JP2023038631A - Sensor having dust/noise resistant structure - Google Patents

Abstract

To provide a sensor (e.g., a pressure sensor) having a dust- and noise-resistant structure and high workability of a lead.SOLUTION: A sensor includes a sensor element, a housing that houses the sensor element, a lead frame that is connected to external wiring, a cover plate that together with the lead frame forms a space surrounding the sensor element, and a port cover that has an outside air inlet hole and is arranged to cover the cover plate in a non-contact manner. In the sensor, the cover plate is fixed to the housing or port cover at multiple points, and only one of the multiple points is electrically connected to the lead frame through a connection with a conductive material to maintain a predetermined potential.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sensor having a dust/noise resistant structure.

2. Description of the Related Art Conventionally, as a pressure sensor, there is known a method of detecting pressure by converting strain detected by a pressure-sensitive element such as a diaphragm into an electric signal using a piezoresistor or the like. Also, there is known a structure in which the pressure sensing unit of such a method is packaged and the pressure sensing element is exposed to the outside air (the gas to be measured or the outside air for obtaining the atmospheric pressure) through an outside air introduction hole provided in the package. (See Patent Documents 1 and 2, for example). A structure is also known in which such a pressure sensing unit is liquid-sealed with silicone oil or the like that also serves as a pressure transmission medium (see, for example, Patent Document 3).

JP 2018-185214 A U.S. Patent No. 10654709 Japanese Patent No. 6820247

By the way, according to the pressure sensors disclosed in Patent Documents 1 and 2, since the pressure-sensitive element is exposed to the outside air introduced from the outside air introduction hole, dust or noise contained in the outside air causes the pressure sensing element to be exposed. The structure is susceptible to adverse effects. In addition, since the leads of the pressure sensor are provided with steps, it is desirable that the leads have high workability. In the case of fixing, if there are many fixing points, the workability of the lead may deteriorate.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems described above, and its ultimate object is to provide a sensor having a dust-resistant/noise-resistant structure and having high workability of leads.

a sensor element;
a housing having a recess for accommodating the sensor element in the recess;
a lead frame connectable to external wiring and to which electrodes of the sensor element are connected;
a cover plate arranged to face the bottom surface of the recess;
a port cover having an outside air introduction hole and arranged to cover the cover plate;
The cover plate is fixed to the housing or the port cover at a plurality of locations, and at least one of the plurality of locations is electrically connected to the lead frame to maintain a predetermined potential. It is a sensor that

By providing at least one or more points where the cover plate is electrically connected to the lead frame in the present invention, the potential of the cover plate can be maintained at the potential of a specific lead frame, and the lead frame can be processed. can improve sexuality. The smaller the number of connection points on the lead frame, the easier it is to deform the lead frame, so that workability can be improved.

Further, in the present invention, the lead frame has a flat portion on which the sensor element is placed on the bottom surface of the recess of the housing, and the cover plate is arranged to face the flat portion. and a space surrounding the sensor element is formed together with the planar portion. According to this, the gas introduced into the inside of the sensor from the outside air introduction hole does not blow directly onto the surface of the sensor element, and moves inside the package by an air flow bypassing the cover plate, so that the adverse effects of dust can be reduced. can. In addition, it is possible to reduce the adverse effects of noise from the outside.

Further, in the present invention, the at least one portion of the cover plate is electrically connected to the lead frame via a connection portion having a through hole filled with a conductive material, It may be a sensor. According to this, the cover plate can be more stably connected to the lead frame. Moreover, since the cover plate can be fixed at an appropriate position on the housing, the degree of freedom in design can be increased.

Further, in the present invention, the sensor may be characterized in that at least a part of the cover plate is made of metal, and is arranged at a position higher than the surface of the sensor element and the lead frame. . According to this, the cover plate is electrically conductive. Furthermore, since metal materials have good thermal conductivity, even if the sensor is exposed to sudden temperature changes and condensation occurs, the condensation will form on the cover plate instead of on the sensor element. The sensor element can be protected. In addition, since the cover plate is arranged at a position higher than the surfaces of the sensor element and the lead frame, for example, when the sensor element and the lead frame are connected to the signal processing element by wires, the wires are not in contact with the cover plate. The risk of shorting can be reduced.

Further, in the present invention, the lead frame has inner leads, which are portions formed inside the housing in plan view, and outer leads, which are portions formed outside the housing in plan view. The sensor may be characterized in that the connecting portion is positioned on a line connecting the inner lead and the outer lead in plan view. According to this, the cover plate and the lead frame can be reliably connected in a shorter distance. Moreover, the structure can be simplified, and the reliability can be enhanced.

Further, in the present invention, the sensor may be characterized in that the height of the cover plate can be adjusted by adjusting the depth of the through hole of the connecting portion with respect to the surface of the inner lead. By adjusting the height of the cover plate, for example, it is possible to adjust the volume of the channel of the gas introduced from the outside air introduction hole.

Further, in the present invention, the sensor may be characterized in that the connecting portion is arranged on the lead frame for either GND or VDD. According to this, the sensor in the present invention is maintained at a predetermined potential as described above.

Further, in the present invention, the sensor may be characterized in that the portion other than the connecting portion is fixed to the housing above the lead frame via an insulating fixing portion. According to this, since the fixed part has insulating properties, it is possible to reduce the risk of short-circuiting in the fixed part.

Further, in the present invention, the fixing portion is a bottomed or bottomless hole filled with an insulating material, or a bottomed hole filled with a conductive material. good too. If the fixing portion is a hole with a bottom, the cover plate is not connected to the lead frame through the fixing portion, so there is no risk of short circuit even if the cover plate is filled with a conductive material. Therefore, the fixed portion may be filled with either an insulating material or a conductive material, which increases material selectivity. If the fixing portion is a bottomless hole, it can be formed more easily than a bottomed hole.

Further, in the present invention, the sensor may be characterized in that the cover plate is integrally formed with the port cover in such a manner that there is a flow path from the outside air introduction hole to the inside of the housing. . According to this, the metal cover can be fixed to the housing only by attaching the port cover to the housing. Moreover, it is possible to secure a flow path from the outside world to the sensor element by detouring the metal plate.

Further, in the present invention, the sensor may be characterized in that the cover plate is made of a multi-layer substrate. According to this, for example, by using a conductive layer as an intermediate layer, it is possible to suppress the occurrence of contamination and a short circuit due to exposure of the conductive layer to the outside air and adhesion of foreign matter from the outside air. .

The means for solving the above problems can be used in combination with each other as much as possible.

According to the present invention, it is possible to provide a sensor having a dust-resistant/noise-resistant structure and having high workability of leads. Further, in the sensor, it is possible to reduce the size of the sensor by reducing the number of locations where the cover plate is adhered to the leads.

1A is a top view showing the appearance of a pressure sensor according to Example 1 of the present invention. FIG. 1B is a first schematic cross-sectional view showing the internal structure of the pressure sensor according to the first embodiment; FIG. 1C is a second schematic cross-sectional view showing the internal structure of the pressure sensor according to the first embodiment; FIG. FIG. 2 is an explanatory diagram showing the flow of gas introduced into the pressure sensor according to the first embodiment. 3A and 3B are explanatory diagrams showing an enlarged part of the configuration shown in FIG. 1C. FIG. 4 is a transparent top view showing the internal structure of the pressure sensor according to Example 1 of the present invention. FIG. 5A is a first diagram illustrating the flow of manufacturing the pressure sensor according to Example 1 of the present invention. FIG. 5B is a second diagram illustrating the flow of manufacturing the pressure sensor according to Example 1 of the present invention. FIG. 5C is a third diagram illustrating the flow of manufacturing the pressure sensor according to Example 1 of the present invention; FIG. 5D is a fourth diagram illustrating the flow of manufacturing the pressure sensor according to Example 1 of the present invention. FIG. 5E is a fifth diagram illustrating the flow of manufacturing the pressure sensor according to the first embodiment of the present invention; 6A and 6B are transparent top views showing the internal structure of a pressure sensor according to Example 2 of the present invention. 7A is a schematic cross-sectional view showing the internal structure of a pressure sensor according to Example 3 of the present invention. FIG. FIG. 7B is an explanatory diagram showing an enlarged part of the configuration shown in FIG. 7A. 8A is a top view showing the outermost layer of the cover plate according to Example 4 of the present invention. FIG. 8B is a top view and a transparent top view showing the outermost layer and the intermediate layer of the cover plate according to Example 4. FIG. FIG. 9A is a transparent top view showing the appearance of a pressure sensor according to Example 5 of the present invention. 9B is a side view showing a cover plate integrally molded with the port cover portion according to the fifth embodiment; FIG. 9C is a schematic cross-sectional view showing the internal structure of a pressure sensor according to Example 5 of the present invention. FIG.

[Example of application]
An outline of an application example of the present invention will be described below with reference to some of the drawings. The present invention can be applied to pressure sensors as shown in FIGS. 1A, 1B and 1C. FIG. 1A is a top view showing the appearance of a pressure sensor 1 according to an application example. FIG. 1B is a schematic sectional view showing the AA section of the pressure sensor 1 shown in FIG. 1A. FIG. 1C is a schematic sectional view showing the BB section of the pressure sensor 1 shown in FIG. 1A. In FIG. 1A, the portion of the outer lead 33a of the lead 33, which is the connection terminal with the external wiring, is omitted.

As shown in FIGS. 1A, 1B, and 1C, the pressure sensor 1 includes a MEMS (Micro Electro Mechanical Systems) sensor chip 10 and a wire 71 between the MEMS sensor chip 10 and the MEMS sensor chip 10 in a package including a case portion 30 and a port cover portion 40. ASIC (Application Specific Integrated Circuit) 20 to be connected is accommodated. The ASIC 20 is not essential for the pressure sensor 1, and may include only the MEMS sensor chip 10 if it is desired to reduce the size of the sensor or reduce the cost. The ASIC 20 includes a power supply circuit, a signal adjustment circuit, an analog-to-digital conversion circuit, and the like. superior in terms of Here, the MEMS sensor chip 10 and the case portion 30 in this application example correspond to the sensor element and housing in the present invention, respectively.

The MEMS sensor chip 10 includes a pressure reference chamber 11, a diaphragm 12, and a plurality of piezoresistive elements 13 provided along the periphery of the diaphragm 12 (not shown in FIGS. 1A, 1B, and 1C). The piezoresistive element 13 is one type of sensor capable of generating an electrical signal corresponding to the deformation of the diaphragm 12 due to the difference between the pressure inside the pressure reference chamber 11 and the external pressure. In this application example, four piezoresistive elements 13 are provided at regular intervals along the periphery of the diaphragm 12 . Note that the MEMS sensor chip 10 is not limited to this, and may be configured to include an arbitrary number of piezoresistive elements 13 according to the required accuracy.

The pressure reference chamber 11 communicates with a reference pressure introduction hole 31 provided in the case portion 30 , and external air having a reference pressure is introduced from the reference pressure introduction hole 31 . On the other hand, a gas whose pressure is to be measured is introduced into the package through a pressure guide hole 41 provided in the port cover portion 40 . That is, the pressure sensor 1 according to this application example is a differential pressure sensor that uses the outside air introduced from the reference pressure introduction hole 31 as a reference pressure. Here, the pressure guide hole 41 in this application example corresponds to the outside air introduction hole in the present invention.

Here, as shown in FIGS. 1B and 1C, the pressure guide hole 41 and the surface of the MEMS sensor chip 10 (that is, the side where the piezoresistive element 13 is provided) are arranged in a facing positional relationship. A cover plate 50 is provided at a position to block both. In addition, in FIG. 1C , portions surrounded by dotted lines (a) and (b) include locations where the cover plate 50 is fixed to the case portion 30 . Details will be described below with reference to FIGS. 3A and 3B. Here, the cover plate 50 is a plate-like member made of, for example, a conductive metal material. The cover plate 50 is configured to cover the entire MEMS sensor chip 10 and ASIC 20. However, as long as the area including the piezoresistive element 13 on the surface of the MEMS sensor chip 10 can be covered, it is necessary to do so. no. For example, a configuration in which the ASIC 20 is not covered is also possible.

As described above, since the pressure sensor 1 according to this application example includes the cover plate 50, the gas introduced into the pressure sensor 1 from the pressure guide hole 41 is directly blown onto the surfaces of the MEMS sensor chip 10 and the ASIC 20. The air flow bypasses the cover plate 50 to move inside the package. In FIG. 2, white arrows indicate the flow of the gas introduced from the pressure guide hole 41 . The gas flowing from the pressure guide hole 41 passes through the narrow space between the cover plate 50 and the port cover portion 40, then passes between the side surface of the cover plate 50 and the side wall of the case portion 30, and reaches the MEMS sensor chip 10 and the ASIC 20. . By detouring and passing through a narrow space, the possibility of dust contained in the gas adhering to the MEMS sensor chip 10 is reduced. Also, by providing the cover plate 50, it is possible to reduce the adverse effects of external noise.

As described above, according to the pressure sensor 1 according to this application example, even when the pressure guide hole 41 and the surface of the MEMS sensor chip 10 are arranged in a facing positional relationship, adverse effects of dust and noise are prevented. can be suppressed. That is, by providing the cover plate 50, regardless of the position of the pressure guide hole 41, the flow path is detoured by the cover plate 50, so that the arrangement of the pressure guide hole 41 is not adversely affected by dust and noise. It becomes possible to freely lay out without thinking. Further, by forming the cover plate 50 from a metal material, even if the pressure sensor 1 is exposed to sudden temperature changes and dew condensation occurs, the dew condensation does not occur on the MEMS sensor chip 10 but on the cover plate 50 . Therefore, the MEMS sensor chip 10 can be protected from condensation. This is because the metal material has good thermal conductivity, and dew condensation occurs earlier than the case portion 30 made of resin.

FIG. 3A is an explanatory diagram showing an enlarged portion surrounded by a dotted line (a) shown in FIG. 1C. One end of the cover plate 50 shown in FIG. 3A is fixed to the case portion 30 by a fixing portion 63a. The hole of the fixing portion 63 a is formed on the case portion 30 , but has a bottom and does not penetrate to the lead 33 . That is, one end of cover plate 50 shown in FIG. 3A is not electrically connected to lead 33 . As shown in FIGS. 3A and 3B, the depth of the hole of the fixing portion 63a is shallower than the depth of the hole of the connecting portion 64 in a side view. On the other hand, FIG. 3B is an explanatory diagram showing an enlarged portion surrounded by a dotted line (b) shown in FIG. 1C. The other end of the cover plate 50 shown in FIG. 3B is fixed to the case portion 30 by a connecting portion 64 . The hole of the connecting portion 64 is bottomless and penetrates from the top of the case portion 30 to the lead 33 . Also, since the connecting portion 64 has a conductive material, the other end of the cover plate 50 shown in FIG. 3B is electrically connected to the lead 33 . The portion where the cover plate 50 is electrically connected to the lead 33 is only one connection portion 64 .

The lead 33 electrically connected to the other end of the cover plate 50 shown in FIG. 3B is also grounded to GND or VDD. In the present invention, the state in which the predetermined potential is maintained means that the cover plate 50 can be positioned at any position (the arrangement of the other end of the cover plate 50 shown in FIG. not limited), it is grounded to GND or VDD through connection 64 and lead 33. FIG.

[Example 1]
Hereinafter, the pressure sensor 1 according to Example 1 of the present invention will be described in more detail with reference to the drawings (including the drawings once described in the application example above). In addition, the pressure sensor according to the present invention is not intended to be limited to the following configuration. Further, in each of the embodiments below, a pressure sensor is illustrated as an example of the sensor, but the sensor is not limited to this, and other types of sensors may be used.

<Structure of pressure sensor>
Now, let us return to the description of FIG. As shown in FIGS. 1A, 1B, and 1C, the pressure sensor 1 according to the first embodiment has a configuration in which a MEMS sensor chip 10 and an ASIC 20 are accommodated in a rectangular package including a case portion 30 and a port cover portion 40. It's becoming That is, since it has the same configuration as the pressure sensor 1 described in the application example, detailed description of the contents described in the application example will be omitted. Also, in this specification, the same components are described using the same reference numerals.

1B and 1C, the MEMS sensor chip 10 and the ASIC 20 are fixed and mounted on the lead plane 32 on the bottom surface of the recess of the case portion 30 by the die bonding resin 60 in side view. The MEMS sensor chip 10 and ASIC 20 are housed in the space surrounded by the cover plate 50 together with the lead plane 32 fixed by the die bond resin 60 . Here, the lead plane 32 in this embodiment corresponds to the plane portion in the present invention.

Further, as shown in FIG. 1B, the port cover portion 40 is fixed to the case portion 30 with a cover bond resin 62 and arranged so as to cover the cover plate 50 .

FIG. 4 is a transparent top view showing the internal structure of the pressure sensor 1 according to Example 1 of the present invention. Specifically, it is a top view of the pressure sensor 1 in a state in which the port cover portion 40 and the cover plate 50 are transparent. The MEMS sensor chip 10 has a plurality of piezoresistive elements 13 and a plurality of electrode pads 14 provided along the periphery of the diaphragm 12 on the surface side. The ASIC 20 also has a plurality of electrode pads 21 on its surface side, and the electrode pads 14 of the MEMS sensor chip 10 and part of the electrode pads 21 of the ASIC 20 are connected by conductive wires 71 .

4, the leads 33 are composed of an outer lead 33a protruding outside the case portion 30 in a plan view (more specifically, an outer lead 33a positioned outside the cover bond resin 62 in a plan view), and an outer lead 33a protruding outside the case portion 30 in a plan view. (more specifically, the inner lead 33b positioned inside the cover bond resin 62 in plan view). The electrode pads 21 of the ASIC 20 are connected by wires 71 to inner leads 33b that serve as connection terminals for external wiring, and lead planes 32 that also serve as die pads and inner leads 33b. The cover plate 50 is arranged at a position higher than the surface where the electrode pads 21 are connected to the inner leads 33b and the lead plane 32 by the wires 71 (more specifically, the cover plate 50 is the MEMS sensor chip 10 and the ASIC 20). (placed higher than the surface of the The wire 71 and each electrode are connected by wire bonding. Here, the lead plane 32 and leads 33 in this embodiment correspond to the lead frame in the present invention. Note that the lead plane 32 and the leads 33 do not necessarily have to be used as long as they are configured to be connectable to external wiring.

3, the cover plate 50 is fixed to the case portion 30 at two points, the fixing portion 63a and the connecting portion 64. As shown in FIG. Furthermore, as shown in FIG. 3, the portion where the cover plate 50 is electrically connected to the lead 33 is only one connection portion 64 . Since the cover plate 50 is fixed to the case portion 30 at the fixing portion 63a and the connecting portion 64, the size of the pressure sensor 1 can be reduced while maintaining a certain degree of fixing strength. In addition, since the portion where the cover plate 50 is electrically connected to the lead 33 is only one connection portion 64, the workability of the lead 33 is improved, and for example, the lead 33 can be easily provided with a step. Become. Furthermore, the cover plate 50 can be connected only to the GND or VDD of the MEMS sensor chip 10 to prevent short circuits with electrodes of other potentials. Furthermore, the potential of the cover plate 50 can be set to GND or VDD, and the shielding effect of the MEMS sensor chip 10 and the ASIC 20 can be enhanced to enhance noise immunity. In addition, the fixing portion 63a and the connection portion 64 are both on a line connecting the outer lead 33a and the inner lead 33b in a plan view (strictly speaking, the connection portion 64 also serves as the outer lead 33a, the die pad, and the inner lead 33b in a plan view). on the line connecting the lead planes 32).

<Manufacturing Flow of Pressure Sensor>
The flow of manufacturing the pressure sensor 1 according to this embodiment will be described below with reference to FIGS. 5A to 5E. FIG. 5A is a schematic cross-sectional view showing a state in which the lead plane 32, the leads 33, and the case portion 30 having the reference pressure introduction hole 31 are coupled in the manufacturing flow of the pressure sensor 1. FIG. The die bonding resin 60 is used to mount (die bond) the MEMS sensor chip 10 and the ASIC 20 on the lead plane 32 in such a state. Then, wire bonding is performed using a wire 71 to connect them (FIG. 5B).

After that, the cover plate 50 is fixed to the case portion 30 by the fixing portion 63a and the connecting portion 64 (FIG. 5C). Further, a cover bond resin 62 is applied near the upper end of the case portion 30 (FIG. 5D), and the port cover portion 40 having the pressure guide hole 41 is joined to the case portion 30 by the cover bond resin 62, and the package is sealed. (Fig. 5E). Note that the cover bond resin 62 must completely seal the port cover portion 40 and the case portion 30 in order to prevent gas leakage. Then, by singulating the lead plane 32 and the leads 33, one pressure sensor chip is completed.

[Example 2]
Next, a pressure sensor 2 according to Example 2 of the present invention will be described with reference to FIGS. 6A and 6B. Since the pressure sensor 2 has many configurations in common with the pressure sensor 1 of the first embodiment, such configurations are denoted by the same reference numerals and will not be described again. Also, the configuration shown for the pressure sensor 2 can be applied to the pressure sensor 1 of the first embodiment.

<Structure of pressure sensor>
6A and 6B are transparent top views showing the internal structure of the pressure sensor 2 according to Example 2 of the present invention. The number of holes in the fixing portion 63a in the pressure sensor 2 shown in FIG. 6A is larger than the number of holes in the fixing portion 63a in the pressure sensor 1 shown in FIG. The fixed portion 63a of is referred to as an "island-shaped fixed portion"). Further, the area of the hole portion of the fixing portion 63b in the pressure sensor 2 shown in FIG. 6B is larger than the area of the hole portion of the fixing portion 63a in the pressure sensor 1 shown in FIG. All shown fixing portions 63b are referred to as “linear fixing portions”). In FIG. 6B, the connecting portion 64 is formed on the linear fixed portion.

Both the area of the opening of the hole of the island-shaped fixing part and the area of the opening of the hole of the linear fixing part are larger than the area of the opening of the fixing part 63a shown in FIG. That is, in the pressure sensor 2 according to the second embodiment, the fixing strength of the cover plate 50 to the case portion 30 is higher than that of the pressure sensor 1 according to the first embodiment.

Comparing FIG. 6A and FIG. 6B, the area of the opening of the hole of the island-shaped fixing part is smaller than the area of the opening of the hole of the linear fixing part. That is, in the manufacture of the pressure sensor 2, when priority is given to reducing the cost required for fixing the cover plate 50 to the case portion 30, it is desirable to adopt the island-shaped fixing portion. If priority is given to increasing the fixing strength, it is desirable to employ a linear fixing portion.

[Example 3]
Next, a pressure sensor 3 according to Example 3 of the present invention will be described with reference to FIGS. 7A and 7B. Since the pressure sensor 3 has many configurations in common with the pressure sensor 1 of the first embodiment, such configurations are denoted by the same reference numerals and will not be described again. Also, the configuration shown for the pressure sensor 3 can be applied to the pressure sensors 1 and 2 of the first and second embodiments.

<Structure of pressure sensor>
FIG. 7A is a schematic cross-sectional view showing the internal structure of the pressure sensor 3 according to Example 3 of the present invention. The point that the cover plate 50 is electrically connected to the lead 33 through only one connecting portion 64 is the same as the pressure sensor 1 of the first embodiment and the pressure sensor 2 of the second embodiment. FIG. 7B is an explanatory diagram showing an enlarged portion surrounded by a dotted line (c) shown in FIG. 7A. The cover plate 50 is fixed to the case portion 30 by the fixing portion 63 c , and the hole portion of the fixing portion 63 c is bottomless and penetrates from the top of the case portion 30 to the lead 33 . As a result, compared to the fixing portion 63a in the pressure sensor 1 of the first embodiment, the fixing strength can be increased. In order to electrically connect the cover plate 50 to the lead 33 through the fixing portion 63c and prevent the pressure sensor 3 from being damaged due to a short failure, the fixing portion 63c must have an insulating material. .

[Example 4]
Next, a cover plate 50a according to Embodiment 4 of the present invention will be described with reference to FIGS. 8A and 8B. The cover plate 50a can be applied to the pressure sensors 1, 2, and 3 of Examples 1 to 3 (that is, it can be used instead of the cover plate 50).

<Structure of cover plate>
FIG. 8A is a top view showing the outermost layer of a cover plate 50a according to Example 4 of the present invention. In Embodiment 1, the cover plate 50 is a plate-shaped member made of a conductive metal material, but the entire surface need not be made of a conductive metal material, as shown in FIG. 8A. , the cover plate 50 a may include the insulating film 52 as long as the conductive film 51 is electrically connected to the connection portion 64 . FIG. 8B is a top view and a transparent top view showing the outermost layer and the intermediate layer of the cover plate 50a according to the fourth embodiment. The upper diagram in FIG. 8B shows the outermost layer formed only from the insulating film 52 excluding the connecting portion 64, and the lower diagram in FIG. It is an intermediate layer formed from the insulating film 52 including the portion where the insulating film 52 is formed. FIG. 8B shows a cover plate 50a as a printed circuit board. Either the cover plate 50a shown in FIG. 8A or the cover plate 50a shown in FIG. 8B may be applied to the pressure sensors 1, 2, and 3 shown in the first to third embodiments.

[Example 5]
Next, a pressure sensor 4 according to Example 5 of the present invention will be described with reference to FIGS. 9A, 9B, and 9C. Since the pressure sensor 4 has many configurations in common with the pressure sensor 1 of the first embodiment, such configurations are denoted by the same reference numerals and will not be described again. Also, the configuration shown for the pressure sensor 4 can be applied to the pressure sensors 1, 2, and 3 of the first to third embodiments. Also, the cover plate 50 a of the fourth embodiment can be applied to the pressure sensor 4 .

<Structure of pressure sensor>
FIG. 9A is a transparent top view showing the appearance of the pressure sensor 4 according to Example 5 of the present invention. As shown in FIG. 9A, the area of the cover plate 50b in plan view is smaller than the area of the port cover portion 40a (in FIG. 9A, the port cover portion 40a covers the cover plate 50b). 9B is a side view of the port cover portion 40a and the cover plate 50b of the pressure sensor 4 shown in FIG. 9A. As shown in FIG. 9B, the cover plate 50b is integrally molded with the port cover portion 40a. As viewed from the side, the cover plate 50b is tightly fixed on the right side of the port cover portion 40a in FIG. 9B, and a space is generated between the port cover portion 40a and the cover plate 50b on the left side of the port cover portion 40a. . Conversely, the cover plate 50b may be tightly fixed on the left side of the port cover portion 40a, and a space may be created between the port cover portion 40a and the cover plate 50b on the right side of the port cover portion 40a. FIG. 9C is a schematic sectional view showing the CC section of the pressure sensor 4 shown in FIG. 9A. The gas flowing from the pressure guide hole 41a passes through the narrow space between the cover plate 50b and the port cover portion 40a, but the narrow space is formed only on the left side in FIG. 9C (or FIG. 9B). Therefore, the inflowing gas tends to flow around the cover plate 50b in one direction without branching and bypassing the cover plate 50b in two directions.

In the manufacturing flow of the pressure sensor 4, by integrally molding the port cover portion 40a with the cover plate 50b, the port cover portion 40a can be formed without fixing the cover plate 50b to the case portion 30 by the fixing portions 63a, 63b, and 63c. Sufficient fixing strength can be obtained by fixing to the case portion 30 with the cover bond resin 62 . Moreover, it is also possible to reduce the number of mounting man-hours.

<Appendix 1>
a sensor element (10);
a housing (30) having a recess for accommodating the sensor element in the recess;
lead frames (32, 33) connectable to external wiring and to which the electrodes of the sensor element are connected;
a cover plate (50, 50a, 50b) arranged to face the bottom surface of the recess;
a port cover (40, 40a) having an outside air introduction hole (41, 41a) and arranged to cover the cover plate;
The cover plate is fixed to the housing or the port cover at a plurality of locations (63a, 63b, 63c, 64), and one of the plurality of locations is electrically connected to the lead frame so as to be at a predetermined potential. A sensor, characterized in that it is maintained.

1, 2, 3, 4: pressure sensor 10: MEMS sensor chip 11: pressure reference chamber 12: diaphragm 13: piezoresistive element 14, 21: electrode pad 20: ASIC
30: Case part 31: Reference pressure introduction hole 32: Lead plane 33: Lead 33a: Outer lead 33b: Inner lead 40, 40a: Port cover part 41, 41a: Pressure introduction hole 50, 50a, 50b: Cover plate 51: Conductive Film 52 : Insulating film 60 : Die bond resin 62 : Cover bond resin 63a, 63b, 63c : Fixed part 64 : Connection part 71 : Wire

Claims (11)

a sensor element;
a housing having a recess for accommodating the sensor element in the recess;
a lead frame connectable to external wiring and to which electrodes of the sensor element are connected;
a cover plate arranged to face the bottom surface of the recess;
a port cover having an outside air introduction hole and arranged to cover the cover plate;
The cover plate is fixed to the housing or the port cover at a plurality of locations, and at least one of the plurality of locations is electrically connected to the lead frame to maintain a predetermined potential. Yes, sensor. The lead frame has a flat portion on which the sensor element is placed on the bottom surface of the recess of the housing,
2. The sensor according to claim 1, wherein the cover plate is arranged to face the flat portion and forms a space surrounding the sensor element together with the flat portion. 3. The lead frame according to claim 1, wherein said at least one portion of said cover plate is electrically connected to said lead frame through a connecting portion having a through hole filled with a conductive material. sensor. 4. The cover plate according to any one of claims 1 to 3, characterized in that the cover plate is at least partly made of metal and is arranged at a position higher than the surface of the sensor element and the lead frame. Described sensor. The lead frame has an inner lead that is a portion formed inside the housing in a plan view and an outer lead that is a portion formed outside the housing in a plan view, and the connection portion comprises: 4. The sensor according to claim 3, wherein the sensor is positioned on a line connecting the inner lead and the outer lead in plan view. 6. The sensor according to claim 5, wherein the height of the cover plate can be adjusted by adjusting the depth of the through hole of the connecting portion with respect to the surface of the inner lead. 7. A sensor according to claim 5 or 6, characterized in that the connection is arranged on the lead frame for either GND or VDD. 8. The lead frame according to any one of claims 1 to 7, wherein portions other than the connecting portion are fixed to the housing at an upper portion of the lead frame via an insulating fixing portion. sensor. 9. The sensor according to claim 8, wherein the fixed part comprises a bottomed or bottomless hole filled with an insulating material, or a bottomed hole filled with a conductive material. 10. The apparatus according to any one of claims 1 to 9, wherein the cover plate is integrally formed with the port cover in such a manner that there is a flow path from the outside air introduction hole to the inside of the housing. Described sensor. 11. The sensor according to any one of claims 1 to 10, characterized in that the cover plate consists of a multi-layer substrate.

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