JP2010107215A - Pressure sensor, pressure sensor package and method for manufacturing the same, pressure sensor module, and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gauge pressure type pressure sensor, being hardly influenced by external factors, capable of being stably operated. <P>SOLUTION: A pressure sensor 1A includes: a base body 13 formed by laminating a first substrate 11 and a second substrate 12; a first cavity 14 expanding substantially in parallel with the second substrate by disposing a first recess 14a at the central area α of the first substrate in the overlapped area of the base body; a diaphragm 16, positioned at the upper portion of the first cavity, composed of the thinned area of the second substrate; a pressure-sensitive element 17 arranged at the diaphragm 16; and a conductive part 18 arranged at the outer periphery area β except the diaphragm in one surface of the base body composed of the outer surface of the second substrate and electrically connected with the pressure-sensitive element. In the overlapped area inside the base body, a second recess 15a whose one end is communicated with the first cavity and the other end forms an opening part at the side surface of the first substrate is arranged at least at a part of the outer periphery area β of the first substrate in the overlapped area inside the base body, so that a second cavity 15 being substantially in parallel with the second substrate is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pressure sensor, a pressure sensor package and a manufacturing method thereof, and a pressure sensor module and an electronic component, and more specifically, a gauge pressure type semiconductor pressure sensor, a miniaturized pressure sensor package and a manufacturing method thereof, And a pressure sensor module and an electronic component.

In recent years, small pressure sensors that make full use of MEMS (Micro Electro-Mechanical Systems) technology have been developed (see, for example, Transducers '03 Proceedings, p. 246).
The structure of a conventional absolute pressure sensor 111 is shown in FIG. The pressure sensor 111 is located on one surface of the semiconductor substrate 112 made of silicon or the like, a space 113 serving as a reference pressure chamber that extends substantially in parallel with the surface of the semiconductor substrate 112 and the one side of the space 113. Diaphragm portion 114 composed of a thinned region, a plurality of strain gauges 115 as pressure-sensitive elements arranged to measure a change in strain resistance of diaphragm portion 114 due to pressure, and the diaphragm portion on one surface An electrode 116 and the like are provided in the outer edge area excluding 114 and electrically connected to each strain gauge 115.

  In such a pressure sensor 111, when the diaphragm portion 114 is bent under pressure, a stress corresponding to the strain amount of the diaphragm portion 114 is generated in each strain gauge 115, and the resistance value of the strain gauge 115 is corresponding to the stress. Change. By taking out this resistance value change as an electrical signal, the pressure sensor 111 detects the pressure.

  However, since the pressure sensor described above has a reference pressure chamber in the substrate and essentially functions as an absolute pressure sensor, it is necessary to measure and correct the external pressure when measuring the gauge pressure. Have difficulty. Therefore, by providing a structure as shown in FIG. 10, that is, a hole communicating with the outside of the semiconductor substrate, a space that is a pressure reference chamber is opened to the outside, and a small size capable of measuring a differential pressure from the external pressure at a time. A differential pressure type pressure sensor has been proposed. (For example, see Patent Document 1)

FIG. 10 is a schematic cross-sectional view (a) and a schematic plan view (b) showing an example of a differential pressure sensor that measures a differential pressure with reference to an external pressure. FIG. The cross section along the AA line shown in FIG.10 (b) is represented. FIG. 10B shows a surface provided with a diaphragm portion.
As shown in FIG. 10, the pressure sensor 211 includes a space 213 serving as a reference pressure chamber that extends substantially parallel to the one surface of the flat semiconductor substrate 212 on the one surface thereof, and the space 213. A diaphragm portion 214 formed of a thinned region located on one side of the diaphragm portion, a plurality of strain gauges 215 serving as pressure-sensitive elements arranged to measure a change in strain resistance of the diaphragm portion 214 due to pressure, One surface includes an electrode 216 or the like that is disposed in an outer edge area excluding the diaphragm portion 214 and is electrically connected to each strain gauge 215, and further, on the other side of the space 213, in addition to the semiconductor substrate 212. It has a structure in which a hole 217 that opens toward the surface and communicates the space 213 and the outside of the semiconductor substrate 212 is provided.
The pressure sensor 211 having the structure shown in FIG. 10 is a conventional absolute pressure sensor in which the space 213 as the reference pressure chamber, the diaphragm portion 214, etc. are already formed. The reference pressure is the external pressure, and no correction is required by measuring the external pressure. This structure is particularly effective when changing to a gauge pressure type sensor.

However, the above pressure sensor has the following problems.
(1) Since the pressure sensor described above has a structure in which a hole communicating with the reference pressure chamber and the outside of the semiconductor substrate is provided immediately below the diaphragm, light irradiation from the hole to the rear surface of the diaphragm is performed. Cannot be prevented, and sensor characteristics may become unstable.
(2) In contrast to the conventional absolute pressure type sensor, when the above-described gauge pressure type pressure sensor is manufactured by forming a communicating hole portion with the outside by etching from the back surface of the substrate, the reference pressure chamber and the outside are also in communication. If the etching is advanced, the etching is performed up to the inner wall of the reference pressure and the rear surface of the diaphragm, and there is a possibility that the sensor characteristics fluctuate and further the sensor itself is destroyed.
(3) Since a step of separately forming a communication hole portion between the reference pressure chamber and the outside is necessary, the number of manufacturing steps increases, and when the substrate is thick, the process time for forming the communication hole portion becomes long. Therefore, it leads to an increase in manufacturing cost.
JP 2007-240250 A

  The present invention has been made in view of the above circumstances, is less affected by external factors, has a new structure capable of stable operation, and a gauge pressure type pressure sensor that reduces the number of manufacturing steps and reduces costs. Another object of the present invention is to provide a method for manufacturing a gauge pressure sensor that can be stably manufactured in a simple process.

  In order to solve the above-described problem, a pressure sensor according to a first aspect of the present invention includes a base formed by stacking a second substrate on a first substrate, and a central surface of the first substrate in an overlapping surface in the base. By arranging one concave portion, a first gap portion that extends substantially parallel to the second substrate, a diaphragm portion that is located on the first gap portion and includes a thinned region of the second substrate, the diaphragm A pressure-sensitive element disposed in a portion, and a conductive portion disposed on an outer peripheral area excluding the diaphragm portion and electrically connected to the pressure-sensitive element on one surface of the base body formed of the outer surface of the second substrate , Wherein at least one part of the outer peripheral area of the first substrate communicates with the first gap, and the other of the first substrate has an overlapping surface in the base. By arranging a second recess that forms an opening on the side It characterized in that a second cavity portion forming said second substrate substantially parallel.

According to a second aspect of the present invention, there is provided a pressure sensor package comprising: the pressure sensor according to the first aspect; and a bump which is disposed on one surface of the base constituting the pressure sensor and electrically connected to the conductive portion. It is structured.
A pressure sensor package according to a third aspect of the present invention is the pressure sensor package according to the second aspect, wherein the bump is disposed on the outer peripheral area of the one surface of the base body and does not overlap the second gap portion. Features.

A pressure sensor according to a fourth aspect of the present invention is the pressure sensor according to the first aspect, wherein one end of the pressure sensor is electrically connected to the conductive portion disposed on one surface of the base and the other end is the first in the outer peripheral region of the base. It has a through-wiring portion that penetrates the base so as to be exposed to the other surface of the base that is formed on the outer surface of the substrate.
A pressure sensor according to a fifth aspect of the present invention is the pressure sensor according to the fourth aspect, wherein the through-wiring portion is disposed in the outer peripheral area on one surface of the base and does not overlap the second gap portion. It is characterized by.

  A pressure sensor package according to a sixth aspect of the present invention is disposed on the pressure sensor according to the fourth or fifth aspect and one end exposed on the other surface of the through wiring portion of the pressure sensor, and electrically connected to the one end. And bumps connected to each other.

  According to a seventh aspect of the present invention, there is provided a pressure sensor manufacturing method comprising: a base body in which a second substrate is stacked on a first substrate; and a first recess is disposed in a central area of the first substrate on an overlapping surface in the base body. A first gap portion extending substantially parallel to the second substrate, a diaphragm portion located on the first gap portion and formed of a thinned region of the second substrate, and disposed on the diaphragm portion. A pressure-sensitive element, and a conductive portion disposed on an outer peripheral area excluding the diaphragm portion and electrically connected to the pressure-sensitive element on one surface of the base body formed of the outer surface of the second substrate. In the overlapping surface in the base body, at least a part of the outer peripheral area of the first substrate has a second recess that communicates with the first gap and the other forms an opening on the side surface of the first substrate. A second space that is substantially parallel to the second substrate. A method of manufacturing a pressure sensor having a portion, the step of forming the first recess and the second recess on the first substrate, the first recess and the second recess of the first substrate Bonding the second substrate together to form the first gap portion and the second gap portion, thinning the second substrate to form the diaphragm portion, and at least the pressure-sensitive element in the diaphragm portion And a step of forming the conductive portion, and a step of forming an opening connected to the second gap on the side surface of the first substrate.

  The pressure sensor package manufacturing method according to claim 8 of the present invention is electrically connected to the conductive portion on the outer surface of the second substrate after being thinned by the pressure sensor manufacturing method according to claim 7. The method further includes the step of forming a bump.

  According to a ninth aspect of the present invention, there is provided a pressure sensor manufacturing method according to the seventh aspect, wherein one end is disposed on one surface of the base body in the outer peripheral region of the base body formed by superimposing the thinned second substrate on the first substrate. A step of forming a through-wiring portion that penetrates the base so that the other end is exposed to the other surface of the base that is electrically connected to the conductive portion and the other end of the first substrate; It is characterized by that.

  The pressure sensor package manufacturing method according to claim 10 of the present invention is electrically connected to one end exposed on the other surface of the through wiring portion by the pressure sensor manufacturing method according to claim 9. The method further includes the step of forming a bump to be formed.

  A pressure sensor module according to an eleventh aspect of the present invention is a pressure sensor package according to any one of the second, third, and sixth aspects, and a mounting substrate electrically connected via bumps of the pressure sensor package. It is characterized by comprising.

  An electronic component according to a twelfth aspect of the present invention includes at least the pressure sensor, the pressure sensor package, or the pressure sensor module according to any one of the first to sixth aspects or the eleventh aspect.

  In the pressure sensor according to claim 1 of the present invention (hereinafter, also referred to as “first pressure sensor”), a reference pressure chamber, a reference pressure chamber, A hole communicating with the outside of the base is provided as a space (first gap and second gap) extending substantially parallel to the base, and the hole (second gap) is opened toward the side of the base. The structure to be made. In such a configuration, in a pressure sensor that functions as a gauge pressure sensor that uses a reference pressure as an external pressure and does not require correction by measurement of the external pressure, light is directly transmitted to the rear surface of the diaphragm portion through a communication hole portion (second gap portion) with the outside. This has the effect of preventing irradiation. Thereby, it is possible to prevent fluctuations in sensor characteristics due to light irradiation. Therefore, according to the present invention, it is possible to provide a gauge pressure type pressure sensor that has a new structure that is not easily influenced by external factors and that can operate stably.

A pressure sensor package according to claim 2 of the present invention (hereinafter also referred to as “first pressure sensor package”) is electrically connected to the pressure sensor according to claim 1 with a conductive portion of the pressure sensor. It was set as the structure provided with the bump. Such a configuration brings about an effect of realizing a chip size package having a pressure sensor functioning as a gauge pressure sensor by the bump. In addition, since it can be directly connected to the mounting board using bumps, there are no housings that contain the pressure sensor and no connection members such as wire bonds or leads that electrically connect the pressure sensor and the external board. Make it unnecessary. Therefore, according to the present invention, it is possible to provide a pressure sensor package that does not require a housing or the like and is downsized.
In a pressure sensor package according to a third aspect of the present invention, in the pressure sensor package according to the second aspect, the bumps are formed in the outer peripheral area of the base body and a communication hole (second gap) with the outside. The configuration is such that it does not overlap. As a result, there is no risk of destruction of the hole by providing bumps at positions overlapping the hole, and a small chip size package can be realized. Therefore, according to the present invention, a compact pressure sensor package with a stable structure can be provided.

  In the pressure sensor according to claim 4 of the present invention (hereinafter also referred to as “second pressure sensor”), the reference pressure chamber and the reference pressure chamber are formed on the overlapping surface of the base body formed by overlapping two substrates. A hole communicating with the outside of the base is provided as a space (first gap and second gap) extending substantially parallel to the base, and the hole (second gap) is opened toward the side of the base. And one end is electrically connected to a conductive part electrically connected to the pressure sensitive element disposed in the outer peripheral area of the base, and the other end is exposed to the other surface of the base so as to penetrate the base. A through-wiring portion is provided for each conductive portion. That is, it is possible to prevent light from being directly irradiated to the rear surface of the diaphragm portion through the communication hole portion (second gap portion) with the outside, and to a surface different from the surface provided with the conductive portion, for example, a bump or the like. This brings about an effect of improving the degree of freedom of arranging the connecting member. Therefore, according to the present invention, there is provided a pressure sensor having a structure that functions as a gauge pressure sensor that is not easily affected by external factors and that can perform a stable operation, and that has a degree of freedom of mounting according to the requirements of an external substrate. Can be provided.

In a pressure sensor package according to claim 5 of the present invention (hereinafter also referred to as “second pressure sensor package”), in the pressure sensor according to claim 4, the through wiring portion is provided in an outer peripheral region of the base body. And it was set as the structure distribute | arranged to the position which does not overlap with the communicating hole part (2nd space | gap part) with the exterior. This eliminates the possibility of breakage of the hole due to the provision of the through-wiring portion, and the hole and the through-wiring portion can be arranged at a position where they do not overlap on the surface of the base. The effect that a package is realizable is brought about. Therefore, according to the present invention, a compact pressure sensor package with a stable structure can be provided.
In a pressure sensor package according to a sixth aspect of the present invention, the pressure sensor package includes a bump that is disposed on an exposed portion of the through wiring portion of the pressure sensor according to the fourth or fifth aspect and is electrically connected to the through wiring portion. The configuration. Such a configuration brings about an effect of realizing a chip size package including a pressure sensor that functions as a gauge pressure sensor and has a high degree of freedom in connection to an external substrate by the bumps. In addition, since it can be directly connected to the mounting board using bumps, there are no housings that contain the pressure sensor and no connection members such as wire bonds or leads that electrically connect the pressure sensor and the external board. Make it unnecessary. Therefore, according to the present invention, it is possible to provide a pressure sensor package that does not require a housing or the like and is downsized. Further, since bumps and the like are formed on the surface opposite to the diaphragm surface, the thermal stress applied to the diaphragm can be further reduced.

  In the pressure sensor manufacturing method according to claim 7 of the present invention, the reference pressure chamber (first gap) and the reference pressure chamber and the outside of the substrate are provided on the overlapping surface of the substrate formed by stacking two substrates. A recess for forming a communicating hole (second gap) is formed at the same time, and then the two substrates are bonded to each other, so that the reference pressure chamber extends substantially parallel to the base, and the reference pressure chamber and the base The step of forming a hole that communicates with the outside is used. Thereby, when manufacturing the pressure sensor that functions as a gauge pressure sensor, the reference pressure chamber and the communication hole can be processed at the same time, so that the number of manufacturing steps can be significantly reduced and the efficiency can be improved. Further, there is no possibility of damaging the diaphragm portion due to over-etching, which is a concern when an absolute pressure type sensor is separately etched to form a communicating hole portion to produce a gauge pressure sensor. Therefore, according to the present invention, it is possible to obtain a manufacturing method that can easily and stably produce a gauge pressure sensor capable of stable operation at low cost.

  In the method for manufacturing a pressure sensor package according to claim 8 of the present invention, the step of forming a bump electrically connected to the conductive portion on the outer surface of the substrate by the method for manufacturing a pressure sensor according to claim 7. Further, a manufacturing method further provided. Thereby, the effect of being able to efficiently produce a small chip size package having a pressure sensor functioning as a gauge pressure sensor is provided by the bump. Therefore, according to this invention, the manufacturing method which can form a pressure sensor package simply and stably at low cost can be provided.

  In the pressure sensor manufacturing method according to claim 9 of the present invention, the reference pressure chamber (first gap) and the reference pressure chamber and the outside of the substrate are provided on the overlapping surface of the substrate formed by stacking two substrates. A concave portion for forming a communicating hole (second gap) is formed at the same time, and then a reference pressure chamber that extends substantially parallel to the base by bonding two substrates together, and the reference pressure chamber A hole communicating with the outside of the base is formed, and then one end is electrically connected to a conductive portion electrically connected to a pressure-sensitive element disposed in the outer peripheral area of the base, and the other end is connected to the base. A step of providing a through-wiring portion penetrating the base for each conductive portion so as to be exposed on the other surface was used. As a result, since the reference pressure chamber and the communication hole can be processed simultaneously, the number of manufacturing steps can be greatly reduced, efficiency can be improved, and a connecting member such as a bump is provided on a surface different from the surface provided with the conductive portion. It is also easy to arrange. Therefore, according to the present invention, it is possible to obtain a manufacturing method capable of easily and stably forming a pressure sensor having a structure having a degree of freedom of mounting according to the requirements of the external substrate at low cost.

  In the pressure sensor package manufacturing method according to claim 10 of the present invention, the pressure sensor manufacturing method according to claim 9 is electrically connected to the one end exposed on the other surface of the through wiring portion. The manufacturing method further comprising the step of forming a bump to be formed. Thus, the bumps have an effect of efficiently producing a small chip size package having a pressure sensor that functions as a gauge pressure sensor and has a high degree of freedom in connection with an external substrate. Therefore, according to the present invention, it is possible to provide a manufacturing method capable of easily and stably forming a pressure sensor package having a structure with a degree of freedom of mounting according to the requirements of the external substrate at low cost.

  A pressure sensor module according to an eleventh aspect of the present invention includes a mounting substrate that is electrically connected via bumps of the pressure sensor package according to any one of the second, third, and sixth aspects. Such a configuration has the effect of realizing a pressure sensor module having a chip size package that functions as a gauge pressure sensor and has a degree of freedom of connection to an external substrate, and a miniaturized chip size package, depending on the mounting substrate. Bring. Therefore, according to the present invention, a miniaturized pressure sensor module can be provided.

  In an electronic component according to claim 12 of the present invention, a pressure sensor, a pressure sensor package, or a pressure sensor module having the above-described configuration is mounted. Since this pressure sensor, pressure sensor package, or pressure sensor module does not require a bulky casing when mounted, the volume for housing the pressure sensor, pressure sensor package, or pressure sensor module is greatly reduced, and the casing Weight corresponding to the body is also reduced. Therefore, according to the present invention, it is possible to provide a small and lightweight electronic component.

Hereinafter, embodiments of a pressure sensor according to the present invention will be described with reference to the drawings.
The pressure sensor according to the present invention includes a reference pressure chamber (first gap portion) formed on an overlapping surface of a base body composed of two semiconductor substrates, and a hole (second second) communicating the reference pressure chamber and the outside of the base body. The reference pressure chamber (first gap) and the reference pressure chamber communicate with the outside of the base body on the overlapping surface of the two semiconductor substrates with the structure (first pressure sensor) provided with the gap. A hole (second gap) is provided, and the conductive portion arranged on one surface of the base is electrically connected to one end and the other end is exposed to the other side. It can be broadly divided into a structure (second pressure sensor) provided with a wiring portion.

"Pressure sensor"
<First embodiment>
First, a 1st pressure sensor is demonstrated based on FIG. 1 and FIG.
FIG. 1 is a schematic cross-sectional view (a) and (b) showing an example of a pressure sensor according to the present invention, and a schematic plan view (c). FIG. 1B shows a cross section taken along the line A1-A1, and FIG. 1B shows a cross section taken along the line A2-A2 shown in FIG. That is, FIG. 1C is a surface provided with a diaphragm portion. FIG. 2 is a schematic wiring diagram of the pressure sensitive element (gauge resistance).

As shown in FIG. 1, the first pressure sensor 1 </ b> A has a base 13 formed by superimposing a second substrate 12 on a flat plate-like first substrate 11, and the first substrate 11 is provided with a first cavity 14 (reference pressure chamber) that extends substantially in parallel with the second substrate 12 by arranging the first recess 14a in the central region α of the first substrate 11 and overlaps with the first cavity 14 to reduce the thickness. The region made of the second substrate 12 thus formed is referred to as a diaphragm portion 16. A plurality of pressure sensitive elements 17 are arranged on the diaphragm portion 16. In addition, a conductive portion 18 electrically connected to the pressure-sensitive element 17 is disposed on an outer peripheral region β excluding the diaphragm portion 16 on one surface of the base body 13 formed from the outer surface of the second substrate 12. Yes. Further, in the overlapping surface in the base body 13, one is in communication with the first gap portion 14 in the outer peripheral region β of the first gap portion 14, and the other is an opening portion in the side surface of the first substrate 11. By arranging two recesses (for example, 15a, 15b, 15c, 15d), the first gap portion 14 and the outside of the base 13 are communicated with the second substrate 12 as a hole portion (communication hole). A second gap 15 is formed.
In FIG. 1, openings in four directions are provided as the second gap 15 toward the side surface of the first substrate 11, but the present invention is not limited to this, and is at least in one direction or more. Any structure having any opening may be used.

  FIG. 1 is an example in which gauge resistors (R1 to R4) functioning as pressure-sensitive elements 17 are arranged, and each gauge resistor constitutes a Whitstone bridge (FIG. 2) via a lead wiring (not shown). So that it is electrically connected. Such a pressure sensitive element 17 is preferably arranged at the peripheral edge of the diaphragm portion 16. Since both compressive and tensile stresses are likely to be applied to the pressure sensitive element 17 at the peripheral edge portion, a pressure sensor 1A with high sensitivity can be obtained.

  Accordingly, in the first pressure sensor 1A, the first gap portion 14 that is a pressure reference chamber is opened to the outside (for example, the atmosphere) by the second gap portion 15 that functions as a communication hole, and functions as a gauge pressure sensor. Since the opening with the outside of the second gap 15 is arranged on the side surface of the base, it is possible to prevent light from being directly irradiated to the back surface of the diaphragm 16 through the second gap 15. As a result, fluctuations in sensor characteristics caused by light irradiation are suppressed, and a pressure sensor that is less affected by external factors and can operate stably is obtained.

Next, the first pressure sensor package 2A will be described with reference to FIG.
FIG. 3 is a schematic cross-sectional view showing an example of a pressure sensor package according to the present invention, and corresponds to a cross section taken along line A1-A1 in FIG.
As shown in FIG. 3, the first pressure sensor package 2 </ b> A includes bumps 19 that are respectively disposed on the conductive portions 18 of the first pressure sensor 1 </ b> A having the above structure and are electrically connected to the conductive portions 18. Is made up of.

  That is, the first pressure sensor 1A constituting the first pressure sensor package 2A according to the present invention uses a base 13 formed by superposing a second substrate 12 on a flat plate-like first substrate 11, and the base 13 In the overlapping surface of the first substrate 11, the first concave portion 14 a is arranged in the central region α of the first substrate 11, thereby providing a first gap portion (reference pressure chamber) 14 that extends substantially parallel to the second substrate 12, A region composed of the thinned second substrate 12 overlapping the first gap portion 14 is referred to as a diaphragm portion 16. A plurality of pressure sensitive elements 17 are arranged on the diaphragm portion 16. In addition, a conductive portion 18 electrically connected to the pressure-sensitive element 17 is disposed on an outer peripheral region β excluding the diaphragm portion 16 on one surface of the base body 13 formed from the outer surface of the second substrate 12. Yes. Further, in the overlapping surface in the base body 13, one is in communication with the first gap portion 14 in the outer peripheral region β of the first gap portion 14, and the other is an opening portion in the side surface of the first substrate 11. By arranging two recesses (for example, 15a, 15b, 15c, 15d), the first gap portion 14 and the outside of the base 13 are communicated with the second substrate 12 as a hole portion (communication hole). It is comprised by providing the 2nd space | gap part 15 which makes | forms.

  Further, in the pressure sensor 1A, as shown in FIG. 1, it is preferable that the outer peripheral region β except for the conductive portion 18 for placing the bump 19 is covered with an insulating portion (not shown). By providing the insulating portion, a configuration in which the pressure sensitive element 17 is covered with an insulating layer is obtained. In the first pressure sensor package 2A configured as described above, when the bumps 19 are connected to, for example, an external substrate (not shown), the outer peripheral region β other than the bumps 19 is entirely covered with an insulating portion. On the other hand, the insulation of the pressure sensitive element 17 is sufficiently ensured. In addition, the insulating part improves the corrosion resistance of the pressure sensitive element 17 to block the contact of the pressure sensitive element 17 with the outside air, and mechanically receives the pressure sensitive element 17 from the outside directly without going through the diaphragm part 16. It also has the effect of greatly reducing the impact.

  At this time, it is preferable that the bumps 19 are arranged in a position that does not overlap with the second gap 15 in the outer peripheral region β. Thereby, the possibility of destruction of the second gap 15 due to the provision of the bumps 19 can be eliminated. Note that the bump 19 is not necessarily limited to be disposed on the conductive portion 18 such as an electrode pad, and a wiring layer (not shown) or the like may be used as long as the bump 19 does not overlap the second gap portion 15. It may be provided at a position shifted from the conductive portion 18.

  Therefore, the first pressure sensor package 2A does not require a housing that contains the pressure sensor, and the pressure sensor package itself also includes, for example, a bump 19 that can be connected to an external substrate. A sensor package is obtained. Further, the bumps can be mounted on the external substrate in a chip size.

<Second embodiment>
Next, the second pressure sensor will be described with reference to FIG.
FIG. 4 is a schematic cross-sectional view (a), (b) showing another example of the pressure sensor according to the present invention, and a schematic plan view (c). FIG. 4B shows a cross section taken along line B1-B1 shown in FIG. 4C, and FIG. 4B shows a cross section taken along line B2-B2 shown in FIG. 4C. That is, FIG. 4C shows a surface provided with a diaphragm portion.

  As shown in FIG. 4, the second pressure sensor 1 </ b> B has a base 13 formed by superposing a second substrate 12 on a flat plate-like first substrate 11, and the first substrate is formed on the overlapping surface of the base 13. 11 is provided with a first cavity 14 (reference pressure chamber) that extends substantially in parallel with the second substrate 12 by arranging the first recess 14a in the central region α of the first substrate 11 and overlaps with the first cavity 14 to reduce the thickness. The region made of the second substrate 12 thus formed is referred to as a diaphragm portion 16. A plurality of pressure sensitive elements 17 are arranged on the diaphragm portion 16. In addition, a conductive portion 18 electrically connected to the pressure-sensitive element 17 is disposed on an outer peripheral region β excluding the diaphragm portion 16 on one surface of the base body 13 formed from the outer surface of the second substrate 12. Yes. Further, in the overlapping surface in the base body 13, one is in communication with the first gap portion 14 in the outer peripheral region β of the first gap portion 14, and the other is an opening portion in the side surface of the first substrate 11. By arranging two recesses (for example, 15a, 15b, 15c, 15d), the first gap portion 14 and the outside of the base 13 are communicated with the second substrate 12 as a hole portion (communication hole). The second gap 15 is formed. Furthermore, a through-wiring that penetrates the base 13 so that one end 20a is electrically connected to the conductive portion 18 and the other end 20b is exposed to the other surface of the base 13 that is the outer surface of the first substrate 11. A portion 20 is provided for each conductive portion 18.

In FIG. 4, as the second gap portion 15, openings in four directions are provided toward the side surface of the first substrate 11, but the present invention is not limited to this, and at least in one direction or more. Any structure having any opening may be used.
At this time, as shown in FIG. 4C, the through wiring portion 20 is preferably arranged at a position that is in the outer peripheral region β and does not overlap with the second gap portion 15. Thereby, the possibility of destruction of the second gap portion 15 due to the provision of the through wiring portion 20 can be eliminated.

  FIG. 4 is an example in which gauge resistors (R1 to R4) functioning as the pressure sensitive elements 17 are arranged, and each gauge resistor constitutes a Whitstone bridge (FIG. 2) via a lead wire (not shown). So that it is electrically connected. Such a pressure sensitive element 17 is preferably arranged at the peripheral edge of the diaphragm portion 16. Since both compressive and tensile stresses are easily applied to the pressure sensitive element 17 at the peripheral edge, a pressure sensor 1B with high sensitivity can be obtained.

  Accordingly, in the second pressure sensor 1B, the first gap 14 that is a pressure reference chamber is opened to the outside (for example, the atmosphere) by the second gap 15 that functions as a communication hole, and functions as a gauge pressure sensor. Since the opening with the outside of the second gap 15 is arranged on the side surface of the base, it is possible to prevent light from being directly irradiated to the back surface of the diaphragm 16 through the second gap 15. As a result, fluctuations in sensor characteristics due to light irradiation are suppressed, stable operation is hardly affected by external factors, and the second gap portion 15 is formed by the through wiring portion 20 penetrating the base 13. Thus, a pressure sensor having a structure capable of drawing electrical wiring on the surface opposite to the diaphragm portion 16 without interfering with the diaphragm portion 16 is obtained.

Next, the second pressure sensor package 2B will be described with reference to FIG.
FIG. 5 is a schematic cross-sectional view (a), (b) showing an example of the pressure sensor package according to the present invention, and a schematic plan view (c). FIG. 5B shows a cross section taken along line B1-B1, and FIG. 5B shows a cross section taken along line B2-B2 shown in FIG. That is, FIG. 5C is a surface provided with a diaphragm portion.
As shown in FIG. 5, the second pressure sensor package 2 </ b> B is disposed on the exposed other end 20 b of the through wiring part 20 of the second pressure sensor 1 </ b> B having the above structure, and is electrically connected to the through wiring part 20. It is comprised by providing the bump 19 connected to.

  The second pressure sensor package 2B shown in FIG. 5 is different from the first pressure sensor package 2A (FIG. 3) described above in that a bump 19 that is electrically connected to the through wiring portion 20 is provided. Is a point. In other respects, the second pressure sensor package 2B and the first pressure sensor package 2A have the same configuration.

  Therefore, in the second pressure sensor package 2B, as in the case of the first pressure sensor package 2A (FIG. 3) described above, a housing that contains the pressure sensor is not necessary and, for example, a bump that can be connected to an external substrate Since the pressure sensor package 19 is also provided, a pressure sensor package that can be extremely miniaturized can be obtained. In addition to this, the second pressure sensor package 2B has a surface on the opposite side to the diaphragm portion 16 without interfering with the second gap portion 15 by providing bumps on the through wiring portion 20 penetrating the base 13. In addition, the electrical wiring can be drawn out and mounted on the external substrate in a chip size.

"Manufacturing method of pressure sensor"
<Third embodiment>
FIG. 6 is a cross-sectional process diagram schematically showing an example of a manufacturing method of the first pressure sensor package 2A shown in FIG.
First, as shown in FIG. 6 (a), on one surface of the first substrate 11 made of a semiconductor such as silicon, for example, a first recess 14a is formed in a central region α, and at least part of an outer peripheral region β, one of which is the first Second recesses 15 a, 15 b, 15 c, and 15 d that communicate with one recess 14 a and the other side forms an opening on the side surface of the first substrate 11 are formed.

This concave portion can be formed by etching, for example, by DRIE (Deep-Reactive Ion Etching) method. In the DRIE method, sulfur hexafluoride (SF6) is used as an etching gas, and high-density plasma etching and passivation film formation on the sidewalls are alternately performed (Bosch process) to deep-etch the first substrate 11. Is.
Note that the method of forming these recesses is not limited to this, and physical processing such as wet etching using a solution of acid or alkali, sandblasting, laser, or the like is also possible.
Moreover, although the opening part is provided in four directions toward the side surface of the 1st board | substrate 11 as a 2nd recessed part, it is not limited to this in this invention, It is a structure which has an opening part in at least one direction. The position is not limited to the central portion of each side, and the number is not limited to one from each side, and can be set as appropriate.

Next, as shown in FIG. 6B, the second substrate 12 made of, for example, silicon is bonded to the surface of the first substrate 11 on which the recesses are formed, for example, by heat treatment at a high temperature. Thereafter, as shown in FIG. 6C, one surface of the second substrate 12 is thinned by polishing or the like to obtain a desired thickness, and the diaphragm portion 16 is formed.
The method for thinning the second substrate 12 is not particularly limited, and in addition to grinding and polishing processes, dry etching using a reactive gas, wet etching using a chemical, or electrochemical etching is also possible. Is possible.

  Next, as shown in FIG. 6 (d), a pressure sensitive element 17 is formed on the outer surface of the thinned second substrate 12, and further electrically connected to the pressure sensitive element 17 on the outer peripheral portion β. By providing the portion 18, the gauge pressure type pressure sensor 1A shown in FIG. 1 is manufactured. At this time, as shown in FIG. 2, the pressure sensitive elements 17 are arranged so as to form a Whitstone bridge.

Next, as shown in FIG. 6E, bumps 19 are formed on the conductive portions 18 so as to be electrically connected to the conductive portions 18. Thereby, the first pressure sensor package 2A shown in FIG. 3 is manufactured.
The bump 19 can be formed by mounting a solder ball made of, for example, Sn—Ag—Cu. The solder ball can be directly mounted on the conductive portion 18 such as an electrode pad, or a rewiring layer is formed once and electrically connected to the rewiring layer at a location different from the conductive portion. It can also be installed.
In the present invention, the bumps 19 are not limited to this, and solders having other compositions, solders made of other metals, bumps made of Cu, Au, or the like can be used. Printing methods using paste, plating methods, stud bumps using wires, and the like are applicable.

According to the manufacturing method of the present invention, when the pressure sensor package 2A that functions as a gauge pressure sensor is manufactured, the first gap portion 14 and the second gap portion 15 can be formed in the same process, which greatly increases the number of manufacturing steps. The efficiency can be improved. Further, there is no possibility of damaging the diaphragm portion due to over-etching, which is a concern when an absolute pressure type sensor is separately etched to form a communicating hole portion to produce a gauge pressure sensor. Therefore, according to the present invention, it is possible to obtain a manufacturing method that can easily and stably produce a gauge pressure sensor capable of stable operation at low cost.
Furthermore, a small chip size package having a pressure sensor functioning as a gauge pressure sensor can be efficiently produced by bumps, and a manufacturing method capable of easily and stably forming a pressure sensor package at low cost is provided. be able to.

<Fourth embodiment>
FIG. 7 is a cross-sectional process diagram schematically showing an example of a method for manufacturing the second pressure sensor package 2B having the through wiring portion 20 shown in FIG.
Note that the same process as that of the first pressure sensor package 2A is used until the process shown in FIG. 6D until the first pressure sensor 1A is completed, and here, the process leading to FIG. 6D. Shall be omitted.

  First, as shown to Fig.7 (a), the through-hole 21 is formed so that it may connect with the back surface of the electroconductive part 18 in 1 A of 1st pressure sensors. The through hole 21 can be formed by etching, for example, by the DRIE method. In addition, the method of forming the through-hole 21 is not limited to this, and physical processing, such as a laser, is also possible.

Next, as shown in FIG. 7 (b), an insulating layer 22 is formed on the other surface of the base 13 consisting of the inner wall of the through hole 21 and the outer surface of the first substrate 11. The insulating layer 22 can be formed, for example, by depositing SiO ₂ with a thickness of 1 μm by plasma CVD.
The insulating layer is not limited to SiO2, but may be other insulating materials such as SiN and resin. In addition, sputtering, spin coating, etc. can be used for the manufacturing method.

Next, as illustrated in FIG. 7C, the through wiring portion 20 is formed by filling the through hole 21 with a conductive material 23 so as to be electrically connected to the conductive portion 18. Thereby, the 2nd pressure sensor 1B shown in FIG. 4 is produced.
The conductive material 23 may be Cu, for example, and fill the through hole 21 by plating. Note that the conductive material 23 is not limited to this, and may be other metal materials or alloys such as solder. Also, the filling method can use CVD or sputtering.

Further, as shown in FIG. 7D, bumps 19 are formed so as to be electrically connected to the through wiring portion 20. Thereby, the 2nd pressure sensor package 2B shown in FIG. 5 is produced.
The bump 19 can be formed by mounting a solder ball made of, for example, Sn—Ag—Cu. Note that the solder balls can be directly mounted on the through wiring portion 20, or a rewiring layer is formed once and electrically connected to the rewiring layer at a location different from the through wiring portion. Can also be installed.
In the present invention, the bumps 19 are not limited to this, and solders having other compositions, solders made of other metals, bumps made of Cu, Au, or the like can be used. Printing methods using paste, plating methods, stud bumps using wires, and the like are applicable.

According to the manufacturing method of the present invention, when the pressure sensor package 2B that functions as a gauge pressure sensor is manufactured, the first gap portion 14 and the second gap portion 15 can be formed in the same process. In addition, the efficiency can be improved, and it is easy to dispose connection members such as bumps on a surface different from the surface provided with the conductive portion. Therefore, according to the present invention, it is possible to obtain a manufacturing method capable of easily and stably forming a pressure sensor having a structure having a degree of freedom of mounting according to the requirements of the external substrate at low cost.
In addition, the bump sensor can efficiently produce a small chip size package equipped with a pressure sensor with a high degree of freedom of connection to an external board, and the pressure sensor package has a structure with the degree of freedom of mounting according to the requirements of the external board. Can be provided at low cost in a simple and stable manner.

FIG. 8 is a schematic plan view of the wafer level package of the first pressure sensor package 2A, and shows a surface provided with a diaphragm portion.
The first and second pressure sensors and the method for manufacturing the package are performed at the wafer level in the normal process. Therefore, as shown in FIG. 8, the same pattern is formed in the pressure sensor package 101 and the adjacent pressure sensor package 102, and each second gap 15 is connected in the region γ near the dicing line. It becomes a structure. After the series of steps is completed, dicing from the broken line CC in the figure and dividing into chips, the second gap 15 is simultaneously opened on the side surface of the chip, and the first gap 14 serving as a reference pressure chamber is formed. Can communicate with the outside of the substrate. Thereby, it is possible to provide a manufacturing method capable of efficiently forming a small chip size package including a pressure sensor functioning as a gauge pressure sensor in a simple process.

A pressure sensor module is manufactured by providing the mounting substrate so that the first or second pressure sensor package is electrically connected through the bumps. Therefore, according to the present invention, a miniaturized pressure sensor module can be provided.
In addition, an electronic component having the above-described configuration and equipped with a pressure sensor, a pressure sensor package, or a pressure sensor module does not require a bulky casing when mounted, so that the pressure sensor, the pressure sensor package Or the volume which accommodates a pressure sensor module is reduced significantly, and the weight equivalent to a housing | casing etc. is also reduced. Therefore, according to the present invention, it is possible to provide a small and lightweight electronic component.

  The pressure sensor, the pressure sensor package, and the pressure sensor module according to the present invention are used for measuring pressure such as air pressure, water pressure, and hydraulic pressure, and have a structure that eliminates the need for a housing and the like due to the wafer level chip size. Therefore, it is suitable for various electronic components that are required to be thin, small, or light.

The figure which shows an example of the 1st pressure sensor which concerns on this invention. Electrical wiring diagram of pressure sensitive element (gauge resistance). The figure which shows an example of the 1st pressure sensor package which concerns on this invention. The figure which shows an example of the 2nd pressure sensor which concerns on this invention. The figure which shows an example of the 2nd pressure sensor package which concerns on this invention. It is typical sectional process drawing which shows an example of the manufacturing method of the 1st pressure sensor package which concerns on this invention. It is typical sectional process drawing which shows an example of the manufacturing method of the 2nd pressure sensor package which concerns on this invention. It is a typical top view showing an example of a wafer level package concerning the present invention. It is a figure which shows the conventional absolute pressure type pressure sensor. It is a figure which shows the conventional differential pressure type pressure sensor.

Explanation of symbols

  α central region, β outer peripheral region, 1A, 1B pressure sensor, 2A, 2B pressure sensor package, 3A pressure sensor module, 11 first substrate, 12 second substrate, 13 base, 14 first gap (reference pressure chamber), 15 Second gap portion (communication hole with outside), 16 Diaphragm portion, 17 Pressure sensitive element, 18 Conductive portion, 19 Bump, 20 Through wiring portion, 21 Through hole, 22 Insulating layer, 23 Conductive substance, 40 Mounting substrate .

Claims (12)

A base formed by superimposing the second substrate on the first substrate, and a first recess formed in a central area of the first substrate on the overlapping surface in the base, so that the first substrate extends substantially parallel to the second substrate. One gap portion, located on the first gap portion, comprising a diaphragm portion made of a thinned region of the second substrate, a pressure-sensitive element disposed on the diaphragm portion, and an outer surface of the second substrate A pressure sensor including at least a conductive portion disposed on an outer peripheral area excluding the diaphragm portion and electrically connected to the pressure sensitive element on one surface of the base;
In the overlapping surface in the base body, at least a part of the outer peripheral area of the first substrate is provided with a second recess that communicates with the first gap and the other forms an opening on the side surface of the first substrate. Thus, a pressure sensor is provided, which is provided with a second gap that is substantially parallel to the second substrate.   A pressure sensor package comprising: the pressure sensor according to claim 1; and a bump disposed on one surface of a base constituting the pressure sensor and electrically connected to the conductive portion.   3. The pressure sensor package according to claim 2, wherein the bump is disposed in the outer peripheral area on one surface of the base body and is not overlapped with the second gap portion. 4.   In the outer peripheral area of the substrate, one end is electrically connected to the conductive portion disposed on one surface of the substrate, and the other end is exposed to the other surface of the substrate including the outer surface of the first substrate. The pressure sensor according to claim 1, further comprising a through wiring portion penetrating the base body.   5. The pressure sensor according to claim 4, wherein the through wiring portion is disposed in the outer peripheral area on one surface of the base body and is not overlapped with the second gap portion.   The pressure sensor according to claim 4, and a bump disposed on one end exposed on the other surface of the through wiring portion of the pressure sensor and electrically connected to the one end. Characteristic pressure sensor package. A base formed by superimposing the second substrate on the first substrate, and a first recess formed in a central area of the first substrate on the overlapping surface in the base, so that the first substrate extends substantially parallel to the second substrate. One gap portion, located on the first gap portion, comprising a diaphragm portion made of a thinned region of the second substrate, a pressure-sensitive element disposed on the diaphragm portion, and an outer surface of the second substrate One surface of the base includes at least a conductive portion disposed in an outer peripheral area excluding the diaphragm portion and electrically connected to the pressure sensitive element, and the outer periphery of the first substrate is overlapped in the base. The second substrate is substantially parallel to the second substrate by disposing at least a part of the region, a second recess that is in communication with the first gap and the other has an opening on the side surface of the first substrate. A method of manufacturing a pressure sensor having two voids,
Forming the first recess and the second recess on the first substrate;
Bonding the second substrate to the first concave portion of the first substrate and the surface on which the second concave portion is formed, and forming the first gap portion and the second gap portion;
Forming the diaphragm portion by thinning the second substrate;
Forming at least the pressure-sensitive element and the conductive portion in the diaphragm portion; and
Forming an opening connected to the second gap on the side surface of the first substrate;
A method for manufacturing a pressure sensor, comprising:   The method for manufacturing a pressure sensor according to claim 7, further comprising: forming a bump electrically connected to the conductive portion on the outer surface of the second substrate after being thinned. A method for manufacturing a pressure sensor package.   In the outer peripheral region of the base body formed by superimposing the thinned second substrate on the first substrate, one end is electrically connected to the conductive portion disposed on one surface of the base, and the other end is connected to the outer surface of the first substrate. The method of manufacturing a pressure sensor according to claim 7, further comprising a step of forming a through-wiring portion that penetrates the base so as to be exposed on the other surface of the base.   The method for manufacturing a pressure sensor according to claim 9, further comprising a step of forming a bump electrically connected to the one end exposed on the other surface of the through wiring portion. A method for manufacturing a pressure sensor package.   7. A pressure sensor module comprising: the pressure sensor package according to claim 2, and a mounting board electrically connected via bumps of the pressure sensor package. .   An electronic component comprising at least the pressure sensor, the pressure sensor package, or the pressure sensor module according to any one of claims 1 to 6.

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