JP4781098B2 - Electronic equipment - Google Patents

Description

  The present invention relates to an electronic device formed by sealing an electronic component having a microelectromechanical mechanism formed on a main surface of a semiconductor substrate using an electronic component sealing substrate.

  2. Description of the Related Art In recent years, an electronic device in which a very small electromechanical mechanism, so-called MEMS (Micro Electro Mechanical System), is formed by applying a processing technology for forming fine wiring such as a semiconductor integrated circuit element on a main surface of a semiconductor substrate such as a silicon wafer. Parts are attracting attention, and development is progressing toward practical application.

  Examples of such micro electromechanical mechanisms include sensors such as acceleration sensors, pressure sensors, and actuators, micro mirror devices in which fine mirror bodies are movably formed, micro chemical systems incorporating optical devices, micro pumps, etc. Prototypes have been developed and developed in a wide range of fields.

  Such a micro-electromechanical mechanism is an electronic device that is hermetically sealed in a hollow container in order to prevent adhesion of foreign matters that interfere with mechanical operation and to ensure a stable mechanical operating environment. After that, it is necessary to mount and use in various devices.

  Conventionally, such a container has been formed by attaching another semiconductor substrate (semiconductor substrate for sealing) to the main surface of the semiconductor substrate on which the microelectromechanical mechanism is formed. In the semiconductor substrate for sealing, for example, a recess is formed so as to surround and seal the micro-electromechanical mechanism.

  On the other hand, in the case of the electronic device manufactured by the above prior art, since each semiconductor substrate cannot form a three-dimensional wiring conductor therein, from the inside of the container in which the microelectromechanical mechanism is mounted, It is difficult to lead out the wiring conductor over the main surface on the opposite exposed side. Therefore, there is a problem that so-called surface mounting, in which the lead-out portion of the wiring conductor is directly connected to face a predetermined portion of the external electric circuit, is difficult.

As a technology that can form an electronic device in a form that can be surface-mounted in response to such a problem, the present applicant has previously encapsulated an electronic component formed by using an insulating substrate made of an insulating material such as a ceramic material. A method for manufacturing an electronic device (a method for sealing a micro-electromechanical mechanism) using the stopping substrate and the electronic component sealing substrate has been proposed (see Patent Document 1).
In the technique described in Patent Document 1, the electronic component sealing substrate includes an insulating substrate, a frame member that houses the micro electromechanical mechanism inside, a connection pad and a connection terminal that are electrically connected to the electrode, Each is disposed opposite to the micro electro mechanical mechanism and the electrode of the electronic component.

  According to this electronic component sealing substrate, for example, it is formed using an insulating substrate such as a ceramic multilayer wiring substrate, so that the insulating substrate is insulated from the inside of the container in which the microelectromechanical mechanism is hermetically sealed. The wiring conductor can be led out over the exposed surface. Therefore, an electronic device capable of surface mounting can be manufactured by connecting the derived end portion to an external electric circuit as a mounting pad.

  Further, according to the method for manufacturing an electronic device using the electronic component sealing substrate, a plurality of so-called multiple electronic component sealing substrates and electronic components are arranged vertically and horizontally on an insulating substrate or a semiconductor substrate, respectively. Thus, an electronic device capable of surface mounting can be manufactured with high productivity. That is, an electronic component sealing substrate (electronic component sealing region) arranged in correspondence with each of the arranged electronic components on a large number of electronic components (micro-electromechanical mechanisms, etc.) arranged on a semiconductor substrate ) Can be sealed together in a lump. In addition, since the electrical connection between the electrode of the electronic component and the wiring conductor of the electronic component sealing substrate can be performed at the same time during the sealing, each of the electronic components in the form of multiple pieces joined together. Further, by dividing the electronic component sealing substrate into individual pieces, a large number of individual electronic devices can be manufactured simultaneously.

  In each manufactured electronic device, for example, a mounting pad is electrically and mechanically connected to a predetermined portion such as a corresponding terminal of an external electric circuit board via a conductive bonding material such as solder.

The mounting pad formed on the lower surface of the electronic component sealing substrate is usually formed along the outer peripheral portion of the lower surface of the electronic component sealing substrate in consideration of connection with an external electric circuit. Yes.
JP 2004-296724 A

  However, in the technique described in Patent Document 1, the productivity of the electronic device is increased by simultaneously performing sealing of the microelectromechanical mechanism and electrical connection for leading the electrode to the outside. In addition, although it is possible to easily produce an electronic device that can be surface-mounted, in recent years, a microelectromechanical mechanism used for a light modulation element, a frequency filter, etc., in particular, a main surface of a semiconductor substrate. In an electronic device having a microelectromechanical mechanism having a structure in which a vibrating portion such as a beam is disposed through a support portion such as a column in the center, the following problems may not be sufficiently suppressed Has arisen.

  That is, in such a micro-electromechanical mechanism having a structure whose operation range is several tens of μm or less, even a slight distortion of the support portion can be used for mechanical operation such as vibration by the vibration portion, for example, turning on a magnetic field or an electric field.・ Inducing a problem such that the response speed of the vibration part with respect to OFF is not constant, and there is a possibility that characteristics and reliability as an electronic device cannot be sufficiently secured.

  As a result of studying such a problem, the present inventor has found that the electronic device obtained by sealing the electronic component on which the micro electro mechanical mechanism is formed is mounted on an external electric circuit using solder or the like. When a thermal load is applied as a part is driven, etc., this occurs due to a difference in thermal expansion between the electronic component sealing substrate formed of a ceramic material and an external electric circuit formed of an epoxy resin or the like. It has been found that deformations such as stress and warpage of the electronic component sealing substrate (insulating substrate) caused by the stress affect the driving of the microelectromechanical mechanism, thereby inducing the above-mentioned problems.

  That is, when the electronic device is heated and then cooled, the electronic component sealing substrate is deformed (warped or the like) due to the stress, and the electronic component sealing substrate and the frame member are caused by the deformation. The semiconductor substrate that is mechanically bonded and formed with the microelectromechanical mechanism is also deformed. For example, when the deformation of the semiconductor substrate acts as a stress on a support portion of a microelectromechanical mechanism having a structure that supports a vibration portion that vibrates when a drive voltage is applied, the vibration portion is deformed or distorted.

  Since the shape of the vibrating part, for example, the length of the beam-like part and the distance between the contacts with the support part, etc. are set according to the operating conditions of the electronic device such as the magnitude of the driving voltage and the frequency of the signal, vibration When the part is deformed or distorted, the response speed of the vibration part is changed, or the vibration part does not properly contact the contact point, thereby causing malfunction of the electronic device. In addition, it has been found that there is a problem that in a part where deformation or distortion occurs, a crack or the like is generated in a vibration part that vibrates repeatedly at high speed over a long period of time, resulting in a decrease in reliability.

  Therefore, a method of connecting the electronic component sealing substrate and the external electric circuit substrate using lead terminals such as a lead frame and a bonding wire is conceivable. For example, when the electronic component sealing substrate and the external electric circuit substrate are electrically and mechanically connected via the lead frame, the difference in thermal expansion between the electronic component sealing substrate and the external electric circuit substrate is caused. Even if stress is generated due to this, the stress is relieved by the deformation of the lead frame.

  Thereby, electrical connection by a lead terminal etc. can be ensured and connection reliability can be improved. In addition, since the stress acting on the electronic component is relaxed through the electronic component sealing substrate, distortion and deformation of the microelectromechanical mechanism can be suppressed.

  However, in this case, since the outer shape of the electronic component sealing substrate is increased by the amount of the lead terminals, the downsizing of the electronic device is hindered. Furthermore, since it is necessary to secure a space for connecting to the lead terminal on the external electric circuit board, an electronic component (electronic device) in which a microelectromechanical mechanism mounted on the external circuit board is formed, or other electronic elements (for example, The mounting density of passive components such as capacitors and resistors may be reduced.

  The present invention has been devised in order to solve the above-described problems, and an object of the present invention is to provide a microelectronic machine that is compact even when heat is applied to an electronic device in which the microelectromechanical mechanism is sealed. An object of the present invention is to provide a highly reliable electronic device with high mechanism driving accuracy.

In the electronic device according to the present invention, an electronic component having a microelectromechanical mechanism formed at the center of the lower surface has a frame-shaped electronic component sealing region surrounding the microelectromechanical mechanism on the upper surface, and an external terminal on the lower surface. The micro electro mechanical mechanism is sealed inside the frame-shaped electronic component sealing region on an electronic component sealing substrate having a mounting region in which mounting pads to be bonded to an external electric circuit board are disposed via The mounting area is composed of four divided areas obtained by dividing the frame-shaped electronic component sealing area into four equal parts by a straight line passing through the center of the frame-shaped electronic component sealing area in a plan view. It is arranged in a region facing three or less of the partition regions without straddling a plurality of regions facing the partition regions, and in the region facing the partition regions, the region other than the mounting region is the region Outside
It is characterized by not being bonded to the partial electric circuit board .

In the electronic device according to the present invention, an electronic component having a microelectromechanical mechanism formed at the center of the lower surface has a frame-shaped electronic component sealing region surrounding the microelectromechanical mechanism on the upper surface, and an external terminal on the lower surface. The micro electro mechanical mechanism is sealed inside the frame-shaped electronic component sealing region on an electronic component sealing substrate having a mounting region in which mounting pads to be bonded to an external electric circuit board are disposed via The mounting area extends from the center of the frame-shaped electronic component sealing area toward the outer periphery in plan view, and divides the frame-shaped electronic component sealing area into four equal parts. It is disposed along a line that faces three or less of the segment half-lines among straight lines, and a region other than the mounting region is not joined to the external electric circuit board in the region facing the segment half-lines. It is a feature.

  According to the electronic device of the present invention, the mounting area in which the mounting pads of the electronic component sealing substrate are arranged is divided into three of four divided areas obtained by dividing the frame-shaped electronic component sealing area into four parts in plan view. Since it is arranged in the area opposite to the following divided areas, stress occurs in the part where the mounting area is not arranged, that is, the part that is not mechanically connected to the external electric circuit board through the mounting pad in the electronic component sealing substrate. Therefore, the stress acting on the electronic component sealing substrate can be kept low in at least one segmented region. Since such a segmented region (low-stressed portion) has a small distortion, at least one segmented region is also defined in the semiconductor substrate mechanically connected to the electronic component sealing substrate via the frame member. It can be formed in a region opposite to.

  The stress generated on the semiconductor substrate of the electronic component due to the deformation of the electronic component sealing substrate due to the stress caused by the difference in thermal expansion coefficient is high in the electronic component region facing the mounting region, and the electron facing the mounting region. It becomes low at the part away from the region of the part. Therefore, a low stress portion can be formed on the semiconductor substrate in a region facing at least one section region in plan view, and the micro electromechanical mechanism can be formed in this low stress portion. It is possible to effectively prevent the microelectromechanical mechanism provided from being distorted due to the stress, and to increase the driving accuracy of the microelectromechanical mechanism.

  According to the electronic device of the present invention, the mounting region where the mounting pads of the electronic component sealing substrate are arranged extends from the center of the frame-shaped electronic component sealing region toward the outer periphery in plan view, and the frame-shaped electronic Since the component sealing area is divided along four lines that divide the component sealing region into four equal parts, and the line is opposed to three or less sectional half lines, the part where the mounting region is not disposed, that is, the electronic component sealing substrate Since stress does not occur in a portion that is not mechanically connected to the external electric circuit board via the mounting pad, the electronic component sealing substrate is formed in a region including the divided half line along at least one divided half line. The acting stress can be kept low. Since the strain (low stress portion) including such a segmented half-line is small, at least one region having low strain is also present on the semiconductor substrate mechanically connected to the electronic component sealing substrate via the frame member. It can be formed in a region facing a region including two segmented half lines.

  The stress generated on the semiconductor substrate of the electronic component due to the deformation of the electronic component sealing substrate due to the stress caused by the difference in thermal expansion coefficient is high in the electronic component region facing the mounting region, and the electron facing the mounting region. It becomes low at the part away from the region of the part. Therefore, a low stress portion can be formed in the semiconductor substrate in a region opposed to the region including at least one section half-line in plan view, and a microelectromechanical mechanism can be formed in the low stress portion. For example, it is possible to effectively prevent distortion caused by the stress in the micro electro mechanical mechanism including the vibrating portion, and to increase the driving accuracy of the micro electro mechanical mechanism.

  The electronic device of the present invention will be described in detail below.

(First configuration)
FIG. 1 is a cross-sectional view showing an example of an embodiment of a first configuration of an electronic device according to the present invention.

  In FIG. 1, reference numeral 11 denotes an electronic component having a micro electro mechanical mechanism 9 formed at the center of the lower surface, and 7 an electronic component sealing region surrounding the micro electro mechanical mechanism 9 on the upper surface, and a mounting pad 6 on the lower surface. It is the board | substrate for electronic component sealing which has the mounting area | region where this is arrange | positioned. The electronic device 12 is basically formed by sealing the microelectromechanical mechanism 9 formed on the lower surface of the electronic component 11 using the electronic component sealing substrate 7.

  In FIG. 1, 1 is an insulating substrate, 2 is a wiring conductor, 3 is a connection pad, 4 is a connection terminal, 5 is a sealing material, and 6 is a mounting pad. In this example, the insulating substrate 1, the wiring conductor 2, the connection pad 3, the connection terminal 4, the sealing material 5 and the mounting pad 6 basically constitute an electronic component sealing substrate 7.

  In this example, the micro electro mechanical mechanism 9 is formed on the lower surface of the semiconductor substrate 8, and the electrode 10 electrically connected to the micro electro mechanical mechanism 9 is formed on the lower surface. The electrode 10 is electrically connected to the connection pad 3 through the connection terminal 4, thereby forming the electronic device 12 sealed in a state in which the micro electromechanical mechanism 9 can be externally connected.

  The semiconductor substrate 8 is made of, for example, a silicon substrate such as a single crystal or polycrystal. A silicon oxide layer is formed on the lower surface of the silicon substrate, and a micro-electromechanical mechanism 9 such as a minute vibration portion is formed at the center of the lower surface by applying a fine wiring processing technique such as photolithography. In addition, the center part in this case is not necessarily a center part, and means the inside of a site | part required in order to ensure the space which arrange | positions the sealing material 5 etc. for sealing the microelectromechanical mechanism 9 etc. . For example, the microelectromechanical mechanism 9 may be arranged slightly biased toward the outer peripheral side of the lower surface as shown in the figure.

  On the lower surface of the semiconductor substrate 8, an electrode 10 electrically connected to the micro-electromechanical mechanism 9 via, for example, a fine wiring formed on the semiconductor substrate 8 using a fine wiring technique is formed in a circular pattern or the like. Is formed. In this example, the electrode 10 is formed on the outer peripheral portion outside the central portion where the micro electro mechanical mechanism 9 is formed.

  In FIG. 1, the microelectromechanical mechanism 9 has a double-supported beam structure that supports a beam-like vibrating portion (no symbol) between a pair of columnar support portions (no symbol). When the microelectromechanical mechanism 9 having the doubly-supported beam structure applies a minute voltage between an upper electrode (not shown) formed on the vibrating portion and a lower electrode (not shown) formed on the semiconductor substrate 8. The vibrating part approaches the lower electrode due to the electrostatic phenomenon, and when the voltage application is stopped, the vibrating part is separated and returns to the original state. Then, by such an operation (vibration) of the vibration part, the height of the upper electrode is changed to modulate the intensity of the reflected light to function as a light modulation element, or the vibration part is vibrated at a specific frequency to be a frequency filter. It can be made to function as.

  However, the microelectromechanical mechanism 9 in the present invention is not limited to this. For example, an electrical switch, an inductor, a capacitor, a resonator, an antenna, a microrelay, an optical switch, a magnetic head for a hard disk, a microphone, a biosensor, a DNA chip, and a microreactor. , An electronic device 12 having functions of various sensors such as a print head, an acceleration sensor, and a pressure sensor, and a display device, and is a component made by a so-called micromachining method based on a semiconductor microfabrication technique, and 10 μm to one element The present invention can be applied if it has a dimension of about several hundred μm and its function is impaired by the deformation of the semiconductor substrate 8 during operation.

  The insulating substrate 1 functions as a lid for sealing the microelectromechanical mechanism 9, and as a base for forming the wiring conductor 2, connection pad 3, connection terminal 4, sealing material 5, and mounting pad 6. Function.

  The insulating substrate 1 is made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, a silicon nitride sintered body, or a glass ceramic sintered body. It is formed.

  If the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, the insulating substrate 1 is formed by laminating and firing ceramic green sheets formed by forming raw material powders of aluminum oxide and glass powder into a sheet shape. Is done. The insulating substrate 1 is not limited to the one formed of an aluminum oxide sintered body, and it is preferable to select a substrate that is suitable for the application and the characteristics of the electronic component 11 to be hermetically sealed.

  For example, since the insulating substrate 1 is mechanically bonded to the semiconductor substrate 8 via the sealing material 5 as will be described later, the reliability of bonding with the semiconductor substrate 8, that is, the sealing of the micro electro mechanical mechanism 9 is performed. In order to increase the air tightness of the aluminum oxide-borosilicate glass system in which the coefficient of thermal expansion is approximated to that of the semiconductor substrate 8 by adjusting the kind and addition amount of the mullite sintered body or the glass component, etc. It is preferable to use a material having a small difference in thermal expansion coefficient from the semiconductor substrate 8, such as a glass ceramic sintered body.

  In addition, a glass ceramic sintered body obtained by sintering glass containing a borosilicate glass system in an aluminum oxide filler can form the wiring conductor 2 with copper or silver having a low electric resistance, and also has a low relative dielectric constant and an electric signal. Since a delay can be prevented, it is preferable as a material for the insulating substrate 1 that handles high-frequency signals.

  In addition, a recess 13 may be formed on the upper surface of the insulating substrate 1 so as to accommodate the microelectromechanical mechanism 9 of the electronic component 11 inside. If a part of the micro electro mechanical mechanism 9 is accommodated in the recess 13, the height of the sealing material 5 for enclosing the micro electro mechanical mechanism 9 can be kept low, and the electronic device 12 can be reduced in height. It will be advantageous to.

  A sealing material 5 is formed in a frame shape on the outer peripheral portion of the upper surface of the insulating substrate 1 so as to surround the micro electro mechanical mechanism 9. The inside of the sealing material 5 is a frame-shaped electronic component sealing region (no reference numeral) surrounding the micro electronic mechanical mechanism 9. The shape of the electronic component sealing region is a polygonal shape such as a quadrangle or octagon, a circular shape, an elliptical shape, or the like in plan view. Moreover, the corner | angular part of these shapes may be shape | molded in circular arc shape, and the unevenness | corrugation may be provided in a part of side part or a circumference part.

  The sealing material 5 is formed in a frame shape and size so as to accommodate the micro electro mechanical mechanism 9 inside thereof, and functions as a side wall for hermetically sealing the micro electro mechanical mechanism 9 of the electronic component 11 inside thereof. To do.

  The sealing material 5 is known as a joining member such as a solder such as tin-silver, tin-silver-copper, a low melting point brazing material such as gold-tin brazing, and a high melting point brazing material such as silver-germanium. It is made of a metal material.

  Further, for example, iron-nickel alloys such as iron-nickel-cobalt alloy and iron-nickel alloy, metal materials such as oxygen-free copper, aluminum, stainless steel, copper-tungsten alloy, copper-molybdenum alloy, or aluminum oxide Tin-silver is formed by forming a conductive film or the like formed by plating a metal layer such as Au, Ag, Cu, Al, Pt, or Pd on an inorganic material such as a sintered body or a glass ceramic sintered body. It is also possible to use those coated with a solder such as a tin-silver-copper type.

  If the sealing material 5 is made of, for example, a joining member such as tin-silver solder, the solder is placed at a predetermined height on the upper surface of the insulating substrate 1 through the sealing material pattern 3a ( For example, it is formed on the upper surface of the insulating substrate 1 by bonding so that the height is equal to or higher than the micro electro mechanical mechanism 9.

  The sealing material pattern 3a is formed of a metal material having good wettability with the solder or brazing material, for example, a metallized layer or a plating layer having at least the outermost surface formed of gold.

  The encapsulant pattern 3a can be formed as follows if, for example, nickel and gold plating layers are sequentially deposited on a tungsten metallization layer. First, a metal paste is prepared by adding and kneading an appropriate organic solvent and binder to tungsten powder, and this is printed on a ceramic green sheet to be an insulating substrate 1 in a predetermined frame-like pattern and fired by screen printing. Then, a tungsten metallization layer is formed. Next, the nickel and gold plating layers are sequentially deposited on the tungsten metallized layer by an electrolytic plating method using an electrolytic nickel plating bath (such as a Watt bath) or an electrolytic gold plating bath (such as a Rinker bath). Moreover, you may use the electroless-plating method which can deposit and form a plating layer, without using the electricity from the outside.

  By bonding the main surface (upper surface in the example of FIG. 1) opposite to the insulating substrate 1 of the sealing material 5 (frame member) to the lower surface of the electronic component 11, The micro electronic mechanical mechanism 9 is hermetically sealed inside, and an electronic component sealing region is formed on the electronic component sealing substrate 7. In this case, the semiconductor substrate 8 serves as a bottom plate and the insulating substrate 1 serves as a lid.

  When the sealing material 5 is made of a material other than a joining member such as an iron-nickel-cobalt alloy, the sealing material 5 is joined to the upper surface of the insulating substrate 1 or the lower surface of the semiconductor substrate 8 of the electronic component 11. As a method, for example, iron-nickel formed into a frame shape through a solder of a tin-silver type solder, a low melting point brazing material such as gold-tin brazing, or a high melting point brazing material such as silver-germanium type. A method such as joining a member such as a cobalt alloy to the sealing material pattern 3a can be used. For forming the sealing material 5 into a frame shape, for example, metal processing means such as etching or punching can be used.

  From the upper surface of the insulating substrate 1 (the side on which the micro electro mechanical mechanism 9 is sealed), the wiring conductor 2 is led out to the lower surface or the side surface. A connection pad 3 connected to the wiring conductor 2 is formed inside the sealing material pattern 3 a on the outer peripheral portion of the upper surface of the insulating substrate 1. The wiring conductor 2 and the connection pad 3 are electrically connected to the electrode 10 of the electronic component 11 through the connection terminal 4 formed on the connection pad 3, and this is led out to the lower surface and the side surface of the insulating substrate 1. It has a function.

  These wiring conductors 2 and connection pads 3 are formed of a metal material such as copper, silver, gold, palladium, tungsten, molybdenum, or manganese.

  As these forming means, for example, when the wiring conductor 2 and the connection pad 3 are made of copper metallization, a metal paste obtained by adding an appropriate organic binder and solvent to copper powder and glass powder is mixed with a green sheet that becomes the insulating substrate 1. And printing by screen printing or the like and firing this together with a green sheet.

  The connection terminal 4 is made of a metal material such as a tin-silver solder, a tin-silver-copper solder, a low melting solder such as gold-tin solder, or a high melting solder such as silver-germanium. ing.

  The connection terminal 4 is made of a metal such as a tin-silver solder, tin-silver-copper solder or the like, a low melting solder such as gold-tin solder, or a high melting solder such as silver-germanium. When formed of a material or the like, it may be formed together with the sealing material 5.

  By joining the connection terminal 4 to the electrode 10 of the electronic component 11, the electrode 10 of the electronic component 11 is led to the lower surface or side surface of the insulating substrate 1 through the connection terminal 4, the connection pad 3 and the wiring conductor 2. The

  A mounting pad 6 is formed at the end of the wiring conductor 2 led out to the lower surface, and the mounting pad 6 is soldered to an external electric circuit of an external electric circuit board (not shown) made of tin-lead solder or the like. The electrodes 10 of the electronic component 11 are electrically connected to an external electric circuit by bonding via external terminals such as bumps.

  When the connection between the external electric circuit and the electronic device 12 is performed using an external terminal such as a solder bump, the electronic component 11 and the electronic component 11 can be connected at or below the bonding temperature between the electronic component 11 and the electronic component sealing substrate 7. This is desirable from the viewpoint of ensuring connection reliability with the electronic component sealing substrate 7.

  The mounting pad 6 is formed of a metal material such as copper, silver, gold, palladium, tungsten, molybdenum, manganese, etc., as with the connection pad 3 described above. For example, the mounting pad 6 is made of copper metallization. In some cases, a paste for a mounting pad in which an appropriate organic binder and solvent are added and mixed with copper powder and glass powder is printed on the green sheet to be the insulating substrate 1 by screen printing or the like, and this is baked together with the green sheet. It is formed by doing.

  Here, in the first configuration, as shown in FIG. 2, the electronic device 12 has a mounting region in which the mounting pads 6 are disposed, the center of the electronic component sealing region inside the sealing material 5 in a plan view. It is important that the electronic component sealing area is divided into four equal parts by a section straight line passing through and is disposed in an area facing three or less section areas (indicated by a one-dot chain line).

  FIG. 2 is a plan view showing an example of an embodiment of the electronic device 12 having the first configuration according to the present invention. The surface of the electronic component sealing substrate 7 on which the mounting pads 6 are formed (FIG. 2). 1 corresponds to the lower surface in FIG. In FIG. 2, the same parts as those in FIG. However, FIG. 2 is simplified to make the configuration of the present invention easy to understand, and mainly shows a partition region and a mounting region (a region where the mounting pads 6 are arranged). Omitted. Moreover, the sealing material 5 is shown in a transparent state.

  As described above, by disposing the mounting area in the area facing three or less of the four divided areas, the external electric circuit board and the machine are arranged via the mounting pad 6 in the electronic component sealing substrate 7. Since the stress is not generated at the part that is not connected to the electronic component, the stress acting on the electronic component sealing substrate 7 in at least one of the divided regions can be kept low. Since such a segmented region (low-stressed portion) has a small distortion, at least a region having a small strain is also present in the semiconductor substrate 8 mechanically connected to the electronic component sealing substrate 7 via the sealing material 5. It can be formed in a region facing one segmented region.

  Specifically, the stress generated in the semiconductor substrate 8 of the electronic component 11 due to the deformation of the electronic component sealing substrate 7 due to the stress caused by the difference in thermal expansion coefficient is in the region of the electronic component 11 facing the mounting region. It is high and becomes low at a part away from the region of the electronic component 11 facing the mounting region. Therefore, a low stress portion can be formed in the semiconductor substrate 8 in a region facing at least one segmented region in plan view, and the microelectromechanical mechanism 9 can be formed in this low stress portion. Distortion due to the stress is effectively prevented from occurring in the micro electromechanical mechanism 9 including the vibrating portion (not shown), and the driving accuracy of the micro electromechanical mechanism 9 can be increased.

  The example shown in FIG. 2 is an example in which the mounting regions are arranged by forming the mounting pads 6 in the regions facing the two divided regions on the lower surface of the insulating substrate 1. In this case, on the lower surface of the electronic component sealing substrate 7, there are two partitioned regions K1 facing the mounting region where the two mounting pads 6 are disposed, and two partitioned regions where the mounting pads 6 are not disposed. K2 exists. A region of the semiconductor substrate 8 facing the two divided regions K2 where the mounting pads 6 are not disposed becomes a low-stress portion with small distortion. If the micro electro mechanical mechanism 9 (not shown in FIG. 2) is formed in the low stress portion, it is effective that the micro electro mechanical mechanism 9 is distorted due to stress due to a difference in thermal expansion coefficient. Thus, the driving accuracy of the micro electro mechanical mechanism 9 can be increased. In this example, the microelectromechanical mechanism 9 is formed on the semiconductor substrate 8 in a region facing about a half of the area of the insulating substrate 1 (particularly the electronic component sealing region) in plan view. Can do.

  Note that at least one mounting pad 6 is necessary for mounting the electronic device 12, and the mounting pad 6 is disposed in a region facing at least one of the divided regions.

  How and how many mounting pads 6 are arranged in the area facing the four segmented areas is determined by the shape, dimensions, and functions of the microelectromechanical mechanism 9, the planar dimensions of the electronic component 11, and the external electric circuit. It adjusts suitably according to the inclination etc. with respect to a board | substrate. These arrangements will be described later with specific examples.

(Second configuration)
In the second configuration, the electronic device of the present invention extends from the center of the electronic component sealing region inside the sealing material 5 toward the outer periphery in a plan view, as shown in FIG. It is important that four stop half lines (indicated by alternate long and short dash lines) that divide the stop region into four equal parts are arranged along a line that faces three or less stop half lines.

  Unlike the electronic device 12 of the first configuration, the electronic device 12 of the second configuration differs from the electronic device 12 of the first configuration in that the mounting area is arranged along a line facing the section half line. Its function is the same as that of the first configuration.

  FIG. 3 is a plan view showing an example of an embodiment of the electronic device 12 having the second configuration according to the present invention. The surface of the electronic component sealing substrate 7 on the side where the mounting pads 6 are formed (FIG. 3). The lower surface in FIG. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. However, FIG. 3 is not a plan view corresponding to the electronic device 12 shown in FIG. 1, but is simplified for easy understanding of the configuration of the present invention, as in FIG.

  As described above, by disposing the mounting region along the line that opposes three or less of the four segment half-lines, the external electric field is provided via the mounting pad 6 of the electronic component sealing substrate 7. Since no stress is generated in a portion that is not mechanically connected to the circuit board, the stress acting on the electronic component sealing substrate 7 can be kept low in a region including the segment half line along at least one segment half line. it can. In such a region including the segmented half line (low stress portion), the distortion is small, and the distortion is also small in the semiconductor substrate 8 mechanically connected to the electronic component sealing substrate 7 via the sealing material 5. The region can be formed by a region facing the region including at least one segmented half line.

  As described above, a low stress portion can be formed in the semiconductor substrate 8 in a region facing the region including at least one section half-line in plan view, and the micro electromechanical mechanism 9 is formed in the low stress portion. Therefore, for example, distortion and deformation caused by the stress in the micro electro mechanical mechanism 9 including the vibrating portion can be effectively prevented, and the driving accuracy of the micro electro mechanical mechanism 9 can be increased.

  Further, in the case where the micro electro mechanical mechanism 9 is such that a beam-like vibration part (not shown) is arranged between the tips of a pair of columnar support parts (not shown), the following An effect can also be obtained.

  When the mounting area is arranged along the segmented half line, the stress generated between the insulating substrate 1 and the semiconductor substrate 8 is insulated via the mounting pad 6 so as to straddle the area facing the mounting area. The support portion of the micromechanical electronic mechanism 9 can be disposed avoiding a region (high stress portion) where high stress is easily transmitted to the substrate 1. In other words, a support portion that is susceptible to mechanical breakage can be formed in a low-stress portion. For example, microelectrons having a so-called doubly supported beam structure (a structure that supports a beam-like vibrating portion between a pair of support portions). The degree of freedom in designing the mechanical mechanism 9 can also be increased.

  FIG. 3 shows a case where the mounting regions are arranged in a line along a line facing two divided half lines that are connected in a straight line among the four divided half lines.

  In this case, on the lower surface of the electronic component sealing substrate 7, two mounting areas each having two mounting pads 6 are arranged, two segmented half straight lines H1 connected in a straight line, and orthogonal thereto. There are two segmented half-lines H2 where the mounting pads 6 are not arranged. A region of the semiconductor substrate 8 other than the linear region facing the two segmented half-lines on which the mounting pads 6 are arranged is a low-stress portion with small distortion. Therefore, if the micro electro mechanical mechanism 9 is formed in the low stress portion, the micro electro mechanical mechanism 9 is effectively prevented from being distorted due to stress caused by the difference in thermal expansion coefficient. The driving accuracy of the mechanism 9 can be increased.

  In the case of the example in FIG. 3, for example, both ends having a beam-like vibrating portion supported by two support portions so as to straddle a linear region facing the section half line H <b> 1 where the mounting region is arranged. If the microelectromechanical mechanism 9 having a beam structure is formed, the support portions of the microelectromechanical mechanism 9 having a double-supported beam structure can be positioned at low stress portions, respectively. Therefore, it is possible to effectively prevent the support portion from being distorted, and the driving accuracy can be increased even when the electronic device 12 is heated and cooled. In addition, since it is possible to form two support portions in the region of the semiconductor substrate 8 facing the region including the segmented half line H2 where the mounting pads 6 are not disposed, the micro electro mechanical mechanism 9 The degree of freedom in designing the arrangement position and the like is increased.

  The electronic device 12 of the present invention is not limited to the example of the embodiment shown in FIGS. 4 and 5 show another example of the embodiment of the electronic device 12 of the present invention.

  FIG. 4 is a plan view showing another example of the embodiment of the first configuration of the present invention similarly to FIG. 2, and is an example in which four or six mounting pads 6 are arranged. Here, FIG. 4A shows a mounting area arranged in an area facing one of the four divided areas obtained by dividing the electronic component sealing area into four equal parts by a straight line, and FIG. 4B shows two divided areas. (C) is an example of what is arrange | positioned in the area | region which opposes an area | region, and is arrange | positioned in the area | region which opposes three division areas.

  As shown in FIG. 4A, the mounting region is arranged in a region facing one of the four divided regions obtained by equally dividing the electronic component sealing region into four by a divided straight line. 8 can form a low stress portion in the widest range. Therefore, the degree of freedom in design when forming the micro electro mechanical mechanism 9 is high, which is particularly preferable when the large micro electro mechanical mechanism 9 is formed.

  Further, the stress generated in the semiconductor substrate 8 of the electronic component 11 due to the deformation of the electronic component sealing substrate 7 due to the stress caused by the difference in thermal expansion coefficient is high in the region of the electronic component 11 facing the mounting region, Since the height is lowered at a position away from the area of the electronic unit 11 facing the mounting area, the position of the electronic component 11 farthest from the facing mounting area (in FIG. In the lower right area), the stress is a lower area, so that the micro electro mechanical mechanism 9 requiring particularly high driving accuracy, the fine micro electro mechanical mechanism 9 having a smaller size, and the like are formed. Is preferred.

  FIG. 4B shows another example in which the electronic component sealing area is divided into four equal areas by dividing straight lines and is arranged in an area facing two divided areas, as in the example shown in FIG. It is an example. When the mounting pad 6 is formed along the outer peripheral portion of the electronic component sealing region in this way, the degree of freedom in connecting to the external electric circuit of the external electric circuit board is high, and the development of the wiring becomes easy. preferable.

  As shown in FIG. 4C, the mounting area is arranged in an area facing the three divided areas among the four divided areas obtained by dividing the electronic component sealing area into four equal parts by dividing straight lines. 6 can be arranged most. Therefore, the structure of the micro electro mechanical mechanism 9 is highly functionalized, and the number of wiring conductors 2 for connecting to an external electric circuit is increased, for example, when a plurality of micro electro mechanical mechanisms 9 are mounted. It is preferable in such a case. Further, since the mounting pad 6 has a high degree of freedom in designing, the mounting pad 6 is arranged so as not to tilt the electronic device 12 according to the outer shape, dimensions, thickness (weight), etc. of the electronic device 12, for example. Therefore, it is easy to ensure parallelism between the electronic device 12 and the external electric circuit board. Further, when a large number of mounting pads 6 are formed, the bonding strength between the electronic device 12 and the external electric circuit board increases, and the reliability against impacts such as dropping can be increased.

  FIG. 5 is a plan view showing another example of the embodiment of the second configuration of the present invention, similarly to FIG. 3, and is an example in which four or six mounting pads 6 are arranged. Here, FIG. 5 (a) is arranged along a line facing one section half line out of four section half lines dividing the electronic component sealing region into four equal parts, and (b) is two section half lines. (C) is an example of what is arrange | positioned along the line which opposes three division half-lines.

  In each case of FIGS. 5A, 5B, and 5C, the same effects as those of FIGS. 4A, 4B, and 4C can be obtained.

  Further, when the mounting region is formed along the segmented half line as described above, for example, when the micro electro mechanical mechanism 9 has the above-mentioned double-supported beam structure, there are the following advantages. That is, the microelectromechanical mechanism 9 can be formed so as to straddle the region facing the mounting region, and the electronic device 12 having a high degree of design freedom and various applications and functions can be obtained. .

Although not particularly illustrated, a convex portion for making the interval between the electronic component sealing substrate 7 and the external electric circuit substrate constant on the lower surface of the electronic component sealing substrate 7 on which the mounting pads 6 are arranged. Is preferably provided. For example, the protrusion is attached to the insulating substrate 1 so that the lower surface of the external terminal for joining the mounting pad 6 of the electronic device 12 to the external electric circuit substrate is the same height, or is integrated with the insulating substrate 1. It is a formed member. For example, the convex portion is provided in a portion of the lower surface of the insulating substrate 1 where the mounting pad 6 is not disposed, and functions as a spacer that keeps a constant distance between the lower surface of the electronic device 12 and the upper surface of the external electric circuit substrate. . By providing such a convex portion, when the electronic device 12 is mounted on the external electric circuit board, the electronic device 12 and the external electric circuit board can be easily kept parallel.

  In this case, if the convex portion is provided in a region other than the mounting region where the mounting pad 6 is not disposed, the electronic device can be supported by the convex portion, which is effective in keeping the electronic device 12 parallel to the external electric circuit board. Is. However, it is necessary to prevent the convex portion from being bonded to the external electric circuit board outside the mounting area. If the convex portion is bonded to the external electric circuit board, thermal stress is applied to the insulating substrate 1 of the electronic device 12 through the convex portion, which causes problems such as distortion of the microelectromechanical mechanism 9 as in the conventional technique. There is a risk of triggering.

  Further, for example, if a convex portion made of a material having a lower elastic modulus (Young's modulus) than the external terminal is provided near the mounting pad 6, an external force is applied to the electronic device 12 after being mounted on the external electric circuit board. In some cases, the stress is distributed to the interface between the convex portion and the insulating substrate 1 of the electronic device 12 and the stress can be effectively relieved by deformation of the convex portion, so that the stress is concentrated on the mounting pad 6. Then, it is possible to suppress the occurrence of destruction from this point.

  If such a convex portion is not bonded to an external electric circuit and is the same as or lower than the height of an external terminal such as a solder bump, various members such as a ceramic material, a metal material, and a resin material can be used. it can. For example, when forming the insulating substrate 1 made of a ceramic material, the bumps are formed in a lump, or solder bumps that become the protrusions in advance on the electronic component sealing substrate 7 using solder balls made of high melting point solder or the like. If a solder bump to be an external terminal is formed after forming the film, it can be easily formed without requiring a separate process for forming the convex portion. Further, when the convex portion is formed using a resin material having a low elastic modulus such as silicone, the stress generated when an external force is applied to the electronic device 12 can be effectively relieved, and the mechanical reliability can be reduced. Can be made higher. In addition, what is necessary is just to form this convex part in the desired positions (The area | region where the mounting pad 6 is not arrange | positioned, a site | part adjacent to a mounting pad, etc.) according to arrangement | positioning of the mounting pad 6, etc. as mentioned above. That is, for example, when it is important to keep the electronic device 12 parallel to the external electric circuit board when the number of the mounting pads 6 is small, it is not bonded to the external electric circuit board in an area other than the mounting area. What is necessary is just to provide a convex part, and when importance is attached to preventing destruction of the mounting pad 6, the low-elasticity mounting pad 6 should just be provided near the mounting pad 6. FIG.

  Although not shown in FIG. 1, a resin material may be filled between the lower surface of the electronic component 11 and the upper surface of the electronic component sealing substrate 7 outside the sealing material 5. When the resin material is filled, the resin material filled with the thermal stress due to the difference in thermal expansion coefficient between the electronic component 11 and the electronic component sealing substrate 7 is dispersed, and excessive stress is applied to the connection terminal 4 and the sealing material. 5 can be suppressed. Furthermore, since it is possible to prevent moisture from entering, it is possible to effectively suppress the occurrence of cracks or corrosion in the connection terminals 4 and the sealing material 5. As a result, the reliability of the electronic device 12 can be further increased.

  Moreover, the electronic component sealing substrate 7 forming the electronic device 12 of the present invention has a wide area of the electronic component sealing region including the connection pads 3 and the sealing material 5 as shown in a sectional view in FIG. A so-called multi-cavity configuration in which the main surface of the mother substrate is arranged vertically and horizontally may be employed.

  In this multi-cavity configuration, the electronic component 11 manufactured in a form in which a large number of microelectromechanical mechanisms 9 and electrodes 10 electrically connected thereto are arranged on the lower surface of the semiconductor substrate 8 is provided. A large number can be hermetically sealed at the same time, and the productivity as the electronic device 12 can be improved.

  Next, a method for manufacturing the electronic device 12 according to such a multi-cavity configuration will be described with reference to FIGS. FIGS. 7A to 7D are cross-sectional views showing an example of an embodiment of the method for manufacturing the electronic device 12 according to the present invention in the order of steps. In FIG. 7, the same parts as those in FIGS. The code | symbol is attached | subjected.

  First, as shown in FIG. 7A, a large number of electronic component regions 11a are vertically and horizontally arranged on a semiconductor mother substrate 8a, and a small number of micro electromechanical mechanisms 9 are arranged at the center of the lower surface of each region. Preparation electronic component 11b is prepared.

  Next, as shown in FIG. 7B, an insulating mother board 1a on which the wiring conductor 2 led out from the upper surface to the lower surface or side surface is formed, and the wiring conductor 2 formed on the upper surface of the insulating mother board 1a. A connection pad 3 electrically connected to the substrate, a sealing material pattern 3a bonded in a frame shape so as to surround a region corresponding to the micro electro mechanical mechanism 9 on the upper surface of the insulating mother substrate 1a, and the connection pad 3 A large number of sealing substrate regions 7a each having the sealing material 5 formed on the sealing material pattern 3a on the connection terminal 4 are arranged in correspondence with the electronic component region 11a of the electronic component 11b. A multi-chip mother board 7b for electronic component sealing is prepared.

  Next, as shown in FIG. 7 (c), the multi-piece electronic component 11b is superimposed on the electronic component sealing mother board 7b so that each electronic component region 11a and each sealing substrate region 7a correspond to each other. The electrode 10 is bonded to the connection terminal 4 and the lower surface of the semiconductor substrate 8 around the micro electro mechanical mechanism 9 is bonded to the main surface (the upper surface in FIG. 7) of the sealing material 5 to seal the micro electro mechanical mechanism 9. The inside of the stopper 5 is hermetically sealed.

  Here, for example, when the connection terminal 4 is made of tin-silver solder and has the same height as the sealing material 5, the connection terminal 4 is aligned on the electrode 10. These are carried out by heat treatment in a reflow furnace at a temperature of about 250 to 300 ° C.

Further, the bonding between the lower surface of the semiconductor mother substrate 8a around the micro-electromechanical mechanism 9 and the upper surface of the sealing material 5 is performed, for example, when the sealing material 5 is made of an iron-nickel-cobalt alloy. Can be performed by sandwiching the same tin-silver solder as the connection terminal 4 and heat-treating in the reflow furnace simultaneously with the joining of the electrode 10 and the connection terminal 4.
The connection terminal 4 and the sealing material 5 are made of tin-silver solder, and the height between the connection terminal 4 and the sealing material 5 varies, or the mother board 7b for electronic component sealing has a warp or the like. In this case, the electronic component 11b and the electronic component sealing mother board 7b can be joined by thermocompression bonding at a temperature of about 250 ° C. to 300 ° C.

Then, as shown in FIG. 7 (d), a multi-cavity electronic component 11b and the electronic component sealing mother substrate 7b which are joined together, by cutting the dicing process or the like, and divided for each encapsulation substrate region 7a Thus, the individual electronic devices 12 are obtained.

  In this individual electronic device 12, the mounting pad 6 on the lower surface is, for example, a section line in which the mounting region in which the mounting pad 6 is disposed passes through the center of the electronic component sealing region inside the sealing material 5 in plan view. The electronic component sealing area is formed and arranged so as to be arranged in an area facing three or less of the four divided areas divided into four equal parts.

  Then, the mounting pads 6 are connected to the external electric circuit via external terminals such as solder balls, thereby mounting on the external electric circuit board. In this case, since no stress is generated in a portion of the electronic component sealing substrate 7 that is not mechanically connected to the external electric circuit substrate via the mounting pad 6, the electronic component sealing substrate 7 is formed in at least one divided region. The acting stress can be kept low.

  Therefore, by arranging the micro electro mechanical mechanism 9 in advance in a region of the semiconductor mother substrate 8a that faces the segmented region where the stress is low, the mounting pad 6 is connected to an external electric circuit as an external terminal such as a solder ball. Even if a stress is generated due to the heat generated when connecting through the micro electro mechanical mechanism, the micro electro mechanical mechanism 9 is effectively prevented from being distorted due to the stress, and the micro electro mechanical mechanism 9 having high driving accuracy is mounted. The manufactured electronic device 12 can be manufactured with high productivity.

  The mounting pad 6 extends from the center of the frame-shaped electronic component sealing region to the outer periphery in a plan view, and is divided into three or less sections out of four section half-lines that divide the frame-shaped electronic component sealing region into four equal parts. You may form so that a mounting area | region may be arrange | positioned along the line which opposes a half line.

  Note that the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. For example, in the example of the above-described embodiment, one microelectromechanical mechanism 9 is hermetically sealed in one electronic device 12, but a plurality of microelectromechanical mechanisms 9 are hermetically sealed in one electronic device 12. May be. Further, although the example in which the electronic component sealing substrate 7 is formed with the concave portion 13 for accommodating the micro-electromechanical mechanism 9, that is, the cavity is shown, the concave portion 13 is not necessarily formed, and the height of the sealing material 5 is high. The sealing space required by the microelectromechanical mechanism 9 may be formed by appropriately setting the length.

It is sectional drawing which shows an example of embodiment of the electronic device of this invention. It is a top view which shows an example of arrangement | positioning of the mounting pad in embodiment in the 1st structure about the electronic device of this invention. It is a top view which shows an example of arrangement | positioning of the mounting pad in embodiment in the 2nd structure about the electronic device of this invention. It is a top view which shows various other examples of arrangement | positioning of the mounting pad in embodiment in the 1st structure about the electronic device of this invention. It is a top view which shows various other examples of arrangement | positioning of the mounting pad in embodiment in the 2nd structure about the electronic device of this invention. It is sectional drawing which shows an example of embodiment at the time of setting the electronic device of this invention into the form of many pieces. (A)-(d) is sectional drawing which shows an example of the manufacturing method of the electronic device of this invention in order of a process, respectively.

Explanation of symbols

1: Insulating substrate 1a: Insulating mother substrate 2: Wiring conductor 3: Connection pad 3a: Sealing material pattern 4: Connection terminal 5: Sealing material 6: Mounting pad 7: Electronic component sealing substrate 7a: Sealing substrate Area 7b: Electronic component sealing mother board 8: Semiconductor substrate 8a: Semiconductor mother board 9: Micro-electromechanical mechanism 10: Electrode 11: Electronic component 11a: Electronic component area 11b: Electronic component (multi-piece)
12: Electronic device 13: Recess

Claims (2)

An electronic component having a microelectromechanical mechanism formed at the center of the lower surface has a frame-shaped electronic component sealing region surrounding the microelectromechanical mechanism on the upper surface, and an external electric circuit board on the lower surface via an external terminal Mounted on an electronic component sealing substrate having a mounting region in which mounting pads to be bonded are disposed, and the micro-electromechanical mechanism is mounted inside the frame-shaped electronic component sealing region, The mounting area is not more than three of the four divided areas obtained by dividing the frame-shaped electronic component sealing area into four equal parts by a straight line passing through the center of the frame-shaped electronic component sealing area in plan view. Is disposed in a region facing the plurality of regions without crossing over the regions facing the partition regions, and regions other than the mounting region are not bonded to the external electric circuit board in the regions facing the partition regions. Electronic Location. An electronic component having a microelectromechanical mechanism formed at the center of the lower surface has a frame-shaped electronic component sealing region surrounding the microelectromechanical mechanism on the upper surface, and an external electric circuit board on the lower surface via an external terminal Mounted on an electronic component sealing substrate having a mounting region in which mounting pads to be bonded are disposed, and the micro-electromechanical mechanism is mounted inside the frame-shaped electronic component sealing region, The mounting area extends from the center of the frame-shaped electronic component sealing area to the outer periphery in plan view, and is less than or equal to three of the four segmented half lines that divide the frame-shaped electronic component sealing area into four equal parts. The electronic device is arranged along a line facing the section half-line, and an area other than the mounting area is not bonded to the external electric circuit board in a region facing the section half-line .

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