JP2011245587A - Mems device, and manufacturing method of cap substrate used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem such as alignment at least partially while preventing the entry of dust into an operation part.SOLUTION: There is provided a manufacturing method of a MEMS device with a cap substrate 50 connected to an element substrate on which a MEMS element mounted. The method includes: a process that forms a non-through trench 300, along a cut pattern of the element substrate, to the raw material substrate of the drench-formed cap substrate; a process that joins the raw material substrate of the cap substrate to the raw material substrate of the element substrate; and a process that etches the joined raw material substrate of the cap substrate at least until the non-through trench passes through.

Description

  The present invention relates to a manufacturing method of a MEMS device in which a cap substrate is bonded to an element substrate on which a MEMS element is mounted, and a manufacturing method of a cap substrate used therefor.

  2. Description of the Related Art Conventionally, a technique is known in which a silicon single crystal thin film of an SOI substrate is previously provided with a groove along a cutting pattern and cut with a dicing saw along the groove to prevent damage to the thin film during cutting ( For example, see Patent Document 1).

JP-A-63-237408

  A MEMS (Micro Electro Mechanical Systems) device is a device in which a structure is formed on a silicon substrate and various functions are obtained by the operation of the structure. For this reason, mixing of dust into the operating part directly affects the malfunction of the device. As a dust mixing prevention method, it is conceivable to cover the MEMS element by bonding a cap substrate to an element substrate on which the MEMS element is mounted. However, when adopting a configuration in which the cap substrate is bonded to the element substrate, in the dicing process in which the cap substrate and the element substrate are separated at the same time after bonding, dust can be prevented from entering the operation site, but alignment is difficult (element substrate). The dicing portion is difficult to specify), and the joint between the cap substrate and the element substrate is peeled off due to an impact during dicing.

  Therefore, the present invention has an object to provide a method for manufacturing a MEMS device and a method for manufacturing a cap substrate used therefor, which can at least partially eliminate problems such as alignment while preventing dust from being mixed into an operation site. And

In order to achieve the above object, according to one aspect of the present invention, there is provided a method of manufacturing a MEMS device in which a cap substrate is bonded to an element substrate on which a MEMS element is mounted.
Forming a non-penetrating trench along the cutting pattern of the element substrate in the raw material substrate of the cap substrate;
A bonding step of bonding the material substrate of the cap substrate in which the trench is formed to the material substrate of the element substrate;
And a step of etching the raw material substrate of the bonded cap substrate until at least the non-penetrating trench penetrates. A method of manufacturing a MEMS device is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a MEMS device and the manufacturing method of a cap board | substrate used for it which can eliminate problems, such as alignment, at least partially can be obtained, preventing mixing of the dust to an operation | movement part.

2 is a cross-sectional view showing a cross-section of an essential part of an example of an electronic component mounting package 10. FIG. 3 is a top view schematically showing a main part of a sensor chip 60 of the electronic component mounting package 10. It is explanatory drawing of the principal part of an example of the manufacturing method of the MEMS device by this invention. It is explanatory drawing of the manufacturing method of the MEMS device by the comparative example when not having the trench 300. FIG. It is explanatory drawing in the case of performing plasma dicing as a dicing method by the other comparative example. It is board | substrate sectional drawing which shows an example of the detailed each process of the manufacturing method of the MEMS device by this invention (the 1). It is board | substrate sectional drawing which shows an example of the detailed each process of the manufacturing method of the MEMS device by this invention (the 2). It is board | substrate sectional drawing which shows another example of the detailed each process of the manufacturing method of the MEMS device by this invention (the 1). It is board | substrate sectional drawing which shows another example of the detailed each process of the manufacturing method of the MEMS device by this invention (the 2). It is a figure which shows an example of a suitable dimension relationship when implement | achieving the manufacturing method of the MEMS device by this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a cross section of an essential part of an example of an electronic component mounting package 10 incorporating a MEMS device related to the present invention. FIG. 2 is a top view schematically showing the main part of the sensor chip 60 of the electronic component mounting package 10.

  The electronic component mounting package 10 includes a package body 17. The package body 17 defines an internal space (cavity) 17a by a bottom portion and side walls standing from the bottom portion. Various electronic components (a sensor chip 60 and a control IC chip 40 described later) of the angular velocity detection device 1 are accommodated in the internal space 17a. The upper side of the internal space 17 a is open and is covered with the lid member 16. The package body 17 may be made of any material such as a ceramic material, or may be made of a resin material (for example, epoxy resin).

  The package body 17 includes a plurality of leads 14. The lead 14 is made of a conductive material. Each electrode of the control IC chip 40 and the lead 14 are electrically connected by wire bonding of a wire 32.

  The lid member 16 is made of a conductive material (typically a metal material). Since the lid member 16 performs a shielding function, the lid member 16 may be connected to a ground potential by a ground structure (not shown).

  The angular velocity detection device 1 mainly includes a control IC chip 40, a cap substrate 50, and a sensor chip 60.

  The control IC chip 40 includes an integrated circuit (IC) that is electrically connected to a yaw rate detection unit 70 (described later) of the sensor chip 60 and has a function of processing a signal from the yaw rate detection unit 70 of the sensor chip 60. . For example, in a vehicle mounted state, the control IC chip 40 is connected to an external control device (not shown) via the lead 14 by the wire 32.

  The cap substrate 50 is formed of a silicon wafer (silicon substrate) as will be described later. The cap substrate 50 is provided so as to cover the sensor chip 60 from below, and seals and protects the movable part of the yaw rate detection unit 70 of the sensor chip 60. Further, the cap substrate 50 may electrically protect the yaw rate detection unit 70 of the sensor chip 60 by connecting most of the region to a constant potential such as ground. The cap substrate 50 also serves to prevent dust from being mixed into the movable part of the sensor chip 60 during manufacturing, as will be described later.

  The sensor chip 60 includes a substrate on which a later-described yaw rate detector 70 is formed on one side. In the illustrated example, the sensor chip 60 is disposed on the cap substrate 50 so that the installation side of the yaw rate detection unit 70 is on the cap substrate 50 side. The sensor chip 60 may be arranged so that the installation side of the yaw rate detection unit 70 is on the upper side. In this case, the cap substrate 50 may be provided so as to cover the upper side of the sensor chip 60. In addition, the sensor chip 60 and the control IC chip 40 do not necessarily have a laminated structure, and may be arranged side by side.

  The sensor chip 60 may function as a yaw rate sensor mounted on a vehicle, for example. In this case, the sensor chip 60 outputs an acceleration sensor that outputs a signal corresponding to the acceleration in the vehicle body longitudinal direction or the vehicle width direction generated in the mounted vehicle, and a yaw rate that outputs a signal corresponding to the angular velocity generated around the center of gravity axis of the vehicle. You may comprise a sensor integrally (refer FIG. 2). In this case, the electronic component mounting package 10 is embodied as a vehicle control sensor unit in which the sensor chip 60 is integrally formed. In this case, the electronic component mounting package 10 is provided in the vicinity of the center of gravity position (floor tunnel or the like) of the vehicle with the sensor chip 60 or the like mounted therein, and the sensor chip 60 includes the yaw rate and acceleration generated at the mounting position. Is detected. The detected yaw rate and acceleration may be used, for example, for vehicle travel control that prevents side slipping and stabilizes the behavior of the vehicle.

  The sensor chip 60 is typically manufactured by a micromachine technique using an SOI (Silicon on Insulator) wafer. In this case, each element of the sensor chip 60 is configured by MEMS (Micro Electro Mechanical Systems).

  The sensor chip 60 generally includes a yaw rate detector 70 having a tuning fork structure in which left and right weights 74a and 74b are coupled by a link spring 78 as shown in FIG. The weights 74a and 74b are arranged at symmetrical positions in the X-axis direction in a state where they are lifted from the sensor chip substrate surface. The weights 74a and 74b are connected to the drive frame 72 via a detection spring 77 that can vibrate in the Y-axis direction. The drive frame 72 is connected to a fixed portion 75 (portion fixed to the sensor chip substrate) via a drive spring 71 that can vibrate in the X-axis direction. Note that the structure of the yaw rate detection unit 70 of the sensor chip 60 is not limited to the illustrated structure, and may be arbitrary.

  The yaw rate detection unit 70 includes various electrodes 79. The electrode 79 is provided for ground connection, signal transmission, and driving, for example. That is, the electrode 79 is used, for example, to supply a signal representing a change in capacitance to the control IC chip 40, to receive a drive signal from the control IC chip 40 that vibrates the weights 74a, 74b in reverse phase, and the like. Used for. The electrode 79 may be connected to the control IC chip 40 via a conduction part 52 formed on the cap substrate 50 as shown in the figure, for example. The conductive portion 52 is electrically insulated from other parts of the cap substrate 50 by surrounding the outer periphery with the insulating trench 54. In addition, the connection between the conductive portion 52 and the electrode 79 is made of a conductive adhesive (for example, an adhesive containing aluminum or the like, ACF / ACP (anisotropic conductive film / Paste) etc.) or flip chip (FC).

  Next, an example of a method for manufacturing a MEMS device according to the present invention (and a method for manufacturing a cap substrate used therefor, the same applies hereinafter) will be described. In one embodiment, the MEMS device manufactured according to this embodiment includes the sensor chip 60 and the cap substrate 50 shown in FIGS. 1 and 2 described above. In the following description, it is assumed that the MEMS device manufactured according to the present embodiment is the sensor chip 60 and the cap substrate 50 shown in FIGS. 1 and 2 described above.

  FIG. 3 is an explanatory view of a main part of an example of a method for manufacturing a MEMS device according to the present invention, and shows main steps in a cross-sectional view of the substrate. In FIG. 3, only a partial cross section of each raw material substrate that finally constitutes the sensor chip 60 and the cap substrate 50 is shown.

  In the example shown in FIG. 3, in the MEMS device manufacturing method, first, as shown in FIG. 3A, a sufficiently deep trench 300 is formed in the dicing portion of the raw material substrate (silicon wafer) 500 of the cap substrate 50. including. The trench 300 is formed with a depth that does not penetrate the raw material substrate of the cap substrate 50. A preferable depth of the trench 300 will be described later with reference to FIG. Note that the pattern of the dicing portion in the raw material substrate of the cap substrate 50 corresponds to the pattern of the dicing portion of the sensor chip 60.

  Next, as shown in FIG. 3B, the raw material substrate (silicon wafer) 500 of the cap substrate 50 in which the trench 300 is formed is the raw material substrate of the sensor chip 60 in which the respective components such as the yaw rate detector 70 are already formed. Bonded (bonded) to (SOI wafer) 600. For this bonding, a conductive adhesive 301 is used.

  Next, as shown in FIG. 3C, the raw material substrate of the cap substrate 50 is entirely thinned by plasma etching (that is, the raw material of the cap substrate 50 uniformly over the entire surface of the raw material substrate of the cap substrate 50). The thickness of the substrate is reduced) and the trench 300 is opened (through).

  Next, as shown in FIG. 3D, further plasma etching is continued, and the raw material substrate of the cap substrate 50 is further thinned, and the dicing of the raw material substrate 600 of the sensor chip 60 facing the penetrating trench 300 is performed. The portion 606 is etched.

  FIG. 4 is an explanatory diagram of a method of manufacturing a MEMS device according to a comparative example in the case where the trench 300 is not provided. In this comparative example, the raw material substrate (silicon wafer) of the cap substrate is bonded to the raw material substrate (SOI wafer) of the sensor chip on which the respective components such as the yaw rate detector are already formed, and then shown in FIG. As described above, the raw material substrate of the cap substrate is polished to be thinned over the entire surface. This thinning is performed for package downsizing. The raw material substrate of the cap substrate is not set to be thin from the beginning. The shape stability of the raw material substrate of the cap substrate is maintained when the two substrates are combined for bonding the raw material substrate of the cap substrate and the raw material substrate of the sensor chip. This is to ensure the rigidity necessary for the purpose (that is, if the raw material substrate of the cap substrate is too thin, it is difficult to bend easily and accurately align the two substrates). Next, as shown in FIG. 4B, the dicing part is divided by a dicing blade. In such a comparative example, when the raw material substrate of the cap substrate is flattened by thinning, the dicing portion cannot be visually detected, and it is necessary to use infrared rays or the like to detect the dicing portion by transmitting it. There is a point. Further, when dicing with a dicing blade, there is a problem that the adhesive layer between the raw material substrate of the sensor chip and the raw material substrate of the cap substrate is likely to be peeled due to the impact of the dicing blade. Since the dicing blade is cut with a water flow for cooling, there is a problem that when the adhesive layer is peeled off, water flows into an element such as a yaw rate detector.

  FIG. 5 is an explanatory diagram in the case of performing plasma dicing as a dicing method according to another comparative example. In this comparative example, it is ideal to use an oxide film or the like as a plasma etching mask, but in actuality, the material used for the adhesive layer between the raw material substrate of the sensor chip and the raw material substrate of the cap substrate is heated. There is a problem that it is weak (for example, aluminum) and a high temperature cannot be used for forming an oxide film. That is, plasma dicing has a problem in that there are many restrictions on the formation of an etching mask that can withstand the etching amount necessary for cutting.

  On the other hand, according to the MEMS device manufacturing method according to the present embodiment shown in FIG. 3, the trench 300 is formed in advance in a portion corresponding to the dicing portion of the sensor chip 60 in the raw material substrate of the cap substrate 50. Thereby, alignment of the dicing part of the raw material substrate of the sensor chip 60 can be automatically realized (detection of the dicing part is unnecessary).

  Further, according to the MEMS device manufacturing method of the present embodiment shown in FIG. 3, the raw material substrate of the cap substrate 50 is formed on the raw material substrate of the cap substrate 50 in advance by performing plasma etching on the entire surface of the raw material substrate. The trench 300 is opened first, and the dicing portion of the raw material substrate of the sensor chip 60 under the trench 300 is also etched. Thereby, the thickness of the raw material substrate of the cap substrate 50 and the dicing of the sensor chip 60 can be simultaneously performed. Further, peeling of the bonding portion between the raw material substrate of the cap substrate 50 and the raw material substrate of the cap substrate 50 does not occur. Further, since the thickness of the raw material substrate of the cap substrate 50 is used as a plasma etching mask, problems that occur when an oxide film or the like is used as the plasma etching mask can be avoided.

  Next, details of the manufacturing method of the MEMS device according to the present invention will be described with reference to FIGS.

  6 and 7 are cross-sectional views of the substrate showing an example of detailed steps of the manufacturing method of the MEMS device according to the present invention, and FIG. 7 shows a continuation (second half) of FIG.

  In the illustrated MEMS device manufacturing method, first, as shown in FIG. 6A, a mask material (for example, a photoresist) 302 is disposed on a raw material substrate (silicon wafer) 500 of the cap substrate 50, and the cap substrate 50 A portion Y facing the element movable portion (the yaw rate detecting portion 70 and the like) on the sensor chip 60 side of the raw material substrate is opened.

  Next, as shown in FIG. 6B, a step Y is formed by etching the portion Y facing the element movable portion. Thereafter, the mask material 302 is removed.

Next, as shown in FIG. 6C, a mask material (SiO ₂ or the like) 308 for forming a trench is formed, and patterning is performed. At this time, the dicing portion 310 is formed so that the portion 306 that becomes the conducting portion 52 (see FIG. 1) that is electrically connected to the electrode 79 (see FIG. 1) of the sensor chip 60 is surrounded by the thin trench that becomes the insulating trench 54. The patterning is performed so that a thick trench is formed.

  Next, as shown in FIG. 6D, trenches 312 and 314 are formed by dry etching (plasma etching) according to the pattern shown in FIG. 6C. At this time, it is preferable to use a condition that the trench depth varies depending on the opening width by utilizing the microloading effect. In the dicing portion 310, dry etching is performed under the condition that the trench 312 is formed sufficiently deep.

  Next, as shown in FIG. 6E, after removing the mask material 308, the cap 306 is formed so that the inside of the narrow trench 314 (see FIG. 6D) to be the insulating trench 54 is completely filled with the oxide film 316. The surface of the raw material substrate of the substrate 50 is sufficiently oxidized.

  Next, as shown in FIG. 7A, the surface oxide film 320 (see FIG. 6E) of the raw material substrate of the cap substrate 50 is replaced with the surface of the portion 306 (see FIG. 6C) that becomes the conductive portion 52. The raw material substrate of the cap substrate 50 is turned over while the oxide film is buried inside the narrow trench 314 (see FIG. 6D), and the raw material substrate (SOI of the sensor chip 60 is removed). The wafer substrate 600 is adjusted so that the raw material substrate of the cap substrate 50 is overlaid on the element movable portion (the yaw rate detection portion 70 or the like) with an accurate positional relationship. Note that the element substrate 600 of the sensor chip 60 used at this time already has an element movable part (yaw rate detection part 70 and the like) formed thereon. At this time, an aluminum pattern 402 is disposed on the electrode 79 on the raw material substrate of the sensor chip 60 for both conduction and adhesion. In addition, a similar aluminum pattern 404 is disposed on a planned joining portion of the raw material substrate of the sensor chip 60. However, preferably, as shown in FIG. 7A, aluminum is removed in the dicing portion 406 in the raw material substrate of the sensor chip 60.

  Next, as shown in FIG. 7B, after the raw material substrate of the cap substrate 50 and the raw material substrate of the sensor chip 60 are overlaid, the two substrates are bonded together by applying an appropriate temperature.

  Next, as shown in FIG. 7C, the raw material substrate of the cap substrate 50 is entirely thinned by plasma etching from the non-joint surface side (upper side of the drawing) of the raw material substrate of the cap substrate 50. At this time, the gas used is preferably SF6 gas having a sufficiently high etching rate for both silicon and oxide films. In this thinning process, the trench 312 in the raw material substrate of the cap substrate 50 opens to the non-joint surface side surface, and accordingly, the dicing portion 406 (part facing the trench 312) in the raw material substrate of the sensor chip 60 is etched. Is started.

  Next, as shown in FIG. 7D, the dicing portion 406 in the raw material substrate of the sensor chip 60 is etched sufficiently deeply. At this time, the oxide film 316 (the portion to be the insulating trench 54) in the raw material substrate of the cap substrate 50 is exposed on the non-joint surface side surface. The end of etching may be realized using an appropriate etching detection technique. For example, the etching may be terminated after a predetermined time from when it is detected that the silicon oxide film 410 inside the raw material substrate of the sensor chip 60 has been reached. In this case, the point of time when the silicon oxide film 410 is reached can be easily detected by detecting the components of the silicon oxide film 410. Alternatively, the etching may be terminated when the oxide film 316 on the raw material substrate of the cap substrate 50 is exposed. When the etching is completed, each set of the cap substrate 50 and the sensor chip 60 is separated by mechanical cleavage or polishing. Thus, the sensor chip 60 to which the cap substrate 50 is bonded is completed. Typically, a plurality of sets of cap substrates 50 and sensor chips 60 are formed from one raw material substrate 500 and 600, respectively.

  According to the method of manufacturing the MEMS device shown in FIGS. 6 and 7, as described above with reference to FIG. 3, the raw material substrate of the cap substrate 50 is entirely plasma-etched, so that the cap substrate 50 is preliminarily formed. The trench 312 formed in the raw material substrate is opened first, and the dicing portion 406 of the raw material substrate of the sensor chip 60 therebelow is also etched. Thereby, the thickness of the raw material substrate of the cap substrate 50 and the dicing of the sensor chip 60 can be simultaneously performed. In addition, alignment of the dicing portion of the raw material substrate of the sensor chip 60 is automatically performed, and peeling of the bonding portion (aluminum patterns 404 and 402) between the raw material substrate of the cap substrate 50 and the raw material substrate of the cap substrate 50 also occurs. do not do.

  Further, as shown in FIGS. 6A to 6E, the trench 312 is formed from the joint surface side of the raw material substrate of the cap substrate 50 with the raw material substrate of the sensor chip 60. Therefore, the raw material substrate of the cap substrate 50 is used. Compared to the case where a similar trench is formed from the opposite side (non-joint surface side), the frequency of turning the raw material substrate of the cap substrate 50 upside down during manufacture is reduced, and there is a possibility that foreign matter enters the trench 312. This can reduce the possibility that the subsequent dry etching is hindered due to the inclusion of foreign matter.

  Further, as shown in FIGS. 6A to 6E, the trench 312 is formed from the joint surface side of the raw material substrate of the cap substrate 50 with the raw material substrate of the sensor chip 60. 52 and other structures or portions such as the insulating trench 54 (a structure or portion cooperating with the yaw rate detection unit 70 including the electrode 79 on the sensor chip 60 side) may be formed simultaneously on the raw material substrate of the cap substrate 50. it can. That is, the trench 312, the counterbore 304, the conductive portion 52, and the insulating trench 54 can be formed by processing and processing from the same surface of the raw material substrate of the cap substrate 50. The counterbore 304 is provided in order to maintain a necessary clearance between the cap substrate 50 and the movable portion (weight 74a, 74b, link spring 78, etc.) of the yaw rate detection unit 70 of the sensor chip 60.

  8 and 9 are cross-sectional views of the substrate showing other examples of detailed steps of the method of manufacturing the MEMS device according to the present invention, and FIG. 9 shows a continuation of FIG. Each step of the MEMS device manufacturing method shown in FIGS. 8 and 9 can be used as an alternative to each step of the MEMS device manufacturing method shown in FIG.

  In the illustrated MEMS device manufacturing method, first, as shown in FIG. 8A, a silicon oxide film 802 is arranged as a mask material on a raw material substrate (silicon wafer) of a cap substrate 50, and an element movable portion (yaw rate detection) is performed. A portion Y facing the portion 70 and the like is opened.

  Next, as shown in FIG. 8B, a resist 804 is applied as a mask for the trenches beside the dicing portion and the conductive portion, and the trenches beside the dicing portion and the conductive portion are patterned. At this time, the resist film thickness is desirably 50 μm or more.

  Next, as shown in FIG. 8C, according to the pattern shown in FIG. 8B, the silicon oxide film in the trenches beside the dicing portion and the conductive portion is etched and opened. At this time, in addition to the oxide film dry etcher, if etching is performed using a silicon dry etcher that performs trench dry etching thereafter, the trench etching can be continuously performed as it is, and the process can be shortened.

  Next, as shown in FIG. 8D, according to the pattern shown in FIG. 8B, the dicing portion of the raw material substrate of the cap substrate 50 and the trench beside the conductive portion are etched. At this time, if the condition for changing the etching rate according to the opening width of the trench pattern (microloading) is used, the dicing portion (trench 312) and the depth of the trench 314 beside the conductive portion are created under the same etching condition. be able to. For example, the etching condition may be that a pressure region of 100 mTorr or more is used, the trench width of the dicing portion is 50 μm, and the trench width beside the conductive portion is 2 μm.

  Next, as shown in FIG. 9A, the resist 804 is removed. The removal of the resist 804 may be realized by generating plasma using oxygen gas in a silicon-based dry etcher subjected to trench etching. By performing this resist removal continuously, the next process shown in FIG. 9B can be performed continuously, and the process can be further shortened.

  Next, as shown in FIG. 9B, the raw material substrate of the cap substrate 50 is etched using the pattern of the silicon oxide film 802 formed by the processes of FIGS. 8A and 8C as a mask. Thereby, a counterbore 304 is formed in a portion Y of the raw material substrate of the cap substrate 50 that faces the element movable portion (the yaw rate detection unit 70 and the like) on the sensor chip 60 side. The etching amount may be about 5 μm. At this time, the dicing portion (trench 312) and the trench 314 beside the conducting portion are also etched.

  Next, as shown in FIG. 9C, a silicon oxide film 808 is formed by thermal oxidation, chemical vapor deposition (CVD), or the like so that the trench inside the conductive portion is filled with the silicon oxide film.

  Next, as shown in FIG. 9D, an unnecessary silicon oxide film (except for the silicon oxide film 810 in the trench 314 beside the conducting portion) in the silicon oxide film 808 formed by the process shown in FIG. 9C. The silicon oxide film) is removed using a technique such as wet etching or dry etching. Thereafter, the process proceeds to the process shown in FIG. 7 to complete the sensor chip 60 to which the cap substrate 50 is bonded.

  According to the MEMS device manufacturing method shown in FIGS. 8 and 9, the processes from FIG. 8C to FIG. 9B can be performed in the same etcher, and a plurality of processes can be performed in one process. It becomes possible to carry out.

  FIG. 10 is a diagram showing an example of a dimensional relationship suitable for realizing the above-described MEMS device manufacturing method according to the present invention. FIG. 10A shows the state of FIG. 7B (the state before performing full plasma etching), and FIG. 10B shows the state of FIG. 7D (the state where plasma etching is completed). ).

  The thickness h1 of the raw material substrate of the cap substrate 50 (thickness in a state before performing the entire plasma etching) is preferably that the raw material substrate of the cap substrate 50 is bent during the process shown in FIG. It is set so as to ensure rigidity that does not sag. For example, h1 may be 200 μm.

  On the other hand, the thickness d4 of the cap substrate 50 after the completion of the process (thickness in the state where the plasma etching is finished) is appropriately set from the viewpoint of downsizing of the electronic component mounting package 10 (particularly downsizing in the thickness direction). . For example, d4 may be 30 μm. Therefore, in this case, the thickness that is reduced by the plasma etching of the raw material substrate of the cap substrate 50 is h1-d4.

  The depth d2 of the insulating trench 54 may be set to a dimension that is the same as or slightly larger than the thickness d4 of the cap substrate 50 after the completion of the process so as to be exposed from the surface side in the state where the plasma etching is completed. For example, d2 may be 30 μm, which is the same as d4.

  The thickness h2 of the raw material substrate of the sensor chip 60 (the thickness of the cap substrate 50 before the entire plasma etching of the raw material substrate) may be 170 μm, for example. The thickness d3 of the yaw rate detection unit 70 including the electrode 79 of the sensor chip 60 may be 40 μm, for example.

  The etching depth (= h2−d5) of the dicing portion in the raw material substrate of the sensor chip 60 is such that the etching of the dicing portion is completed immediately before penetrating the raw material substrate of the sensor chip 60 (ie, leaving only the thickness of d5). Set to For example, d5 may be 20 μm.

  The depth (= h1-d1) of the trench 312 in the raw material substrate of the cap substrate 50 is reduced from the thickness (= h1-d4) which is reduced by plasma etching in the raw material substrate of the cap substrate 50, so that the opening of the trench 312 is opened. The value obtained by subtracting the etching depth d1 necessary for the above is determined so as to coincide with the etching depth (= h2-d5) in the raw material substrate of the sensor chip 60. That is, d1 is determined so that h1-d4-d1 = h2-d5. For example, if h1 = 200 μm, d4 = 30 μm, h2 = 170 μm, d5 = 20 μm, d1 = 20 μm. In this case, the depth (= h1-d1) of the trench 312 in the raw material substrate of the cap substrate 50 is set to 180 μm. By setting various dimensions in such a relationship, it is possible to simultaneously perform the thinning of the raw material substrate of the cap substrate 50 and the etching for dicing of the sensor chip 60.

  In the description of FIG. 10, in order to prevent the description from becoming complicated, the microloading effect does not occur (that is, the thinning of the raw material substrate of the cap substrate 50 and the etching of the dicing portion of the raw material substrate of the sensor chip 60 are performed. It is assumed that the process proceeds at the same etching rate. In addition, when a micro loading effect arises, what is necessary is just to adapt various dimensions in consideration of it.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, as a preferable embodiment, the trench (300 or 312) is formed from the bonding surface side of the raw material substrate of the cap substrate 50 to the raw material substrate of the sensor chip 60. It is also possible to form a similar trench from the surface side. That is, a similar non-penetrating trench having an opening on the non-bonding surface side of the raw material substrate of the cap substrate 50 may be formed.

  In the above-described embodiment, the thinning of the raw material substrate of the cap substrate 50 and the etching for dicing the sensor chip 60 are performed simultaneously. However, after the trench (300 or 312) is opened by plasma etching. If so (for example, after the state shown in FIG. 7C), the same function may be realized by another method. For example, in the state shown in FIG. 7C, the dicing portion (portion facing the trench 312) 406 in the raw material substrate of the sensor chip 60 may be cut by a dicing blade or may be cut by another method. . Further, in the state shown in FIG. 7C, the thinning of the raw material substrate of the cap substrate 50 to the state shown in FIG. 7D may be realized by polishing.

DESCRIPTION OF SYMBOLS 1 Angular velocity detection apparatus 10 Electronic component mounting package 14 Lead 16 Lid member 17 Package main body 17a Internal space 32 Wire 40 Control IC chip 50 Cap board 52 Conduction part 54 Insulation trench 60 Sensor chip 70 Yaw rate detection part 71 Drive spring 72 Drive frame 74a, 74b Weight 75 Fixed portion 77 Detection spring 78 Link spring 79 Electrode 300, 312 Trench 304 Counterbore

Claims (6)

A manufacturing method of a MEMS device in which a cap substrate is bonded to an element substrate on which a MEMS element is mounted,
Forming a non-penetrating trench along the cutting pattern of the element substrate in the raw material substrate of the cap substrate;
A bonding step of bonding the material substrate of the cap substrate in which the trench is formed to the material substrate of the element substrate;
And a step of etching the material substrate of the bonded cap substrate until at least the non-penetrating trench penetrates. A method of manufacturing a MEMS device, comprising:   2. The method of manufacturing a MEMS device according to claim 1, wherein, in the bonding step, the raw material substrate of the cap substrate is bonded to the raw material substrate of the element substrate in a direction in which the opening side of the trench faces the raw material substrate of the element substrate. .   The MEMS device according to claim 1, further comprising a step of forming a structure or a portion that cooperates with a MEMS element or an electrode on the raw material substrate side of the element substrate on the opening side of the trench in the raw material substrate of the cap substrate. Manufacturing method.   The method for manufacturing a MEMS device according to claim 1, wherein in the etching step, the raw material substrate of the cap substrate is entirely thinned by etching. The etching process is continued even after the trench penetrates the raw material substrate of the bonded cap substrate,
The portion of the raw material substrate of the element substrate facing the trench is etched while the raw material substrate of the cap substrate is entirely thinned in the etching step after the penetration of the trench. The manufacturing method of the MEMS device of any one of these. A manufacturing method of a cap substrate bonded to an element substrate on which a MEMS element is mounted,
Forming a non-penetrating trench along the cutting pattern of the element substrate in the raw material substrate of the cap substrate,
The method of manufacturing a cap substrate, wherein the non-penetrating trench is penetrated by etching after joining the raw material substrate of the cap substrate to the raw material substrate of the element substrate.

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