JP4853142B2 - Micro device module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a micro device module and a manufacturing method thereof, and more particularly, a SAW (Surface Acoustic Wave) element having a comb-shaped electrode portion on a piezoelectric substrate, or a MEMS (Micro Electro Mechanical Systems) having a movable portion or a vibrator on a functional surface. In particular, the present invention relates to a micro device module modularized by incorporating a micro device such as a thin film bulk acoustic wave resonator (F-BAR).

In recent years, portable electronic devices such as mobile phones have been reduced in size and weight so that they can be easily carried, and the reduction in size and weight of electronic components mounted on portable electronic devices has been promoted.
For miniaturization of electronic components, so-called high-density mounting modules in which a plurality of chips and components are mounted inside one device are very effective, and various research and development are underway.

  On the other hand, as parts mounted on these portable electronic devices, MEMS (Micro Electro Mechanical Systems) having a SAW (Surface Acoustic Wave) element having a comb-shaped electrode portion on a piezoelectric substrate or a movable portion or a vibrator on a functional surface. ) And F-BAR (Thin Film Bulk Acoustic Wave Resonators) and other microdevice modules that are modularized are also important components, and are becoming smaller and lighter.

  The above-mentioned microdevice requires a hollow sealing structure, and in recent years, development of a high-density mounting type microdevice module in which a plurality of microdevices are mounted in a hollow seal has become important.

Patent Documents 1 and 2 disclose a technique in which a single microdevice is hollow-sealed with a resin layer such as a resin sheet.
However, in the methods of Patent Documents 1 and 2, since the adhesion area between the resin sheet and the substrate is large, and this area cannot be mounted with other components, it becomes a useless area for realizing high-density mounting. It has become a major obstacle.
JP-A-10-125825 Japanese Patent Application No. 9-504976

  An object of the present invention is a micro device module in which a micro device having a vibrator or a movable portion such as a MEMS, F-BAR, or SAW element is incorporated into a functional surface, and the micro device is sealed. An object of the present invention is to provide a micro device module capable of realizing high-density mounting by reducing the bonding area between a resin sheet and a substrate to be manufactured and a manufacturing method thereof.

  In order to solve the above problems, a micro device module of the present invention is formed on a module substrate, a first electrode formed in the micro device mounting region of the module substrate, and outside the micro device mounting region of the module substrate. And a functional element having a movable part or vibrator formed on the functional surface, and a bump formed on the functional surface, the bump being connected to the first electrode, A microdevice mounted in the microdevice mounting region of the module substrate so that the surface does not contact the module substrate, and the functional surface of the microdevice so that the functional surface is sealed to form a hollow portion An opening for exposing the second electrode is formed, covering the module substrate and the module substrate. That has a resin-impregnated sheet comprising a resin impregnated with fibers.

In the micro device module of the present invention, the first electrode is formed in the micro device mounting region of the module substrate, the second electrode is formed outside the micro device mounting region of the module substrate, and the movable portion or the vibrator is formed on the functional surface. The micro device having the functional element formed with the bump and the bump formed on the functional surface is connected to the first electrode and the micro device mounting region of the module substrate so that the functional surface does not contact the module substrate. Mounted.
In addition, a resin is applied to the fiber in which an opening for exposing the second electrode is formed so as to cover the surface excluding the functional surface of the microdevice and the module substrate so that the functional surface is sealed to form a hollow portion. A resin-impregnated sheet formed by impregnating with is formed.

  In addition, in order to solve the above-described problem, a method of manufacturing a micro device module according to the present invention includes a module substrate in which a first electrode is formed in a micro device mount region and a second electrode is formed outside the micro device mount region. A microdevice having a functional element having a movable portion or a vibrator formed on a functional surface and a bump formed on the functional surface in the microdevice mount region, and the bump is connected to the first electrode; Mounting the functional surface so as not to contact the module substrate, and covering the surface excluding the functional surface of the microdevice and the module substrate with a resin-impregnated sheet in which fibers are impregnated with resin; Forming a hollow portion and forming an opening for exposing the second electrode to the resin-impregnated sheet And a that process.

In the manufacturing method of the micro device module of the present invention described above, first, a module substrate is prepared in which a first electrode is formed in the micro device mount region and a second electrode is formed outside the micro device mount region.
Next, a micro device having a functional element having a movable portion or a vibrator formed on the functional surface and a bump formed on the functional surface is connected to the first electrode in the micro device mounting region of the module substrate. Mount so that the functional surface does not touch the module substrate.
Next, the surface excluding the functional surface of the microdevice and the module substrate are covered with a resin-impregnated sheet obtained by impregnating the resin with fibers, and the functional surface is sealed to form a hollow portion.
Next, an opening for exposing the second electrode is formed in the resin-impregnated sheet.

  The micro device module of the present invention is a micro device module that is modularized by incorporating a micro device having a vibrator or a movable portion such as a MEMS, F-BAR, or SAW element on the functional surface. An opening for exposing the second electrode is formed in the resin-impregnated sheet for sealing the mounted micro device, and the bonding area between the resin sheet for sealing the micro device and the substrate can be reduced to realize high-density mounting. .

  The method of manufacturing a microdevice module according to the present invention is a method of manufacturing a microdevice module that is modularized by incorporating a microdevice having a vibrator or a movable part such as a MEMS, F-BAR, or SAW element on the functional surface. In this method, a micro device mounted on a module substrate is sealed with a resin-impregnated sheet, and an opening for exposing the second electrode is formed in the resin-impregnated sheet, and further wiring and electronic components are formed on the second electrode. Can be mounted, and the high-density mounting can be realized by reducing the bonding area between the resin sheet for sealing the microdevice and the substrate.

  Hereinafter, a micro device module and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a perspective view of a micro device module according to this embodiment, and FIG. 1B is a cross-sectional view. The micro device module according to the present embodiment is obtained by modularizing a micro device including a functional element having a movable part or a vibrator such as a SAW element, MEMS, or F-BAR.
For example, the first electrode 11 is formed in the micro device mounting region R1 on one surface of the module substrate 10 made of, for example, a 0.3 mm resin substrate, and the second electrode 12 is formed in the region R2 outside the micro device mounting region. Is formed. The first electrode 11 and the second electrode 12 have a thickness of 30 μm, for example.
A plurality (for example, three) of micro devices (20A, 20B, 20C) having functional elements having movable portions or vibrators formed on the functional surface are mounted on the micro device mounting region R1 of the module substrate 10.

  Here, the micro device will be described. FIG. 2 is a cross-sectional view of a micro device modularized by the micro device module of FIG. 1, and typically shows a SAW element, but is particularly limited to a SAW element, MEMS, F-BAR, or the like. is not.

As shown in FIG. 2, for example, a comb-shaped electrode 21 is formed on a functional surface of a piezoelectric substrate 20 such as LiTaO ₃ , LiNbO ₃ , or quartz to constitute a functional element such as a SAW element. Further, on the functional surface where the functional element is formed, a pad electrode 22 made of aluminum or the like formed by connecting to the functional element or the like is formed, and a bump (projection electrode) 23 is formed on the pad electrode 22. Yes. Further, a protective film (not shown) may be formed.
The micro device on which the SAW element is formed has, for example, 1 × 2 mm and a thickness of 125 μm. The bump 23 formed on the micro device is, for example, a solder bump having a diameter of 200 μm and a height of 60 μm.

  As shown in FIG. 1B, a plurality of (for example, three) microdevices (20A, 20B, 20C) having the above-described configuration have bumps connected to the first electrode 11, and a functional surface is a module substrate. It is mounted on the micro device mounting region R1 of the module substrate 10 so as not to come into contact with the module 10.

Further, the surface excluding the functional surface of the microdevice (20A, 20B, 20C) and the module substrate 10 are coated, and the resin impregnated sheet 30 is formed by impregnating the resin with the fiber, and the hollow portion V is configured. Thus, the functional surfaces of the micro devices (10A, 20B, 20C) are sealed.
Here, in the present embodiment, a plurality (for example, three) of micro devices (20A, 20B, 20C) are mounted on the module substrate 10, but the resin-impregnated sheet 30 has a plurality of micro devices (20A, 20B, 20C) are collectively sealed.

  The resin-impregnated sheet 30 is obtained by impregnating fibers such as carbon fiber or glass fiber or fibers aligned in one direction with various resins such as epoxy resin, for example, maintaining its own shape. However, it is not completely cured, and is a film obtained by sealing a prepreg molded into a sheet shape in a reactive state (so-called B state) and then curing it. It is.

Further, in the region R2 outside the micro device mount region, an opening H that exposes the second electrode is formed in the resin-impregnated sheet 30, and the opening H in the region R2 outside the micro device mount region is formed. On the upper side, a frame-like substrate 40 is mounted.
For example, the frame-shaped substrate 40 has electrodes (41, 42) formed on both sides thereof, a through-wiring 43 penetrating the frame-shaped substrate 40 is formed so as to connect both electrodes (41, 42), and one electrode 42 is further formed. A solder resist 44 is formed on the surface on the side.
The electrode 41 of the frame-shaped substrate 40 having the above configuration is connected to the second electrode 12 of the module substrate 10 exposed from the opening H by the solder layer 45.

  In addition to the configuration in which the wiring of the frame-like substrate 40 is formed on the second electrode 12 and connected to the second electrode 12 as described above, the second electrode 12 is mounted with electronic components. You can also. Moreover, it can also be set as the structure by which wiring is formed and electronic components are mounted.

  Further, a back electrode 13 or the like is formed on the back surface of the surface of the module substrate on which the micro device is mounted, and the second electrode 12 and the back electrode 13 and the like are connected by a through wiring 14 penetrating the module substrate 10. . A solder resist 15 is formed except for the region where the back electrode 13 is formed. The back electrode 13 has a thickness of, for example, 30 μm.

Also, other electronic components (50, 51) may be mounted on the back surface of the surface of the module substrate 10 on which the micro devices (20A, 20B, 20C) are mounted.
For example, the lead 50a of the electronic component 50 packaged with a lead frame may be connected to the back electrode 13, or the terminal 51a of the electronic component 51 may be directly connected to the back electrode 13.

The hollow portion V sealed with the resin impregnated sheet 30 is maintained in, for example, a vacuum, a reduced pressure, a reducing atmosphere, or an inert gas atmosphere.
In general, microdevices such as SAW elements, MEMS, and F-BARs are not configured to be covered with a thick protective film or the like. Therefore, in order to increase the durability and reliability of the elements, the above-mentioned atmosphere is used. It is preferable to hold.

  In the present embodiment, the first electrode, the second electrode, and the back electrode are referred to as electrodes. However, the structure is a wiring itself, or a part of the wiring is a land for mounting an element or the like. Including the configuration.

  The micro device module according to the present embodiment having the above-described configuration can be used by being mounted on another mounting substrate or the like from the electrode 42 side formed on the frame substrate 40.

  The micro device module of the above-described embodiment is a micro device module in which a micro device having a vibrator or a movable part such as a MEMS, F-BAR, or SAW element is incorporated into a functional surface, and is modularized. An opening that exposes the second electrode is formed in the resin-impregnated sheet that seals the micro device mounted on the module substrate, and the high-density mounting is achieved by reducing the bonding area between the resin sheet that seals the micro device and the substrate. Can be realized.

Next, a manufacturing method of the micro device module according to the present embodiment will be described.
In the manufacturing method according to the present embodiment, a plurality of micro device modules are manufactured by being integrated, and finally manufactured by singulation.

First, as shown in the cross-sectional view of FIG. 3A, for example, a module substrate 10 in which a plurality of module substrates for micro device modules are integrated is prepared.
On one surface of the module substrate 10, the first electrode 11 is formed in the micro device mount region R1, and the second electrode 12 is formed in the region R2 outside the micro device mount region.
Further, a back electrode 13 is formed on the back surface of the surface of the module substrate having the micro device mount region R1, and the second electrode 12 and the back electrode 13 are connected by a through wiring 14 penetrating the module substrate 10. . A solder resist 15 is formed except for the region where the back electrode 13 is formed. The formation surface of the microdevice should not form a solder resist.

Next, a plurality (for example, three) of micro devices (20A, 20B, 20C) having functional elements having movable parts or vibrators formed on the functional surface are mounted on the micro device mounting region R1 of the module substrate 10. Here, the flux is cleaned as necessary.
Here, the microdevices (20A, 20B, 20C) are mounted such that the bumps are connected to the first electrode 11 and the functional surfaces are not in contact with the module substrate 10. When the bump of the micro device is a solder bump, it may be mounted by reflow or the like, or may be a mount by ultrasonic bonding using a stud bump such as gold or a mount by thermocompression bonding.

  As a result of mounting as described above, the state shown in the cross-sectional view of FIG. 3B and the perspective view of FIG. 4 is obtained.

Next, as shown in the cross-sectional view of FIG. 5A, as the resin-impregnated sheet 30, for example, fibers such as carbon fiber and glass fiber or fibers aligned in one direction are impregnated with various resins such as epoxy resin. Prepare a so-called prepreg that is shaped to maintain its own shape but not fully cured, and is formed into a sheet in a reactive state (so-called B state). The prepreg (resin impregnated sheet 30) is pressed through the silicon resin sheet 31 having a thickness of 0.5 to 5 mm, for example, using the mold 32 in which the concave portion corresponding to the micro device mount region is formed. By using the silicon resin sheet 31, release of the resin-impregnated sheet 30 is improved and molding can be performed efficiently.
As the prepreg, for example, MCL-E-679FG (trade name) manufactured by Hitachi Chemical Co., Ltd. can be used. In this case, the treatment is performed at 1 to 100 mmHg, 100 to 150 ° C., 10 to 100 kg weight / 10 cm □, and 30 minutes to 2 hours.
Note that a prepreg having glass fibers is strong and has a characteristic that it is not easily torn even when a corner of a microdevice hits.

As a result, as shown in the cross-sectional view of FIG. 5B, the prepreg (resin impregnated sheet 30) covers the surface excluding the functional surface of the microdevice (20A, 20B, 20C) and the module substrate 10 to obtain the functional surface. Can be sealed to form the hollow portion V.
The prepreg (resin impregnated sheet 30) can be cured by heating to a predetermined temperature or higher while pressing the mold as described above. Alternatively, after the mold is released, it can be cured by applying heat.

  Here, in the present embodiment, a plurality of (for example, three) micro devices (20A, 20B, 20C) are mounted on the module substrate 10 per module. Devices (20A, 20B, 20C) can be sealed together. This can be realized because the resin component of the resin-impregnated sheet has a high viscosity and can be prevented from flowing out from the gaps between the plurality of microdevices to the inside of the hollow portion.

When the mold is released, the state shown in the sectional view of FIG. 6A and the perspective view of FIG.
Next, as shown in the cross-sectional view of FIG. 6B and the perspective view of FIG. 7B, an opening H that exposes the second electrode 12 is formed in the resin-impregnated sheet 30.
Here, for example, CO ₂ laser light is irradiated to form the opening H having a diameter of 250 μm. For example, a prepreg having a thickness of about 0.1 mm can easily form an opening that penetrates with CO ₂ laser light. Since the lower electrode of the prepreg is a metal layer and has a high reflectance, the laser beam is reflected so that the opening stops on the electrode surface. Since the CO ₂ laser beam has a high output, it is suitable for forming a wide opening.
Thereafter, if necessary, a cleaning process called desmearing is performed to clean the inside of the opening.

Next, as shown in the perspective view of FIG. 8 , the frame-shaped substrate 40 is mounted above the opening H in the region R <b> 2 outside the micro device mounting region. The frame-shaped substrate 40 is also a frame-shaped substrate 40 formed by integrating a plurality of frame-shaped substrates for micro device modules, and a through portion corresponding to a convex portion that is mounted with a micro device and covered with a resin-impregnated sheet The shape is such that T is formed.
The frame-like substrate 40 is mounted by fitting the through portion T to a convex portion formed by mounting a micro device and covering with a resin-impregnated sheet.

As a result of mounting the frame-shaped substrate, the state shown in the cross-sectional view of FIG.
For example, the frame-shaped substrate 40 has electrodes (41, 42) formed on both sides thereof, a through-wiring 43 penetrating the frame-shaped substrate 40 is formed so as to connect both electrodes (41, 42), and one electrode 42 is further formed. The solder resist 44 is formed on the surface on the side, and the electrode 41 of the frame-shaped substrate 40 having the above-described configuration is applied to the second electrode 12 of the module substrate 10 exposed from the opening H by the solder layer 45. Connecting. Also for the frame-like substrate, a solder resist is formed only on one surface, and the penetrating portion T is formed by punching or the like.

The frame-shaped substrate 40 has a thickness of 0.2 mm, for example, is aligned and mounted using a previously formed alignment mark or the like, and is connected by a reflow process or the like with a solder layer 45 having a thickness of 50 to 100 μm, for example.
Further, the gap between the convex part mounted with the microdevice and covered with the resin-impregnated sheet and the inner wall of the penetrating part of the frame-like substrate 40 is, for example, about 0.1 to 0.3 mm. In this embodiment, since a micro device is mounted and a frame-like substrate or the like can be mounted with a narrow gap of about 0.1 to 0.3 mm with respect to a convex portion formed by coating with a resin-impregnated sheet, Can be improved.

  Next, as shown in FIG. 9B, the lead 50a of the electronic component 50 packaged with the lead frame is provided on the back surface of the module substrate 10 on which the micro devices (20A, 20B, 20C) are mounted. The electronic component (50, 51) is mounted by connecting to the electrode 13 or connecting the terminal 51a of the electronic component 51 directly to the back electrode 13.

As a result of mounting the frame-shaped substrate and mounting the electronic component on the back surface, the state shown in the perspective view of FIG. 10 is obtained.
As a subsequent step, the micro device module shown in FIGS. 1A and 1B can be manufactured by cutting into individual micro device modules by individualization (dicing) processing.

  As described above, the wiring of the frame-like substrate 40 is formed on the upper layer of the second electrode 12 so as to be connected to the second electrode 12, and an electronic component may be mounted on the second electrode 12. Also, wiring can be formed and electronic components can be mounted.

  Further, the step of covering the hollow portion V sealed with the resin impregnated sheet 30 with the resin impregnated sheet so as to be maintained in, for example, vacuum, reduced pressure, reducing atmosphere, or inert gas atmosphere, The reaction can be performed under reduced pressure, a reducing atmosphere, or an inert gas atmosphere.

  According to the manufacturing method of the micro device module of the present embodiment described above, a micro device in which a micro device having a vibrator or a movable portion such as a MEMS, F-BAR, or SAW element is incorporated into a functional surface is modularized. A method for manufacturing a module, in which a microdevice mounted on a module substrate is sealed with a resin-impregnated sheet, and an opening for exposing the second electrode is formed in the resin-impregnated sheet, and further wiring is provided on the second electrode. And electronic components can be mounted, and the high-density mounting can be realized by reducing the bonding area between the resin sheet for sealing the microdevice and the substrate.

Moreover, as a resin-impregnated sheet for hollow sealing, the prepreg can easily form an opening. Further, since the material cost of the prepreg is very low, the cost can be greatly reduced as compared with the conventional technology.
Moreover, as a resin-impregnated sheet for hollow sealing, for example, a prepreg made of glass fabric impregnated with an epoxy resin has less resin flow during heating and pressurization, and the resin flows into the functional surface side of the microdevice in the sealing process. Therefore, high yields can be realized.

The present invention is not limited to the above embodiment.
For example, in addition to the SAW element, a module incorporating a micro device having a functional element such as MEMS or F-BAR may be used.
In the area outside the micro device mounting area, various components such as a frame-like base and electronic components can be mounted.
In addition, various modifications can be made without departing from the scope of the present invention.

The micro device module of the present invention can be applied to a module in which a micro device having a movable portion or a vibrator on a functional surface such as a SAW element, MEMS, or F-BAR is packaged.
The manufacturing method of the micro device module of the present invention can be applied to a method of manufacturing a module in which a micro device having a movable part or a vibrator on a functional surface such as a SAW element, MEMS, or F-BAR is packaged.

FIG. 1A is a perspective view of a micro device module according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view. FIG. 2 is a cross-sectional view of a micro device modularized by the micro device module of FIG. 3 (a) and 3 (b) are cross-sectional views illustrating manufacturing steps of a method for manufacturing a microdevice module according to an embodiment of the present invention. FIG. 4 is a perspective view showing a manufacturing process of the manufacturing method of the micro device module according to the embodiment of the present invention. 5 (a) and 5 (b) are cross-sectional views showing the manufacturing process of the manufacturing method of the micro device module according to the embodiment of the present invention. 6 (a) and 6 (b) are cross-sectional views illustrating manufacturing steps of a method for manufacturing a microdevice module according to an embodiment of the present invention. FIGS. 7A and 7B are perspective views showing the manufacturing process of the manufacturing method of the micro device module according to the embodiment of the present invention. FIG. 8 is a perspective view showing a manufacturing process of the manufacturing method of the micro device module according to the embodiment of the present invention. FIGS. 9A and 9B are cross-sectional views illustrating manufacturing steps of a method for manufacturing a microdevice module according to an embodiment of the present invention. FIG. 10 is a perspective view showing a manufacturing process of the manufacturing method of the micro device module according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Module board | substrate, 11 ... 1st electrode, 12 ... 2nd electrode, 13 ... Back electrode, 14 ... Through wiring, 15 ... Solder resist, 20, 20A, 20B, 20C ... Micro device, 21 ... Comb type electrode, 22 ... Pad electrode, 23 ... Bump, 30 ... Resin impregnated sheet, 31 ... Silicone resin sheet, 32 ... Mold, 40 ... Frame substrate, 41,42 ... Electrode, 43 ... Penetration wiring, 44 ... Solder resist, 45 ... Solder 50 ... electronic component, 50a ... lead, 51 ... electronic component, 51a ... terminal, H ... opening, R1 ... micro device mounting region, R2 ... region outside the micro device mounting region, T ... penetrating portion, V ... Hollow part

Claims (8)

A module board;
A first electrode formed in a micro device mounting region of the module substrate;
A second electrode formed outside the micro device mounting region of the module substrate;
A functional element having a movable portion or a vibrator formed on a functional surface; and a bump formed on the functional surface, wherein the bump is connected to the first electrode, and the functional surface is in contact with the module substrate. A micro device mounted in the micro device mounting region of the module substrate so as not to
An opening for exposing the second electrode is formed, covering the surface excluding the functional surface of the microdevice and the module substrate so that the functional surface is sealed to form a hollow portion. We have, have a resin-impregnated sheet comprising a resin impregnated in the fiber,
A micro device module in which at least a wiring is formed on an upper layer of the second electrode and connected to the second electrode, or an electronic component is mounted . A plurality of the micro devices are mounted on the module substrate,
The micro device module according to claim 1, wherein the resin-impregnated sheet is formed so as to collectively seal the plurality of micro devices. Micro device module according to claim 1 or 2 other electronic components on the back surface of the micro device of the module substrate is mounted is mounted It said hollow portion, vacuum, reduced pressure, a reducing atmosphere or microdevice module according to claim 1 which is held in an inert gas atmosphere. A function in which a movable part or a vibrator is formed on the functional surface in the micro device mount region of the module substrate in which the first electrode is formed in the micro device mount region and the second electrode is formed outside the micro device mount region. Mounting a microdevice having an element and a bump formed on the functional surface such that the bump is connected to the first electrode and the functional surface is not in contact with the module substrate;
A step of covering the surface excluding the functional surface of the microdevice and the module substrate with a resin-impregnated sheet obtained by impregnating a fiber with resin, and sealing the functional surface to form a hollow portion;
Forming an opening exposing the second electrode in the resin-impregnated sheet ;
After the step of forming the opening , a micro device module having at least a step of forming a wiring or a step of mounting an electronic component connected to the second electrode above the second electrode Method. In the step of mounting the micro device on the module substrate, mounting a plurality of micro devices on the module substrate,
The method for manufacturing a microdevice module according to claim 5 , wherein in the step of coating with the resin-impregnated sheet, the plurality of microdevices are covered with the resin-impregnated sheet so as to be collectively sealed. The method for manufacturing a micro device module according to claim 5 , further comprising a step of mounting another electronic component on a back surface of the surface of the module substrate on which the micro device is mounted. The step of coating with the resin-impregnated sheet so that the hollow portion is maintained in a vacuum, reduced pressure, reducing atmosphere, or inert gas atmosphere is performed in a vacuum, reduced pressure, reducing atmosphere, or inert gas atmosphere. Item 8. A method for producing a microdevice module according to any one of Items 5 to 7 .

Images