JP5328479B2 - Pressure sensor module, pressure sensor package, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensor module whose size can be reduced to a chip size, and which has an integrated circuit for controlling a pressure sensor. <P>SOLUTION: The pressure sensor module 20A (20) includes at least: a pressure sensor 10A (10) including at least a base 2 made by stacking a first substrate 3 and a second substrate 4, a space part 5 disposed at the inside of a central region of a stacking surface in the base, a diaphragm part 6 located on the space part and comprising a region obtained by thinning down the first substrate, a pressure sensitive element 7 disposed at the diaphragm part, and a conductive part 8 disposed at a peripheral region excluding the diaphragm part of the first substrate and electrically connected to the pressure sensitive element; and the integrated circuit disposed at the second substrate, for controlling the pressure sensor. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a pressure sensor module, a pressure sensor package, and a manufacturing method thereof. More specifically, the present invention relates to a semiconductor pressure sensor formed on a semiconductor substrate, a pressure sensor module and a pressure sensor package for mounting in a chip size of an integrated circuit for controlling the semiconductor pressure sensor, and a manufacturing method thereof.

  A semiconductor pressure sensor (hereinafter referred to as “pressure sensor”) is a sensor having a function of converting a pressure change generated on a semiconductor substrate such as silicon into a voltage signal by utilizing a piezoresistance effect or the like.

  As an example, for example, the one shown in FIG. The pressure sensor 100 includes a semiconductor substrate 102 made of silicon or the like, a space portion 103 formed in the central region thereof, a diaphragm portion 104 (pressure-sensitive portion) formed of a region thinned by the space portion 103, A plurality of strain gauges 105 as pressure-sensitive elements disposed in the diaphragm section 104 and electrodes (pad sections) 106 disposed in the outer edge area excluding the diaphragm section 104 and electrically connected to each strain gauge 105. Etc.

Such a pressure sensor 100 is used as an electronic component of a pressure sensor by being disposed in a package mainly made of resin (hereinafter referred to as “pressure sensor package”).
FIG. 10 is a structural example of the pressure sensor package 110 made of resin. In this example, a housing 111 made of a resin plate or the like and having a pressure introducing hole 111a is provided, and the pressure sensor 100 is placed on a support substrate 112 made of an insulating material in a space formed inside the housing 111. The electrode part 106 of the pressure sensor 100 and the metal lead 114 provided in the housing 111 are electrically connected by a wire bond 113 using a gold wire or the like. FIG. 10A is a configuration example of an absolute pressure type pressure sensor, and FIG. 10B is a configuration example of a relative pressure type pressure sensor.

  However, in order to reduce the size of the housing of such a pressure sensor package, it is necessary to reduce the size of the lead frame and the space inside the housing. Since it is difficult to reduce the size of the pressure sensor package due to the processing accuracy of the resin and lead frame, the semiconductor substrate on which the pressure-sensitive elements are formed is made of resin or metal in order to mount the pressure sensor at high density. There is a problem that it is difficult to adopt a configuration of a conventional pressure sensor package in a form of covering with a housing.

  Technology for forming bumps that serve as electrodes on a semiconductor substrate (hereinafter referred to as “bump formation”) Technology (referred to as “technology”) is known (see, for example, Patent Document 1).

  FIG. 11 shows a pressure sensor package manufactured using a bump forming technique. The pressure sensor package manufactured by the bump formation technology can be mounted on a mounting substrate for electronic components in the same size as the semiconductor substrate of the pressure sensor. In addition, as shown in FIG. 12, a through hole 121 is formed in the semiconductor substrate 102 from the pressure sensing element 105 formation surface to the opposing surface in the outer peripheral region of the diaphragm portion 104 on the semiconductor substrate surface. A metal film 122 is deposited by sputtering or the like, and the bump 120 formed on the facing surface is electrically connected to the pressure-sensitive element (hereinafter referred to as “penetration wiring forming technique”). As described above, a small pressure sensor package can be manufactured by using the bump forming technique and the through wiring forming technique.

In order to achieve high-precision pressure resolution in such a pressure sensor, it is effective to reduce the temperature dependence of the electrical signal of the output, and in addition, the electrical signal of a desired output value is obtained. Amplification and correction are required.
Therefore, in addition to a semiconductor substrate (hereinafter referred to as “pressure sensor body”) on which a pressure-sensitive element having the above characteristics is formed, a semiconductor integrated circuit is connected to compensate for an electric signal from the pressure-sensitive element. May be.

  A pressure sensor module (hereinafter referred to as “integrated pressure sensor”) in which the integrated circuit is formed on the outer surface of the pressure sensitive element on the same surface as the pressure sensitive element forming surface of the pressure sensor body is known. The integrated pressure sensor can compensate the electric signal from the pressure sensitive element. However, since the integrated circuit is formed on the same surface as the pressure sensitive element, the area of the integrated pressure sensor is larger than the area of the pressure sensor body. However, there is a problem that it increases not a little.

  In order to electrically connect the pressure sensor main body and the integrated circuit for controlling the pressure sensor (hereinafter referred to as “ASIC”) to other electronic components, the pressure sensor main body and the ASIC are each made of a resin or the like. When mounting on a resin substrate or the like in a state of being installed inside, a mounting area corresponding to the pressure sensor main body and the ASIC package and an area of a wiring portion for electrically connecting the packages are required. In particular, when the pressure sensor package is mounted on a small portable terminal or the like, there is a problem that the mounting area is large.

  Further, when the pressure sensor main body and the ASIC are stacked, a package area equivalent to the package of the pressure sensor alone can be realized, but there is a problem that the height of the package increases. Since the height of the pressure sensor package after mounting depends on the height of the package, there is a problem that it is difficult to reduce the thickness of the package.

  On the other hand, a mounting technique using a chip size package (hereinafter referred to as “CSP”) using bumps has been studied for the purpose of small and thin mounting on the pressure sensor body. By this method, the mounting area is smaller and thinner than the conventional package in which the pressure sensor is installed in a package made of resin or the like. However, in order to realize a highly accurate pressure sensor with compensated temperature characteristics, a pressure sensor module combined with an ASIC is required.

  When mounting a semiconductor substrate on which a pressure-sensitive element is formed and an ASIC on a substrate intended for connection to other electronic components, the ASIC is also mounted on the CSP in the same manner as the pressure sensor body, so that the CSP of the pressure sensor alone is mounted. There is a problem that the mounting area is increased as compared with mounting by. In addition, a method of mounting an ASIC with bumps formed on a sensor chip surface with bumps is known (see, for example, Non-Patent Document 1). Although this method allows a small mounting, there is a problem that the thickness of the bump and the ASIC chip must be precisely controlled.

JP 2002-82009 A

Press release (October 31, 2007), VTI Technology Corporation homepage

The present invention has been devised in view of such a conventional situation, and provides a pressure sensor module that can be miniaturized to a chip size in a pressure sensor module including an integrated circuit for pressure sensor control. The primary purpose is to do.
A second object of the present invention is to provide a pressure sensor package that can be miniaturized to a chip size in a pressure sensor package having an integrated circuit for controlling the pressure sensor.
The present invention provides a manufacturing method of a pressure sensor module that can be obtained in a simple manner, a pressure sensor module that includes an integrated circuit for controlling the pressure sensor and can be reduced to a chip size. Three purposes.
The present invention provides a method for manufacturing a pressure sensor package, which includes a pressure sensor control integrated circuit and can be reduced to a chip size by a simple method. Four purposes.

According to a first aspect of the present invention, there is provided a pressure sensor module according to the first aspect of the present invention, wherein the first substrate and the second substrate are superposed on each other, a space portion disposed inside the central region on the overlapping surface in the base, and the space A diaphragm portion formed of a thinned region of the first substrate, a pressure-sensitive element disposed in the diaphragm portion, and an outer peripheral region excluding the diaphragm portion of the first substrate. the pressure-sensitive element and electrically connected to the conductive portion, a pressure sensor having at least, the disposed on the second substrate, and a control integrated circuit of the pressure sensor, at the peripheral region of the substrate, one end The first substrate and the second substrate constituting the base are aligned so that the conductive portion of the base is electrically connected and the other end is exposed to the other surface of the base made of the outer surface of the second substrate. a through wiring section made through Te, and Characterized by comprising even without.
The pressure sensor module according to claim 2 of the present invention is characterized in that, in claim 1, an integrated circuit for controlling the pressure sensor is arranged on the other surface of the base body formed of the outer surface of the second substrate. To do.
A pressure sensor module according to a third aspect of the present invention is the pressure sensor module according to the first aspect, characterized in that an integrated circuit for controlling the pressure sensor is disposed on a surface that is in contact with the space formed by the inner surface of the second substrate. And
The pressure sensor module according to a fourth aspect of the present invention is the pressure sensor module according to any one of the first to third aspects, wherein the space portion is constituted by a concave portion arranged in a central region of the first substrate. It is characterized by that.
The pressure sensor package according to claim 5 of the present invention, a pressure sensor module according to any one of claims 1 to 4, the other end of the through-wiring portion electrically connected to the bump , At least.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a pressure sensor module, comprising: a base body formed by stacking a first substrate and a second substrate; and an overlapping surface in the base body, A space portion disposed substantially in parallel; a diaphragm portion located on the space portion and formed of a thinned region of the first substrate; a pressure-sensitive element disposed in the diaphragm portion; and the first substrate A pressure sensor disposed at an outer peripheral area excluding the diaphragm portion and having at least a conductive portion electrically connected to the pressure sensitive element; an integrated circuit for controlling the pressure sensor disposed on the second substrate; The base is configured such that, in the outer peripheral area of the base, one end is electrically connected to the conductive portion of the base and the other end is exposed to the other surface of the base made of the outer surface of the second substrate. Combine the first substrate and the second substrate And penetrating formed by penetrating wiring portion, and at least comprising a pressure sensor module manufacturing method of the, on the other surface of the substrate made of an outer surface of the second substrate, the second made is the control integrated circuit form A substrate is used.
According to a seventh aspect of the present invention, there is provided a method for manufacturing a pressure sensor module, comprising: a base body formed by stacking a first substrate and a second substrate; and an overlapping surface in the base body, A space portion disposed substantially in parallel; a diaphragm portion located on the space portion and formed of a thinned region of the first substrate; a pressure-sensitive element disposed in the diaphragm portion; and the first substrate A pressure sensor disposed at an outer peripheral area excluding the diaphragm portion and having at least a conductive portion electrically connected to the pressure sensitive element; an integrated circuit for controlling the pressure sensor disposed on the second substrate; The base is configured such that, in the outer peripheral area of the base, one end is electrically connected to the conductive portion of the base and the other end is exposed to the other surface of the base made of the outer surface of the second substrate. Combine the first substrate and the second substrate And penetrating formed by penetrating wiring portion, and at least comprising a pressure sensor module manufacturing method and a surface in contact with the space portion formed of an inner surface of the second substrate, the said control integrated circuit is formed Two substrates are used.
A method for manufacturing a pressure sensor module according to an eighth aspect of the present invention is the method according to the sixth or seventh aspect, wherein the first substrate having the pressure-sensitive element formed on the outer surface is formed with a recess from the inner surface side. Electrically bonding the second substrate on which the control integrated circuit is formed to the first substrate with the inner surface facing the concave portion, the pressure sensor, and the control integrated circuit. And a step C of connecting to the substrate in order.
The method of manufacturing a pressure sensor package according to claim 9 of the present invention is the method of manufacturing the pressure sensor package according to claim 8, wherein the through wiring portion penetrating the first substrate and the second substrate bonded together in the step B is formed. Thus, the pressure sensor and the control integrated circuit are electrically connected.
According to a tenth aspect of the present invention, there is provided a pressure sensor package manufacturing method, wherein the pressure sensor module manufacturing process according to any one of the sixth to ninth aspects and the control integrated circuit are electrically connected separately. The method further includes a step G of forming a bump connected to the substrate.

In the present invention, a pressure sensor is arranged on the first substrate constituting the base to constitute a pressure sensor, and the integrated circuit for controlling the pressure sensor is arranged on the second substrate constituting the base. Compared to a conventional integrated pressure sensor in which the sensor and the integrated circuit are formed on the same surface of the substrate, the sensor can be configured with a chip area of a pressure sensor with a small area. Accordingly, the present invention can provide a pressure sensor module that is smaller and has a compensation function than the conventional one.
In the present invention, the pressure sensor is arranged on the first substrate constituting the base to constitute a pressure sensor, and the integrated circuit for controlling the pressure sensor is arranged on the second substrate constituting the base. A pressure sensor module configured with a chip area of a small area pressure sensor is provided. Accordingly, the present invention can provide a pressure sensor package that is smaller and has a compensation function than the conventional one.
Further, in the present invention, a pressure sensor comprising a pressure sensor in which a pressure sensitive element is arranged on a first substrate constituting a base, and a control circuit for controlling the pressure sensor on a second substrate constituting the base. In the module manufacturing method, a second substrate on which a control integrated circuit is formed is used as the second substrate constituting the substrate. Thus, the present invention can provide a method of manufacturing a pressure sensor module that can provide a pressure sensor module that includes an integrated circuit for controlling the pressure sensor and is miniaturized to a chip size by a simple method.
Further, in the present invention, a pressure sensor comprising a pressure sensor in which a pressure sensitive element is arranged on a first substrate constituting a base, and a control circuit for controlling the pressure sensor on a second substrate constituting the base. In the package manufacturing method, a second substrate on which a control integrated circuit is formed is used as the second substrate constituting the substrate. Furthermore, it is packaged by combining bump formation techniques. Thus, the present invention can provide a method for manufacturing a pressure sensor package that can provide a pressure sensor package that includes an integrated circuit for controlling the pressure sensor and is miniaturized to a chip size by a simple method.

It is sectional drawing which shows typically an example (1st embodiment) of the pressure sensor package of this invention. It is sectional drawing which shows the manufacturing method of a pressure sensor package in order of a process. It is sectional drawing which shows the manufacturing method of a pressure sensor package in order of a process. It is sectional drawing which shows typically an example (1st embodiment) of the pressure sensor package of this invention. It is sectional drawing which shows typically an example (2nd embodiment) of the pressure sensor package of this invention. It is sectional drawing which shows the manufacturing method of a pressure sensor package in order of a process. It is sectional drawing which shows the manufacturing method of a pressure sensor package in order of a process. It is sectional drawing which shows typically an example (2nd embodiment) of the pressure sensor package of this invention. It is sectional drawing which shows an example of the conventional pressure sensor typically. It is sectional drawing which shows an example of the conventional pressure sensor package typically. It is sectional drawing which shows an example of the conventional pressure sensor package typically. It is sectional drawing which shows an example of the conventional pressure sensor package typically.

  Hereinafter, embodiments of a pressure sensor module and a pressure sensor package according to the present invention will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a cross-sectional view schematically showing one configuration example of the pressure sensor package of the present invention.
The pressure sensor package 1A (1) includes a pressure sensor module 20A (20). The pressure sensor module 20A (20) includes a base 2 formed by stacking a first substrate 3 and a second substrate 4, and the base 2 Of the first substrate 3, a diaphragm portion 6 (which is located on the space portion 5 and is formed of a thinned region of the first substrate 3). Four pressure resistors (piezoresistive elements) R _{1 to} R ₄ (in the figure, R ₁ and R ₂ ) that are pressure sensitive elements 7 arranged in the diaphragm part 6. Only, and on the one surface 2a of the base 2 composed of the outer surface 3b of the first substrate 3, the conductive material is arranged in the outer peripheral area excluding the diaphragm portion 6 and is electrically connected to the pressure sensitive element 7. Pressure sensor 10 having at least part 8 A (10) and at least an integrated circuit for controlling the pressure sensor 10A (10) disposed on the other surface 2b of the base 2 composed of the outer surface 4b of the second substrate 4.

The pressure sensor package 1A (1) is electrically connected to the pressure sensor module 20A (20) and one end of the outer periphery of the base body 2 with the conductive portion 8 disposed on the base body 2. The through wiring portion 11 penetrating the base 2 and the other end of the through wiring portion 11 are electrically connected so that the end is exposed to the other surface 2b of the base 2 formed of the outer surface 4b of the second substrate 4. And at least a bump 21 connected to.
In the pressure sensor 10 </ b> A (10) constituting the pressure sensor module 20 </ b> A (20), the space portion 5 is configured by the recess 3 a disposed in the central region of the first substrate 3.

  In the present invention, the second substrate 4 on which an integrated circuit (ASIC) for controlling the pressure sensor 10 is bonded to the surface opposite to the surface on which the pressure-sensitive element 7 is formed on the first substrate 3, thereby A pressure sensor module 20 having a chip size equivalent to that of the sensor 10 is formed, and further, a pressure sensor package 1 having a chip size equivalent to that of the pressure sensor 10 is formed by a through wiring forming technique and a bump 21 forming technique.

  That is, in the present invention, the pressure sensor 7 is arranged on the one surface 2a of the base 2 to constitute the pressure sensor 10, and the control integrated circuit for the pressure sensor 10 is arranged on the other surface 2b of the base 2. Compared with the conventional integrated pressure sensor in which the pressure sensor and the integrated circuit are formed on the same surface of the substrate, the pressure sensor 10 can be configured with a chip size of a small area. Thereby, in this invention, the pressure sensor module 20 provided with the compensation function smaller than before can be provided.

  Further, in the present invention, the pressure sensitive element 7 is arranged on the one surface 2a of the base 2 to constitute the pressure sensor 10, and the control integrated circuit for the pressure sensor 10 is arranged on the other surface 2b of the base 2. The pressure sensor module 20 is configured with a chip size of the pressure sensor 10 having a small area. Thus, the present invention can provide a pressure sensor package 1 that is smaller and has a compensation function than the conventional one.

As shown in FIG. 1, the pressure sensor 10 </ b> A (10) has a flat plate-like first substrate 3 and second substrate 4 as a base 2, and one surface of the first substrate 3 has the one surface inside the central region. And a space portion 5 (reference pressure chamber) that extends substantially in parallel with each other. In the present embodiment, in the pressure sensor 10 </ b> A (10), the space portion 5 is configured by the concave portion 3 a disposed in the central region of the first substrate 3. A thinned region located on one side (the first substrate 3 side) of the space 5 is referred to as a diaphragm portion 6 (also referred to as a pressure sensitive portion). Resistors R _{1 to} R ₄ that are pressure-sensitive elements 7 are arranged in the pressure-sensitive portion (only R ₁ and R ₂ are shown in the figure).

The p-type resistors (piezoresistive elements) R _{1 to} R ₄ that function as the pressure-sensitive element 7 constitute a detection circuit (strain gauge) that detects pressure fluctuations in the diaphragm section 6, and are connected via lead wires. Are connected to form a so-called Whitstone bridge circuit. Each of the resistors R _{1 to} R ₄ is electrically connected to the pad portion on the outer periphery of the pressure sensor by the conductive portion 8.

In the one surface, a conductive portion 8 electrically connected to each of the resistors R _{1 to} R ₄ is disposed in an outer edge area excluding the diaphragm portion 6. Therefore, the pressure sensor 10 has a structure that functions as an absolute pressure sensor.
Thereby, when the base | substrate 2 is seen from the outside, it can be set as the structure in which the outer edge area | region and the center area | region have substantially the same thickness.

Such resistors R _{1 to} R ₄ are preferably arranged at the peripheral edge of the diaphragm portion 6. Since both compressive and tensile stresses are likely to be applied to the resistors R _{1 to} R ₄ at the peripheral edge, the pressure sensor 10 with good sensitivity can be obtained. The resistors R _{1 to} R ₄ are arranged on the surface of the diaphragm portion 6 and can be formed, for example, by injecting a diffusion source such as boron into a silicon substrate.

The first substrate 3 is provided with a conductive portion 8. The conductive portion 8 can be formed, for example, by forming a metal thin film or the like on the outer surface 3b surface of the first substrate 3, and further patterning by photolithography. One end portion of the conductive portion 8 is electrically connected to the p-type resistors R _{1 to} R _4, and the other end portion is electrically connected to the through wiring portion 11 disposed through the base 2. Has been. Further, the conductive portion 8, via the line obtained by injecting a high concentration diffusion source than P-type resistor R ₁ to R _4, electrically connected to the P-type resistor R ₁ to R ₄ May be.

It is desirable to form an insulating part (not shown) with an insulating material on the outer surface 3b surface of the first substrate 3 excluding the conductive part 8. By providing the insulating part, a structure in which the pressure sensitive element 7 is covered with the insulating part is obtained.
The insulating part blocks the contact of the pressure sensitive element 7 with the outside air, so that the corrosion resistance of the pressure sensitive element 7 is improved and the pressure sensitive element 7 is directly connected to the outside without going through the space part 5 (pressure reference chamber). There is also an effect of suppressing the characteristic fluctuation of the pressure sensor 10 due to the mechanical influence received from the pressure sensor 10.

The through wiring portion 11 includes a through hole 12 provided so as to avoid the space portion 5 and penetrate the base body 2, and a conductive substance 13 filled in the through hole 12. Examples of the conductive material 13 include Cu.
One end portion of the through wiring portion 11 is electrically connected to the conductive portion 8 on the one surface 2a of the base 2, and the other end portion is electrically connected to the electrode portion 14 of the control integrated circuit of the pressure sensor 10 on the other surface 2b. Connected. Thereby, the pressure sensor 10 and the control integrated circuit of the pressure sensor 10 are electrically connected.

  The solder bump 21 can be formed, for example, by mounting a solder ball. Note that the solder bumps 21 do not necessarily indicate only those directly mounted on the pad portion, but a rewiring layer is formed once, and the solder bump 21 is located at a place different from the pad portion via the rewiring layer. Solder balls can also be mounted so as to be electrically connected to the rewiring layer. Thereby, it can have a high freedom degree about a connection position with a mounting substrate or a package.

Next, a manufacturing method of the pressure sensor module 20 and the pressure sensor package 1 as described above will be described.
The manufacturing method of the pressure sensor module according to the present invention includes a base 2 in which the first substrate 3 and the second substrate 4 are overlapped, and the overlapping surface in the base 2 is substantially the same as the first substrate 3 inside the central region. A space portion 5 arranged in parallel; a diaphragm portion 6 located on the space portion 5 and made of a thinned region of the first substrate 3; a pressure-sensitive element 7 arranged in the diaphragm portion 6; and On one surface 2a of the base body 2 composed of the outer surface 3b of the first substrate 3, it has at least a conductive portion 8 that is arranged in an outer peripheral area excluding the diaphragm portion 6 and is electrically connected to the pressure sensitive element 7. A method for manufacturing a pressure sensor module 20 comprising at least a pressure sensor 10 and an integrated circuit for controlling the pressure sensor 10 disposed on the second substrate 4, comprising the outer surface 4 b of the second substrate 4. The other surface 2b of the base body Characterized by using the second substrate 4 to the control integrated circuit is formed.

  In the present invention, a pressure sensor module comprising a pressure sensor 10 having a pressure-sensitive element 7 arranged on one surface 2a of the base 2, and an integrated circuit for controlling the pressure sensor 10 on the other surface 2b of the base 2. In the manufacturing method 20, the second substrate 4 in which the control integrated circuit is formed on the outer surface 4 b forming the other surface 2 b of the base 2 is used. Thus, in the present invention, the pressure sensor module 20 having an integrated circuit for controlling the pressure sensor and reduced in size to a chip size can be obtained by a simple method.

Furthermore, the manufacturing method of the pressure sensor package of the present invention further includes a manufacturing process of the pressure sensor module 20 and a process G of forming bumps 21 that are individually electrically connected to the control integrated circuit. Features.
In the present invention, the bump forming technology is combined and packaged. Accordingly, in the present invention, a pressure sensor package that includes an integrated circuit for controlling the pressure sensor and is miniaturized to a chip size can be obtained by a simple method.
Hereafter, it demonstrates in detail using a figure in order of a process.

FIG. 2 is a cross-sectional view showing the method of manufacturing the pressure sensor package in the order of steps.
(1) First, as shown in FIG. 2 (a), the first substrate 3 having the pressure sensitive element 7 formed on the outer surface 3b is prepared, and the inner surface 3c of the first substrate 3 is first in the central region. A recess 3a is formed (step A).
The first substrate 3 is made of, for example, a semiconductor such as silicon, and is electrically connected to the pressure-sensitive element 7 in the central region and the pressure-sensitive element 7 in the outer peripheral portion of the outer surface 3b that forms one surface 2a of the base 2. A conductive portion 8 is formed in advance. At this time, the pressure-sensitive element 7 is formed to constitute a Whitstone bridge.

  In the present embodiment, first, the first substrate 3 on which the pressure sensitive element 7 is formed is eroded from the surface (inner surface 3c) opposite to the pressure sensitive element 7 forming surface (outer surface 3b). Thus, the recess 3a is formed. The method of forming the recess 3a may be a wet etching method using a potassium hydroxide aqueous solution (hereinafter referred to as a KOH aqueous solution) or the like, or dry etching using a fluorine-based gas and plasma. In the case of dry etching, it can be formed by etching, for example, by DRIE (Deep-Reactive Ion Etching) method.

The DRIE method uses sulfur hexafluoride (SF ₆ ) as an etching gas, and alternately etches with high-density plasma and forms a passivation film on the sidewall (Bosch process), thereby mining and etching the first substrate 3. To do.
The method for forming these recesses 3a 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.

(2) Then, as shown in FIG. 2B, the second substrate 4 having the control integrated circuit formed on the outer surface 4b is opposed to the recess 3a on the inner surface 4c side, and the first substrate 3 is disposed. (Step B). Examples of the bonding method include a method in which the second substrate 4 made of, for example, silicon is bonded to the inner surface 3c side of the first substrate 3 where the concave portion 3a is formed by, for example, heat treatment at a high temperature.
On the second substrate 4, an integrated circuit for controlling the pressure sensor 10 is formed in advance on the outer surface 4 b forming the other surface 2 b of the base 2.

In this embodiment, a case where a substrate bonding technique is used will be described. The second substrate 4 on which the integrated circuit for control is formed is bonded to the opposing surface (the inner surface 3c) of the first substrate 3 on which the pressure sensitive element 7 is formed.
When silicon single crystals are used for the first substrate 3 and the second substrate 4, the surfaces of the first substrate 3 and the second substrate 4 are oxidized by a thermal oxidation method or the like, and then the first substrate 3 and the second substrate 4 are oxidized. There is known a method of bonding substrates by bringing the surfaces on which the films are formed into contact with each other and performing heat treatment. Moreover, in order to remove the natural oxide film of the 1st board | substrate 3 and the 2nd board | substrate 4, and to make it hydrophobic, the hydrogen termination process is performed, and the surface of the 1st board | substrate 3 and the 2nd board | substrate 4 which performed the hydrogen termination process is applied. There is known a method for bonding semiconductor substrates by bringing them into contact and then heat-treating them in an atmosphere containing oxygen after bonding by intermolecular force to desorb hydrogen from the substrate surface and simultaneously form bonds between silicon.

Further, the first substrate 3 is anodized to grow a porous silicon layer on the substrate, and further subjected to heat treatment to form an epitaxial growth layer of silicon on the porous silicon layer, and then the surface is oxidized. A method is known in which silicon is bonded to the oxidized second substrate 4 by intermolecular force and a dehydration condensation reaction is performed by heat treatment.
In this embodiment, it is possible to produce a sealed space using any of the above-described substrate bonding techniques.
In this way, the first substrate 3 having the recesses 3a and the second substrate 4 having the control integrated circuit are bonded using the substrate bonding technique, whereby the pressure sensitive element 7 and the control integrated circuit are formed. The pressure sensor module 20 formed on the opposing surface is obtained.

Next, a method of manufacturing the chip-sized pressure sensor package 1 using such a through wiring formation technique and a bump formation technique will be described for such a pressure sensor module 20.
(3) First, as shown in FIG. 2 (c), the through hole 12 is formed so as to be connected to the back surface of the conductive portion 8 in the pressure sensor 10.
Specifically, as shown in FIG. 2 (c), the outer peripheral portion of the diaphragm portion 6 of the first substrate 3 is in the vicinity of the conductive portion 8 for energizing the pressure sensitive element 7, and of the control integrated circuit. A through hole 12 for electrically connecting the pressure sensor main body and the control integrated circuit is formed in the vicinity of the current introduction portion.
The through hole 12 can be formed by etching, for example, by the DRIE method (Bosch process). In addition, the method of forming the through-hole 12 is not limited to this, and physical processing, such as a laser, is also possible.

(4) Next, an insulating portion (not shown) is formed on the other surface 2 b of the base 2 composed of the inner wall of the through hole 12 and the outer surface 4 b of the second substrate 4. By forming the insulating portion, the surface of the base 2 can be protected when the through wiring portion 11 to be described later is formed.
The insulating part can be formed, for example, by depositing SiO ₂ with a thickness of 1 μm by plasma CVD. This insulating part is not limited to SiO ₂ but may be other insulating material such as SiN or resin. In addition, sputtering, spin coating, etc. can be used for the manufacturing method.

(5) Next, as shown in FIG. 2D, the through wiring portion 11 is formed by filling the through hole 12 with a conductive substance 13 so as to be electrically connected to the conductive portion 8. .
As the conductive substance 13, for example, Cu can be filled in the through hole 12 by plating. Note that the conductive substance 13 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. Furthermore, since the conductive substance 13 filling the through hole 12 is intended to form an electrical connection on both sides of the base body 2, it is not necessary to completely fill the through hole 12 so that there is no space.

(6) Next, as shown in FIG. 3A, the pressure sensor 10 and the control integrated circuit are electrically connected (step C).
On the other surface 2b of the base 2 made of the outer surface 4b of the second substrate 4, the electrode portion 14 of the control integrated circuit is formed so as to be electrically connected to the through wiring portion 11.
One end of the through wiring portion 11 is electrically connected to the conductive portion 8, and the other end is electrically connected to the electrode portion 14 of the control integrated circuit on the other surface 2b. The control integrated circuit is electrically connected.

(7) Next, as shown in FIG. 3B, bumps 21 that are individually electrically connected to the control integrated circuit are formed (step G).
Bumps 21 are formed so as to be individually electrically connected to the control integrated circuit.
The bump 21 can be formed by mounting a solder ball made of, for example, Sn—Ag—Cu. The solder ball can be directly mounted on a conductive portion 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 mounted.
In the present invention, the bumps 21 are not limited to this, and solders of other compositions, solders made of other metals, bumps made of Cu, Au, etc. can be used. A printing method or a plating method using a solder paste, a stud bump using a wire, or the like is applicable.

The bumps 21 can be formed directly on the through wiring portion 11 or can be electrically joined to the through wiring portion 11 on the bump forming surface on the second substrate before the bump 21 is formed. A conductive part (rewiring) may be formed, and a solder ball may be formed at a position different from the through wiring part 11 so as to be electrically connected to the rewiring.
Thereby, the pressure sensor package 1A (1) shown in FIG. 1 is manufactured.

Through the above steps, the pressure sensor package 1A (1) in which the conductive portion 8 of the pressure sensor 10 and the electrode of the control integrated circuit are connected to the pressure sensor module using the through wiring portion 11 is manufactured.
By forming the bump 21 using the through wiring portion 11 penetrating through the inside of the base body 2, the electric wiring is drawn out to the opposite surface side of the diaphragm portion 6, so that the pressure sensor 10 and the electronic component can be formed only by the bump 21. Since it can be electrically bonded to the mounting substrate, high-density mounting is possible.

  In the pressure sensor package shown in FIG. 1, the bumps 21 are provided on the same surface as the control integrated circuit disposed on the other surface 2b of the substrate 2, but the present invention is not limited to this. For example, as shown in FIG. 4, the control circuit is electrically connected to the control integrated circuit through a through wiring portion that is provided through the base 2 and provided separately from the through wiring portion 11. The bump 21 may be provided on the one surface 2a of the base 2. In this case, the mounting substrate of the electronic component connected via the bumps 21 can protect the pressure sensitive element 7 disposed on the one surface 2a of the base 2.

  In the structure shown in FIGS. 1 and 4, since the space portion 5 (pressure reference chamber) is hermetically sealed, an absolute pressure type pressure sensor module can be manufactured, but the space portion 5 communicates with the outside of the pressure sensor module. A gauge pressure type pressure sensor module is manufactured by forming holes on the second substrate 4 on which the integrated circuit for control is formed or on the first substrate 3 on which the pressure sensitive element 7 is formed other than the diaphragm portion 6. Can do.

<Second embodiment>
FIG. 5 is a cross-sectional view schematically showing a configuration example of the pressure sensor package of the present invention.
The pressure sensor package 1C (1) includes a pressure sensor module 20C (20). The pressure sensor module 20C (20) includes a base body 2 in which a first substrate 3 and a second substrate 4 are stacked, Of the first substrate 3, a diaphragm portion 6 (which is located on the space portion 5 and is formed of a thinned region of the first substrate 3). Four pressure resistors (piezoresistive elements) R _{1 to} R ₄ (in the figure, R ₁ and R ₂ ) that are pressure sensitive elements 7 arranged in the diaphragm part 6. Only, and on the one surface 2a of the base 2 composed of the outer surface 3b of the first substrate 3, the conductive material is arranged in the outer peripheral area excluding the diaphragm portion 6 and is electrically connected to the pressure sensitive element 7. Pressure sensor 10 having at least part 8 C (10) and at least a control integrated circuit for controlling the pressure sensor 10C (10) disposed on the surface of the second substrate 4 that is in contact with the space 5 formed by the inner surface 4c.

The pressure sensor package 1C (1) is electrically connected to the pressure sensor module 20C (20) and the conductive portion 8 disposed on the base body 2 at the outer peripheral area of the base body 2. In the through wiring portion 11 penetrating the base 2 and the second substrate 4, one end is the penetrating hole so that the end is exposed to the other surface 2 b of the base 2 made of the outer surface 4 b of the second substrate 4. A first through-wiring portion 24 penetrating through the second substrate 4 so as to be electrically connected to the wiring portion 11 and exposed at the other end to the surface 4c in contact with the space portion 5; and the second substrate 4 The second through-wiring portion 27 penetrating the second substrate 4 such that one end is exposed to the surface 4c in contact with the space portion 5 and the other end is exposed to the outer surface 4b, and the second penetration A bump 21 electrically connected to the other end of the wiring portion 27; Characterized by comprising even without.
In the pressure sensor 10C (10) constituting the pressure sensor module 20C (20), the space portion 5 is configured by the recess 3a disposed in the central region of the first substrate 3.

  In the present invention, an integrated circuit (ASIC) for controlling the pressure sensor 10 formed on the second substrate 4 is bonded so as to face the space portion 5 disposed inside the base body 2. The pressure sensor module 20 having a chip size equivalent to 10 is formed, and further, the pressure sensor package 1 having a chip size equivalent to that of the pressure sensor 10 is formed by the through wiring formation technology and the bump 21 formation technology.

  That is, in the present invention, the pressure sensor 7 is arranged on the one surface 2 a of the base 2 to constitute the pressure sensor 10, and the surface that is in contact with the space portion 5 formed by the inner surface 4 c of the second substrate 4 constituting the base 2. Since the control integrated circuit for the pressure sensor 10 is disposed, the chip size of the pressure sensor 10 with a small area is obtained as compared with the conventional integrated pressure sensor in which the pressure sensor and the integrated circuit are formed on the same surface of the substrate. Can be configured. Thereby, in this invention, the pressure sensor module 20 provided with the compensation function smaller than before can be provided.

  Further, in the present invention, the pressure sensor 7 is arranged on the one surface 2 a of the base 2 to constitute the pressure sensor 10, and the surface that is in contact with the space portion 5 formed by the inner surface 4 c of the second substrate 4 constituting the base 2. By providing an integrated circuit for controlling the pressure sensor 10, a pressure sensor module 20 having a chip size of the pressure sensor 10 having a small area is provided. Thus, the present invention can provide a pressure sensor package 1 that is smaller and has a compensation function than the conventional one.

As shown in FIG. 5, this pressure sensor 10C (10) has a flat plate-like first substrate 3 and second substrate 4 as a base 2, and one surface of the first substrate 3 has the one surface inside the central region. And a space portion 5 (reference pressure chamber) that extends substantially in parallel with each other. In the present embodiment, in the pressure sensor 10 </ b> C (10), the space portion 5 is configured by the concave portion 3 a disposed in the central region of the first substrate 3. A thinned region located on one side (the first substrate 3 side) of the space 5 is referred to as a diaphragm portion 6 (also referred to as a pressure sensitive portion). Resistors R _{1 to} R ₄ that are pressure-sensitive elements 7 are arranged in the pressure-sensitive portion (only R ₁ and R ₂ are shown in the figure).

The p-type resistors (piezoresistive elements) R _{1 to} R ₄ that function as the pressure-sensitive element 7 constitute a detection circuit (strain gauge) that detects pressure fluctuations in the diaphragm section 6, and are connected via lead wires. Are connected to form a so-called Whitstone bridge circuit. Each of the resistors R _{1 to} R ₄ is electrically connected to the pad portion on the outer periphery of the pressure sensor by the conductive portion 8.

In the one surface, a conductive portion 8 electrically connected to each of the resistors R _{1 to} R ₄ is disposed in an outer edge area excluding the diaphragm portion 6. Therefore, the pressure sensor 10 has a structure that functions as an absolute pressure sensor.
Thereby, when the base | substrate 2 is seen from the outside, it can be set as the structure in which the outer edge area | region and the center area | region have substantially the same thickness.

Such resistors R _{1 to} R ₄ are preferably arranged at the peripheral edge of the diaphragm portion 6. Since both compressive and tensile stresses are likely to be applied to the resistors R _{1 to} R ₄ at the peripheral edge, the pressure sensor 10 with good sensitivity can be obtained. The resistors R _{1 to} R ₄ are arranged on the surface of the diaphragm portion 6 and can be formed, for example, by injecting a diffusion source such as boron into a silicon substrate.

The first substrate 3 is provided with a conductive portion 8. The conductive portion 8 can be formed, for example, by forming a metal thin film or the like on the outer surface 3b surface of the first substrate 3, and further patterning by photolithography. One end portion of the conductive portion 8 is electrically connected to the p-type resistors R _{1 to} R _4, and the other end portion is electrically connected to the through wiring portion 11 disposed through the base 2. Has been. Further, the conductive portion 8, via the line obtained by injecting a high concentration diffusion source than P-type resistor R ₁ to R _4, electrically connected to the P-type resistor R ₁ to R ₄ May be.

It is desirable to form an insulating part (not shown) with an insulating material on the outer surface 3b surface of the first substrate 3 excluding the conductive part 8. By providing the insulating part, a structure in which the pressure sensitive element 7 is covered with the insulating part is obtained.
The insulating part blocks the contact of the pressure sensitive element 7 with the outside air, so that the corrosion resistance of the pressure sensitive element 7 is improved and the pressure sensitive element 7 is directly connected to the outside without going through the space part 5 (pressure reference chamber). There is also an effect of suppressing the characteristic fluctuation of the pressure sensor 10 due to the mechanical influence received from the pressure sensor 10.

The through wiring portion 11 includes a through hole 12 provided so as to avoid the space portion 5 and penetrate the base body 2, and a conductive substance 13 filled in the through hole 12. Examples of the conductive material 13 include Cu.
One end portion of the through wiring portion 11 is electrically connected to the conductive portion 8 on the one surface 2a of the base 2, and the other end portion is electrically connected to the conductive portion 14 on the other surface 2b.
Further, the first through wiring part 24 and the second through wiring part 27 different from the through wiring part 11 are provided so as to penetrate the space overlapping the space part 5 of the second substrate 4 and communicate with the space part 5. ing. At this time, the second through wiring portion 27 is provided farther from the first through wiring portion 24 with respect to the through wiring portion 11.
The conductive portion 14 is electrically connected to one end of the first through wiring portion 24 arranged through the second substrate 4, and the other end of the first through wiring portion 24 is connected to the inner surface of the second substrate 4. The surface in contact with the space portion 5 made of 4c is electrically connected to the electrode portion 28 of the control integrated circuit of the pressure sensor 10. Thereby, the pressure sensor 10 and the control integrated circuit of the pressure sensor 10 are electrically connected.

  Further, the electrode part 29 of the control integrated circuit is electrically connected to one end of the second through wiring part 27 arranged through the second substrate 4 on the surface in contact with the space part 5 formed by the inner surface 4 c of the second substrate 4. The other end of the second through wiring portion 27 is electrically connected to the solder bump 21 on the other surface 2 b of the base 2.

  The solder bump 21 can be formed, for example, by mounting a solder ball. Note that the solder bumps 21 do not necessarily indicate only those directly mounted on the other surface 2b of the base body 2 in the space 5, but once the rewiring layer is formed, For example, solder balls can be mounted so as to be electrically connected to the rewiring layer at the pad portion. Thereby, it can have a high freedom degree about a connection position with a mounting substrate or a package.

Next, a manufacturing method of the pressure sensor module 20 and the pressure sensor package 1 as described above will be described.
The manufacturing method of the pressure sensor module according to the present invention includes a base 2 in which the first substrate 3 and the second substrate 4 are overlapped, and the overlapping surface in the base 2 is substantially the same as the first substrate 3 inside the central region. A space portion 5 arranged in parallel; a diaphragm portion 6 located on the space portion 5 and made of a thinned region of the first substrate 3; a pressure-sensitive element 7 arranged in the diaphragm portion 6; and On one surface 2a of the base body 2 composed of the outer surface 3b of the first substrate 3, it has at least a conductive portion 8 that is arranged in an outer peripheral area excluding the diaphragm portion 6 and is electrically connected to the pressure sensitive element 7. A method of manufacturing a pressure sensor module 20 comprising at least a pressure sensor 10 and an integrated circuit for controlling the pressure sensor 10 disposed on the second substrate 4, comprising the inner surface 4 c of the second substrate 4. In contact with the space 5 The surface, which comprises using the second substrate 4 to the control integrated circuit is formed.

  In the present invention, the pressure sensor 10 formed by arranging the pressure sensitive element 7 on the one surface 2a of the base 2 and the surface in contact with the space portion 5 formed by the inner surface 4c of the second substrate 4 constituting the base 2 are described above. In the manufacturing method of the pressure sensor module 20 including the control integrated circuit of the pressure sensor 10, the surface of the pressure sensor 10 is arranged on the surface that is in contact with the space portion 5 formed by the inner surface 4 c of the second substrate 4 constituting the base 2. A second substrate 4 on which a control integrated circuit is formed is used. Thus, in the present invention, the pressure sensor module 20 having an integrated circuit for controlling the pressure sensor and reduced in size to a chip size can be obtained by a simple method.

Furthermore, the manufacturing method of the pressure sensor package of the present invention further includes a manufacturing process of the pressure sensor module 20 and a process G of forming bumps 21 that are individually electrically connected to the control integrated circuit. Features.
In the present invention, the bump forming technology is combined and packaged. Accordingly, in the present invention, a pressure sensor package that includes an integrated circuit for controlling the pressure sensor and is miniaturized to a chip size can be obtained by a simple method.
Hereafter, it demonstrates in detail using a figure in order of a process.

FIG. 6 is a cross-sectional view showing the method of manufacturing the pressure sensor package in the order of steps.
(1) First, as shown in FIG. 6A, the first substrate 3 having the pressure sensitive element 7 formed on the outer surface 3 b is prepared, and the first region 3 c of the first substrate 3 is first in the central region. A recess 3a is formed (step A).
The first substrate 3 is made of, for example, a semiconductor such as silicon, and is electrically connected to the pressure-sensitive element 7 in the central region and the pressure-sensitive element 7 in the outer peripheral portion of the outer surface 3b that forms one surface 2a of the base 2. A conductive portion 8 is formed in advance. At this time, the pressure-sensitive element 7 is formed to constitute a Whitstone bridge.

  In the present embodiment, first, the first substrate 3 on which the pressure sensitive element 7 is formed is eroded from the surface (inner surface 3c) opposite to the pressure sensitive element 7 forming surface (outer surface 3b). Thus, the recess 3a is formed. The method of forming the recess 3a may be a wet etching method using a potassium hydroxide aqueous solution (hereinafter referred to as a KOH aqueous solution) or the like, or dry etching using a fluorine-based gas and plasma. In the case of dry etching, it can be formed by etching, for example, by DRIE (Deep-Reactive Ion Etching) method.

The DRIE method uses sulfur hexafluoride (SF ₆ ) as an etching gas, and alternately etches with high-density plasma and forms a passivation film on the sidewall (Bosch process), thereby mining and etching the first substrate 3. To do.
The method for forming these recesses 3a 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.

(2) Then, as shown in FIG. 6B, the second substrate 4 on which the control integrated circuit and the electrode portions 28 and 29 of the control integrated circuit are formed in the central region of the inner surface 4c is formed on the inner surface. 4c side is made to oppose the said recessed part 3a, and it bonds together to said 1st board | substrate 3 (process B). Examples of the bonding method include a method in which the second substrate 4 made of, for example, silicon is bonded to the inner surface 3c side of the first substrate 3 where the concave portion 3a is formed by, for example, heat treatment at a high temperature.
On the second substrate 4, an integrated circuit for controlling the pressure sensor 10 is formed in advance on the surface in contact with the space portion 5 formed by the inner surface 4 c of the second substrate 4 constituting the base 2. The electrode portions 28 and 29 are formed in advance at positions where the first through wiring portion 24 and the second through wiring portion 27 are formed, respectively.

In this embodiment, a case where a substrate bonding technique is used will be described. The second substrate 4 on which the integrated circuit for control is formed is bonded to the opposing surface (the inner surface 3c) of the first substrate 3 on which the pressure sensitive element 7 is formed.
When silicon single crystals are used for the first substrate 3 and the second substrate 4, the surfaces of the first substrate 3 and the second substrate 4 are oxidized by a thermal oxidation method or the like, and then the first substrate 3 and the second substrate 4 are oxidized. There is known a method of bonding substrates by bringing the surfaces on which the films are formed into contact with each other and performing heat treatment. Moreover, in order to remove the natural oxide film of the 1st board | substrate 3 and the 2nd board | substrate 4, and to make it hydrophobic, the hydrogen termination process is performed, and the surface of the 1st board | substrate 3 and the 2nd board | substrate 4 which performed the hydrogen termination process is applied. There is known a method for bonding semiconductor substrates by bringing them into contact and then heat-treating them in an atmosphere containing oxygen after bonding by intermolecular force to desorb hydrogen from the substrate surface and simultaneously form bonds between silicon.

Further, the first substrate 3 is anodized to grow a porous silicon layer on the substrate, and further subjected to heat treatment to form an epitaxial growth layer of silicon on the porous silicon layer, and then the surface is oxidized. A method is known in which silicon is bonded to the oxidized second substrate 4 by intermolecular force and a dehydration condensation reaction is performed by heat treatment.
In this embodiment, it is possible to produce a sealed space using any of the above-described substrate bonding techniques.
In this way, the first integrated circuit board 3 in which the recess 3a is formed and the second integrated circuit board 4 in which the control integrated circuit is formed are bonded using the substrate bonding technique, so that the control integrated circuit is The pressure sensor module 20 formed inside is obtained.

Next, a method of manufacturing the chip-sized pressure sensor package 1 using such a through wiring formation technique and a bump formation technique will be described for such a pressure sensor module 20.
(3) First, as shown in FIG. 6C, the through hole 12 is formed so as to be connected to the back surface of the conductive portion 8 in the pressure sensor 10. Further, through holes 22 and 25 are formed so as to be connected to the back surfaces of the electrode portions 28 and 29 of the inner surface 4c.
Specifically, as shown in FIG. 6C, a through hole 12 is formed in the vicinity of the conductive portion 8 for energizing the pressure sensitive element 7 on the outer peripheral portion of the diaphragm portion 6 of the first substrate 3. Further, there are through-holes in the vicinity of the electrode portion 28 formed in the current introduction portion of the pressure sensor control integrated circuit and the electrode portion 29 formed in the current lead-out portion of the pressure sensor control integrated circuit. 22 and 25 are formed.
The through holes 12, 22, and 25 can be formed by etching, for example, by the DRIE method (Bosch process). Note that the method of forming the through holes 12, 22, and 25 is not limited to this, and physical processing such as laser is also possible.

(4) Next, an insulating portion (not shown) is formed on the inner surface of the through holes 12, 22, and 25 and the other surface 2 b of the base 2 including the outer surface 4 b of the second substrate 4. By forming the insulating portion, the surface of the substrate 2 can be protected when the through wiring portions 11, 24, and 27, which will be described later, are formed.
The insulating part can be formed, for example, by depositing SiO ₂ with a thickness of 1 μm by plasma CVD. This insulating part is not limited to SiO ₂ but may be other insulating material such as SiN or resin. In addition, sputtering, spin coating, etc. can be used for the manufacturing method.

(5) Next, as shown in FIG. 6D, the through wiring portion 11 is formed by filling the through hole 12 with a conductive substance 13 so as to be electrically connected to the conductive portion 8. . Further, the through wiring portions 24 and 27 are formed by filling the through holes 22 and 25 with the conductive materials 23 and 26 so as to be electrically connected to the electrode portions 28 and 29.
The conductive materials 13, 23, and 26 may be Cu, for example, and may be filled in the through holes 12, 22, and 25 by plating. Note that the conductive substances 13, 23, and 26 are not limited to this, and may be other metal materials or alloys such as solder. Also, the filling method can use CVD or sputtering. Furthermore, the conductive materials 13, 23 and 26 filling the through holes 12, 22 and 25 form an electrical connection on both sides of the base 2 and an electrical connection on both sides of the second substrate 4. Therefore, it is not necessary to completely fill the through holes 12, 22, and 25 so that there is no space.

(6) Next, as shown in FIG. 7A, the pressure sensor 10 and the control integrated circuit are electrically connected (step C).
The conductive portion 14 is formed so that the through wiring portion 11 and the first through wiring portion 24 are electrically connected to each other on the other surface 2b of the base body 2 including the outer surface 4b of the second substrate 4.
One end of the through wiring portion 11 is electrically connected to the conductive portion 8, and the other end is electrically connected to the conductive portion 14 on the other surface 2b. Further, one end portion of the first through wiring portion 24 is electrically connected to the conductive portion 14 on the other surface 2b, and the other end portion is electrically connected to the electrode portion 28 on the inner surface 4c. Thereby, the pressure sensor 10 and the control integrated circuit are electrically connected.

(7) Next, as shown in FIG. 7B, bumps 21 that are individually electrically connected to the control integrated circuit are formed (step G).
Bumps 21 are formed so as to be individually electrically connected to the control integrated circuit.
The bump 21 can be formed by mounting a solder ball made of, for example, Sn—Ag—Cu. Note that the solder ball can be directly mounted on the second through wiring portion 27 on the outer surface 4b, or a rewiring layer is formed once and the solder ball is re-installed at a place different from the second through wiring portion 27. It can also be mounted so as to be electrically connected to the wiring layer.
In the present invention, the bumps 21 are not limited to this, and solders of other compositions, solders made of other metals, bumps made of Cu, Au, etc. can be used. A printing method or a plating method using a solder paste, a stud bump using a wire, or the like is applicable.

The bumps 21 can be formed directly on the second through wiring part 27 on the outer surface 4b, or on the bump forming surface on the second substrate before the bump 21 is formed. It is also possible to form a conductive portion (redistribution) so as to be electrically connected to the solder, and to form a solder ball so as to be electrically connected to the redistribution at a position different from the second through wiring portion 27.
Thereby, the pressure sensor package 1C (1) shown in FIG. 5 is manufactured.

Through the above steps, the pressure sensor package 1C (1) in which the conductive portion 8 of the pressure sensor 10 and the electrode of the control integrated circuit are connected to the pressure sensor module using the through wiring portion 11 and the first through wiring portion 24. ) Is produced.
The bump 21 is formed by using the through wiring portion 11 penetrating the inside of the base body 2 and the first through wiring portion 24 and the second through wiring portion 27 penetrating the second substrate, so that the opposing surface of the diaphragm portion 6 is formed. By drawing out the electrical wiring to the side, the bumps 21 alone can be electrically joined to the pressure sensor 10 and the electronic component mounting substrate, so that high-density mounting is possible.

  In the pressure sensor package shown in FIG. 5, the bumps 21 are provided on the other surface 2b of the base 2. However, the present invention is not limited to this. For example, as shown in FIG. Bumps 21 are provided on one surface 2a of the base 2 so as to be electrically connected to the control integrated circuit through a through wiring portion provided separately from the through wiring portion 11. May be. In this case, the mounting substrate of the electronic component connected via the bumps 21 can protect the pressure sensitive element 7 disposed on the one surface 2a of the base 2.

  In the structure shown in FIGS. 5 and 8, since the space portion 5 (pressure reference chamber) is sealed, an absolute pressure type pressure sensor module can be manufactured. However, the space portion 5 communicates with the outside of the pressure sensor module. A gauge pressure type pressure sensor module is manufactured by forming holes on the second substrate 4 on which the integrated circuit for control is formed or on the first substrate 3 on which the pressure sensitive element 7 is formed other than the diaphragm portion 6. Can do.

  By the way, in the structure shown in FIG. 1, FIG. 4, FIG. 5, and FIG. 8, the substrate for protecting the pressure sensitive element is not installed on the pressure sensitive element. Compared to a conventional pressure sensor package that is electrically connected and the pressure sensor is sealed in a space composed of resin, etc., it becomes difficult to maintain the mechanical strength of the pressure sensor due to disturbance, and the sensor characteristics fluctuate. Problem arises. Therefore, subsequently, a protective substrate for the pressure sensor may be formed on the pressure-sensitive element 7 (not shown).

  First, an adhesive between a semiconductor substrate on which a pressure sensor is formed and a protective substrate is placed on a region outside the diaphragm portion 6 on the surface of the first substrate 3 on which the pressure sensitive element 7 is formed. The adhesive may be acrylic, epoxy, polyimide, etc., and may be thermosetting or room temperature curable. However, when the metal material contained in the conductive portion 8 is melted at the time of bonding and is electrically disconnected due to aggregation or the like, a current for observing a voltage change due to a change in electric resistance of the pressure sensitive element 7 is applied to the pressure sensitive element 7. Therefore, it is desirable to use an adhesive that can be cured at a temperature lower than the melting point of the metal material.

  Subsequently, a protective substrate is installed on the first substrate 3 on which the pressure-sensitive element 7 on which the adhesive is installed is formed, and the first substrate 3 and the protective substrate are bonded. In this embodiment, since the pressure reference chamber has a sealed absolute pressure type pressure sensor, it is necessary to apply an external gas pressure on the formation surface of the pressure sensitive element 7. Therefore, it is necessary that there is a gap between the protective substrate and the first substrate 3 on which the pressure-sensitive element 7 is formed, and it is not sealed with an adhesive. When bonding, the first substrate 3 and the protective substrate may be heated depending on the type of adhesive. Even if it arrange | positions so that a space | gap may be formed between the 1st board | substrate 3 and a protective substrate, a protective substrate may deform | transform by heat processing and a space | gap may lose | disappear. Therefore, when the first substrate 3 and the protective substrate are bonded by heat treatment, it is desirable to use a protective substrate whose main component is a material that does not deform below the heating temperature.

  Further, when the protective substrate or the adhesive resin has conductivity, a part of the current may be applied to the pressure sensitive element 7 through the conductive portion 8 from the resin or the protective substrate. It is desirable to have an insulating property.

  On the other hand, it is desirable that the protective substrate has a mechanical strength equal to or higher than that of the resin material of the conventional pressure sensor package. Further, since the semiconductor substrate on which the pressure sensor is formed and the protective substrate are connected via the resin material, the difference in thermal expansion coefficient between the protective substrate and the semiconductor substrate on which the pressure sensor is formed is reduced. Therefore, there is an effect that fluctuations in sensor characteristics of the pressure sensor can be suppressed as compared with the case where bumps are formed on the surface of the semiconductor substrate on which the pressure sensitive elements are formed. More preferably, it is desirable that the semiconductor substrate on which the pressure sensor is formed and the protective substrate have the same thermal expansion coefficient. For example, when the semiconductor substrate is silicon, it is desirable to use a material having an insulating property such as glass and having a thermal expansion coefficient comparable to that of silicon.

  The protective substrate shown in the present embodiment is formed for the purpose of protecting the pressure sensitive element 7 after the pressure sensor module 20 is formed, but is used as a protective substrate for the pressure sensitive element 7 when forming the through wiring portion 11 and the like. It is also possible. Therefore, the protective substrate may be formed on the pressure sensitive element 7 before forming the through wiring portion 11 and the like.

  In addition, when the pressure sensor module 20 is mounted on a mounting board for electronic components, the height of the pressure sensor module 20 after mounting depends on the sum of the thicknesses of the protective substrate and the semiconductor substrate. There is a problem that it becomes disadvantageous when implementing. Thus, after the protective substrate is attached to the semiconductor substrate, thinning the protective substrate by lapping or the like is effective for reducing the thickness at the time of mounting.

  In the above-described embodiment, the case where the concave portion 3a is formed from the inner surface 3c side with respect to the first substrate 3 on which the pressure-sensitive element 7 has been previously formed on the outer surface 3b has been described as an example. When forming the concave portion 3a, the concave portion 3a is first formed until the diaphragm portion 6 has an appropriate thickness, and the semiconductor substrate is bonded to the semiconductor substrate. Alternatively, the pressure-sensitive element 7 may be formed after the diaphragm portion 6 is processed to an appropriate thickness by grinding or polishing the surface. Thereby, a pressure sensor with stable sensor characteristics can be obtained.

As described above, the pressure sensor module and the pressure sensor package of the present invention and the manufacturing method thereof have been described. However, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention. is there.
For example, regarding the arrangement and number of p-type resistors that function as a strain gauge, various modifications can be considered. In short, as long as the pressure strain of the diaphragm portion (pressure-sensitive portion) can be detected, any arrangement or number can be used. It doesn't matter.

  The present invention is widely applicable to pressure sensors and pressure sensor packages, and methods for manufacturing these.

  1A, 1B, 1C, 1D (1) Pressure sensor package, 2 base, 3 first substrate, 3a recess, 4 second substrate, 5 space, 6 diaphragm portion (pressure sensitive portion), 7 pressure sensitive element, 8 conductive Part, 10A, 10B, 10C, 10D (10) Pressure sensor, 11 Through wiring part, 12 Through hole, 13 Conductive substance, 14 Electrode for control integrated circuit, 20A, 20B, 20C, 20D (20) Pressure sensor module , 21 Bump, 22 Through-hole, 23 Conductive material, 24 Through-wiring part, 25 Through-hole, 26 Conductive substance, 27 Through-wiring part, 28 Control integrated circuit electrode, 29 Control integrated circuit electrode

Claims (10)

A substrate formed by stacking a first substrate and a second substrate;
In the overlapping surface in the base body, a space portion arranged inside the central area,
A diaphragm portion that is located on the space portion and includes a thinned region of the first substrate,
A pressure-sensitive element disposed in the diaphragm, and
A pressure sensor disposed at an outer peripheral area excluding the diaphragm portion of the first substrate and having at least a conductive portion electrically connected to the pressure sensitive element;
An integrated circuit for controlling the pressure sensor, disposed on the second substrate;
In the outer peripheral area of the base body, the first base that constitutes the base body is configured such that one end is electrically connected to the conductive portion of the base body and the other end is exposed to the other surface of the base body that is the outer surface of the second substrate. A through-wiring portion formed by penetrating through one substrate and the second substrate;
A pressure sensor module comprising at least 2. The pressure sensor module according to claim 1, wherein an integrated circuit for controlling the pressure sensor is disposed on the other surface of the base body formed of the outer surface of the second substrate. 2. The pressure sensor module according to claim 1, wherein an integrated circuit for controlling the pressure sensor is disposed on a surface of the second substrate that contacts the space portion. The pressure sensor module according to any one of claims 1 to 3, wherein the space portion is configured by a concave portion disposed in a central region of the first substrate. The pressure sensor module according to any one of claims 1 to 4 ,
A pressure sensor package comprising at least a bump electrically connected to the other end of the through wiring portion. A substrate formed by stacking a first substrate and a second substrate;
In the overlapping surface in the base body, a space portion arranged substantially parallel to the first substrate inside the central region,
A diaphragm portion that is located on the space portion and includes a thinned region of the first substrate,
A pressure-sensitive element disposed in the diaphragm, and
A pressure sensor disposed at an outer peripheral area excluding the diaphragm portion of the first substrate and having at least a conductive portion electrically connected to the pressure sensitive element;
An integrated circuit for controlling the pressure sensor disposed on the second substrate;
In the outer peripheral area of the base body, the first base that constitutes the base body is configured such that one end is electrically connected to the conductive portion of the base body and the other end is exposed to the other surface of the base body that is the outer surface of the second substrate. A through-wiring portion formed by penetrating through one substrate and the second substrate;
A method of manufacturing a pressure sensor module comprising at least
A method of manufacturing a pressure sensor module, comprising using a second substrate in which the control integrated circuit is formed on the other surface of the base body, which is an outer surface of the second substrate. A substrate formed by stacking a first substrate and a second substrate;
In the overlapping surface in the base body, a space portion arranged substantially parallel to the first substrate inside the central region,
A diaphragm portion that is located on the space portion and includes a thinned region of the first substrate,
A pressure-sensitive element disposed in the diaphragm, and
A pressure sensor disposed at an outer peripheral area excluding the diaphragm portion of the first substrate and having at least a conductive portion electrically connected to the pressure sensitive element;
An integrated circuit for controlling the pressure sensor disposed on the second substrate;
In the outer peripheral area of the base body, the first base that constitutes the base body is configured such that one end is electrically connected to the conductive portion of the base body and the other end is exposed to the other surface of the base body that is the outer surface of the second substrate. A through-wiring portion formed by penetrating through one substrate and the second substrate;
A method of manufacturing a pressure sensor module comprising at least
A method for manufacturing a pressure sensor module, comprising: using a second substrate in which the control integrated circuit is formed on a surface of the second substrate in contact with the space portion. Forming a recess from the inner surface side on the first substrate having the pressure-sensitive element formed on the outer surface; and
Bonding the second substrate on which the control integrated circuit is formed to the first substrate with the inner surface facing the concave portion; and
8. The method of manufacturing a pressure sensor module according to claim 6, further comprising a step C of electrically connecting the pressure sensor and the control integrated circuit. The pressure sensor and the control integrated circuit are electrically connected by forming the through wiring portion penetrating through the first substrate and the second substrate bonded together in the step B. A method for manufacturing a pressure sensor module according to claim 8. A manufacturing process of the pressure sensor module according to any one of claims 6 to 9 ,
A method of manufacturing a pressure sensor package, further comprising a step G of forming a bump electrically connected to the control integrated circuit individually.

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