JP2009145331A - Semiconductor acceleration sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inexpensive resin packaging by filling and covering an inside and a periphery of an MEMS (Micro-electromechanical systems) chip with gel material. <P>SOLUTION: A periphery of a spindle part 52 of an acceleration sensor chip 50 fixed on a die pad part 41 is covered with gel resin member 61 with low elasticity, but is easily varied in response to acceleration applied from an external. Thus, the acceleration can be accurately detected. Furthermore, parts except for a part necessary for acceleration detection is sealed with a resin member 62. Thus, long term reliability equal to general resin packaging can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin-encapsulated type package, and more particularly to a semiconductor acceleration sensor device using MEMS (Micro-electromechanical systems) or MCP (Multi Chip Package) in which MEMS and a semiconductor circuit chip are mounted in the same package.

2. Description of the Related Art In recent years, attention has been focused on MEMS technology that realizes sensors, mechanical parts, and the like with micron-level dimensions as electronic devices become smaller and thinner.

  8A to 8C are cross-sectional views showing a configuration example of a semiconductor acceleration sensor device using a conventional MEMS package, where FIG. 8A is a single chip type, and FIG. 8B is a multichip. The type (stacked (stacked) type) and the figure (c) are figures which show a multichip type (horizontal installation type).

  A hollow ceramic package is usually used for packaging a semiconductor acceleration sensor device. For example, in the single chip type of FIG. 8A, the acceleration sensor chip 10 is housed in a hollow ceramic package 20. In the acceleration sensor chip 10, a weight part 11 is formed by etching at the center part of a silicon chip bulk part based on a semiconductor manufacturing process, and a beam part 12 is formed in a cross shape on the chip surface to support the weight part 11. Four locations are formed. A gap 13 is formed between the weight portion 11 and the surrounding silicon. When acceleration is applied to the chip, the beam portion 12 is deformed, and stress is detected by a piezoelectric element (not shown) formed in the beam portion 12 to accelerate the acceleration. Is obtained. Also, when an allowable amount of acceleration is applied, the distortion of the beam part 12 exceeds the breaking strength, and the upper surface side is above the beam part 12 and the lower surface side so as not to cause a certain amount of variation. A stopper is formed below the weight portion 11.

  Such an acceleration sensor chip 10 is fixed on a ceramic header 21 constituting the ceramic package 20, and the electrode pad of the acceleration sensor chip 10 and the post portion of the ceramic header 21 are connected by a wire 15 which is a thin metal wire. ing. A ceramic cap 22 constituting the ceramic package 20 is put on the acceleration sensor chip 10 and fixed to the ceramic header 21.

  The reason why the hollow ceramic package 20 is used is that the sensitivity and the repeatability are higher when the air gap 23 in the ceramic cap 22 is made vacuum or gas or the like and the drag is not applied to the weight portion 11 when acceleration is applied. . Note that when the gap 13 is filled with oil or gel, if the viscoelastic characteristics are stable, it can be realized by tuning (adjusting) accordingly.

  As a related technique filled with such oil or gel, a semiconductor pressure sensor device as described in Patent Document 1 below is known. In this semiconductor pressure sensor device, in order to protect the built-in semiconductor pressure sensor chip from contamination, the outside of the semiconductor pressure sensor chip is covered with an elastic resin.

JP-A-10-170380

  In the stack type of FIG. 8B, the semiconductor circuit chip 16 that processes the stress detection result of the acceleration sensor chip 10 and generates a detection signal is fixed on the ceramic header 21, and the electrode pad of the semiconductor circuit chip 16 is fixed. The post portion of the ceramic header 21 is connected by a wire 17. The acceleration sensor chip 10 is fixed on the semiconductor circuit chip 16, and the electrode pads of the acceleration sensor chip 10 and the electrode pads of the semiconductor circuit chip 16 are connected by wires 15.

  8C, the acceleration sensor chip 10 and the semiconductor circuit chip 16 are fixed on a ceramic header 21, and a ceramic cap 22 is put on these to be hermetically sealed.

  However, the conventional semiconductor acceleration sensor device using the ceramic package 20 has the following problems (1) to (3).

  (1) The ceramic package 20 as shown in FIG. 8 is expensive because it uses expensive member costs. Further, it is necessary to hermetically seal the ceramic header 21 and the ceramic cap 22 with low melting point glass, solder (solder) or the like. For this hermetic sealing, 360 ° C. or higher (400 ° C. with low melting point glass). Therefore, when the semiconductor circuit chip 16 is packaged at the same time as shown in FIGS. 8B and 8C, the semiconductor circuit chip 16 has a characteristic variation.

  (2) In the case of MCP, in the stack type of FIG. 8B, when an organic material adhesive is used for stacking the semiconductor circuit chip 16 and the acceleration sensor chip 10, the ceramic header 21 and the ceramic are manufactured in the manufacturing process. Since sealing (adhesion) with the cap 22 also needs to be made of resin, there was a problem of moisture resistance in the long-term life test. On the other hand, in the horizontal type shown in FIG. 8C, the package 20 becomes large, and it cannot be said that the package density is satisfactory.

  (3) In order to solve the problems (1) and (2), it is conceivable to use the technique of Patent Document 1 and resin-encapsulate the chip instead of the ceramic package 20. In Patent Document 1, corresponding to FIG. 8C, the pressure sensor chip and the semiconductor circuit chip are horizontally placed, the entire semiconductor circuit chip is resin-sealed, and the chip receiving recess is exposed to the outside. A resin package is formed. Since the pressure sensor chip needs to be exposed to the outside in order to detect external stress, the pressure sensor chip is fixed to the chip housing recess, and outside the pressure sensor chip to prevent contamination from the outside. Is covered with a protective resin having elasticity that does not prevent pressure transmission.

  When the technique of Patent Document 1 is used, for example, when the entire semiconductor circuit chip 16 of FIG. 8C is sealed with resin and the outside of the acceleration sensor chip 10 is covered with an elastic resin, acceleration is achieved. There was a problem with the moisture resistance of 10 sensor chips, and it was difficult to solve the problems (1) and (2).

  The present invention has been made to solve the above-mentioned problems, and its main purpose is to maintain long-term reliability by filling and covering the inside and the periphery of the MEMS chip with a gel material to form an inexpensive resin package. However, the present invention provides a semiconductor acceleration sensor device that is inexpensive and excellent in mass productivity.

  In order to solve the above problems, a semiconductor acceleration sensor device of the present invention includes an acceleration sensor chip, an elastic first resin member, and a second resin member that covers the first resin member. .

  The acceleration sensor chip includes a weight portion having an upper surface, a lower surface, and a side surface, a support portion connected to one end of the weight portion for flexible support, and the other end of the support portion connected to the weight portion. And a pedestal portion surrounding and spaced apart. The first resin member is a member that covers the upper surface, the lower surface, the side surface, and the support portion of the weight portion.

  Another semiconductor acceleration sensor device of the present invention is a semiconductor acceleration sensor device in which an acceleration sensor chip is sealed with a second sealing resin.

  The acceleration sensor chip includes a weight portion having an upper surface, a lower surface, and a side surface, a support portion connected to the weight portion and flexibly supported, and a pedestal portion connected to the support portion and surrounding the weight portion The upper surface, the lower surface, the side surface, and the support portion of the weight portion are wrapped by a first sealing resin having elasticity.

According to the semiconductor acceleration sensor device of the present invention, the weight portion of the acceleration sensor chip is covered with the first resin member having elasticity, but it is easily mutated with respect to acceleration applied from the outside. , Acceleration can be detected accurately. Moreover, since the portions other than those necessary for acceleration detection are resin-sealed with the second resin member, long-term reliability equivalent to that of a normal resin package can be obtained. Therefore, compared with the conventional apparatus, it can be expected to be inexpensive and have high mass productivity.

  According to another semiconductor acceleration sensor device of the present invention, since the acceleration sensor chip is mounted on the semiconductor circuit chip, the package can be reduced in size.

  The best mode for carrying out the invention will become apparent from the following description of the preferred embodiments when read in conjunction with the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Constitution)
FIGS. 1A to 1F are configuration diagrams of a semiconductor acceleration sensor device of a QFN (Quad Flat Nonlead; four-way plane lead-out terminal) package type showing Embodiment 1 of the present invention, and FIG. FIG. 6B is a perspective view of the acceleration sensor chip in the semiconductor acceleration sensor device, FIG. 10C is a perspective view of the cross section along line A1-A2 in FIG. FIG. 4D is a two-part perspective view of the B1-B2 cross section in FIG. 2B, FIG. 3E is a plan view of FIG. 2B, and FIG. It is a C1-C2 sectional view taken on the line.

  The semiconductor acceleration sensor device 30 is mounted on the lead frame 40. The lead frame 40 has a die pad portion 41 that is a rectangular support plate in which a first through hole 41 a is formed in a central first region, and a plurality of leads 42 are conductive in four directions around the die pad portion 41. A portion (for example, a post portion) 42a is provided. On the lower surface side of the die pad portion 41, a lid portion 43 for closing the through hole 41a is fixed. An acceleration sensor chip 50 that detects acceleration applied from the outside is fixed to the second region surrounding the first region at the center on the upper surface of the die pad portion 41.

  The acceleration sensor chip 50 includes a pedestal (for example, a silicon chip that is a semiconductor chip) 51, and a weight 52 is formed at the center of the silicon chip 51 by etching based on a semiconductor manufacturing process. In order to support the weight portion 52, four support portions (for example, beam portions) 53 are formed on the upper surface of the silicon chip 51 in a cross shape. A gap 54 is formed between the weight 52 and surrounding silicon, and the gap 54 communicates with a second through hole 55 formed on the upper surface of the silicon chip 51. Stress detecting elements (for example, piezo elements) 56 are respectively formed in the beam portions 53 provided at four locations. The piezo element 56 is an element that detects the stress from the change in electric resistance when the beam portion 53 is deformed by applying stress to the beam 53 due to acceleration. These piezo elements 56 are electrically connected to a plurality of electrode pads 57 provided on the upper surface of the silicon chip 51. The plurality of electrode pads 57 are connected by wires 58 to the upper surface of the lower surface (first surface) and the upper surface (second surface) of the plurality of post portions 42a.

  The gap 54 in the acceleration sensor chip 50 is filled with a gel-like first resin member 61, and the beam portion 53 on the upper surface side of the acceleration sensor chip 50 is covered with the resin member 61. The gel-like first resin member 61 is formed of, for example, a silicone resin and is a liquid having a viscosity at first, and changes to a gel-like resin when heated (about 150 ° C.). (For example, an elastic modulus of 1 × 10 −2 MPa (= 1 × 10 −3 kg / mm 2) and a viscosity of about 2 Pa · s). The periphery of the acceleration sensor chip 50 covered with the resin member 61 and the connection portion of the wire 58 are resin-sealed with a thermosetting second resin member 62 such as an epoxy resin, a silicone resin, or a phenol resin.

  When the acceleration sensor chip 50 is subjected to an allowable acceleration, the distortion of the beam portion 53 is damaged beyond the breaking strength. In addition, it is desirable to form a stopper on the lower surface side below the weight portion 52, respectively. In the first embodiment, the upper portion of the beam portion 53 is covered with a solid resin member 62 via a gel resin member 61, and the resin member 62 has a stopper function. In addition, a first region of the die pad portion 41 is provided under the weight portion 52, and this first region has a stopper function. In addition, when the vertical length of the weight portion 52 is short and the die pad portion 41 is insufficient as a stopper, a stopper spacer having a through hole may be provided on the die pad portion 41 in advance.

(Operation)
When acceleration is applied to the semiconductor acceleration sensor device, the weight portion 52 tends to move. Although the periphery of the weight portion 52 is covered with a gel-like resin member 61, the gel-like resin member 61 has a low elasticity (solid has high elasticity and liquid has low elasticity). Therefore, the flow resistance is small with respect to the applied force, and the weight 52 is easily displaced (the viscosity of the resin member 61 greatly affects the force applied at a low speed such as pressure). Therefore, due to acceleration applied from the outside, the beam portion 53 supporting the weight portion 52 is deformed, and the electric resistance of the piezo element 56 changes. As a result, the stress applied to the beam portion 53 is detected, and the stress detection result is output from the electrode pad 57 to the post portion 42 a via the wire 58. If the relationship between acceleration and variation (stress) is previously determined and set in a semiconductor circuit or the like connected to the lower surface of the post portion 42a, the applied acceleration can be accurately obtained.

(effect)
In Example 1, the following effects (1) to (4) are obtained.

  (1) Although the periphery of the weight portion 52 and the beam portion 53 in the acceleration sensor chip 50 is covered with a low-elasticity gel-like resin member 61, it is easily mutated with respect to acceleration applied from the outside. Acceleration can be detected accurately. In addition, since portions other than those necessary for acceleration detection are sealed with the resin member 62, long-term reliability equivalent to that of a normal resin package can be obtained. Therefore, compared with the conventional apparatus, it can be expected to be inexpensive and have high mass productivity.

  (2) Since the upper and lower displacements of the weight portion 52 and the beam portion 53 are restricted by the upper resin member 62 and the lower die pad portion 41, it is not necessary to provide a stopper for restricting the upper and lower displacements. It will be easy. When the weight portion 52 is short and the die pad portion 41 is insufficient as a stopper, a stopper spacer having a through hole may be installed on the die pad portion 41 in advance.

  (3) The lid 43 can be omitted if the viscosity of the gel-like resin member 61 filled in the gap 54 is appropriately set so as not to leak from the through hole 41a of the die pad 41. Thereby, the structure can be further simplified.

  (4) Although the QFN package type has been described with reference to FIG. 1, the first embodiment can be applied to all resin packages.

(Example of manufacturing method)
2A to 2D are manufacturing process diagrams showing an example of a manufacturing method of the second embodiment in the semiconductor acceleration sensor device 30 of FIG.

  The semiconductor acceleration sensor device 30 is manufactured by, for example, the following processes (1) to (4).

(1) Step of FIG. 2A The acceleration sensor chip 50 of FIG. 1 is manufactured in advance. In the lead frame 40, the acceleration sensor chip 50 is positioned on the die pad portion 41 connected by a plurality of leads 42, and the lower surface of the acceleration sensor chip 50 is die bonded (adhered to the surface of the die pad portion 41 with an adhesive or the like. ) When the weight portion 52 is short and the die pad portion 41 is insufficient as a stopper, a stopper spacer having a through hole may be installed on the die pad portion 41 in advance. Next, after the electrode pads 57 on the upper surface of each acceleration sensor chip 50 and the respective post portions 42a of the lead frame 40 are wire-bonded (connected) with wires 58, as shown in FIG. The frame 40 is turned upside down.

(2) Step of FIG. 2B The positions of the central through hole 41a of each die pad portion 41 and the resin injection needle (needle) 63 are aligned, and the liquid resin having viscosity from the needle 63 ( For example, a thermosetting silicone resin or the like) 61a is injected into each through hole 41a. The resin 61 a injected into the through hole 41 a is filled in the gap 54 of the acceleration sensor chip 50 and covers the beam portion 53 on the upper surface side of the acceleration sensor chip 50 through the through hole 55.

(3) Step of FIG. 2C After the resin 61a is filled in the gap 54 of each acceleration sensor chip 50 and the beam portion 53 on the upper surface side of each acceleration sensor chip 50 is covered with the resin 61a, The lid portion 43 is fixed to the through hole 41 a of the die pad portion 41. Also, a heat treatment (for example, about 150 ° C.) is performed to cure the liquid resin 61 a and change it to a gel resin member 61.

(4) Step of FIG. 2D The lead frame 40 is reversed and returned to its original state. When the coating amount of the resin member 61 that covers the beam portion 53 on the upper surface side of the acceleration sensor chip 50 is insufficient, the liquid resin 61a is also supplied from the upper surface side of the acceleration sensor chip 50 as necessary. Then, it is cured by heat treatment to change to the gel-like resin member 61, and the coating on the beam portion 53 is completed.

  Thereafter, similarly to a normal resin package, the periphery of each acceleration sensor chip 50 is resin-sealed with a resin member 62 by transfer molding or the like, lead processing such as cutting of the lead 42, and the surface of the post portion 42a such as plating. If the processing is performed, the manufacture of the semiconductor acceleration sensor device 30 of FIG. 1 is completed.

(effect)
In Example 2, the following effects (1) to (3) are obtained.

  (1) Since the weight portion 52 and the beam portion 53 of the acceleration sensor chip 50 are covered with the gel-like resin member 61 and then resin-sealed with the resin member 62 from the periphery thereof, the resin is sealed with a relatively simple process. The semiconductor acceleration sensor device 30 having excellent long-term reliability can be mass-produced at low cost.

  (2) The lid 43 can be omitted if the viscosity of the gel-like resin member 61 filled in the gap 54 is appropriately set so as not to leak from the through hole 41a of the die pad 41. Thereby, a manufacturing process can be simplified.

  (3) As the liquid resin 61a having viscosity, a thermosetting silicone resin or the like is used, but when a non-thermosetting silicone resin or the like is used, it is left for a predetermined time instead of the heat treatment. What is necessary is just to harden in gel form. Further, when a gel-like resin is used as the resin 61a from the beginning, the acceleration sensor chip 50 is passed through the through hole 55 when filling the gap 54 of the acceleration sensor chip 50 in the process of FIG. Since it is difficult to completely cover the beam portion 53 on the upper surface side of the substrate, it is necessary to supply the resin 61a from the upper surface side of the acceleration sensor chip 50 in the next step of FIG.

(Example of manufacturing method)
FIGS. 3A to 3D are manufacturing process diagrams illustrating an example of a manufacturing method according to the third embodiment in the semiconductor acceleration sensor device 30 of FIG.

  The manufacturing method of the semiconductor acceleration sensor device 30 is similar to the manufacturing method of the second embodiment, and is manufactured by the following processes (1) to (4), for example.

(1) Process of FIG. 3A Similarly to FIG. 2A, the acceleration sensor chip 50 is die-bonded on the die pad portion 41 of the lead frame 40, and the electrode pad 57 and the lead frame 40 of the acceleration sensor chip 50 are bonded. After the wire portion 58 is wire-bonded to the post portion 42a, the lead frame 40 is turned upside down as shown in FIG.

(2) Step of FIG. 3B The positions of the central through hole 41a of each die pad portion 41 and the resin injection needle 63 are aligned, and a viscous liquid resin (for example, thermosetting) is formed from the needle 63. 61a) is injected into each through hole 41a in such an amount that the upper surface side of the acceleration sensor chip 50 is immersed. Then, the resin 61 a injected into the through hole 41 a covers the beam portion 53 on the upper surface side through the through hole 55 of the acceleration sensor chip 50. Next, heat treatment (for example, about 150 ° C.) is performed to gel the resin 61 a that covers the beam portion 53.

(3) Step of FIG. 3C Again, liquid resin 61a is injected from the through holes 41a of the die pad portions 41, and the gaps 54 of the acceleration sensor chips 50 are filled with the resin 61a. Thereafter, the lid portion 43 is fixed to the through hole 41 a of each die pad portion 41. Also, heat treatment (for example, about 150 ° C.) is performed to gel the resin 61a in each gap 54. Thereby, the weight part 52 and the beam part 53 of each acceleration sensor chip 50 are covered with the gel-like resin member 61.

(4) Step of FIG. 3D After the lead frame 40 is reversed and returned to its original state, the periphery of each acceleration sensor chip 50 is resin-sealed with a resin member 62 by transfer molding or the like, as in a normal resin package. When the lead processing such as cutting of the lead 42 and the surface treatment such as plating of the post portion 42a are performed, the manufacture of the semiconductor acceleration sensor device 30 of FIG. 1 is completed.

(effect)
The third embodiment has the following effects (1) and (2).

  (1) The resin 61a is injected in two stages, and the beam portion 53 of the acceleration sensor chip 50 is covered with the gel-like resin member 61 by the first stage resin injection, and then the second stage resin injection. Since the weight portion 52 is covered with the gel-like resin member 61, two-stage resin injection can be continuously performed with the lead frame 40 turned over, and the resin member 61 can be efficiently coated. Can do.

  (2) Similarly to the second embodiment, if the viscosity of the gel-like resin member 61 filled in the gap 54 is appropriately set and the device is not leaked from the through hole 41a of the die pad portion 41, the lid portion 43 is removed. Can be omitted. Thereby, a manufacturing process can be simplified.

(Configuration / Operation)
FIG. 4 is a cross-sectional view of a SON (Small Outline Nonlead) package type semiconductor acceleration sensor device showing Embodiment 4 of the present invention, and is common to the elements in FIG. Are marked with a common reference.

  The semiconductor acceleration sensor device 30 </ b> A is mounted on a substrate (for example, a wiring substrate) 70. The wiring board 70 is provided with a plurality of post portions 71 on the upper surface and a plurality of conductive portions 72 on the lower surface, and these post portions 71 and the conductive portions 72 are connected to each other by through holes or the like (not shown). Has been. On the post portion 71 of the wiring board 70, an acceleration sensor chip 50 similar to that shown in FIG. 1 is bonded by flip chip bonding. That is, bumps 59 electrically connected to these are formed on the plurality of electrode pads 57 provided on the upper surface side of the acceleration sensor chip 50, and these bumps 59 are formed on the post of the wiring board 70. It is placed on the part 71 and mechanically and electrically connected.

  The gap 54 of the acceleration sensor chip 50 is filled with a resin member 61 such as a gel-like silicone resin, and the gap between the upper surface side of the acceleration sensor chip 50 and the upper surface side of the wiring board 70 is also A gel-like resin member 61 is filled. A lid 44 for closing the gap 54 is fixed to the lower surface of the acceleration sensor chip 50. The periphery of these acceleration sensor chips 50 is sealed with a thermosetting resin member 2 such as an epoxy resin, a silicone resin, or a phenol resin.

  In the fourth embodiment, the wiring board 70 functions as a lower stopper for the beam portion 53 on the upper surface side of the acceleration sensor chip 50, and the lid 44 functions as an upper stopper function for the weight portion 52 of the acceleration sensor chip 50. . When the length of the weight portion 52 is short and the lid 44 is insufficient as a stopper, the central portion of the lid 44 protrudes into a concave shape by drawing or the like, or the upper surface of the lid 44 is used as a stopper. A spacer may be attached.

  The operation of the semiconductor acceleration sensor device 30A having such a configuration is substantially the same as in the first embodiment. When acceleration is applied from the outside and the weight portion 52 is about to move, the gel-like resin member 61 covering the periphery is provided. However, due to the low elasticity, a variation easily occurs, which can be detected by the piezo element 56 of the beam portion 53. The detection result of the piezo element 56 is sent to the post portion 71 on the wiring board 70 side via the electrode pad 57 and the bump 59 and output from the conductive portion 72. Therefore, if the relationship between acceleration versus variation (stress) is previously investigated and set in a semiconductor circuit or the like connected to the wiring board 70, the applied acceleration can be accurately obtained.

(Example of manufacturing method)
In the semiconductor acceleration sensor device 30A of the fourth embodiment, for example, the semiconductor acceleration sensor device 30A is manufactured by the following processes (a) to (c).

(A) First Step On the plurality of post portions 71 formed on the wiring board 70, the upper surface side of the acceleration sensor chip 50 manufactured in advance is positioned and provided on the upper surface side of the acceleration sensor chip 50. The plurality of bumps 59 are bonded to the plurality of post portions 71 on the wiring substrate 70 side by flip chip bonding.

(B) Second Step A viscous liquid resin (for example, a thermosetting silicone resin) 61 a is injected into the gap 54 of the acceleration sensor chip 50, and the acceleration sensor chip 50 has a through hole 55. The gap between the upper surface side and the upper surface side of the wiring board 70 is filled with the resin 61a to cover the beam portion 53, and the gap 54 is filled with the resin 61a. Thereafter, the lid 44 is fixed to the lower surface of the acceleration sensor chip 50 to close the gap 54. Also, a heat treatment (for example, about 150 ° C.) is performed to cure the liquid resin 61 a and change it to a gel resin member 61.

(C) Third Step If the periphery of the acceleration sensor chip 50 is resin-sealed with the resin member 62 by transfer molding or the like in the same manner as a normal resin package, the manufacture of the semiconductor acceleration sensor device 30A in FIG. 4 is completed. To do.

(effect)
The fourth embodiment has the following effects (1) to (5).

  (1) Almost the same as in the first embodiment, the weight 52 of the acceleration sensor chip 50 is covered with a low-elasticity gel-like resin member 61. Because it mutates, it can accurately detect acceleration. In addition, since portions other than those necessary for acceleration detection are sealed with the resin member 62, long-term reliability equivalent to that of a normal resin package can be obtained.

  (2) Since the upper and lower displacements of the weight portion 52 and the beam portion 53 are regulated by the upper lid 44 and the lower wiring board 70, it is not necessary to provide a stopper for regulating the vertical displacement and the structure is simple. become. If the weight portion 52 is short and the lid 44 is insufficient as a stopper, the central portion of the lid 44 may be protruded in a concave shape, or a stopper spacer may be bonded to the lower surface of the lid 44. good.

  (3) The acceleration sensor chip 50 is joined to the wiring board 70 by flip chip bonding, and the gap 54 in the acceleration sensor chip 50 and the gap between the upper surface of the acceleration sensor chip 50 and the upper face of the wiring board 70 are After filling with the gel-like resin member 61, the periphery is sealed with the resin member 62, so that the package can be expected to be smaller than in the first embodiment, and the manufacturing process can be simplified, and the long-term operation can be realized. The semiconductor acceleration sensor device 30A having excellent reliability can be mass-produced at a lower cost.

  (4) As another manufacturing method of FIG. 4, liquid resin 61a is injected in two stages in substantially the same manner as in FIGS. 3B and 3C, and acceleration is achieved by the first stage of resin injection. The space between the upper surface of the sensor chip 50 and the upper surface of the wiring board 70 is filled with the resin 61a, heat-treated to change to the gel-like resin member 61, and then the inside of the space 54 is filled by the second stage resin injection. It may be filled with the liquid resin 61a and heat-treated to change to the gel-like resin member 61.

  (5) Although the SON package type has been described with reference to FIG. 4, the fourth embodiment can be applied to all resin packages.

(Configuration / Operation)
FIG. 5 is a cross-sectional view of a SON package type semiconductor acceleration sensor device showing a fifth embodiment of the present invention. Elements common to those in FIG. 4 showing the fourth embodiment are denoted by common reference numerals. .

  In the semiconductor acceleration sensor device 30B, the lid 44 is omitted by optimizing the viscosity characteristics of the gel-like resin member 61 in FIG. 4 (that is, by changing the viscosity). Other configurations are the same as those of the fourth embodiment shown in FIG.

  The operation of the semiconductor acceleration sensor device 30B having such a configuration is similar to that in the fourth embodiment. When acceleration is applied from the outside and the weight portion 52 is about to move, the gel-like resin member 61 covering the periphery is moved. Due to the low elasticity, mutation easily occurs and can be detected by the piezo element 56 of the beam portion 53. Even when acceleration is applied and the weight 52 is deformed to the lower surface side (upper side in FIG. 5) of the acceleration sensor chip 50, the solid resin member 62 serves as a stopper to prevent damage.

(Example of manufacturing method)
In the semiconductor acceleration sensor device 30B of the fifth embodiment, for example, the semiconductor acceleration sensor device 30B is manufactured by the following processes (a) to (c).

(A) First Step The acceleration sensor chip 50 is positioned on the plurality of post portions 71 of the wiring board 70, and the plurality of bumps 59 on the upper surface side of the acceleration sensor chip 50 are arranged on the wiring board 70 side. Bonding is performed on each post portion 71 by flip chip bonding.

(B) Second Step A viscous liquid resin (for example, a thermosetting silicone resin having a slightly higher viscosity) 61 a is injected into the gap 54 of the acceleration sensor chip 50, and this acceleration is made through the through hole 55. The gap between the upper surface side of the sensor chip 50 and the upper surface side of the wiring substrate 70 is filled with the resin 61a to cover the beam portion 53, and the gap 54 is filled with the resin 61a. Thereafter, heat treatment (for example, about 150 ° C.) is performed to cure the liquid resin 61 a and change it to a gel resin member 61.

(C) Third Step If the periphery of the acceleration sensor chip 50 is resin-sealed with the resin member 62 by transfer molding or the like as in the case of a normal resin package, the manufacture of the semiconductor acceleration sensor device 30B of FIG. 5 is completed. To do.

(effect)
In the fifth embodiment, there are substantially the same effects as the effects (1) and (3) to (5) of the fourth embodiment, and the following effects (i) and (ii). There is also.

  (I) Since the viscosity characteristic of the gel-like resin member 61 is optimized (that is, by changing the viscosity) so that it does not leak from the periphery of the acceleration sensor chip 50, the lid 44 is not required. Compared to the above, the structure and the manufacturing process can be further simplified and can be provided at a lower cost.

  (Ii) Since the upper and lower displacements of the weight part 52 and the beam part 53 are restricted by the upper resin member 62 and the lower wiring board 70, it is not necessary to provide a stopper for restricting the upper and lower displacements. It becomes easier.

(Constitution)
FIG. 6 is a cross-sectional view of an MCP type semiconductor acceleration sensor device showing Embodiment 6 of the present invention. Elements common to those in FIG. 4 showing Embodiment 4 are denoted by common reference numerals.

  The semiconductor acceleration sensor device 30C includes, for example, a semiconductor circuit chip 80 that generates a detection signal by performing signal processing on the stress detection result of the acceleration sensor chip 50 in the semiconductor acceleration sensor device 30A of FIG. This is an MCP type device in which 80 is stacked on the acceleration sensor chip 50 and sealed with resin.

  A semiconductor circuit chip 80 is die-bonded on the upper surface of the wiring board 70 having a plurality of post portions 71 on the upper surface and a plurality of conductive portions 72 on the lower surface. A plurality of electrode pads 81 are provided on the periphery of the upper surface of the semiconductor circuit chip 80, and a plurality of mounting pad portions 82 are provided inside these electrode pads 81. The plurality of electrode pads 81 are wire-bonded to the plurality of post portions 71 on the wiring board 70 side by wires 83. On the plurality of pad portions 82, an acceleration sensor chip 50 similar to that shown in FIG. 4 is bonded by flip chip bonding. That is, bumps 59 electrically connected to these are formed on the plurality of electrode pads 57 provided on the upper surface side of the acceleration sensor chip 50, and these bumps 59 are formed on the semiconductor circuit chip 80. It is placed on the pad portion 82 and mechanically and electrically connected.

  The gap 54 of the acceleration sensor chip 50 is filled with a resin member 61 such as a gel-like silicone resin, and the gap between the upper surface side of the acceleration sensor chip 50 and the upper surface side of the semiconductor circuit chip 80 is also filled. The gel-like resin member 61 is filled. A lid 44 for closing the gap 54 is fixed to the lower surface of the acceleration sensor chip 50. The periphery of the acceleration sensor chip 50 and the semiconductor circuit chip 80 is resin-sealed with a thermosetting resin member 62 such as an epoxy resin, a silicone resin, or a phenol resin.

  In the sixth embodiment, the upper surface side of the semiconductor circuit chip 80 serves as a lower stopper function for the beam portion 53 on the upper surface side of the acceleration sensor chip 50, and the lid 44 serves as an upper stopper function for the weight portion 52 of the acceleration sensor chip 50. Plays. When the length of the weight portion 52 is short and the lid 44 is insufficient as a stopper, the central portion of the lid 44 protrudes into a concave shape by drawing or the like, or the lower surface of the lid 44 is used as a stopper. A spacer may be attached.

(Operation)
When acceleration is applied to the semiconductor acceleration sensor device 30C and the weight portion 52 tries to move, the gel-like resin member 61 covering the periphery is easily deformed due to low elasticity, and this is caused by the deformation of the beam portion 53. The piezo element 56 detects, and the detection result is output to the pad portion 82 on the semiconductor circuit chip 80 side via the electrode pad 57 and the bump 59. In the semiconductor circuit chip 80, the relationship of acceleration versus variation (stress) is set in advance, and the stress detection result from the acceleration sensor chip 50 is signal-processed to generate an acceleration detection signal. The stress detection signal is sent to the post portion 71 on the wiring board 70 side via the electrode pad 81 and the wire 83 and is output from the conductive portion 72.

(Example of manufacturing method)
In the semiconductor acceleration sensor device 30C of the sixth embodiment, for example, the semiconductor acceleration sensor device 30C is manufactured by the following processes (a) to (d).

(A) First Step The lower surface of the semiconductor circuit chip 80 manufactured in advance is positioned and die-bonded on the wiring board 70. A plurality of electrode pads 81 formed on the upper surface side of the semiconductor circuit chip 80 and a plurality of post portions 71 formed on the upper surface side of the circuit substrate 70 are wire-bonded by wires 83.

(B) Second Step On the plurality of mounting pad portions 82 formed on the upper surface side of the semiconductor circuit chip 80, the lower surface side of the acceleration sensor chip 50 manufactured in advance is positioned, and this acceleration sensor chip A plurality of bumps 59 respectively formed on a plurality of electrode pads 57 on the upper surface side of 50 are bonded to a plurality of pad portions 82 on the semiconductor circuit chip 80 side by flip chip bonding. Note that, after the flip chip bonding, the wire bonding of the wire 83 in the first step may be performed.

(C) Third Step A viscous liquid resin (for example, thermosetting silicone resin) 61 a is injected into the gap 54 of the acceleration sensor chip 50, and the acceleration sensor chip 50 is formed through the through hole 55. The gap between the upper surface side and the upper surface side of the semiconductor circuit chip 80 is filled with the resin 61a to cover the beam portion 53, and the gap 54 is filled with the resin 61a. Thereafter, the lid 44 is fixed to the lower surface of the acceleration sensor chip 50 to close the gap 54. Also, a heat treatment (for example, about 150 ° C.) is performed to cure the liquid resin 61 a and change it to a gel resin member 61.

(D) Fourth Step Similar to a normal resin package, if the periphery of the acceleration sensor chip 50 and the semiconductor circuit chip 80 is resin-sealed with the resin member 62 by transfer molding or the like, the semiconductor acceleration sensor device of FIG. 30C production is complete.

(effect)
In the sixth embodiment, in addition to the effects (1), (2), and (5) that are substantially the same as the effects of the fourth embodiment, the following effects (i) and (ii) are also provided. There is also.

  (I) The acceleration sensor chip 50 is bonded to the semiconductor circuit chip 80 fixed on the wiring board 70 by flip chip bonding, the air gap 54 in the acceleration sensor chip 50, the upper surface of the acceleration sensor chip 50, and the semiconductor circuit. Since the gap between the upper surface of the chip 80 is filled with the gel-like resin member 61 and the periphery thereof is sealed with the resin member 62, the MCP composed of the acceleration sensor chip 50 and the semiconductor circuit chip 80 is formed. It can be provided inexpensively and in a low temperature process.

  (Ii) As another manufacturing method of FIG. 6, the liquid resin 61 a is injected in two stages almost in the same manner as in FIGS. 3B and 3C, and the acceleration is achieved by the first stage of resin injection. The space between the upper surface of the sensor chip 50 and the upper surface of the semiconductor circuit chip 80 is filled with the resin 61a, heat-treated to change to the gel-like resin member 61, and then injected into the space 54 by second-stage resin injection. May be filled with a liquid resin 61a and heat-treated to change to a gel-like resin member 61.

(Configuration / Operation)
FIG. 7 is a cross-sectional view of an MCP type semiconductor acceleration sensor device showing Embodiment 7 of the present invention. Elements common to those in FIG. 6 showing Embodiment 6 are denoted by common reference numerals.

  In this semiconductor acceleration sensor device 30D, the lid 44 is omitted by optimizing the viscosity characteristics of the gel-like resin member 61 in FIG. 6 (that is, by changing the viscosity). Other configurations are the same as those of the sixth embodiment shown in FIG.

  The operation of the semiconductor acceleration sensor device 30D having such a configuration is similar to that of the sixth embodiment. When acceleration is applied from the outside and the weight portion 52 is about to move, the gel-like resin member 61 covering the periphery is moved. A variation easily occurs due to low elasticity, and this is detected by the piezo element 56 of the beam portion 53. From this detection result, an acceleration detection signal is generated by the semiconductor circuit chip 80, sent to the post portion 71 on the wiring board 70 side, and output from the conductive portion 72. Even when acceleration is applied and the weight 52 is mutated to the lower surface side (upper side in FIG. 7) of the acceleration sensor chip 50, the solid resin member 62 can serve as a stopper to prevent damage.

(Example of manufacturing method)
In the semiconductor acceleration sensor device 30D of the seventh embodiment, for example, the semiconductor acceleration sensor device 30D is manufactured by the following processes (a) to (d).

(A) First Step The bottom surface of the semiconductor circuit chip 80 is positioned and die bonded onto the wiring board 70. A plurality of electrode pads 81 on the upper surface side of the semiconductor circuit chip 80 and a plurality of post portions 71 on the upper surface side of the wiring substrate 70 are wire-bonded by wires 83.

(B) Second Step The upper surface side of the acceleration sensor chip 50 is positioned on the plurality of mounting pad portions 82 on the upper surface side of the semiconductor circuit chip 80, and the plurality of electrodes on the upper surface side of the acceleration sensor chip 50. A plurality of bumps 59 respectively formed on the pad 57 are bonded to the plurality of pad portions 82 on the semiconductor circuit chip 80 side by flip chip bonding. Note that, after the flip chip bonding, the wire bonding of the wire 83 in the first step may be performed.

(C) Third Step A viscous liquid resin (for example, thermosetting silicone resin) 61 a is injected into the gap 54 of the acceleration sensor chip 50, and the acceleration sensor chip 50 is formed through the through hole 55. The gap between the upper surface side and the upper surface side of the semiconductor circuit chip 80 is filled with the resin 61a to cover the beam portion 53, and the gap 54 is filled with the resin 61a. Thereafter, heat treatment (for example, about 150 ° C.) is performed to cure the liquid resin 61 a and change it to a gel resin member 61.

(D) Fourth Step Similar to a normal resin package, if the periphery of the acceleration sensor chip 50 and the semiconductor circuit chip 80 is resin-sealed with the resin member 62 by transfer molding or the like, the semiconductor acceleration sensor device of FIG. 30D manufacturing is complete.

(effect)
In the seventh embodiment, in addition to the effects (1), (2), (5) such as the effects of the fourth embodiment, and the effects (i) such as the effects of the sixth embodiment, the following further There are also effects such as (I) and (II).

  (I) Since the lid 44 is not required by optimizing the viscosity characteristics of the gel-like resin member 61 (that is, by changing the viscosity) and preventing leakage from the periphery of the acceleration sensor chip 50, the sixth embodiment Compared to the above, the structure and the manufacturing process can be further simplified and can be provided at a lower cost.

  (II) As another manufacturing method of FIG. 7, the liquid resin 61a is injected in two stages in substantially the same manner as in FIGS. 3B and 3C, and acceleration is achieved by the first stage of resin injection. The space between the upper surface of the sensor chip 50 and the upper surface of the semiconductor circuit chip 80 is filled with the resin 61a, heat-treated to change to the gel-like resin member 61, and then injected into the space 54 by second-stage resin injection. May be filled with a liquid resin 61a and heat-treated to change to a gel-like resin member 61.

  In the present invention, the semiconductor acceleration sensor device has been described. However, the present invention can be applied to various semiconductor sensor devices mounted with other sensor chips instead of the acceleration sensor chip.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the QFN package type semiconductor acceleration sensor apparatus which shows Example 1 of this invention. It is a manufacturing process figure which shows the manufacturing method of Example 2 in the semiconductor acceleration sensor apparatus of FIG. It is a manufacturing process figure which shows the manufacturing method of Example 3 in the semiconductor acceleration sensor apparatus of FIG. It is sectional drawing of the SON package type semiconductor acceleration sensor apparatus which shows Example 4 of this invention. It is sectional drawing of the SON package type semiconductor acceleration sensor apparatus which shows Example 5 of this invention. It is sectional drawing of the MCP type semiconductor acceleration sensor apparatus which shows Example 6 of this invention. It is sectional drawing of the MCP type semiconductor acceleration sensor apparatus which shows Example 7 of this invention. It is sectional drawing of the semiconductor acceleration sensor apparatus using the conventional MEMS package.

Explanation of symbols

30, 30A to 30D Semiconductor acceleration sensor device 40 Lead frame 41 Die pad part 41a, 55 Through hole 42 Lead 42a Post part 43 Lid part 44 Lid 50 Acceleration sensor chip 51 Silicon chip 52 Weight part 53 Beam part 54 Air gap 56 Piezo element 57, DESCRIPTION OF SYMBOLS 81 Electrode pad 58, 83 Wire 59 Bump 61, 62 Resin member 61a Resin 70 Wiring board 71 Post part 72 Conductive part 80 Semiconductor circuit chip 81 Electrode pad 82 Pad part

Claims (7)

A weight portion having an upper surface, a lower surface, and a side surface, a support portion that connects one end to the side surface of the weight portion and supports it flexibly, and a pedestal portion that connects the other end of the support portion and surrounds the weight portion separately An acceleration sensor chip having
A first resin member that covers the upper surface, the lower surface, and the side surface and the support portion of the weight portion and has elasticity;
A second resin member covering the first resin member;
A semiconductor acceleration sensor device comprising: The semiconductor acceleration sensor device according to claim 1,
The pedestal portion of the acceleration sensor chip has an electrode pad,
A conductive portion electrically connected to the electrode pad, and a wiring board on which the acceleration sensor chip is mounted;
The semiconductor acceleration sensor device, wherein the second resin member covers an upper surface of the wiring board. The semiconductor acceleration sensor device according to claim 1,
The pedestal portion of the acceleration sensor chip has a first electrode pad,
A semiconductor circuit chip having a second electrode pad electrically connected to the electrode pad and on which the acceleration sensor chip is mounted;
A conductive part electrically connected to the second electrode pad of the semiconductor circuit chip; and a wiring substrate on which the semiconductor circuit chip is mounted,
The semiconductor acceleration sensor device, wherein the second resin member covers an upper surface of the semiconductor circuit chip and an upper surface of the wiring board. A semiconductor acceleration sensor device in which an acceleration sensor chip is sealed with a second sealing resin,
The acceleration sensor chip includes a weight portion having an upper surface, a lower surface, and a side surface, a support portion connected to the weight portion and flexibly supported, and a pedestal portion connected to the support portion and surrounding the weight portion. The semiconductor acceleration sensor device is characterized in that the upper surface, the lower surface, the side surface, and the support portion of the weight portion are wrapped by a first sealing resin having elasticity. The semiconductor acceleration sensor device according to claim 4,
The pedestal portion of the acceleration sensor chip has an electrode pad,
A wiring board having a conductive portion electrically connected to the electrode pad and on which the acceleration sensor chip is mounted;
The semiconductor acceleration sensor device, wherein the second resin member covers an upper surface of the wiring board. The semiconductor acceleration sensor device according to claim 4,
The pedestal portion of the acceleration sensor chip has a first electrode pad,
A semiconductor circuit chip having a second electrode pad electrically connected to the electrode pad and on which the acceleration sensor chip is mounted;
A wiring board having a conductive portion electrically connected to the second electrode pad of the semiconductor circuit chip and on which the semiconductor circuit chip is mounted;
The semiconductor acceleration sensor device, wherein the second resin member covers an upper surface of the semiconductor circuit chip and an upper surface of the wiring board. The semiconductor acceleration sensor device according to any one of claims 1 to 6,
The semiconductor acceleration sensor device, wherein the first resin member is a thermosetting silicone resin.

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