WO2024075462A1

WO2024075462A1 - Pressure sensor

Info

Publication number: WO2024075462A1
Application number: PCT/JP2023/032460
Authority: WO
Inventors: 徹樋口; 宏介山城
Original assignee: ローム株式会社
Priority date: 2022-10-03
Filing date: 2023-09-06
Publication date: 2024-04-11

Abstract

This pressure sensor comprises: a package exterior body having an upper wall; and a MEMS chip. The MEMS chip has a membrane and is disposed in an internal space of the package exterior body. A plurality of holes passing through the upper wall in the thickness direction of the upper wall are formed in the upper wall.

Description

Pressure Sensors

This disclosure relates to a pressure sensor.

For example, JP 2019-125675 A (Patent Document 1) describes a pressure sensor. The pressure sensor described in Patent Document 1 has a case, a substrate, and a MEMS (Micro Electro Mechanical System) chip.

The case has a side wall and an upper wall that is continuous with the upper end of the side wall. The case is connected to the substrate at the lower end of the side wall. The case and the substrate constitute the package exterior of the pressure sensor described in Patent Document 1. The MEMS chip has a membrane. The MEMS chip is disposed in the internal space of the package exterior that is defined by the side wall and upper wall of the case and the substrate.

A hole is formed in the top wall of the package exterior (top wall of the case). The hole penetrates the top wall in the thickness direction. The hole is connected to the internal space of the package exterior. As a result, in the pressure sensor described in Patent Document 1, external pressure changes are transmitted through the hole to the internal space of the package exterior, causing the membrane to deflect. In this way, the pressure sensor described in Patent Document 1 detects external pressure changes.

JP 2019-125675 A

[overview]
In the pressure sensor described in Patent Document 1, only one hole is formed in the upper wall of the package exterior body, making it difficult for gas or liquid that has entered the internal space of the package exterior body to escape through the hole, which can result in air bubbles or liquid pools forming in the internal space of the package exterior body.

For example, if cleaning is performed using liquid when there are air bubbles trapped in the internal space of the package exterior, the flow of the liquid may be blocked by the air bubbles, and cleaning may not be performed properly. As a result, foreign matter or dirt remaining in the internal space of the package exterior may hinder the membrane from bending. If ultrasonic cleaning is performed when there are air bubbles remaining in the internal space of the package exterior, abnormal impacts may occur around the air bubbles, damaging the membrane.

If liquid (e.g. rainwater or sweat) that enters the internal space of the package exterior through the holes during cleaning or the internal space of the package exterior through the holes during use does not escape from the internal space of the package exterior and forms a pool of liquid, the pool of liquid can deflect the membrane or block contact with the outside air, causing malfunctions.

The pressure sensor disclosed herein comprises a package exterior having an upper wall, and a MEMS chip. The MEMS chip has a membrane and is disposed in the internal space of the package exterior. The upper wall has a plurality of holes formed therein that penetrate the upper wall in the thickness direction.

FIG. 2 is a plan view of the pressure sensor 100. FIG. 2 is a cross-sectional view of the pressure sensor 100. 2 is a cross-sectional view of the MEMS chip 40. FIG. 3A to 3C are manufacturing process diagrams of the pressure sensor 100. FIG. 4 is a cross-sectional view illustrating a preparation step S1. 11 is a cross-sectional view illustrating a first chip mounting step S2. FIG. 11 is a cross-sectional view illustrating a second chip mounting step S3. FIG. FIG. 11 is a cross-sectional view illustrating a wire bonding step S4. FIG. 11 is a cross-sectional view illustrating a gel filling step S5. FIG. 11 is a cross-sectional view illustrating a lid bonding step S6. FIG. 2 is a plan view of a pressure sensor 100 according to a first modified example. FIG. 11 is a plan view of a pressure sensor 100 according to a second modified example. FIG. 2 is a plan view of the pressure sensor 100A. FIG. 2 is a cross-sectional view of the pressure sensor 100A. FIG. FIG. 2 is a plan view of the pressure sensor 100B. FIG. 2 is a cross-sectional view of the pressure sensor 100B. FIG. 11 is a plan view of a pressure sensor 100B according to a first modified example. FIG. 11 is a plan view of a pressure sensor 100B according to a second modified example. FIG. 13 is a plan view of a pressure sensor 100B according to a third modified example.

Detailed Description
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and redundant description will not be repeated.

First Embodiment
The pressure sensor according to the first embodiment will be described below. The pressure sensor according to the first embodiment is designated as pressure sensor 100.

<Configuration of Pressure Sensor 100>
The configuration of the pressure sensor 100 will be described below.

The pressure sensor 100 is a sensor that detects pressure in the external space of the pressure sensor 100. FIG. 1 is a plan view of the pressure sensor 100. FIG. 2 is a cross-sectional view of the pressure sensor 100. As shown in FIGS. 1 and 2, the pressure sensor 100 has a case 10, a lid 20, a semiconductor chip 30, and a MEMS chip 40. The pressure sensor 100 may further have a gel material 50. The case 10 and the lid 20 form an exterior package body of the pressure sensor 100. The lid 20 forms an upper wall of the exterior package body of the pressure sensor 100.

The case 10 is made of, for example, a ceramic material. The case 10 has a side wall 11 and a bottom wall 12. The bottom wall 12 is connected to the lower end of the side wall 11. The space defined by the side wall 11 and the bottom wall 12 is referred to as an internal space 13. The internal space 13 constitutes the internal space of the package exterior of the pressure sensor 100. The case 10 is, for example, rectangular in plan view. The upper end of the side wall 11 is formed of, for example, a metal layer 11a.

External connection pads 12a are arranged on the outer wall surface of the bottom wall 12. The pressure sensor 100 is electrically connected to a printed wiring board or the like via the external connection pads 12a. A plurality of internal connection pads 12b are arranged on the inner wall surface of the bottom wall 12. The internal connection pads 12b are electrically connected to the external connection pads 12a via conductors (not shown) embedded in the case 10. A step portion 11b is formed on the inner wall surface of the side wall 11. An internal connection pad 11c is arranged on the step portion 11b. The internal connection pad 11c is electrically connected to the external connection pads 12a and/or the internal connection pads 12b via conductors (not shown) embedded in the case 10.

The lid 20 is a plate-shaped member. The lid 20 is formed, for example, from a metal material. The lid 20 is, for example, rectangular in plan view. The outer peripheral edge of the lid 20 in plan view is joined to the upper end of the side wall 11. More specifically, the outer peripheral edge of the lid 20 in plan view is welded to the metal layer 11a. In this way, the lid 20 forms the upper wall of the package exterior of the pressure sensor 100.

The lid 20 has a plurality of holes 21 formed therein. The holes 21 penetrate the lid 20 in the thickness direction. From another perspective, the internal space 13 communicates with the external space of the package exterior body of the pressure sensor 100 through the holes 21. In the example shown in FIG. 1, the number of holes 21 is two. One of the two holes 21 is hole 21a, and the other of the two holes 21 is hole 21b. In a plan view, the

holes

21a and 21b are, for example, near the four corners of the lid 20 in a plan view. From another perspective, no hole 21 is formed in the center of the lid 20 in a plan view. The

holes

21a and 21b are, for example, symmetrically positioned with respect to the center of the lid 20 in a plan view. However, the arrangement of the plurality of holes 21 is not limited to this.

Hole 21 is, for example, circular in plan view. The opening diameter of hole 21 is, for example, 20 μm or more and 300 μm or less. The opening diameter of hole 21 may be 30 μm or more and 250 μm or less. The shape of hole 21 in plan view does not have to be circular. If the shape of hole 21 in plan view is not circular, the opening diameter of hole 21 is obtained by the square root of the opening area of hole 21 divided by π/4.

The semiconductor chip 30 has a first surface 30a and a second surface 30b. The first surface 30a and the second surface 30b are end surfaces in the thickness direction of the semiconductor chip 30. The semiconductor chip 30 is disposed on the inner wall surface of the bottom wall 12 so that the first surface 30a faces the inner wall surface of the bottom wall 12. On the second surface 30b, the semiconductor chip 30 is electrically connected to the internal connection pads 12b by bumps 31. The bumps 31 are formed of, for example, gold.

FIG. 3 is a cross-sectional view of the MEMS chip 40. As shown in FIG. 3, the MEMS chip 40 has a silicon substrate 41, a glass substrate 45, an interlayer insulating film 46, and a plurality of wirings 47. The silicon substrate 41 has a first surface 41a and a second surface 41b. The first surface 41a and the second surface 41b are end surfaces in the thickness direction of the silicon substrate 41.

The silicon substrate 41 has a first silicon layer 42, a silicon oxide layer 43, and a second silicon layer 44. The silicon oxide layer 43 is disposed on the first silicon layer 42. The second silicon layer 44 is disposed on the silicon oxide layer 43. That is, the silicon oxide layer 43 is sandwiched between the first silicon layer 42 and the second silicon layer 44 in the thickness direction of the silicon substrate 41. The first silicon layer 42 and the second silicon layer 44 respectively constitute a first surface 41a and a second surface 41b.

A cavity 42a is formed in the first silicon layer 42. The cavity 42a penetrates the first silicon layer 42 in the thickness direction. The cavity 42a is closed by the silicon oxide layer 43 and the glass substrate 45. In other words, the glass substrate 45 is disposed on the first surface 41a.

Although not shown, resistors 44a and wiring 44b are formed in the second silicon layer 44. The second silicon layer 44 in the portion in which the resistors 44a and wiring 44b are formed is doped with impurities. The resistors 44a are formed in the second silicon layer 44 above the cavity 42a. A portion of the wiring 44b is formed in the second silicon layer 44 above the cavity 42a, and another portion of the wiring 44b is formed in the second silicon layer 44 above the first silicon layer 42 around the cavity 42a. The second silicon layer 44 has a plurality of resistors 44a. The plurality of resistors 44a are connected to each other by the wiring 44b to form a bridge circuit.

The interlayer insulating film 46 is formed of, for example, silicon oxide. The interlayer insulating film 46 is disposed on the second surface 41b (on the second silicon layer 44). The wiring 47 is disposed on the interlayer insulating film 46 above the first silicon layer 42 around the cavity 42a. The wiring 47 is formed of, for example, a metal material. One end of the wiring 47 is a bonding pad 47a. The other end of the wiring 47 is electrically connected to the wiring 44b.

The silicon oxide layer 43 on the cavity 42a, the second silicon layer 44 above the cavity 42a, and the interlayer insulating film 46 above the cavity 42a constitute a membrane 48. A power supply voltage, for example, is applied between a pair of bonding pads 47a electrically connected to the resistor 44a. When the membrane 48 bends, the electrical resistance value of the resistor 44a changes, and the voltage between a pair of bonding pads 47a other than the pair of bonding pads 47a to which the power supply voltage is applied changes from the above power supply voltage.

As shown in FIG. 2, the MEMS chip 40 is placed on the semiconductor chip 30 with the adhesive member 32 interposed therebetween so that the glass substrate 45 faces the second surface 30b. As a result, the MEMS chip 40 is placed in the internal space 13. One end of the bonding wire 49 is joined to the bonding pad 47a, and the other end of the bonding wire 49 is joined to the internal connection pad 11c. As a result, the MEMS chip 40 is electrically connected to the semiconductor chip 30 by the bonding wire 49, the conductor embedded inside the case 10, the internal connection pad 12b, and the bump 31. The bonding wire 49 is made of, for example, gold.

The gel material 50 fills the internal space 13. As a result, the semiconductor chip 30 and the MEMS chip 40 are sealed with the gel material 50.

<Operation of the Pressure Sensor 100>
The operation of the pressure sensor 100 will now be described.

The pressure change in the external space of the pressure sensor 100 is transmitted to the internal space 13 through the hole 21. When the pressure in the internal space 13 changes, the membrane 48 is deflected due to the difference with the internal pressure of the cavity 42a. When the membrane 48 is deflected, as described above, the change in the electrical resistance value of the resistor 44a fluctuates the voltage between a pair of bonding pads 47a electrically connected to the resistor 44a.

This voltage change is output to the semiconductor chip 30, where signal processing is performed, and the pressure in the external space of the package exterior of the pressure sensor 100 is calculated. A signal indicating the calculated pressure in the external space of the package exterior of the pressure sensor 100 is output from the semiconductor chip 30 via the external connection pad 12a.

<Method of Manufacturing Pressure Sensor 100>
A method for manufacturing the pressure sensor 100 will now be described.

FIG. 4 is a manufacturing process diagram of the pressure sensor 100. As shown in FIG. 4, the manufacturing method of the pressure sensor 100 includes a preparation process S1, a first chip mounting process S2, a second chip mounting process S3, a wire bonding process S4, a gel filling process S5, and a lid bonding process S6.

FIG. 5 is a cross-sectional view illustrating the preparation step S1. As shown in FIG. 5, in the preparation step S1, the case 10 is prepared.

The first chip mounting process S2 is carried out after the preparation process S1. FIG. 6 is a cross-sectional view explaining the first chip mounting process S2. As shown in FIG. 6, in the first chip mounting process S2, the semiconductor chip 30 is mounted on the inner wall surface of the bottom wall 12. At this time, the semiconductor chip 30 is electrically connected to the internal connection pads 12b by the bumps 31.

The second chip mounting process S3 is performed after the first chip mounting process S2. FIG. 7 is a cross-sectional view illustrating the second chip mounting process S3. As shown in FIG. 7, in the second chip mounting process S3, the MEMS chip 40 is mounted on the semiconductor chip 30. In the second chip mounting process S3, first, uncured adhesive material 32 is applied onto the second surface 30b. Second, the MEMS chip 40 is mounted on the second surface 30b with the adhesive material 32 interposed therebetween. Third, the adhesive material 32 is heated and cured.

The wire bonding process S4 is performed after the second chip mounting process S3. Figure 8 is a cross-sectional view illustrating the wire bonding process S4. As shown in Figure 8, in the wire bonding process S4, one end of the bonding wire 49 is bonded to the bonding pad 47a, and the other end of the bonding wire 49 is bonded to the internal connection pad 11c.

The gel filling step S5 is performed after the wire bonding step S4. FIG. 9 is a cross-sectional view illustrating the gel filling step S5. As shown in FIG. 9, in the gel filling step S5, the internal space 13 is filled with a gel material 50. The lid bonding step S6 is performed after the gel filling step S5. FIG. 10 is a cross-sectional view illustrating the lid bonding step S6. As shown in FIG. 10, in the lid bonding step S6, for example, an electrode 60 is brought into contact with the outer peripheral edge portion of the lid 20 in a planar view and welded, thereby bonding the outer peripheral edge portion of the lid 20 in a planar view to the upper end of the sidewall 11 (more specifically, the metal layer 11a). In this way, the pressure sensor 100 having the structure shown in FIG. 1 and FIG. 2 is manufactured.

After the pressure sensor 100 is manufactured, the pressure sensor 100 may be cleaned. This cleaning is performed while supplying a cleaning liquid from the hole 21 into the internal space 13. During this cleaning, ultrasonic waves may be applied.

<Effects of the Pressure Sensor 100>
The effects of the pressure sensor 100 will be described below.

If only one hole 21 is formed in the lid 20, it is difficult for the gas or liquid that has entered the internal space 13 to escape through the hole 21, and air bubbles or liquid pools may form in the internal space 13. For example, if cleaning is performed using liquid when there are air bubbles in the internal space 13, the flow of the liquid may be blocked by the air bubbles, and cleaning may not be performed properly. As a result, foreign matter or dirt remaining in the internal space 13 may hinder the bending of the membrane 48. If ultrasonic cleaning is performed when there are air bubbles remaining in the internal space 13, abnormal impacts may occur around the air bubbles, damaging the membrane 48.

In addition, if only one hole 21 is formed in the lid 20, if liquid (e.g., rainwater or sweat) that enters the internal space 13 through the hole 21 during cleaning or the internal space 13 through the hole 21 during use does not drain out of the internal space 13 and forms a pool of liquid, the pool of liquid can deflect the membrane 48 or block contact with the outside air, causing malfunction.

On the other hand, in the pressure sensor 100, multiple holes 21 are formed in the lid 20. Therefore, gas or liquid that enters the internal space 13 through one hole 21 (hole 21a in the example of FIG. 1) can easily escape from the internal space 13 through another hole 21 (hole 21b in the example of FIG. 1). Therefore, with the pressure sensor 100, liquid pools or air bubble pools are less likely to remain in the internal space 13, making it possible to suppress insufficient cleaning, damage to the membrane 48, and obstruction of the operation of the membrane 48.

When

holes

21a and 21b are located symmetrically with respect to the center of the lid 20 in a plan view, liquid or gas that enters the internal space 13 through one of

holes

21a and 21b can easily escape through the other of

holes

21a and 21b. Also, in this case, since hole 21 is not formed in the center of the lid 20 in a plan view, the lid 20 can be easily adsorbed and held, improving handling of the lid 20.

If the opening diameter of the hole 21 is small, the flow of liquid through the hole 21 will be slow. Also, if the opening diameter of the hole 21 is small, there is a risk of clogging of the hole 21. On the other hand, if the opening diameter of the hole 21 is large, small particles will easily enter the internal space 13 through the hole 21. Therefore, if the opening diameter of the hole 21 is 20 μm or more and 300 μm or less, it is possible to suppress the intrusion of particles into the internal space 13 while ensuring the flow of liquid through the hole 21 and preventing clogging of the hole 21.

When the internal space 13 is filled with gel material 50 and the semiconductor chip 30 and the MEMS chip 40 are sealed with gel material 50, it is possible to improve the water resistance of the semiconductor chip 30 and the MEMS chip 40.

<First Modification>
Fig. 11 is a plan view of the pressure sensor 100 according to the first modification. As shown in Fig. 11, the number of holes 21 formed in the lid 20 may be, for example, four. The four holes 21 are

holes

21c, 21d, 21e, and 21f.

Holes

21c, 21d, 21e, and 21f are located near the four corners of the lid 20 in a plan view.

Holes

21c and 21f are located symmetrically with respect to the center of the lid 20 in a plan view, and holes 21d and 21e are located symmetrically with respect to the center of the lid 20 in a plan view.

<Second Modification>
Fig. 12 is a plan view of a pressure sensor 100 according to a second modified example. As shown in Fig. 12, the holes 21 may be arranged in a lattice pattern in a plan view.

Second Embodiment
A pressure sensor according to a second embodiment will be described. The pressure sensor according to the second embodiment is designated as pressure sensor 100A. Here, differences from pressure sensor 100 will be mainly described, and overlapping descriptions will not be repeated.

<Configuration of Pressure Sensor 100A>
The configuration of the pressure sensor 100A will be described below.

FIG. 13 is a plan view of pressure sensor 100A. FIG. 14 is a cross-sectional view of pressure sensor 100A. As shown in FIGS. 13 and 14, pressure sensor 100A has a case 10, a lid 20, a semiconductor chip 30, and a MEMS chip 40. Pressure sensor 100A may further have a gel material 50. In these respects, the configuration of pressure sensor 100A is common to the configuration of pressure sensor 100.

In the pressure sensor 100A, the lid 20 does not have a hole 21 formed therein. FIG. 15 is a plan view of the case 10. As shown in FIG. 15, the upper end of the side wall 11 is divided into a plurality of first regions 11d and a plurality of second regions 11e. The second regions 11e are located between two adjacent first regions 11d. The first regions 11d are preferably located at the four corners of the upper end of the side wall 11 in a plan view. In FIG. 13, the joints between the outer peripheral edge of the lid 20 in a plan view and the upper end of the side wall 11 are shown by dotted lines. In the pressure sensor 100A, the outer peripheral edge of the lid 20 in a plan view is joined only to the second region 11e, and not to the first region 11d. In this respect, the configuration of the pressure sensor 100A differs from the configuration of the pressure sensor 100.

<Effects of Pressure Sensor 100A>
The effects of the pressure sensor 100A will be described below.

In pressure sensor 100A, the outer peripheral edge of lid 20 in a plan view is joined only to second region 11e, so there is a gap between each of the first regions 11d and lid 20. Liquid or gas that enters internal space 13 through one of these gaps is discharged through another of these gaps. Therefore, with pressure sensor 100A, liquid pools or air bubbles are less likely to remain in internal space 13, making it possible to suppress insufficient cleaning, damage to membrane 48, and obstruction of membrane 48 operation.

In addition, in the pressure sensor 100A, the number of joints between the outer peripheral edge of the lid 20 in a plan view and the upper end of the side wall 11 is reduced, so the time required for the lid bonding process S6 is reduced.

In the pressure sensor 100, the entire periphery of the side wall 11 is joined to the outer peripheral edge of the lid 20 in a plan view, so there are areas near the upper end of the side wall 11 where liquid is likely to remain. On the other hand, in the pressure sensor 100A, a portion of the upper end of the side wall 11 is not joined to the outer peripheral edge of the lid 20 in a plan view, so there are fewer areas where liquid is likely to remain, as described above.

Third Embodiment
A pressure sensor according to a third embodiment will be described. The pressure sensor according to the third embodiment will be referred to as pressure sensor 100B. Here, differences from pressure sensor 100A will be mainly described, and overlapping descriptions will not be repeated.

<Configuration of pressure sensor 100B>
The configuration of the pressure sensor 100B will be described below.

FIG. 16 is a plan view of pressure sensor 100B. FIG. 17 is a cross-sectional view of pressure sensor 100B. As shown in FIGS. 16 and 17, pressure sensor 100B has a case 10, a lid 20, a semiconductor chip 30, and a MEMS chip 40. Pressure sensor 100B may further have a gel material 50. In pressure sensor 100B, the outer peripheral edge portion of the lid 20 in a plan view is bonded only to the second region 11e. In pressure sensor 100B, no hole 21 is formed in the lid 20. In these respects, the configuration of pressure sensor 100A is common to the configuration of pressure sensor 100.

In pressure sensor 100B, there are multiple notches 22 on the outer peripheral edge of lid 20 in plan view. The internal space 13 is exposed from the notches 22. The internal space 13 exposed from the notches 22 is, for example, triangular (right-angled triangular) in plan view. In the example shown in FIG. 16, there are two notches 22. The two notches 22 are

notches

22a and 22b, respectively. It is preferable that

notches

22a and 22b are located symmetrically with respect to the center of lid 20 in plan view. In these respects, the configuration of pressure sensor 100B differs from the configuration of pressure sensor 100A.

<Effects of Pressure Sensor 100B>
In the pressure sensor 100B, since the internal space 13 is exposed from the notches 22, liquid or gas that has entered the internal space 13 from one of the multiple notches 22 (e.g., notch 22a) is easily discharged from the other notches 22 (e.g., notch 22b). Therefore, according to the pressure sensor 100B, liquid pools or air bubble pools are unlikely to remain in the internal space 13, and it is possible to suppress insufficient cleaning, damage to the membrane 48, obstruction of the operation of the membrane 48, and the like.

When the

notches

22a and 22b are located symmetrically with respect to the center of the lid 20 in a plan view, liquid or gas that enters the internal space 13 through one of the

notches

22a and 22b can easily escape through the other of the

notches

22a and 22b.

<First Modification>
Fig. 18 is a plan view of a pressure sensor 100B according to a first modified example. As shown in Fig. 18, the number of notches 22 in the outer peripheral edge portion of the lid 20 in a plan view may be four. In other words, the number of notches 22 is not particularly limited.

<Second and third modified examples>
Fig. 19A is a plan view of a pressure sensor 100B according to a second modified example. Fig. 19B is a plan view of a pressure sensor 100B according to a third modified example. As shown in Fig. 19A and Fig. 19B, the internal space 13 exposed from the notch 22 does not have to be triangular in plan view. As shown in Fig. 19A, the notch 22 is located at the four corners of the lid 20 in plan view, and the internal space 13 exposed from the notch 22 may be substantially rectangular in plan view. From another perspective, in the pressure sensor 100B, the lid 20 may be cross-shaped in plan view.

As shown in FIG. 19B, the notches 22 may be formed on opposing sides of the outer peripheral edge of the lid 20 in a plan view. In this case, the internal space 13 exposed through the notches 22 has a rectangular shape in a plan view.

(Verification test)
Demonstration experiments carried out on Samples 1 to 4 will be described below.

Sample 1 has a similar configuration to pressure sensor 100, except that there is only one hole 21 (only hole 21a) formed in the lid 20. Sample 2 has a similar configuration to pressure sensor 100B, except that there is only one notch 22 (only notch 22a) on the outer peripheral edge of the lid 20 in a plan view. Sample 3 has a similar configuration to pressure sensor 100B, and sample 4 has a similar configuration to pressure sensor 100B according to the first modified example.

Samples 1 to 4 were immersed in water and then taken out into the air. After that, it was checked with a microscope whether or not a pool of liquid remained in the internal space 13. In Samples 1 and 2, it was confirmed that a pool of liquid remained in the internal space 13 after being taken out into the air. From this, it can be understood that when the lid 20 has only one hole 21 or notch 22, there is a risk that a pool of liquid may remain in the internal space 13.

On the other hand, in Samples 3 and 4, no liquid pools remained in the internal space 13 after they were taken out into the atmosphere. From this, it can be understood that by having multiple notches 22 in the lid 20, it becomes easier for liquid to escape from the internal space 13, and liquid pools are less likely to remain in the internal space 13. Note that, although samples with multiple holes 21 were not used in the demonstration test, given that liquid pools remained in the internal space 13 in Sample 2 while no liquid pools existed in the internal space 13 in Samples 3 and 4, it is believed that samples in which multiple holes 21 are formed in the lid 20 also suppress liquid pools from remaining in the internal space 13.

(Additional Note)
As described above, the embodiments of the present disclosure include the following configurations.

<Appendix 1>
a package outer body having a top wall;
and a MEMS chip.
the MEMS chip has a membrane and is disposed in an internal space of the package exterior body;
The pressure sensor, wherein the upper wall has a plurality of holes formed therein penetrating the upper wall in a thickness direction.

<Appendix 2>
The package exterior further includes a case and a lid,
The case has a side wall and a bottom wall connected to a lower end of the side wall,
an outer peripheral edge portion of the lid in a plan view is joined to an upper end of the side wall;
2. The pressure sensor of claim 1, wherein the lid forms the top wall.

<Appendix 3>
Further comprising a gel material;
3. The pressure sensor according to claim 2, wherein the gel material is filled in the internal space so as to seal the MEMS chip.

<Appendix 4>
A pressure sensor as described in Appendix 2 or Appendix 3, wherein a first hole, which is one of the plurality of holes, is located symmetrically with a second hole, which is another of the plurality of holes, with respect to the center of the lid in a planar view.

<Appendix 5>
4. The pressure sensor according to claim 2, wherein the holes are arranged in a lattice pattern in a plan view.

<Appendix 6>
6. The pressure sensor according to claim 2, wherein the opening diameter of each of the plurality of holes is 20 μm or more and 300 μm or less.

<Appendix 7>
a package exterior having a case and a lid;
and a MEMS chip.
The case has a side wall and a bottom wall connected to a lower end of the side wall,
The upper end of the side wall is divided into a plurality of first regions and a plurality of second regions in a plan view,
each of the first regions is between two adjacent ones of the second regions;
an outer peripheral edge portion of the lid in a plan view is joined only to the second regions;
The MEMS chip has a membrane and is disposed in the internal space of the package exterior body, forming a pressure sensor.

<Appendix 8>
Further comprising a gel material;
8. The pressure sensor of claim 7, wherein the gel material is filled in the internal space so as to seal the MEMS chip.

<Appendix 9>
The outer periphery has a plurality of notches,
9. The pressure sensor according to claim 7 or 8, wherein the internal space is exposed from each of the plurality of cutouts.

<Appendix 10>
A pressure sensor as described in Appendix 9, wherein a first notch, one of the plurality of notches, is located symmetrically with respect to a center of the lid in a planar view relative to a second notch, another of the plurality of notches.

Although the embodiments of the present disclosure have been described above, the above-described embodiments can be modified in various ways. Furthermore, the scope of the present invention is not limited to the above-described embodiments. The scope of the present invention is indicated by the claims, and is intended to include all modifications that are equivalent in meaning and scope to the claims.

100, 100A, 100B pressure sensor, 10 case, 11 side wall, 11a metal layer, 11b step portion, 11c internal connection pad, 11d first region, 11e second region, 12 bottom wall, 12a external connection pad, 12b internal connection pad, 13 internal space, 20 lid, 21 hole, 21a, 21b, 21c, 21d, 21e, 21f hole, 22 notch, 22a, 22b notch, 30 semiconductor chip, 30a first surface, 30b second surface, 31 bump, 32 adhesive member, 40 MEMS chip, 4 1 silicon substrate, 41a first surface, 41b second surface, 42 first silicon layer, 42a cavity, 43 silicon oxide layer, 44 second silicon layer, 44a resistor, 44b wiring, 45 glass substrate, 46 interlayer insulating film, 47 wiring, 47a bonding pad, 48 membrane, 49 bonding wire, 50 gel material, 60 electrode, S1 preparation step, S2 first chip mounting step, S3 second chip mounting step, S4 wire bonding step, S5 gel filling step, S6 lid bonding step.

Claims

a package outer body having a top wall;
and a MEMS chip.
the MEMS chip has a membrane and is disposed in an internal space of the package exterior body;
The upper wall has a plurality of holes formed therein, the holes penetrating the upper wall in a thickness direction.
The package exterior further includes a case and a lid,
The case has a side wall and a bottom wall connected to a lower end of the side wall,
an outer peripheral edge portion of the lid in a plan view is joined to an upper end of the side wall;
The pressure sensor of claim 1 , wherein the lid defines the top wall.
Further comprising a gel material;
The pressure sensor according to claim 2 , wherein the gel material is filled in the internal space so as to seal the MEMS chip.
The pressure sensor according to claim 2 or 3, wherein a first hole, which is one of the plurality of holes, is located symmetrically with a second hole, which is another of the plurality of holes, with respect to the center of the lid in a plan view.
The pressure sensor according to claim 2 or claim 3, wherein the holes are arranged in a lattice pattern in a plan view.
The pressure sensor according to any one of claims 2 to 5, wherein the opening diameter of each of the plurality of holes is 20 μm or more and 300 μm or less.
a package exterior having a case and a lid;
and a MEMS chip.
The case has a side wall and a bottom wall connected to a lower end of the side wall,
The upper end of the side wall is divided into a plurality of first regions and a plurality of second regions in a plan view,
each of the first regions is between two adjacent ones of the second regions;
an outer peripheral edge portion of the lid in a plan view is joined only to the second regions;
The MEMS chip has a membrane and is disposed in the internal space of the package exterior body, forming a pressure sensor.
Further comprising a gel material;
The pressure sensor according to claim 7 , wherein the gel material is filled in the internal space so as to seal the MEMS chip.
The outer periphery has a plurality of notches,
The pressure sensor according to claim 7 or 8, wherein the internal space is exposed from each of the plurality of cutouts.
The pressure sensor according to claim 9, wherein a first notch, which is one of the plurality of notches, is located symmetrically with respect to a center of the lid in a plan view with respect to a second notch, which is another of the plurality of notches.