIG. 6 is a plan view showing a second substrate 20B according to a first modified example. FIG. 6 shows the second substrate 20B before being bonded to the first substrate 10. A plurality of cavities 30 may be opened in the second substrate 20B. The plurality of cavities 30 are aligned, for example, in the Y-axis direction. For example, three cavities 30 are formed in the second substrate 20B. A semiconductor sensor element 40 is mounted in each of the plurality of cavities 30. Two or more cavities 30 may be formed in the second substrate 20B.

[0028] [Second Substrate 20C According to Second Modification] FIG. 7 is a plan view showing a second substrate 20C according to a first modified example. FIG. 7 shows the second substrate 20C before being bonded to the first substrate 10. A plurality of cavities 30 may be opened in the second substrate 20C. The plurality of cavities 30 may be arranged apart from each other in the X-axis direction, for example. The center points of the plurality of cavities 30 may be arranged at different positions in the X-axis direction and the Y-axis direction. The plurality of cavities 30 may be aligned in a direction intersecting both the X-axis direction and the Y-axis direction. A semiconductor sensor element 40 is mounted in each of the plurality of cavities 30.

[0029] [Sensor module 100 according to a third modification] The sensor module 100 according to the third modification may include a plurality of semiconductor chips that are a plurality of semiconductor sensor elements 40. The sensor module 100 may include a plurality of cavities 30. One semiconductor chip or a plurality of semiconductor chips may be mounted in the cavity 30. Furthermore, in the sensor module 100, a semiconductor chip may be mounted outside the cavity 30. The sensor module 100 may include a semiconductor chip disposed in the cavity 30 and a semiconductor chip mounted on the upper surface 20a of the second substrate 20.

[0030] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0031] 100: sensor module (cavity substrate), 10: first substrate, 20, 20B, 20C: second substrate, 30: cavity, 40: semiconductor sensor element (semiconductor element), X: X-axis direction, Y: Y-axis direction, Z: Z-axis direction (plate thickness direction).

Claims

1. a first substrate; a second substrate laminated on the first substrate and having a cavity; a semiconductor element mounted in the cavity, The cavity is formed by moving a bit in the thickness direction of the second substrate using an NC processing machine.

2. The cavity substrate according to claim 1 , wherein the cavity has a circular shape when viewed in the thickness direction.

3. The cavity substrate according to claim 1 , wherein a plurality of the cavities are formed in the second substrate.

4. A method for manufacturing a cavity substrate including a first substrate, a second substrate stacked on the first substrate and having a cavity, and a semiconductor element mounted in the cavity, the method comprising: a step of moving a bit in a thickness direction of the second substrate using an NC processing machine to machine the cavity in the second substrate; a step of joining the first substrate and the second substrate in the plate thickness direction; and mounting the semiconductor element in the cavity.

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