JP5345346B2 - Mounting method of micro electro mechanical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging configuration of MEMS which intercepts external oscillating disturbance while ensuring reliability in wire bonding in the mounting process of an MEMS which is susceptible to oscillating disturbance of signals other than a signal to be measured. <P>SOLUTION: A support 11 for enhancing the reliability of wire bonding, and a semiconductor chip CHP1 provided with a movable portion by an elastic support 13 for intercepting oscillating disturbance are fixed to the outer frame 10. Since the support 11 is deformed thermally and separated, the semiconductor chip CHP1 is ultimately connected only by the soft elastic support 13 in the outer frame 10 and thereby a suspension structure is attained. Consequently, transmission of spontaneous oscillation or oscillating disturbance is prevented. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a mounting method of a micro electro mechanical system including a step of housing a semiconductor chip having a movable part such as an acceleration sensor, an angular velocity sensor, a vibrator, and a micromirror in an outer frame.

  In the case of MEMS (micro electro mechanical systems) type acceleration sensors and angular velocity sensors, vibrations outside the measurement frequency band of the sensor or the resonance frequency of the movable part that constitutes the sensor or vibrations in the vicinity of the vibration act on the movable part. Then, the vibration may affect the output of the sensor. For example, considering the case of an acceleration sensor, there is a possibility that the acceleration output from the acceleration sensor is not 1G even though the gravitational acceleration (1G) is applied. Even in the case of the angular velocity sensor, a signal for detecting the angular velocity may be output or a value different from the angular velocity actually applied may be output even though the angular velocity is not applied. That is, if vibration other than vibration to be detected is applied to the movable part of the sensor, there is a possibility that the detection sensitivity fluctuates and the detection accuracy decreases.

  In order to solve such a problem, the movable part of the sensor itself is devised to have insensitive characteristics to vibrations outside the measurement frequency band, or vibrations other than the measurement band are not transmitted to the movable part of the sensor. It is necessary to devise like this.

  As an example, when considering an acceleration sensor used for game consoles, car navigation and car attitude control, the signal to be measured is vibration in the 0-50 Hz band, and for signals in the 50 Hz band or higher (vibration disturbance) Therefore, it is necessary to make the movable part of the sensor have insensitive characteristics or not to transmit vibration disturbance other than the signal to be measured to the movable part.

  Here, in order for the moving part of the acceleration sensor to be insensitive to vibration disturbances in the 50 Hz band or higher, the damping and cut-off frequency and natural frequency of the acceleration sensor structure are well designed, non-resonant, and cut It is necessary to lower the off frequency to 50 Hz or lower. However, in the case of the MEMS type acceleration sensor, downsizing is promoted, and with this downsizing, the natural frequency of the movable part of the MEMS type acceleration sensor tends to increase to several to several tens of kHz. For this reason, in order to realize non-resonance and a low cutoff frequency, very large damping is required. Therefore, in reality, the measures regarding the structure of the MEMS type acceleration sensor are limited.

  Furthermore, in the case of an angular velocity sensor, in order to drive at a low voltage, the movable part is vacuum-sealed and driven using a resonance phenomenon at the natural frequency of the movable part, thereby obtaining a drive amplitude necessary for angular velocity detection. ing. Therefore, unlike the acceleration sensor, making the moving part itself insensitive to vibration disturbance by a non-resonant design contradicts the principle of the sensor. Therefore, in the case of the angular velocity sensor, it is necessary to devise not to transmit the vibration disturbance to the movable part by devising the mounting form of the movable part rather than the measure by the movable part itself.

  In the case of an angular velocity sensor, it is necessary to constantly vibrate on the principle as described above. Therefore, the drive vibration of the angular velocity sensor may cause leakage noise and vibration to the outside.

As a conventional technique, for example, there is JP-A-2003-28647 (Patent Document 1). Based on the specification of Patent Document 1, as shown in FIG. 44, the semiconductor chip 101 is fixed to the pedestal portion of the package 100 via a spacer, and then formed on the side surface of the semiconductor chip 101 and the side surface of the package 100. The elastic support member 102 softened in a spot manner is formed in the gap. Thereafter, the elastic support member 102 is cured, whereby the side surface of the semiconductor chip 101 is partially fixed to the package 100 by the elastic support member 102. Then, after the semiconductor chip 101 and the package 100 are connected by the wire 103, the spacer is removed to form a gap 104 between the bottom surface of the semiconductor chip 101 and the pedestal surface of the package 100. Finally, the package 100 is hermetically sealed with the lid 105, so that it is possible to take a vibration-proof measure inside the package 100.
JP 2003-28647 A

  However, in the technique described in Patent Document 1, after the elastic support member 102 is formed, the spacer is removed by an etchant, gas, heat, or the like. 102 needs to be formed in a spot shape in order to secure an entrance and exit for an etchant and gas. However, the elastic support member 102 is often a soft gel like silicon gel, for example. Therefore, since the elastic support member 102 is cured by heat treatment such as baking, it is necessary to control the shape of the elastic support member 102 by devising the shape of the package 100 in advance in order to obtain the desired spring characteristics. It is necessary to pay close attention.

  Further, when the spacer is removed with an etchant or gas, the etchant or gas needs to be supplied from the outside of the package 100, and the spacer removal operation is necessarily performed before the package 100 is sealed with the lid 105. It is necessary to do in. For this reason, it is necessary to perform the spacer removal work in a clean environment with little foreign matter such as dust, and it is necessary to perform the package 100 with care.

  Furthermore, in the technique described in Patent Document 1, a film resist is cited as an example of a spacer, but this film resist can be removed using a liquid organic solvent such as acetone. However, since the melted film resist contaminates the components (components) formed inside the package 100 such as the semiconductor chip 101 and the wire 103, after the film resist is removed with an organic solvent, the inside of the package 100 is further removed. In order to clean the components formed in the above, a separate cleaning process is required. In this case, since the semiconductor chip 101, the package 100, the wire 103, and the like are immersed in the flow of the solution and the dissolved film resist, there is a possibility that current leakage due to deformation or contamination of the wire 103 may occur.

  In addition, the spacer is disposed between the semiconductor chip 101 having a relatively large area (several to several tens of mm square) and the pedestal portion of the package 100, and the thickness thereof is on the order of several to several hundred μm. Reliable removal with an etchant or gas is considered difficult in practice.

  Moreover, in order to confirm whether or not the spacer can be surely removed by any of the etchant, gas, and heat removal methods, vibration is applied to the package 100 or the semiconductor chip 101 from the outside and the movement is measured. Therefore, an excitation means and a measurement means for applying vibration from the outside are required.

  Accordingly, the present invention has been made to solve the above-described technical problems, and is capable of moving an angular velocity sensor, an acceleration sensor, a combined sensor (a sensor in which the angular velocity sensor and the acceleration sensor are integrated), a micromirror, and the like. For the purpose of providing technology that can suppress the transmission of disturbance vibration from the outside to the inside of the package while ensuring the reliability at the time of wire bonding in the mounting process of MEMS (micro electro mechanical system) equipped with a part Yes.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  A method for mounting a microelectromechanical system according to a representative embodiment includes: (a) a step of preparing a first semiconductor chip on which a structure including a cavity and a movable movable body provided in the cavity is formed. And (b) a second semiconductor chip that forms an integrated circuit that processes an output from the structure formed on the first semiconductor chip as an electrical signal and has a planar shape larger than that of the first semiconductor chip. Providing a step. Next, (c) a step of preparing an outer frame body having a concave shape and an open top, and (d) a bottom portion of the outer frame body and the second semiconductor chip are discretely arranged. A step of connecting via a plurality of support members; and (e) a step of mounting the first semiconductor chip on the second semiconductor chip after the step (d). Subsequently, (f) after the step (e), the first terminal formed on the first semiconductor chip and the second terminal formed on the second semiconductor chip are connected by a first wire, Connecting a third terminal formed on the second semiconductor chip and a fourth terminal formed on the outer frame with a second wire. Thereafter, (g) after the step (f), the cap on which the elastic support member is formed is disposed so that the elastic support member adheres to the first semiconductor chip, and the cap is used for the inside of the outer frame body. And (h) after the step (g), by heating the plurality of support members, the plurality of support members are melted, and the melted surfaces that act on the plurality of support members A step of separating the second semiconductor chip and the bottom of the outer frame body by using tension.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  In the mounting process of MEMS (micro electro mechanical system), it is possible to suppress the transmission of disturbance vibration from the outside to the inside of the package while ensuring the reliability at the time of wire bonding.

  In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. There are some or all of the modifications, details, supplementary explanations, and the like.

  Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say.

  Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., unless otherwise specified, and in principle, it is not considered that it is clearly apparent in principle. Including those that are approximate or similar to the shape. The same applies to the above numerical values and ranges.

  In all the drawings for explaining the embodiments, the same members are denoted by the same reference symbols in principle, and the repeated explanation thereof is omitted. In order to make the drawings easy to understand, even a plan view may be hatched.

(Embodiment 1)
The MEMS in the first embodiment will be described with reference to the drawings. In the first embodiment, an acceleration sensor will be described as an example of MEMS. FIG. 1 is a plan view showing a structure constituting the acceleration sensor formed on the semiconductor chip CHP1. As shown in FIG. 1, the semiconductor chip CHP <b> 1 is provided with a fixing portion 1, and a beam 2 is connected to the fixing portion 1. And the beam 2 is connected with the movable part 3 used as the weight of an acceleration sensor. That is, the fixed portion 1 and the movable portion 3 are connected by the elastically deformable beam 2 so that the movable portion 3 can be displaced in the x direction of FIG. And the fixed electrode 4 is provided so that the movable part 3 may be pinched | interposed. The structure of the acceleration sensor configured as described above is made of a semiconductor material such as silicon. Therefore, the fixed part 1 and the movable part 3 connected to each other via the beam 2 are electrically connected, and the potential applied to the movable part 3 is from a terminal 1 a formed on the fixed part 1. It is configured to be supplied. On the other hand, the fixed electrode 4 is also supplied with a potential from a terminal 4 a connected to the fixed electrode 4.

  2 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 2, the semiconductor chip CHP includes a buried insulating layer 5 formed on the substrate layer S and a silicon layer formed on the buried insulating layer 5. That is, in the first embodiment, the semiconductor chip CHP constituting the acceleration sensor is constituted by an SOI (Silicon On Insulator) substrate including the substrate layer S, the buried insulating layer 5 and the silicon layer. The fixed portion 1 and the beam 2 not shown in FIG. 2 and the movable portion 3 and the fixed electrode 4 shown in FIG. 2 are formed by processing the silicon layer of the SOI substrate. For example, in FIG. 2, it can be seen that the fixed electrode 4 is formed on the buried insulating layer 5 and fixed. This configuration is the same for the fixing portion 1 not shown in FIG. On the other hand, although the movable part 3 is also formed of a silicon layer, the buried insulating layer 5 formed in the lower layer of the movable part 3 is removed. Similarly, the buried insulating layer 5 formed in the lower layer of the beam 2 not shown in FIG. 2 is also removed. Therefore, the movable part 3 is arranged in the cavity and is supported by the beam 2. From this, the movable part 3 is formed so that it can be displaced.

  The MEMS (acceleration sensor) in the first embodiment is configured as described above, and the operation thereof will be described below. First, as shown in FIG. 1, it is assumed that the acceleration sensor is placed in a stationary state. At this time, since the movable part 3 and the fixed electrode 4 are arranged apart from each other by a predetermined distance and both are made of a semiconductor material (conductive material), a capacitive element is formed. . That is, a capacitive element is formed in which the movable portion 3 is one electrode and the fixed electrode 4 is the other electrode.

  In this state, for example, when acceleration is generated in the x direction in FIG. 1, the movable portion 3 is displaced in the x direction under the influence of the acceleration. On the other hand, the fixed electrode 4 is not displaced because it is fixed. Therefore, the distance between the movable part 3 and the fixed electrode 4 changes. The change in the distance between the movable part 3 and the fixed electrode 4 means that the electric capacity (capacitance) of the capacitive element composed of the movable part 3 and the fixed electrode 4 changes. This structure constitutes the detection capacitor section 6 shown in FIG. That is, the detection capacitor unit 6 is formed of a capacitor element including the movable unit 3 and the fixed electrode 4.

  The capacitance change of the capacitive element is an amount corresponding to the acceleration, and the capacitance change detected by the detection capacitance unit 6 is converted into a voltage signal by the capacitance voltage conversion unit 7. Thereafter, the voltage signal converted by the capacity voltage conversion unit 7 is subjected to signal processing by the signal processing unit 8 and finally output to the outside as an acceleration signal. An acceleration signal can be detected by the thus configured acceleration sensor.

  For example, in the acceleration sensor described above, the MEMS structure (including the detection capacitor 6), the capacitor voltage converter 7, and the signal processor 8 can all be formed on one semiconductor chip. The first semiconductor chip that forms the structure and the second semiconductor chip that forms the integrated circuit are formed separately. Therefore, as an acceleration sensor, a first semiconductor chip forming a MEMS structure and a second semiconductor chip forming an integrated circuit are mounted in one package. Below, an example of mounting structure of MEMS, such as an acceleration sensor, is demonstrated, for example.

  FIG. 4 is a top view showing a mounting configuration of the MEMS according to the first embodiment. In FIG. 4, a cap that actually covers the outer frame 10 is provided, but the illustration of the cap is omitted. In FIG. 4, a semiconductor chip CHP2 having a size smaller than that of the outer frame body 10 is disposed inside the outer frame body 10, and is smaller than the semiconductor chip CHP2 and is rectangular on the rectangular semiconductor chip CHP2. A semiconductor chip CHP1 having a shape is mounted. An elastic support portion 13 is formed on the semiconductor chip CHP1, and the elastic support portion 13 is configured to connect the semiconductor chip CHP1 and a cap (not shown).

  A MEMS structure is formed inside the semiconductor chip CHP1. For example, the MEMS structure includes the fixed portion 1, the beam 2, the movable portion 3, and the fixed electrode 4 of the acceleration sensor shown in FIGS. In this semiconductor chip CHP1, for example, in addition to the above-described MEMS structure (detection capacitor unit 6), semiconductor elements such as MISFETs are formed. Capacitance voltage conversion is performed by using these semiconductor elements. Part 7 is formed. That is, in the semiconductor chip CHP1, for example, the MEMS structure and the capacitance-voltage conversion unit 7 are formed, but only the MEMS structure may be formed. A plurality of pads PD1 for extracting input / output signals to / from the MEMS structure are formed on the surface of the semiconductor chip CHP1 thus configured.

  Next, an integrated circuit including a plurality of semiconductor elements such as MISFETs is formed inside the semiconductor chip CHP2. With this integrated circuit, the signal processing unit 8 shown in FIG. 3 is formed in the semiconductor chip CHP2. Also in the semiconductor chip CHP2, a plurality of pads PD2 and pads PD3 for taking out input / output signals from the integrated circuit formed therein are formed.

  Further, a pad PD4 is formed on the outer frame body 10 in which the semiconductor chip CHP1 and the semiconductor chip CHP2 are arranged. Although not shown in FIG. 4, wiring is drawn out of the outer frame body 10 through the pad PD4. The pad PD1 formed on the semiconductor chip CHP1 and the pad PD2 formed on the semiconductor chip CHP2 are electrically connected by a wire W1. Further, the pad PD3 formed on the semiconductor chip CHP2 and the pad PD4 formed on the outer frame body 10 are electrically connected by a wire W2.

  With the above configuration, the input / output signals of the MEMS structure formed in the semiconductor chip CHP1 and the capacitance voltage conversion unit 7 are transmitted to the signal processing unit 8 formed in the semiconductor chip CHP2, and are transmitted to the signal processing unit 8. The input / output signals are drawn to the outside of the outer frame body 10 through the pads PD4 formed on the outer frame body 10. In this way, the semiconductor chip CHP1 and the semiconductor chip CHP2 constituting the MEMS (for example, acceleration sensor) are mounted inside the outer frame body 10, and input / output signals from the MEMS are taken out from the outer frame body 10 to the outside. Be able to.

  5 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 5, the second electrode E <b> 2 is formed on the surface of the pedestal that exists at the bottom of the outer frame body 10, and the wiring L <b> 2 that is electrically connected to the second electrode E <b> 2 It passes through the inside and is drawn out of the outer frame body 10. The semiconductor chip CHP2 is suspended in the air above the pedestal that is the bottom of the outer frame 10 by a certain distance. An electrode E1 is formed on the back surface of the semiconductor chip CHP2 (the surface facing the bottom of the outer frame 10). The electrode E1 is electrically connected by a wiring L1 formed on the back surface of the semiconductor chip CHP2. The electrode E1 formed on the back surface of the semiconductor chip CHP2 and the electrode E2 formed on the bottom of the outer frame body 10 are spaced apart from each other by a certain distance, but are arranged to face each other. And the support part 11 is formed in the surface of the electrode E1 and the electrode E2. The support portion 11 is made of, for example, a solder material. The pad PD3 formed on the semiconductor chip CHP2 is electrically connected to the pad PD4 formed on the outer frame body 10 by a wire W2, and the pad PD4 is connected by a wiring passing through the inside of the outer frame body 10. Has been pulled out.

  The semiconductor chip CHP1 is mounted on the semiconductor chip CHP2 via the adhesive material 12. A pad PD1 is formed on the surface (upper surface) of the semiconductor chip CHP1, and the pad PD1 and the pad PD2 formed on the semiconductor chip CHP2 are electrically connected by a wire W1. The upper surface of the semiconductor chip CHP1 and the cap 14 that seals the outer frame body 10 are connected by an elastic support portion 13. The elastic support member constituting the elastic support portion 13 is made of a material softer than the support member constituting the support portion 11. For example, the elastic support part 13 is comprised from the silicon gel. As described above, in the first embodiment, the semiconductor chip CHP1 disposed inside the outer frame body 10 is connected by the elastic support portion 13 provided between the upper surface of the semiconductor chip CHP1 and the cap. The semiconductor chip CHP2 is mounted on the lower surface (back surface) of the semiconductor chip CHP1 via an adhesive. That is, the semiconductor chip CHP2 and the semiconductor chip CHP1 disposed on the semiconductor chip CHP2 are suspended by the elastic support portion 13 that connects the semiconductor chip CHP1 and the cap 14. This means that in the MEMS mounting configuration according to the first embodiment, the semiconductor chip CHP1 on which the MEMS structure is formed is supported only by the soft elastic support portion 13. Therefore, the vibration disturbance generated outside the outer frame body 10 is transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed only through the elastic support portion 13 that is in contact with the outer frame body 10. In this case, since the elastic support part 13 is comprised from soft materials, such as a silicon gel, for example, the effect which absorbs the vibration disturbance from the outside is acquired. That is, the vibration disturbance from the outside of the outer frame body 10 is absorbed by the soft elastic support portion 13 before being transmitted to the semiconductor chip CHP1. As a result, according to the MEMS mounting configuration in the first embodiment, it is possible to reduce the vibration disturbance transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed, and to improve the detection sensitivity of the MEMS. It can be done.

  Next, main components in the MEMS mounting configuration of the first embodiment will be described in more detail. FIG. 6 is an enlarged view showing a cross section of the electrode E <b> 2 formed on the bottom part (pedestal part) of the outer frame body 10. As shown in FIG. 6, a wiring L <b> 2 is connected to the electrode E <b> 2 formed on the bottom of the outer frame body 10. As shown in FIG. 5, the wiring L <b> 2 is drawn through the bottom surface of the outer frame body 10. FIG. 7 is a diagram illustrating a planar configuration of the electrode E2. As shown in FIG. 7, the electrode E2 is not arranged in a straight line, but is formed to meander from side to side. The electrode E2 configured in this way is formed of, for example, a gold film or a copper film.

  Next, the configuration of the electrode E1 formed on the back surface of the semiconductor chip CHP2 (surface facing the bottom surface of the outer frame body 10) will be described. FIG. 8 is a plan view showing the back surface of the semiconductor chip CHP2. As shown in FIG. 8, a plurality of electrodes E1 are formed on the back surface of the semiconductor chip CHP2. In FIG. 8, rectangular electrodes E1 are formed at three locations that are not in the same straight line. These three electrodes E1 are connected to each other by a wiring L1 formed on the back surface of the semiconductor chip CHP2. Therefore, the three electrodes E1 are electrically connected by the wiring L1. And the support part 11 is formed on each electrode E1. The support portion 11 is made of, for example, a solder material.

  9 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 9, it can be seen that a plurality of electrodes E1 are formed on the back surface (lower surface) of the semiconductor chip CHP2, and these electrodes E1 are connected by a wiring L1. The electrode E1 and the wiring L1 are made of, for example, a copper film or a gold film. It can be seen that the support portion 11 is formed on the electrode E1.

  Although not shown, a semiconductor element (such as a MISFET) constituting an integrated circuit is formed inside the semiconductor chip CHP2. A wiring connected to the semiconductor element is formed on the semiconductor chip CHP2, and a pad PD2 (pad PD3) connected to the semiconductor element via the wiring is formed on the surface (upper surface) of the semiconductor chip CHP2.

  Next, the main configuration of the semiconductor chip CHP1 mounted on the semiconductor chip CHP2 will be described. FIG. 10 is a plan view seen from the upper surface (front surface) of the semiconductor chip CHP1. As shown in FIG. 10, a plurality of vias V and a plurality of pads PD1 are formed on the upper surface of the semiconductor chip CHP1, and each via V and each pad PD1 are connected by a wiring L, respectively. 11 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 11, the semiconductor chip CHP1 includes a substrate layer 15 and a buried insulating layer 16 formed on the substrate layer 15 and a silicon layer 17 formed on the buried insulating layer 16. The substrate layer 15, the buried insulating layer 16 and the silicon layer 17 constitute an SOI substrate. A cap layer 20 is formed on the silicon layer 17 constituting the SOI substrate. A MEMS structure is formed on the SOI substrate. For example, a movable part 19 formed by processing the silicon layer 17 inside a cavity 18 formed by removing the buried insulating layer 16 and the silicon layer 17 is provided. Is formed. The movable portion 19 of the MEMS structure corresponds to the movable portion 3 in FIG. 1 when the MEMS is an acceleration sensor shown in FIG. And the fixing | fixed part 19a shown in FIG. 11 respond | corresponds to the fixing | fixed part 1 if it says the acceleration sensor shown in FIG. A via V is connected to the fixed portion 1, and the via V is connected to a pad PD 1 formed on the cap layer 20 via a wiring L. As described above, in the semiconductor chip CHP1, for example, a MEMS structure constituting a MEMS such as an acceleration sensor is formed.

  The MEMS mounting configuration in the first embodiment is as described above. Hereinafter, a MEMS mounting method that is a feature of the present invention will be described with reference to the drawings.

  First, the outer frame 10, the semiconductor chip CHP2, and the semiconductor chip CHP1 are prepared. Specifically, a semiconductor chip CHP1 in which a MEMS structure including the cavity 18 shown in FIG. 11 and a displaceable movable body 19 provided in the cavity 18 is formed is prepared. Then, an integrated circuit for processing the output from the MEMS structure formed on the semiconductor chip CHP1 as shown in FIGS. 8 and 9 as an electrical signal is formed, and the semiconductor chip has a larger planar shape than the semiconductor chip CHP1. CHP2 is prepared. Further, an outer frame body 10 having a concave shape and having an open top as shown in FIG. 12 is prepared.

  Subsequently, as illustrated in FIG. 12, the semiconductor chip CHP <b> 2 is disposed on the pedestal portion of the outer frame body 10. Specifically, the semiconductor chip CHP2 is disposed on the pedestal portion of the outer frame body 10 while the semiconductor chip CHP2 is held by the vacuum chuck. At this time, the electrode E1 is formed on the back surface of the semiconductor chip CHP2, and the support portion 11 is formed on the electrode E1. For example, the support portion 11 made of a solder material can be formed on the electrode E1 by, for example, a solder printing method or mounting a solder ball or a solder column. On the other hand, an electrode E <b> 2 is formed on the pedestal portion of the outer frame body 10. The semiconductor chip CHP2 is arranged on the pedestal portion of the outer frame body 10 so that the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the pedestal portion of the outer frame body 10 face each other. That is, alignment is performed so that the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the outer frame body 10 are in contact with each other via the support portion 11, and the semiconductor chip CHP2 is placed on the base of the outer frame body 10. Place on the department. On the back surface of the semiconductor chip CHP2, for example, electrodes E1 are formed at three places that are not in the same straight line, and a support portion 11 is formed on the electrode E1. Therefore, since the semiconductor chip CHP2 is supported by three portions that are not in the same straight line, the semiconductor chip CHP2 can be disposed on the base portion of the outer frame body 10 in a stable state.

  Then, as shown in FIG. 13, by heating the bottom of the outer frame body 10, the support portion 11 is melted to form an electrode E <b> 1 formed on the semiconductor chip CHP <b> 2 and an electrode E <b> 2 formed on the outer frame body 10. Make sure that the connection is secure. That is, since the support part 11 is heated by heating the bottom part of the outer frame 10, the support part 11 is melted and liquefied. Since the liquefied support portion 11 has contact with the electrode E2 and the support portion 11 due to surface tension, the connection between the support portion 11 and the electrode E2 can be ensured.

  Below, the detail of this process is demonstrated. FIG. 14 shows a state in which the semiconductor chip CHP2 is arranged on the outer frame body 10. In this state, the hemispherical support portion 11 formed on the electrode E1 is in contact with the electrode E2. FIG. 15 is a diagram illustrating a region where the electrode E2 and the support portion 11 are in contact with each other. As shown in FIG. 15, the electrode E2 and the support portion 11 are in contact with each other at the contact point 11a on the electrode E2. That is, only by mounting the semiconductor chip CHP2 on the pedestal portion of the outer frame body 10, the contact between the electrode E2 formed on the outer frame body 10 and the support portion 11 is a point contact with a small contact area. In this state, the support part 11 is only physically in contact with the electrode E2, and the electrode E2 and the support part 11 are not yet in a state of being reliably coupled. Therefore, in this state, the connection between the semiconductor chip CHP2 and the outer frame body 10 is unstable.

  Therefore, in the first embodiment, heat treatment is performed on the bottom of the outer frame body 10 in order to ensure the connection between the semiconductor chip CHP2 and the outer frame body 10. FIG. 16 shows a state in which the semiconductor chip CHP2 is heat-treated after being placed on the pedestal portion of the outer frame 10. As shown in FIG. 16, the heat applied to the bottom of the outer frame 10 by this heat treatment is transferred to the support 11 through the electrode E2. For this reason, the support part 11 is heated. As a result, for example, the support portion 11 made of a solder material is melted and liquefied. The liquefied support portion 11 is deformed so that the contact area with the electrode E2 is increased by the surface tension. That is, as shown in FIG. 16, the support portion 11 has a hemispherical shape, so that the diameter of the end portion of the support portion 11 in contact with the electrode E1 or the electrode E2 is larger than the diameter of the central portion of the support portion 11. Change. Due to the change in the shape of the support portion 11, the contact area between the electrode E2 and the support portion 11 is increased.

  FIG. 17 is a diagram showing a region where the electrode E2 after heat treatment and the support portion 11 are in contact with each other. As shown in FIG. 17, it can be seen that the area of the contact region 11b where the electrode E2 and the support portion 11 are in contact with each other is increased. That is, as can be seen from a comparison between FIG. 15 and FIG. 17, it can be seen that the contact between the electrode E2 and the support portion 11 has changed from a point contact to a surface contact. Therefore, the heat treatment ensures the connection between the electrode E2 and the support portion 11, and the semiconductor chip CHP2 is firmly fixed to the outer frame body 10.

  Here, although the connection between the electrode E2 and the support portion 11 is ensured by the heat treatment, the contact area between the electrode E2 and the support portion 11 is increased by actually performing the heat treatment and melting the support portion 11. It is desirable to be able to verify. That is, it is desirable to be able to verify how much heat treatment is performed to actually increase the contact area between the electrode E2 and the support portion 11. Therefore, the first embodiment has means for performing a heat treatment to verify that the contact area between the support portion 11 and the electrode E2 is increased. This verification means will be described. First, for example, as shown in FIG. 12, an electrode E <b> 2 is formed on the outer frame body 10, a wiring L <b> 2 is connected to the electrode E <b> 2, and the wiring L <b> 2 is drawn out of the outer frame body 10. . Further, as shown in FIGS. 8 and 9, the electrodes E1 formed on the semiconductor chip CHP2 are connected to each other by a wiring L1. Therefore, when the semiconductor chip CHP2 and the outer frame body 10 are arranged, the electrode E1 and the electrode E2 are connected via the support portion 11. At this time, for example, as shown in FIG. 13, the left wiring L2, the left electrode E2, the left support 11, the left electrode E1, the wiring L1, the right electrode E1, the right support 11, and the right electrode A closed loop circuit composed of E2 and the right wiring L2 is formed. In this closed loop circuit, the contact state between the support 11 and the electrode E2 can be confirmed by measuring the contact resistance between the support 11 and the electrode E2. That is, as shown in FIG. 15, before the heat treatment is performed, the electrode E2 and the support portion 11 are in point contact, so that the contact resistance between the electrode E2 and the support portion 11 is increased. On the other hand, as shown in FIG. 17, after the heat treatment, the electrode E2 and the support portion 11 come into surface contact, so that the contact resistance between the electrode E2 and the support portion 11 becomes small. Therefore, if the contact resistance between the electrode E2 and the support part 11 is measured, the contact state between the electrode E2 and the support part 11 can be confirmed.

  FIG. 18 is a flowchart for verifying the contact state between the electrode E2 and the support portion 11. For example, as shown in FIG. 18, first, after the semiconductor chip CHP2 is disposed on the outer frame body 10, the bottom of the outer frame body 10 is heated. Then, the contact resistance between the electrode E2 and the support part 11 is measured (S101). Next, a value obtained by measuring a contact resistance between the electrode E2 and the support portion 11 is a resistance value in an initial state where the semiconductor chip CHP2 is disposed on the outer frame body 10 and is not subjected to heat treatment (resistance value at the time of coupling). ) Is compared (S102). At this time, if the measured resistance value is not smaller than the resistance value in the initial state, the heat treatment is continued and the heating temperature is increased by increasing the value of the current passed through the heater for heating the outer frame body 10. (S103). On the other hand, if the measured resistance value is smaller than the initial resistance value, the heat treatment is terminated (S104). With the above verification means, the connection state between the electrode E2 and the support portion 11 can be confirmed. As described above, in the first embodiment, when the semiconductor chip CHP2 and the outer frame body 10 are arranged on the pedestal portion, the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the outer frame body 10 are combined. By configuring so as to be connected by the support portion 11, the electrode E <b> 2 and the support portion 11 can be reliably connected, and verification means for confirming the contact state between the electrode E <b> 2 and the support portion 11 can be provided. It is. Specifically, by using a material having good wettability with the support part 11 for the electrode E1 and the electrode E2, after the support part 11 is melted by heat treatment, for example, the contact area between the electrode E2 and the support part 11 is reduced. Can be bigger. Thereby, the connection between the electrode E2 and the support portion 11 is ensured, and the semiconductor chip CHP2 can be stably fixed to the outer frame body 10. Further, by making the electrode E2 meander to the left and right, the contact area with the hemispherical support part 11 before melting is made point contact, while the contact area with the support part 11 after melting is made sufficiently large. Therefore, the difference in contact resistance between the support portion 11 and the electrode E2 before and after melting can be increased. As a result, the reliability of the verification means described above can be improved.

  Subsequently, as shown in FIG. 19, after the adhesive 12 is formed on the upper surface (front surface) of the semiconductor chip CHP2, the semiconductor chip CHP1 is mounted on the semiconductor chip CHP2 via the adhesive 12. Specifically, the semiconductor chip CHP1 is disposed on the semiconductor chip CHP2 while holding the semiconductor chip CHP1 with a vacuum chuck.

  Thereafter, as shown in FIG. 20, the pad PD1 formed on the upper surface of the semiconductor chip CHP1 and the pad PD2 formed on the upper surface of the semiconductor chip CHP2 are connected by the wire W1. Further, the pad PD3 formed on the semiconductor chip CHP2 and the pad PD4 formed on the outer frame body 10 are connected by the wire W2 (wire bonding process). At this time, when the semiconductor chip CHP1 and the semiconductor chip CHP2 are not firmly fixed, the wire bonding cannot be sufficiently performed. However, in the first embodiment, the semiconductor chip CHP2 and the outer frame body 10 are the support portions. 11, the wire bonding reliability can be improved. That is, in the first embodiment, the semiconductor chip CHP2 and the outer frame body 10 are securely fixed by the support portion 11, but this purpose is for reliably performing the wire bonding described above. The semiconductor chip CHP1 and the semiconductor chip CHP2 are connected to each other through an adhesive material 12. The adhesive material 12 is selected to be sufficiently hard so as not to hinder wire bonding.

  Next, as shown in FIG. 21, after the elastic support portion 13 made of, for example, silicon gel is formed on the upper surface of the semiconductor chip CHP1, the cap 14 is attached to the outer frame body 10 so as to come into contact with the elastic support portion 13. Mount on top. The semiconductor chip CHP1 and the cap 14 are connected by the elastic support portion 13 by performing a baking process and curing the elastic support portion 13. Here, the wire W1 connecting the pad PD1 formed on the semiconductor chip CHP1 and the pad PD2 formed on the semiconductor chip CHP2, or the pad PD3 formed on the semiconductor chip CHP2 and the outer frame body 10 is formed. The wire W <b> 2 connecting the pad PD <b> 4 may be covered with the elastic support portion 13. Thereby, since the wire W1 and the wire W2 are fixed by the elastic support part 13, the shake of the wire W1 and the wire W2 by external vibration can be suppressed. For this reason, since the capacity | capacitance change between the wires W1 and the wires W2 can be reduced, the stable measurement can be implemented and the reliability of MEMS can be improved.

  Thereafter, the cap 14 is joined to the outer frame body 10 by seam welding or the like. Thus, the semiconductor chip CHP1 and the semiconductor chip CHP2 are sealed inside the outer frame body 10. At this time, since the elastic support part 13 is comprised from soft materials, such as a silicon gel, the effect which absorbs the vibration disturbance from the outside is acquired. That is, vibration disturbance from the outside of the outer frame body 10 is absorbed by the soft elastic support portion 13 before being transmitted to the semiconductor chip CHP1.

  On the other hand, the support portion 11 that connects the semiconductor chip CHP2 and the outer frame body 10 is indispensable in the wire bonding process. However, after the wire bonding process, it causes a problem. That is, the support portion 11 is configured to firmly fix the semiconductor chip CHP2 and the outer frame body 10. In other words, this is a property that it is easy to transmit vibration disturbance from the outside of the outer frame body 10. You can also have. Since the semiconductor chip CHP1 in which the MEMS structure is formed is disposed in the semiconductor chip CHP2, vibration disturbance from the outside of the outer frame body 10 is transmitted to the semiconductor chip CHP2 via the support portion 11, and is transmitted to the semiconductor chip CHP2. The vibration disturbance is transmitted to the semiconductor chip CHP1. If vibration disturbance is transmitted to the semiconductor chip CHP1, the movable body may malfunction and the MEMS detection accuracy may be reduced. Therefore, after performing the wire bonding step, it is desirable to disconnect the support portion 11 that firmly connects the semiconductor chip CHP2 and the outer frame body 10. Therefore, in the first embodiment, after performing the wire bonding step, the step of separating the support portion 11 that connects the electrode E1 and the electrode E2 is performed. Below, this process is demonstrated.

  FIG. 22 is a diagram illustrating a state in which the semiconductor chip CHP2 and the outer frame body 10 are connected after performing the wire bonding step. As shown in FIG. 22, the pad PD3 formed on the semiconductor chip CHP2 and the pad PD4 formed on the outer frame body 10 are connected by a wire W2. At this time, the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the outer frame body 10 are firmly connected by the support portion 11. That is, the contact area between the support part 11 and the electrode E2 is large, and the electrode E2 and the support part 11 are securely connected.

  Next, FIG. 23 shows a state in which the bottom of the outer frame body 10 in the state shown in FIG. 22 is further heated. As shown in FIG. 23, since the electrode E1 and the electrode E2 are composed of members having good wettability with the support portion 11, when the support portion 11 is further heated, the support portion 11 is It melts again and liquefies. The liquefied support portion 11 is pulled by the surface tension to the electrode E1 side and the electrode E2 side having good wettability. As a result of the liquefied support portion 11 being pulled from both the electrode E1 side and the electrode E2 side, the support portion 11 is separated between the electrode E1 and the electrode E2. Thereby, the electrode E1 and the electrode E2 are physically separated. At this time, the separation of the support portion 11 can be accelerated by the contraction force (the force that pulls the semiconductor chip CHP1 upward on the cap 14 side) by the elastic support portion 13 connecting the semiconductor chip CHP1 and the cap 14.

  Note that the distance between the bottom surface of the semiconductor chip CHP2 and the pedestal portion of the outer frame 10 (specifically, the distance between the electrode E1 where the support portion 11 is formed and the electrode E2 where the support portion 11 is formed). h is the combined weight of the semiconductor chip CHP1 and the semiconductor chip CHP2, m is the spring constant of the elastic support part 13 in the direction perpendicular to the surface of the semiconductor chip CHP1, and kz is the maximum allowable acceleration of vibration disturbance acting from the outside ( When Amax is the maximum value of acceleration allowed for maintaining normal operation, it is desirable that h> (m / kz) · Amax is satisfied. Thus, by setting the distance between the bottom surface of the semiconductor chip CHP2 and the pedestal portion of the outer frame body 10, the semiconductor chip CHP2 and the outer frame body 10 do not collide even when the maximum allowable acceleration Amax is applied. The function as a MEMS can be maintained. The relationship described above can be applied not only to the distance between the bottom surface of the semiconductor chip CHP2 and the pedestal portion of the outer frame body 10, but also to the interval between the side surface of the semiconductor chip CHP2 and the outer frame body 10. .

  Separation of the support portion 11 connecting the electrode E1 and the electrode E2 can be confirmed by measuring the contact resistance between the electrode E1 and the electrode E2 in the above-described closed loop circuit. That is, as shown in FIG. 22, the electrode E2 and the support portion 11 are in surface contact before further heat treatment, so the contact resistance between the electrode E2 and the electrode E1 is reduced. On the other hand, as shown in FIG. 23, after further heat treatment, the support portion 11 connecting the electrode E2 and the electrode E1 is separated, and the electrode E1 and the electrode E2 are separated, so that the electrode The contact resistance between E2 and the electrode E1 is infinite. Therefore, if the contact resistance between the electrode E2 and the electrode E1 is measured, the contact state between the electrode E2 and the electrode E1 can be confirmed.

  FIG. 24 is a flowchart for verifying the contact state between the electrode E2 and the electrode E1. For example, as shown in FIG. 24, first, a wire bonding step is performed, and after sealing the outer frame body 10 with the cap 14, the bottom of the outer frame body 10 is heated. Thereafter, the contact resistance between the electrode E2 and the electrode E1 is measured (S201). Next, it is determined whether the value obtained by measuring the contact resistance between the electrode E2 and the electrode E1 is infinite (S202). At this time, when the measured resistance value is smaller than infinity, the heat treatment is continued, and the current value passed through the heater for heating the outer frame 10 is increased to raise the heating temperature (S203). On the other hand, if the measured resistance value is infinite, the heat treatment is terminated (S204). With the above verification means, the connection state between the electrode E2 and the electrode E1 can be confirmed.

  Through the above steps, a MEMS mounting configuration as shown in FIG. 5 can be obtained. In the first embodiment, the semiconductor chip CHP1 disposed inside the outer frame body 10 is connected by the elastic support portion 13 provided between the upper surface of the semiconductor chip CHP1 and the cap, and the semiconductor chip CHP1 The semiconductor chip CHP2 is mounted on the lower surface (back surface) via an adhesive. And the support part 11 which connected the semiconductor chip CHP2 and the outer frame 10 is cut away. That is, the semiconductor chip CHP2 and the semiconductor chip CHP1 disposed on the semiconductor chip CHP2 are suspended by the elastic support portion 13 that connects the semiconductor chip CHP1 and the cap 14.

  That is, the electrode E1 and the electrode E2 are made of a material having good wettability with respect to the support portion 11. For this reason, if the support part 11 is heated until the resistance value between the electrode E1 and the electrode E2 becomes infinite, the support part 11 will soften and will be cut | disconnected like an electric fuse. At that time, the support 11 remaining on the electrode E1 and the electrode E2 extends so as to cover the surface of the electrode E1 and the surface of the electrode E2 by surface tension. Thereby, the outer frame body 10 and the semiconductor chip CHP2 are separated, and the semiconductor chip CHP2 has a suspended structure.

  This means that in the MEMS mounting configuration according to the first embodiment, the semiconductor chip CHP1 on which the MEMS structure is formed is supported only by the soft elastic support portion 13. Therefore, the vibration disturbance generated outside the outer frame body 10 is transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed only through the elastic support portion 13 that is in contact with the outer frame body 10. In this case, since the elastic support part 13 is comprised from soft materials, such as a silicon gel, for example, the effect which absorbs the vibration disturbance from the outside is acquired. That is, the vibration disturbance from the outside of the outer frame body 10 is absorbed by the soft elastic support portion 13 before being transmitted to the semiconductor chip CHP1. As a result, according to the MEMS mounting configuration in the first embodiment, it is possible to reduce the vibration disturbance transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed, and to improve the detection sensitivity of the MEMS. It can be done.

  The technical idea of the first embodiment is characterized in that the support portion 11 is deformed by heat to couple or separate between the semiconductor chip CHP2 and the outer frame body 10. That is, in the first embodiment, the coupling / separation between the semiconductor chip CHP2 and the outer frame body 10 is controlled by deforming the support portion 11 by heat, so that an etchant for removing the support portion 11 Does not require gas. For this reason, an entrance / exit of an etchant or a gas is not required, and the elastic support portion 13 made of silicon gel or the like is not necessarily formed in spots. Therefore, the attachment place of the elastic support part 13 can be selected freely. Therefore, for example, when designing the spring constant of the elastic support portion 13, the elastic support portion 13 is completely filled between the semiconductor chip CHP 1 and the cap 14, so that the shape of the outer frame body 10 (package) Even if the shape) is not specially devised, the spring constant error due to the lateral expansion of the elastic support portion 13 can be reduced.

  Furthermore, if the elastic support portion 13 is completely filled, the amount of expansion and contraction at the time of curing becomes uniform, and the effect of preventing the inclination and bias of the semiconductor chip CHP1 can be obtained. In particular, when the elastic support portion 13 is disposed on the upper surface of the semiconductor chip CHP1, the yield and productivity are improved because the work space is wide.

  The technical idea of the first embodiment is characterized in that after the outer frame body 10 is sealed, the support portion 11 is deformed to separate the semiconductor chip CHP2 from the outer frame body 10. That is, since the separation process of the support portion 11 is performed after the outer frame body 10 is sealed, there is no wire collapse during work, and no foreign matter (moisture or dust) is mixed inside the outer frame body 10. Does not require a highly controlled work environment. For this reason, it is possible to realize MEMS production with high reliability, high yield, and low cost.

  Furthermore, the technical idea in the first embodiment includes a detecting unit that detects the coupling / separation of the support portion 11. That is, the electrical resistance between the electrode E2 formed on the outer frame body 10 side, the support portion 11, and the electrode E1 formed on the semiconductor chip CHP2 can be measured. Therefore, by measuring this electric resistance, it can be determined whether the semiconductor chip CHP2 is coupled to the outer frame body 10 or separated. For this reason, the semiconductor chip CHP2 can be securely bonded, and more reliable wire bonding can be realized. Similarly, since the separation between the semiconductor chip CHP2 and the outer frame body 10 can also be confirmed, it is not necessary to confirm by separately vibrating the outer frame body 10 from the outside in order to confirm the separation state. Furthermore, since it can be confirmed even when the outer frame 10 is sealed, the workability is good and the work environment can be freely selected, so that MEMS can be produced at low cost.

  In the first embodiment, the elastic support portion 13 is formed on the upper surface of the semiconductor chip CHP1 having a relatively large area. For this reason, when forming the elastic support part 13, since high position control and quantity control are not required, the high reliability of MEMS and the simplicity of work are obtained, and MEMS can be produced at low cost. .

(Embodiment 2)
A MEMS mounting configuration according to the second embodiment will be described with reference to the drawings. In the first embodiment, the entire bottom portion of the outer frame body 10 is heated to connect / separate the support portion 11, but in the second embodiment, not the entire bottom portion of the outer frame body 10, An example in which a micro heater is provided in the vicinity of the support portion 11 and only the support portion 11 is heated will be described.

  FIG. 25 is a top view showing the mounting structure of the MEMS according to the second embodiment, which is the same as the top view (FIG. 4) showing the mounting structure of the MEMS according to the first embodiment. Next, FIG. 26 is a cross-sectional view taken along line AA of FIG. Since this FIG. 26 has substantially the same configuration as FIG. 5, a different configuration will be described. The feature of the second embodiment is that a microheater H1, which is a local heating means, is formed at the bottom of the outer frame 10 below the electrode E2. The microheater H1 is formed of, for example, a tungsten film, and is configured so as to heat the support portion 11 disposed on the microheater H1. That is, the support part 11 can be heated by the microheater H1 via the electrode E2 disposed on the microheater H1.

  FIG. 27 is a cross-sectional view showing the configuration of the microheater H1. As shown in FIG. 27, an electrode E2 is formed on the bottom of the outer frame 10, and this electrode E2 is connected to the wiring L2. A microheater H1 that is electrically separated from the electrode E2 is formed below the electrode E2, and the microheater H1 is connected to the wiring L3. The wiring L3 is drawn to the outside of the outer frame body 10, and is configured so that the microheater H1 can be controlled from the outside of the outer frame body 10. For example, the microheater H1 is composed of a resistance element made of tungsten, and functions as the microheater H1 by using Joule heat generated by passing a current through the resistance element. That is, the microheater H1 is formed as an electrical resistor, and has a mechanism in which the temperature of the resistance is increased by passing a current. The current can be supplied from the outside of the outer frame body 10 via the wiring L3 connected to the micro heater H1.

  Thus, in this Embodiment 2, since the microheater H1 is provided as a means to heat the support part 11, it is not necessary to heat the whole bottom part of the outer frame body 10 in order to heat the support part 11. . Therefore, since it can suppress that a thermal load is applied to members other than the support part 11, the reliability of MEME can be improved.

  The MEMS in the second embodiment is mounted and configured as described above, and a method for mounting the MEMS will be described below. In addition, the place which overlaps with the said Embodiment 1 is abbreviate | omitted.

  As shown in FIG. 28, the semiconductor chip CHP <b> 2 is disposed on the pedestal portion of the outer frame body 10. Specifically, the semiconductor chip CHP2 is disposed on the pedestal portion of the outer frame body 10 while the semiconductor chip CHP2 is held by the vacuum chuck. At this time, the electrode E1 is formed on the back surface of the semiconductor chip CHP2, and the support portion 11 is formed on the electrode E1. For example, the support portion 11 made of a solder material can be formed on the electrode E1 by, for example, a solder printing method or mounting a solder ball or a solder column. On the other hand, an electrode E <b> 2 is formed on the pedestal portion of the outer frame body 10. The semiconductor chip CHP2 is arranged on the pedestal portion of the outer frame body 10 so that the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the pedestal portion of the outer frame body 10 face each other. At this time, a microheater H1 is formed at the bottom of the outer frame 10 below the electrode E2.

  Next, a process of joining the semiconductor chip CHP2 and the outer frame body 10 will be described. FIG. 29 shows a state immediately after the electrode E1 of the semiconductor chip CHP2 is mounted on the electrode E2 of the outer frame body 10, and the shape of the support portion 11 remains the initial shape (hemisphere). At this stage, the semiconductor chip CHP2 and the outer frame body 10 are only in physical contact, and the electrode E1, the electrode E2, and the support portion 11 are not in a coupled state.

  In this state, as shown in FIG. 30, an electric current is passed through the microheater H1 formed in a state of being electrically separated below the electrode E2. Thereby, Joule heat generated from the microheater H1 is transmitted to the support portion 11 via the electrode E2. As a result, the support part 11 is heated and deformed. FIG. 30 shows the support 11 in a deformed state. Here, the support part 11 is heated and deformed in a state where the position in the height direction of the semiconductor chip CHP2 is fixed by a vacuum chuck. However, such a method is not necessarily required, and the support portion 11 may be heated and deformed with the vacuum chuck removed.

  Since the electrode E1 and the electrode E2 are configured as materials having good wettability with respect to the support part 11, if the support part 11 is heated by the microheater H1, the support part 11 in contact with the electrode E1 and the electrode E2 is Dissolve and liquefy. As a result, the liquefied support portion 11 is deformed so as to cover the electrode E1 and the electrode E2 by surface tension. For this reason, the contact state between the support part 11 and the electrode E2 or between the support part 11 and the electrode E1 changes from point contact to surface contact, and the electrical resistance between the electrode E1 and the electrode E2 becomes small. By monitoring the change in the resistance value and controlling the value of the current flowing through the microheater H1, the end point of the joining process of the electrode E2 and the support portion 11 can be confirmed. The support portion 11 after being coupled to the electrode E2 has a large diameter on the electrode side (electrode E2 and electrode E1) and a thin diameter at the center portion of the support portion due to the action of surface tension.

  For example, as shown in FIG. 18, first, after the semiconductor chip CHP2 is disposed on the outer frame body 10, the current is passed through the microheater H1 to heat the support portion 11. Then, the contact resistance between the electrode E2 and the support part 11 is measured (S101). Next, it is compared whether the measured value of the contact resistance between the electrode E2 and the support portion 11 is smaller than the initial resistance value (resistance value at the time of coupling) (S102). At this time, if the measured resistance value is not smaller than the resistance value in the initial state, the amount of current flowing through the microheater H1 is increased to increase the heating temperature and the heating process is continued (S103). On the other hand, if the measured resistance value is smaller than the initial resistance value, the current flowing through the microheater H1 is stopped and the heating process is terminated (S104). With the above verification means, the connection state between the electrode E2 and the support portion 11 can be confirmed while controlling the value of the current flowing through the microheater H1.

  Subsequently, as illustrated in FIG. 31, the semiconductor chip CHP <b> 1 is placed on the semiconductor chip CHP <b> 2 using a vacuum chuck, and then the semiconductor chip CHP <b> 1 is fixed to the semiconductor chip CHP <b> 2 via the adhesive 12. Here, the adhesive 12 is selected to be sufficiently hard so as not to hinder wire bonding.

  Thereafter, the pad PD1 of the semiconductor chip CHP1 and the pad PD2 of the semiconductor chip CHP2 are connected by the wire W1. Similarly, the pad PD3 of the semiconductor chip CHP2 and the pad PD4 formed on the outer frame body 10 are connected by the wire W2. At this time, when the semiconductor chip CHP1 and the semiconductor chip CHP2 are not firmly fixed, the wire bonding cannot be sufficiently performed. However, in the second embodiment, the semiconductor chip CHP2 and the outer frame body 10 are supported. Since it is securely fixed by the portion 11, the reliability of wire bonding can be improved.

  Next, as shown in FIG. 32, after the elastic support portion 13 made of, for example, silicon gel is formed on the upper surface of the semiconductor chip CHP1, the cap 14 is attached to the outer frame body 10 so as to come into contact with the elastic support portion 13. Mount on top. The semiconductor chip CHP1 and the cap 14 are connected by the elastic support portion 13 by performing a baking process and curing the elastic support portion 13.

  Subsequently, the cap 14 is joined to the outer frame body 10 by seam welding or the like. Thus, the semiconductor chip CHP1 and the semiconductor chip CHP2 are sealed inside the outer frame body 10. At this time, since the elastic support part 13 is comprised from soft materials, such as a silicon gel, the effect which absorbs the vibration disturbance from the outside is acquired. That is, vibration disturbance from the outside of the outer frame body 10 is absorbed by the soft elastic support portion 13 before being transmitted to the semiconductor chip CHP1.

  FIG. 33 is a diagram illustrating a state in which the semiconductor chip CHP2 and the outer frame body 10 are connected after performing the wire bonding step. As shown in FIG. 33, a pad PD3 formed on the semiconductor chip CHP2 and a pad PD4 formed on the outer frame 10 are connected by a wire W2. At this time, the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the outer frame body 10 are firmly connected by the support portion 11. That is, the contact area between the support part 11 and the electrode E2 is large, and the electrode E2 and the support part 11 are securely connected.

  Next, FIG. 34 shows a state in which the bottom of the outer frame 10 in the state shown in FIG. 33 is further heated by the microheater H1. As shown in FIG. 34, since the electrode E1 and the electrode E2 are composed of members having good wettability with the support part 11, when the support part 11 is further heated, the support part 11 is It melts again and liquefies. The liquefied support portion 11 is pulled by the surface tension to the electrode E1 side and the electrode E2 side having good wettability. As a result of the liquefied support portion 11 being pulled from both the electrode E1 side and the electrode E2 side, the support portion 11 is separated between the electrode E1 and the electrode E2. Thereby, the electrode E1 and the electrode E2 are physically separated.

  Separation of the support portion 11 connecting the electrode E1 and the electrode E2 can be confirmed by measuring the contact resistance between the electrode E1 and the electrode E2 in the above-described closed loop circuit. That is, as shown in FIG. 33, since the electrode E2 and the support portion 11 are in surface contact before further heat treatment, the contact resistance between the electrode E2 and the electrode E1 is reduced. On the other hand, as shown in FIG. 34, after further heat treatment, the support part 11 connecting the electrode E2 and the electrode E1 is separated and the electrode E1 and the electrode E2 are separated. The contact resistance between E2 and the electrode E1 is infinite. Therefore, if the contact resistance between the electrode E2 and the electrode E1 is measured, the contact state between the electrode E2 and the electrode E1 can be confirmed.

  For example, as shown in FIG. 24, first, a wire bonding step is performed, the outer frame body 10 is sealed with a cap 14, and then the support portion 11 is heated with a microheater H1. Thereafter, the contact resistance between the electrode E2 and the electrode E1 is measured (S201). Next, it is determined whether the value obtained by measuring the contact resistance between the electrode E2 and the electrode E1 is infinite (S202). At this time, if the measured resistance value is smaller than infinity, the heat treatment by the microheater H1 is continued, and the heating current is raised by increasing the value of the current passed through the microheater H1 (S203). On the other hand, if the measured resistance value is infinite, the heat treatment by the microheater H1 is terminated (S204). With the above verification means, the connection state between the electrode E2 and the electrode E1 can be confirmed while controlling the current flowing through the microheater H1.

  Through the above steps, a MEMS mounting configuration as shown in FIG. 26 can be obtained. According to the second embodiment, the support portion 11 is locally heated and deformed by the microheater H1 (local heating means) formed on the outer frame body 10, whereby the gap between the semiconductor chip CHP2 and the outer frame body 10 is obtained. Can be combined or separated. For this reason, the other members of the outer frame body 10 are hardly affected by heat, and an effect of preventing the thermal support or deformation of the elastic support portion 13 is obtained. Furthermore, the effect which does not need to consider the thermal selectivity between the components of MEMS including the outer frame 10 is acquired.

  Furthermore, in the second embodiment, it is possible to control the amount of heat or temperature generated by controlling the current value flowing through the microheater H1 that is heated by generating Joule heat. At this time, the resistance value between the electrode E1 and the electrode E2 is measured using a closed loop circuit including the electrode E1, the support portion 11, and the electrode E2, and the amount of current flowing through the microheater H1 is controlled based on the measured resistance value. doing. That is, when the support portion 11 is firmly coupled to the electrode E2, the heat treatment is performed by the microheater H1 until the resistance value between the electrode E1 and the electrode E2 is equal to or less than a certain value, and between the electrode E1 and the electrode E2 is physically performed. When the separation is performed, the current is controlled to flow through the microheater H1 until the resistance value between the electrode E1 and the electrode E2 becomes infinite. Thereby, the coupling and separation between the semiconductor chip CHP2 and the outer frame body 10 (specifically, the electrode E1 and the electrode E2) can be performed by the micro heater H1 which is the same local heating means.

(Embodiment 3)
A MEMS mounting configuration according to the third embodiment will be described with reference to the drawings. In the second embodiment, the example in which the suspended structure is realized by supporting the cap 14 and the semiconductor chip CHP1 disposed on the upper portion of the outer frame body 10 with the elastic support portion 13 has been described. Now, a mounting configuration in which the bottom portion (pedestal portion) of the outer frame body 10 and the semiconductor chip CHP2 are supported by the elastic support portion 13 will be described.

  FIG. 35 is a top view showing the MEMS mounting configuration in the third embodiment, which is substantially the same as the top view (FIG. 25) showing the MEMS mounting configuration in the second embodiment. The difference between the second embodiment and the third embodiment is that the elastic support portion 13 does not exist on the upper surface of the semiconductor chip CHP1 in the third embodiment. Next, FIG. 36 is a cross-sectional view taken along line AA of FIG. 36 has almost the same configuration as that of FIG. 26, and therefore a different configuration will be described. That is, in FIG. 36, the semiconductor chip CHP2 and the bottom of the outer frame body 10 are connected by the elastic support portion 13. As described above, in the second embodiment (FIG. 26) and the third embodiment (FIG. 36), the laminated structure of the semiconductor chip CHP1 and the semiconductor chip CHP2 is connected to the outer frame body 10 by the elastic support portion 13. There is a common point. However, in the second embodiment (FIG. 26), the semiconductor chip CHP1 and the cap 14 are connected by the elastic support portion 13, whereas in the third embodiment (FIG. 36), the semiconductor chip CHP2 and the cap 14 are externally connected. The bottom of the frame 10 is connected by an elastic support 13. Also in the third embodiment, the stacked structure of the semiconductor chip CHP2 and the semiconductor chip CHP1 is connected to the outer frame body 10 only through the elastic support portion 13. This means that the semiconductor chip CHP1 on which the MEMS structure is formed is supported only by the soft elastic support portion 13 as in the second embodiment. Therefore, the vibration disturbance generated outside the outer frame body 10 is transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed only through the elastic support portion 13 that is in contact with the outer frame body 10. In this case, since the elastic support part 13 is comprised from soft materials, such as a silicon gel, for example, the effect which absorbs the vibration disturbance from the outside is acquired. That is, the vibration disturbance from the outside of the outer frame body 10 is absorbed by the soft elastic support portion 13 before being transmitted to the semiconductor chip CHP1. As a result, even in the MEMS mounting configuration of the third embodiment, vibration disturbance transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed can be reduced, and the detection sensitivity of the MEMS can be improved.

  The MEMS according to the third embodiment is mounted and configured as described above, and a method for mounting the MEMS will be described below. In addition, the place which overlaps with the said Embodiment 1 is abbreviate | omitted.

  As shown in FIG. 37, the semiconductor chip CHP <b> 2 is disposed on the pedestal portion of the outer frame body 10. Specifically, the semiconductor chip CHP2 is disposed on the pedestal portion of the outer frame body 10 while the semiconductor chip CHP2 is held by the vacuum chuck. At this time, the electrode E1 is formed on the back surface of the semiconductor chip CHP2, and the support portion 11 is formed on the electrode E1. On the other hand, an electrode E <b> 2 is formed on the pedestal portion of the outer frame body 10. The semiconductor chip CHP2 is arranged on the pedestal portion of the outer frame body 10 so that the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the pedestal portion of the outer frame body 10 face each other. At this time, a microheater H1 is formed at the bottom of the outer frame 10 below the electrode E2.

  In the third embodiment, as shown in FIG. 37, the electrode E1 and the support portion 13 are formed in the vicinity of the outer edge region on the back surface of the semiconductor chip CHP2, but in the central region on the back surface of the semiconductor chip CHP2. There is a large space. Generally, a region having a diameter of several mm can be secured in the central region on the back surface of the semiconductor chip CHP2 that is several to several tens of mm square. For this reason, in the third embodiment, an elastic support member such as silicon gel constituting the elastic support portion 13 is applied to the bottom portion (pedestal portion) of the outer frame body 10.

  Subsequently, as shown in FIG. 38, the semiconductor chip CHP2 is mounted on the elastic support portion 13 applied to the bottom portion (pedestal portion) of the outer frame body 10, and then the elastic support portion 13 is attached from the bottom portion of the outer frame body 10. By baking, the outer frame body 10 and the semiconductor chip CHP2 are connected. At this time, the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the bottom of the outer frame body 10 are in contact with each other at the support portion 11.

  In this state, a current is passed through the microheater H1 formed in a state of being electrically separated below the electrode E2. Thereby, Joule heat generated from the microheater H1 is transmitted to the support portion 11 via the electrode E2. As a result, the support part 11 is heated and deformed. FIG. 38 shows the support 11 in a deformed state. Here, the support part 11 is heated and deformed in a state where the position in the height direction of the semiconductor chip CHP2 is fixed by a vacuum chuck. However, such a method is not necessarily required, and the support portion 11 may be heated and deformed with the vacuum chuck removed.

  Since the electrode E1 and the electrode E2 are configured as materials having good wettability with respect to the support part 11, if the support part 11 is heated by the microheater H1, the support part 11 in contact with the electrode E1 and the electrode E2 is Dissolve and liquefy. As a result, the liquefied support portion 11 is deformed so as to cover the electrode E1 and the electrode E2 by surface tension. For this reason, the contact state between the support part 11 and the electrode E2 or between the support part 11 and the electrode E1 changes from point contact to surface contact, and the electrical resistance between the electrode E1 and the electrode E2 becomes small. By monitoring the change in the resistance value and controlling the value of the current flowing through the microheater H1, the end point of the joining process of the electrode E2 and the support portion 11 can be confirmed. The support portion 11 after being coupled to the electrode E2 has a large diameter on the electrode side (electrode E2 and electrode E1) and a thin diameter at the center portion of the support portion due to the action of surface tension.

  For example, as shown in FIG. 18, first, after the semiconductor chip CHP2 is disposed on the outer frame body 10, the current is passed through the microheater H1 to heat the support portion 11. Then, the contact resistance between the electrode E2 and the support part 11 is measured (S101). Next, it is compared whether the measured value of the contact resistance between the electrode E2 and the support portion 11 is smaller than the initial resistance value (resistance value at the time of coupling) (S102). At this time, if the measured resistance value is not smaller than the resistance value in the initial state, the amount of current flowing through the microheater H1 is increased to increase the heating temperature and the heating process is continued (S103). On the other hand, if the measured resistance value is smaller than the initial resistance value, the current flowing through the microheater H1 is stopped and the heating process is terminated (S104). With the above verification means, the connection state between the electrode E2 and the support portion 11 can be confirmed while controlling the value of the current flowing through the microheater H1.

  Subsequently, as shown in FIG. 39, after the semiconductor chip CHP1 is placed on the semiconductor chip CHP2 using a vacuum chuck, the semiconductor chip CHP1 is fixed to the semiconductor chip CHP2 via the adhesive material 12. Here, the adhesive 12 is selected to be sufficiently hard so as not to hinder wire bonding.

  Thereafter, the pad PD1 of the semiconductor chip CHP1 and the pad PD2 of the semiconductor chip CHP2 are connected by the wire W1. Similarly, the pad PD3 of the semiconductor chip CHP2 and the pad PD4 formed on the outer frame body 10 are connected by the wire W2. At this time, when the semiconductor chip CHP1 and the semiconductor chip CHP2 are connected only by the soft elastic support portion 13 and are not firmly fixed, the wire bonding cannot be sufficiently performed. Since the semiconductor chip CHP2 and the outer frame body 10 are securely fixed by the support portion 11, the reliability of wire bonding can be improved.

  Next, the cap 14 is mounted on the upper portion of the outer frame body 10. Then, the cap 14 is joined to the outer frame body 10 by seam welding or the like. Thus, the semiconductor chip CHP1 and the semiconductor chip CHP2 are sealed inside the outer frame body 10.

  Subsequently, the bottom of the outer frame body 10 is further heated by the microheater H1. At this time, since the electrode E1 and the electrode E2 are composed of members having good wettability with the support portion 11, if the support portion 11 is further heated, the support portion 11 is melted again by this heat treatment. Liquefy. The liquefied support portion 11 is pulled by the surface tension to the electrode E1 side and the electrode E2 side having good wettability. As a result of the liquefied support portion 11 being pulled from both the electrode E1 side and the electrode E2 side, the support portion 11 is separated between the electrode E1 and the electrode E2. Thereby, the electrode E1 and the electrode E2 are physically separated.

  Separation of the support portion 11 connecting the electrode E1 and the electrode E2 can be confirmed by measuring the contact resistance between the electrode E1 and the electrode E2 in the above-described closed loop circuit. That is, before the further heat treatment is performed, the electrode E2 and the support portion 11 are in surface contact with each other, so that the contact resistance between the electrode E2 and the electrode E1 is reduced. On the other hand, after further heat treatment, the support part 11 connecting the electrode E2 and the electrode E1 is separated and the electrode E1 and the electrode E2 are separated. The contact resistance between them becomes infinite. Therefore, if the contact resistance between the electrode E2 and the electrode E1 is measured, the contact state between the electrode E2 and the electrode E1 can be confirmed.

  For example, as shown in FIG. 24, first, a wire bonding step is performed, the outer frame body 10 is sealed with a cap 14, and then the support portion 11 is heated with a microheater H1. Thereafter, the contact resistance between the electrode E2 and the electrode E1 is measured (S201). Next, it is determined whether the value obtained by measuring the contact resistance between the electrode E2 and the electrode E1 is infinite (S202). At this time, if the measured resistance value is smaller than infinity, the heat treatment by the microheater H1 is continued, and the heating current is raised by increasing the value of the current passed through the microheater H1 (S203). On the other hand, if the measured resistance value is infinite, the heat treatment by the microheater H1 is terminated (S204). With the above verification means, the connection state between the electrode E2 and the electrode E1 can be confirmed while controlling the current flowing through the microheater H1.

  In the third embodiment, in consideration of production efficiency, the fixing by the support portion 11 is released after the outer frame body 10 is sealed. However, the present invention is not limited to this. good. For example, after the wire bonding process is performed, the fixing by the support portion 11 can be released before the outer frame body 10 is sealed with the cap 14. In this case, heat treatment is applied to the support portion 11 in a state where the sealing is not performed. That is, when the heat treatment causes a problem in the release of the OUT gas from the components inside the outer frame body 10, the fixing by the support portion 11 can be released before sealing. For example, when the MEMS is an angular velocity sensor or the like, it is necessary to seal the semiconductor chip CHP1 on which the MEMS structure is formed in a state close to a vacuum state in order to maintain the reference vibration. In this case, according to the MEMS mounting method in the third embodiment, the fixing by the support portion 11 can be released before the outer frame body 10 is sealed with the cap 14, which is suitable for mounting the angular velocity sensor. It can be said that. That is, since the support portion 11 is heated before the outer frame body 10 is sealed with the cap 14, the OUT gas generated at this time is discharged out of the outer frame body 10. Therefore, the outer frame body 10 can be vacuum sealed without considering the influence of the OUT gas generated by heating the support portion 11. Through the above steps, a MEMS mounting configuration as shown in FIG. 36 can be obtained.

(Embodiment 4)
A MEMS mounting configuration according to the fourth embodiment will be described with reference to the drawings. In the second embodiment, the example in which the suspended structure is realized by supporting the cap 14 and the semiconductor chip CHP1 disposed on the upper portion of the outer frame body 10 with the elastic support portion 13 has been described. Now, a mounting configuration in which the side surface of the outer frame body 10 and the side surface of the semiconductor chip CHP2 are supported by the elastic support portion 13 will be described.

  FIG. 40 is a top view showing the MEMS mounting configuration in the fourth embodiment, which is substantially the same as the top view (FIG. 25) showing the MEMS mounting configuration in the second embodiment. The difference between the second embodiment and the fourth embodiment is that, in the fourth embodiment, the elastic support portions 13 are present on the side surface of the semiconductor chip CHP2 and the side surface of the outer frame body 10. Next, FIG. 41 is a cross-sectional view taken along line AA in FIG. 41 has almost the same configuration as that of FIG. 26, and therefore a different configuration will be described. That is, in FIG. 41, the side surface of the semiconductor chip CHP2 and the side surface of the outer frame body 10 are connected by the elastic support portion 13.

  Also in the fourth embodiment, the stacked structure of the semiconductor chip CHP2 and the semiconductor chip CHP1 is connected to the outer frame body 10 only through the elastic support portion 13. This means that the semiconductor chip CHP1 on which the MEMS structure is formed is supported only by the soft elastic support portion 13 as in the second embodiment. Therefore, the vibration disturbance generated outside the outer frame body 10 is transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed only through the elastic support portion 13 that is in contact with the outer frame body 10. In this case, since the elastic support part 13 is comprised from soft materials, such as a silicon gel, for example, the effect which absorbs the vibration disturbance from the outside is acquired. That is, the vibration disturbance from the outside of the outer frame body 10 is absorbed by the soft elastic support portion 13 before being transmitted to the semiconductor chip CHP1. As a result, even in the MEMS mounting configuration of the fourth embodiment, vibration disturbance transmitted to the semiconductor chip CHP1 in which the MEMS structure is formed can be reduced, and the detection sensitivity of the MEMS can be improved.

  The MEMS in the fourth embodiment is mounted and configured as described above, and a method for mounting the MEMS will be described below. In addition, the place which overlaps with the said Embodiment 1 is abbreviate | omitted.

  As shown in FIG. 42, the semiconductor chip CHP <b> 2 is disposed on the pedestal portion of the outer frame body 10. Specifically, the semiconductor chip CHP2 is disposed on the pedestal portion of the outer frame body 10 while the semiconductor chip CHP2 is held by the vacuum chuck. At this time, the electrode E1 is formed on the back surface of the semiconductor chip CHP2, and the support portion 11 is formed on the electrode E1. On the other hand, an electrode E <b> 2 is formed on the pedestal portion of the outer frame body 10. The semiconductor chip CHP2 is arranged on the pedestal portion of the outer frame body 10 so that the electrode E1 formed on the semiconductor chip CHP2 and the electrode E2 formed on the pedestal portion of the outer frame body 10 face each other. At this time, a microheater H1 is formed at the bottom of the outer frame 10 below the electrode E2.

  In this state, a current is passed through the microheater H1 formed in a state of being electrically separated below the electrode E2. Thereby, Joule heat generated from the microheater H1 is transmitted to the support portion 11 via the electrode E2. As a result, the support part 11 is heated and deformed. FIG. 42 shows the support portion 11 in a deformed state.

  Since the electrode E1 and the electrode E2 are configured as materials having good wettability with respect to the support part 11, if the support part 11 is heated by the microheater H1, the support part 11 in contact with the electrode E1 and the electrode E2 is Dissolve and liquefy. As a result, the liquefied support portion 11 is deformed so as to cover the electrode E1 and the electrode E2 by surface tension. For this reason, the contact state between the support part 11 and the electrode E2 or between the support part 11 and the electrode E1 changes from point contact to surface contact, and the electrical resistance between the electrode E1 and the electrode E2 becomes small. By monitoring the change in the resistance value and controlling the value of the current flowing through the microheater H1, the end point of the joining process of the electrode E2 and the support portion 11 can be confirmed. The support portion 11 after being coupled to the electrode E2 has a large diameter on the electrode side (electrode E2 and electrode E1) and a thin diameter at the center portion of the support portion due to the action of surface tension.

  For example, as shown in FIG. 18, first, after the semiconductor chip CHP2 is disposed on the outer frame body 10, the current is passed through the microheater H1 to heat the support portion 11. Then, the contact resistance between the electrode E2 and the support part 11 is measured (S101). Next, it is compared whether the measured value of the contact resistance between the electrode E2 and the support portion 11 is smaller than the initial resistance value (resistance value at the time of coupling) (S102). At this time, if the measured resistance value is not smaller than the resistance value in the initial state, the amount of current flowing through the microheater H1 is increased to increase the heating temperature and the heating process is continued (S103). On the other hand, if the measured resistance value is smaller than the initial resistance value, the current flowing through the microheater H1 is stopped and the heating process is terminated (S104). With the above verification means, the connection state between the electrode E2 and the support portion 11 can be confirmed while controlling the value of the current flowing through the microheater H1.

  Subsequently, after placing the semiconductor chip CHP1 on the semiconductor chip CHP2 using a vacuum chuck, the semiconductor chip CHP1 is fixed to the semiconductor chip CHP2 via the adhesive material 12. Here, the adhesive 12 is selected to be sufficiently hard so as not to hinder wire bonding.

  And, by filling the gap between the side surface of the semiconductor chip CHP2 and the side surface of the outer frame body 10 with an elastic support member made of, for example, silicon gel, and then curing the elastic support member by heat treatment such as baking, The space between the side surface of the semiconductor chip CHP2 and the side surface of the outer frame body 10 is filled with the elastic support portion 13. Thus, the semiconductor chip CHP2 and the outer frame body 10 can be connected by the elastic support portion 13.

  Thereafter, as shown in FIG. 43, the pad PD1 of the semiconductor chip CHP1 and the pad PD2 of the semiconductor chip CHP2 are connected by the wire W1. Similarly, the pad PD3 of the semiconductor chip CHP2 and the pad PD4 formed on the outer frame body 10 are connected by the wire W2. At this time, when the semiconductor chip CHP1 and the semiconductor chip CHP2 are connected only by the soft elastic support portion 13 and are not firmly fixed, the wire bonding cannot be sufficiently performed. Since the semiconductor chip CHP2 and the outer frame body 10 are securely fixed by the support portion 11, the reliability of wire bonding can be improved.

  Next, the cap 14 is mounted on the upper portion of the outer frame body 10. Then, the cap 14 is joined to the outer frame body 10 by seam welding or the like. Thus, the semiconductor chip CHP1 and the semiconductor chip CHP2 are sealed inside the outer frame body 10.

  Subsequently, the bottom of the outer frame body 10 is further heated by the microheater H1. At this time, since the electrode E1 and the electrode E2 are composed of members having good wettability with the support portion 11, if the support portion 11 is further heated, the support portion 11 is melted again by this heat treatment. Liquefy. The liquefied support portion 11 is pulled by the surface tension to the electrode E1 side and the electrode E2 side having good wettability. As a result of the liquefied support portion 11 being pulled from both the electrode E1 side and the electrode E2 side, the support portion 11 is separated between the electrode E1 and the electrode E2. Thereby, the electrode E1 and the electrode E2 are physically separated.

  Separation of the support portion 11 connecting the electrode E1 and the electrode E2 can be confirmed by measuring the contact resistance between the electrode E1 and the electrode E2 in the above-described closed loop circuit. That is, before the further heat treatment is performed, the electrode E2 and the support portion 11 are in surface contact with each other, so that the contact resistance between the electrode E2 and the electrode E1 is reduced. On the other hand, after further heat treatment, the support part 11 connecting the electrode E2 and the electrode E1 is separated and the electrode E1 and the electrode E2 are separated. The contact resistance between them becomes infinite. Therefore, if the contact resistance between the electrode E2 and the electrode E1 is measured, the contact state between the electrode E2 and the electrode E1 can be confirmed.

  For example, as shown in FIG. 24, first, a wire bonding step is performed, the outer frame body 10 is sealed with a cap 14, and then the support portion 11 is heated with a microheater H1. Thereafter, the contact resistance between the electrode E2 and the electrode E1 is measured (S201). Next, it is determined whether the value obtained by measuring the contact resistance between the electrode E2 and the electrode E1 is infinite (S202). At this time, if the measured resistance value is smaller than infinity, the heat treatment by the microheater H1 is continued, and the heating current is raised by increasing the value of the current passed through the microheater H1 (S203). On the other hand, if the measured resistance value is infinite, the heat treatment by the microheater H1 is terminated (S204). With the above verification means, the connection state between the electrode E2 and the electrode E1 can be confirmed while controlling the current flowing through the microheater H1. Through the above steps, a MEMS mounting configuration as shown in FIG. 41 can be obtained.

  In the fourth embodiment, for example, the elastic support portion 13 is provided on the entire surface where the side surface of the semiconductor chip CHP2 and the side surface of the outer frame body 10 face each other. Thereby, the characteristics in the x direction (not shown) and the y direction (not shown) constituting the plane of the semiconductor chip CHP2 can be made uniform. That is, the natural frequency of the system constituted by the semiconductor chip CHP2 (including the semiconductor chip CHP1) and the outer frame body 10 through the elastic support portion 13 can be made uniform in the x direction and the y direction. This means that the shielding characteristic against the vibration disturbance transmitted from the x direction and the y direction can be made uniform, and the reliability of the MEMS can be improved. However, the elastic support portion 13 may be disposed so as to be partially scattered, for example, without providing the elastic support portion 13 on the entire surface where the side surface of the semiconductor chip CHP2 and the side surface of the outer frame body 10 face each other.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  In the first to fourth embodiments, the mounting configuration in which the semiconductor chip CHP1 in which the MEMS structure is formed and the semiconductor chip CHP2 in which the integrated circuit is formed is stacked. For example, the MEMS structure and the integrated circuit are 1 The mounting configuration and mounting method of the present invention can also be applied when forming on one semiconductor chip CHP1.

  Further, in the first to fourth embodiments, an acceleration sensor is cited as an example of MEMS. However, the present invention is not limited to this, and the present invention is widely applied to MEMS including movable parts such as angular velocity sensors, vibrators, and micromirrors. can do.

  The present invention can be widely used in the manufacturing industry for manufacturing MEMS.

It is a top view which shows the structure which comprises the acceleration sensor formed in the semiconductor chip. It is sectional drawing cut | disconnected by the AA line of FIG. It is a figure which shows the structure which detects an acceleration sensor. It is a top view which shows the mounting structure of MEMS in Embodiment 1 of this invention. It is sectional drawing cut | disconnected by the AA line of FIG. It is a figure which shows the structure of the electrode currently formed in the outer frame. It is a figure which shows the planar shape of the electrode shown in FIG. It is a figure which shows the structure of the back surface of the semiconductor chip in which the integrated circuit is formed. It is sectional drawing cut | disconnected by the AA line of FIG. It is a figure which shows the structure of the upper surface of the semiconductor chip in which the MEMS structure is formed. It is sectional drawing cut | disconnected by the AA line of FIG. FIG. 6 is a cross-sectional view showing a MEMS mounting process in the first embodiment. FIG. 13 is a cross-sectional view showing a MEMS mounting process following FIG. 12. It is a figure which shows the initial state which has arrange | positioned the semiconductor chip on the outer frame. It is a figure which shows the area | region where an electrode and a support part contact in the state shown in FIG. It is a figure which shows the state which heat-processed, after arrange | positioning a semiconductor chip on the base part of an outer frame. It is a figure which shows the area | region where an electrode and a support part contact in the state shown in FIG. It is a flowchart for verifying the contact state of an electrode and a support part. FIG. 14 is a cross-sectional view showing a MEMS mounting process following FIG. 13. FIG. 20 is a cross-sectional view showing a MEMS mounting process following FIG. 19. FIG. 21 is a cross-sectional view showing a MEMS mounting process following FIG. 20. It is a figure which shows a mode that the semiconductor chip and the outer frame are connected after implementing a wire bonding process. It is a figure which shows a mode that the bottom part of the outer frame body of the state shown in FIG. 22 is further heated. It is a flowchart for verifying the contact state between the electrode formed on the semiconductor chip and the electrode formed on the outer frame. FIG. 10 is a top view showing a MEMS mounting configuration in a second embodiment. It is sectional drawing cut | disconnected by the AA line of FIG. It is a figure which shows the electrode and micro heater which were formed in the outer frame. FIG. 10 is a cross-sectional view showing a MEMS mounting process in the second embodiment. It is a figure which shows the initial state which has arrange | positioned the semiconductor chip on the outer frame. It is a figure which shows the state which heat-processed, after arrange | positioning a semiconductor chip on the base part of an outer frame. FIG. 29 is a cross-sectional view showing a MEMS mounting process following FIG. 28. FIG. 32 is a cross-sectional view showing a MEMS mounting process following FIG. 31. It is a figure which shows a mode that the semiconductor chip and the outer frame are connected after implementing a wire bonding process. It is a figure which shows a mode that the bottom part of the outer frame body of the state shown in FIG. 33 is further heated. FIG. 12 is a top view showing a mounting configuration of MEMS in the third embodiment. It is sectional drawing cut | disconnected by the AA line of FIG. FIG. 11 is a cross-sectional view showing a MEMS mounting process in the third embodiment. FIG. 38 is a cross-sectional view showing a MEMS mounting process following FIG. 37; FIG. 39 is a cross-sectional view showing a MEMS mounting process following FIG. 38. FIG. 10 is a top view showing a mounting configuration of a MEMS according to a fourth embodiment. It is sectional drawing cut | disconnected by the AA line of FIG. FIG. 10 is a cross-sectional view showing a MEMS mounting process in the fourth embodiment. FIG. 43 is a cross-sectional view showing a MEMS mounting process following FIG. 42. It is sectional drawing which shows the mounting structure of MEMS which this inventor examined.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed part 1a Terminal 2 Beam 3 Movable part 4 Fixed electrode 4a Terminal 5 Embedded insulation layer 6 Detection capacity | capacitance part 7 Capacitance voltage conversion part 8 Signal processing part 10 Outer frame 11 Support part 11a Contact 11b Contact area 12 Adhesive material 13 Elasticity Support part 14 Cap 15 Substrate layer 16 Embedded insulating layer 17 Silicon layer 18 Cavity part 19 Movable part 19a Fixed part 20 Cap layer 100 Package 101 Semiconductor chip 102 Elastic support member 103 Wire 104 Spacing 105 Lid CHP semiconductor chip CHP1 Semiconductor chip CHP2 Semiconductor chip E1 Electrode E2 Electrode H1 Microheater L Wiring L1 Wiring L2 Wiring L3 Wiring Pa Package PD1 Pad PD2 Pad PD3 Pad PD4 Pad S Substrate Layer V Via W1 Wire W2 Wire

Claims (21)

(A) preparing a first semiconductor chip on which a structure including a cavity and a movable movable body provided in the cavity is formed;
(B) An integrated circuit that processes an output from the structure formed on the first semiconductor chip as an electrical signal is formed, and a second semiconductor chip having a larger planar shape than the first semiconductor chip is prepared. And a process of
(C) a step of preparing an outer frame body having a concave shape and having an open top;
(D) The bottom portion of the outer frame body and the second semiconductor chip are connected via a plurality of discretely arranged support members , and then the plurality of support members are heated to be melted and heated. Increasing the contact area by the plurality of support members than before ;
(E) after the step (d), mounting the first semiconductor chip on the second semiconductor chip;
(F) After the step (e), a first terminal formed on the first semiconductor chip and a second terminal formed on the second semiconductor chip are connected by a first wire, and the second semiconductor is connected. Connecting a third terminal formed on the chip and a fourth terminal formed on the outer frame with a second wire;
(G) After the step (f), the cap formed with the elastic support member is disposed so that the elastic support member adheres to the first semiconductor chip, and the inside of the outer frame body is sealed by the cap. And a process of
(H) After the step (g), the plurality of support members are heated to melt the plurality of support members, and the second semiconductor is utilized by utilizing surface tension acting on the melted plurality of support members. A method of mounting a micro electro mechanical system, comprising: a step of separating a chip and a bottom portion of the outer frame body. A method of mounting a microelectromechanical system according to claim 1,
In the step (h), the plurality of support members are heated by heating a bottom portion of the outer frame body. A method of mounting a microelectromechanical system according to claim 1,
Immediately below the plurality of support members at the bottom of the outer frame, a plurality of micro heaters embedded in the bottom of the outer frame are formed,
In the step (h), the plurality of support members are heated by the plurality of micro heaters. A method of mounting a microelectromechanical system according to claim 1,
The method for mounting a micro electro mechanical system, wherein the elastic support member is softer than the plurality of support members. A method of mounting a microelectromechanical system according to claim 1,
The method for mounting a micro electro mechanical system, wherein the plurality of support members are made of a conductive material and formed of a material that melts when heated. A method of mounting a microelectromechanical system according to claim 5,
The method of mounting a micro electro mechanical system, wherein the plurality of support members are made of a solder material. A method of mounting a microelectromechanical system according to claim 5,
Each of the plurality of support members is configured to connect a first electrode formed on a back surface of the second semiconductor chip and a second electrode formed on a bottom surface of the outer frame; and The first electrode, the plurality of support members, and the second electrode form a closed loop circuit,
The step (h) includes a step of detecting whether the second semiconductor chip and the outer frame body are in a coupled state or a separated state by measuring electrical resistances of the plurality of support members. A method of mounting a microelectromechanical system, comprising: A method of mounting a microelectromechanical system according to claim 1,
The spring constant in the direction perpendicular to the surface of the first semiconductor chip of the elastic support member is kz, and the total mass of the first semiconductor chip and the second semiconductor chip supported by the elastic support member is m, When the maximum allowable acceleration applied from the outside of the outer frame body is Amax, the distance h between the second semiconductor chip separated in the step (h) and the outer frame body is h> ( m / kz) · Amax is satisfied. A method of mounting a microelectromechanical system, A method of mounting a microelectromechanical system according to claim 1,
In the step (g), the first wire and the second wire are covered with the elastic support member. A method of mounting a microelectromechanical system according to claim 1,
The method for mounting a micro electro mechanical system, wherein the elastic support member is made of silicon gel. A method of mounting a microelectromechanical system according to claim 1,
The structure formed in the first semiconductor chip includes a detection capacitance section in which the capacitance changes according to the displacement of the movable body,
The first semiconductor chip further includes a capacitance / voltage conversion unit that converts a change in capacitance detected by the detection capacitance unit into a voltage signal and outputs the voltage signal. How to implement A method of mounting a microelectromechanical system according to claim 11,
An integrated circuit formed on the second semiconductor chip processes a voltage signal converted by the capacitance-voltage conversion unit, and the mounting method of the micro electro mechanical system. (A) preparing a first semiconductor chip on which a structure including a cavity and a movable movable body provided in the cavity is formed;
(B) An integrated circuit that processes an output from the structure formed on the first semiconductor chip as an electrical signal is formed, and a second semiconductor chip having a larger planar shape than the first semiconductor chip is prepared. And a process of
(C) a step of preparing an outer frame body having a concave shape and having an open top;
(D) By connecting the bottom of the outer frame body and the second semiconductor chip by both the elastic support member and the plurality of discretely arranged support members, and then heating the plurality of support members Melting and increasing the contact area by the plurality of support members than before heating ; and
(E) after the step (d), mounting the first semiconductor chip on the second semiconductor chip;
(F) After the step (e), a first terminal formed on the first semiconductor chip and a second terminal formed on the second semiconductor chip are connected by a first wire, and the second semiconductor is connected. Connecting a third terminal formed on the chip and a fourth terminal formed on the outer frame with a second wire;
(G) After the step (f), by heating the plurality of support members, the plurality of support members are melted, and the second semiconductor is utilized by utilizing surface tension acting on the melted plurality of support members. A step of separating each of the plurality of support members connecting the chip and the outer frame body, and supporting the second semiconductor chip and the bottom of the outer frame body only by the elastic support member. A method of mounting a microelectromechanical system characterized by the above. A method of mounting a microelectromechanical system according to claim 13,
Immediately below the plurality of support members at the bottom of the outer frame, a plurality of micro heaters embedded in the bottom of the outer frame are formed,
In the step (g), the plurality of support members are heated by the plurality of micro heaters. A method for mounting a microelectromechanical system according to claim 14,
Each of the plurality of support members is configured to connect a first electrode formed on a back surface of the second semiconductor chip and a second electrode formed on a bottom surface of the outer frame; and The first electrode, the plurality of support members, and the second electrode form a closed loop circuit,
The step (g) includes a step of detecting whether the second semiconductor chip and the outer frame body are in a coupled state or a separated state by measuring electrical resistances of the plurality of support members. A method of mounting a microelectromechanical system, comprising: (A) preparing a first semiconductor chip on which a structure including a cavity and a movable movable body provided in the cavity is formed;
(B) An integrated circuit that processes an output from the structure formed on the first semiconductor chip as an electrical signal is formed, and a second semiconductor chip having a larger planar shape than the first semiconductor chip is prepared. And a process of
(C) a step of preparing an outer frame body having a concave shape and having an open top;
(D) The bottom portion of the outer frame body and the second semiconductor chip are connected by a plurality of support members that are discretely arranged , and then the plurality of support members are heated to be melted, before being heated. Also increasing the contact area by the plurality of support members ;
(E) after the step (d), mounting the first semiconductor chip on the second semiconductor chip;
(F) After the step (e), a step of forming an elastic support member so as to fill a gap between a side surface of the second semiconductor chip and a side surface of the outer frame body;
(G) After the step (f), a first terminal formed on the first semiconductor chip and a second terminal formed on the second semiconductor chip are connected by a first wire, and the second semiconductor is connected. Connecting a third terminal formed on the chip and a fourth terminal formed on the outer frame with a second wire;
(H) After the step (g), the plurality of support members are heated to melt the plurality of support members, and the second semiconductor is utilized by utilizing surface tension acting on the melted plurality of support members. A method of mounting a micro electro mechanical system, comprising: a step of separating a chip and a bottom portion of the outer frame body. A method for mounting a microelectromechanical system according to claim 16,
Immediately below the plurality of support members at the bottom of the outer frame, a plurality of micro heaters embedded in the bottom of the outer frame are formed,
In the step (h), the plurality of support members are heated by the plurality of micro heaters. A method for mounting a microelectromechanical system according to claim 17,
Each of the plurality of support members is configured to connect a first electrode formed on a back surface of the second semiconductor chip and a second electrode formed on a bottom surface of the outer frame; and The first electrode, the plurality of support members, and the second electrode form a closed loop circuit,
The step (h) includes a step of detecting whether the second semiconductor chip and the outer frame body are in a coupled state or a separated state by measuring electrical resistances of the plurality of support members. A method of mounting a microelectromechanical system, comprising: (A) A step of preparing a first semiconductor chip in which a structure including a hollow portion and a movable movable body provided in the hollow portion and an integrated circuit that processes an output from the structure as an electric signal are formed. When,
(B) a step of preparing an outer frame body having a concave shape and having an open top;
(C) The bottom portion of the outer frame body and the first semiconductor chip are connected via a plurality of discretely arranged support members , and then the plurality of support members are heated to be melted and heated. Increasing the contact area by the plurality of support members than before ;
(D) After the step (c), connecting a first terminal formed on the first semiconductor chip and a fourth terminal formed on the outer frame with a third wire;
(E) After the step (d), the cap formed with the elastic support member is disposed so that the elastic support member adheres to the first semiconductor chip, and the inside of the outer frame body is sealed by the cap. And a process of
(F) After the step (e), by heating the plurality of support members, the plurality of support members are melted, and the first semiconductor is utilized by utilizing surface tension acting on the melted plurality of support members. A method of mounting a micro electro mechanical system, comprising: a step of separating a chip and a bottom portion of the outer frame body. A method of mounting a microelectromechanical system according to claim 19,
The structure formed in the first semiconductor chip includes a detection capacitance section in which the capacitance changes according to the displacement of the movable body,
The first semiconductor chip further includes a capacitance / voltage conversion unit that converts a change in capacitance detected by the detection capacitance unit into a voltage signal and outputs the voltage signal. How to implement A method of mounting a microelectromechanical system according to claim 20,
The micro electro mechanical system mounting method, wherein the first semiconductor chip further includes an integrated circuit for processing a voltage signal converted by the capacitance voltage converter.

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