KR20070040291A - Mems module package - Google Patents

Abstract

The present invention relates to a MEMS package, and more particularly, to the structure of a MEMS package. According to an aspect of the invention, the lower substrate; An optical modulator positioned on the lower substrate and transmitting an optical signal through the lower substrate; A driver IC mounted around the light modulator to drive the light modulator; Circuit wiring formed on the lower substrate to transmit a signal for driving the optical modulator; And a printed circuit board positioned on the optical modulator and the driver IC to face the lower substrate and serving as a signal connection function with an external circuit. MEMS module package according to the present invention has an effect that can reduce the overall size by changing the interlayer configuration.

MEMS, optical modulators, printed circuit boards, caps, driver ICs.

Description

MEMS module package {MEMS MODULE PACKAGE}

1 is an exploded perspective view of an optical modulator module package according to the prior art.

2A is a perspective view of one type of diffractive light modulator module using a piezoelectric body applicable to a preferred embodiment of the present invention.

2B is a perspective view of another type of diffractive light modulator module using a piezoelectric body applicable to a preferred embodiment of the present invention.

2C is a plan view of a diffractive light modulator array applicable to a preferred embodiment of the present invention.

FIG. 2D is a schematic diagram in which an image is generated on a screen by a diffractive light modulator array applicable to a preferred embodiment of the present invention. FIG.

3 is a perspective view of an optical modulator module package according to a first preferred embodiment of the present invention.

4A is a cross-sectional view of an optical modulator module package according to a first preferred embodiment of the present invention.

4B is a cross-sectional view of an optical modulator module package according to a second preferred embodiment of the present invention.

5 is a cross-sectional view of an optical modulator module package according to a third preferred embodiment of the present invention.

6 is a cross-sectional view of an optical modulator module package according to a fourth preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

310: lower substrate

320 (1), 320 (2): Driver IC

330: light modulator

340: sealing cap

350: printed circuit board

360: Bonding Wire

370: Flexible PCB

The present invention relates to a MEMS package, and more particularly, to the structure of a MEMS package.

An optical modulator is a circuit or device that transmits a signal to light (optical modulation) in a transmitter when the optical medium or free space of an optical frequency band is used as a transmission medium. Optical modulators are used in the fields of optical memory, optical display, printer, optical interconnection, hologram, etc., and researches on the development of display devices using the same are being actively conducted. Such an optical modulator is related to MEMS technology, and MEMS (Micro Electro Mechanical System) is a technology for forming a three-dimensional structure on a silicon substrate using a semiconductor manufacturing technology. The fields of application of MEMS are very diverse, and examples thereof include various sensors for vehicles, inkjet printer heads, HDD magnetic heads, and portable communication devices that are rapidly progressing in miniaturization and high functionality. The MEMS element has a portion floating from the substrate to enable fine driving on the substrate for mechanical operation. MEMS can be called a micro electromechanical system or device, which is one of the applications in the field of optics. Micromachining technology enables the fabrication of optical components smaller than 1mm, enabling ultra-compact optical systems. Separately manufactured semiconductor lasers can be mounted on a stand made by micromachining technology, and micro Fresnel lenses, beam splitters, and 45 ㅀ reflector mirrors can be fabricated by micromachining technology. Existing optical system constructs the system using assembling mechanism on mirror and lens on large and heavy optical bench. In addition, the size of the laser is also large. In order to obtain the performance of the optical system configured as described above, there is a problem in that the optical axis, the reflection angle, and the reflection surface must be aligned with a considerable amount of effort using a precise stage.

Currently, micro optical systems have been applied to information and communication devices, information displays, and recording devices due to advantages such as fast response speed, small loss, and ease of integration and digitization. For example, micro-optical components such as micromirrors, microlenses, optical fiber holders, and the like can be applied to information storage and recording devices, large image display devices, optical communication devices, and adaptive optics.

Here, the micro-mirror is applied in various ways depending on the direction and dynamic and static motion of the vertical direction, rotation direction, sliding direction and the like. Up and down motion is applied to phase compensator or diffractometer, and tilting motion is scanner, switch, optical signal divider, optical signal attenuator, light source array, etc., and sliding direction is light shield or switch optical signal. It is applied as a dispenser.

Micromirrors vary in size and number depending on the application, and the application varies depending on the direction of motion and dynamic or static operation. Of course, the manufacturing method of the micro mirror accordingly is also different.

1 is an exploded perspective view of an optical modulator module package according to the prior art. Referring to FIG. 1, the optical modulator module package 100 includes a printed circuit board 110, a light transmissive substrate 120, a light modulator 130, driver integrated circuits (ICs) 140a to 140d, and heat radiating plates 150. ) And connector 160.

The printed circuit board 110 is a printed circuit board for a semiconductor package which is generally used, and the lower surface of the light transmissive substrate 120 is attached on the printed circuit board 110. The light modulator 130 is attached to the upper surface of the light transmissive substrate 120 to correspond to the hole formed in the printed circuit board 110.

The light modulator 130 emits diffracted light by modulating incident light incident through the hole of the substrate 110. The light modulator 130 is flip chip connected to the light transmissive substrate 120. An adhesive is formed around the light modulator 130 to provide sealing from the external environment and to maintain electrical connection by electrical wiring formed along the surface of the light transmissive substrate 120.

The driver ICs 140a to 140d are flip-chip connected to the periphery of the optical modulator 130 attached to the light transmissive substrate 120 and provide a driving voltage to the optical modulator 130 according to a control signal input from the outside. Play a role.

The heat dissipation plate 150 is provided to dissipate the heat generated by the optical modulator 130 and the driver ICs 140a to 140d, and a metallic material that emits heat well is used.

The method of manufacturing the optical modulator module package 100 shown in FIG. 1 includes attaching the connector 160 to the printed circuit board 110, the optical modulator 130 and the driver IC 140a to the light transmissive substrate 120. 140d) attaching, applying and sealing an adhesive around the light modulator 130, laminating the light transmissive substrate 120 on the printed circuit board 110 and performing wire bonding, the light modulator 130 And attaching the heat radiating plate 150 to the driver ICs 140a to 140d.

Here, the optical modulator module package 100 shown in FIG. 1 has a large number of components, and since a large number of components must be mounted in a proper space, there is a limit to minimizing the module package. That is, since the light transmissive substrate 120 is positioned on the printed circuit board 110, the substrate 110 is formed larger than the light transmissive substrate 120, and thus, the size of the overall light modulator module package 100 is increased. have.

The present invention provides a MEMS module package that can reduce the overall size by changing the interlayer configuration.

In addition, the present invention provides a MEMS module package in which electrical / optical characteristics are not concentrated in the light transmissive cover by not mounting the light modulator directly on the light transmissive cover.

In addition, the present invention provides a MEMS module package that can reduce the overall size by using a cap, a sealing method of various shapes for protecting the optical modulator.

Technical problems other than the present invention will be easily understood through the following description.

According to an aspect of the invention, the lower substrate; An optical modulator positioned on the lower substrate and modulating an optical signal; A driver IC mounted around the light modulator to drive the light modulator; Circuit wiring formed on the lower substrate to transmit a signal for driving the optical modulator; And a printed circuit board positioned on the optical modulator and the driver IC to face the lower substrate and serving as a signal connection function with an external circuit.

The lower substrate may be transparent to a portion corresponding to the light modulator.

Here, the portion corresponding to the light modulator of the lower substrate may be formed of anti-reflective optical coating glass so that the light transmission loss is small.

In addition, the optical modulator module package according to an embodiment of the present invention may further include a sealing cap located between the printed circuit board and the optical modulator to perform a sealing function of the optical modulator.

The sealing cap may have a groove formed therein so as to accommodate the optical modulator element and the driver IC, and may be sealed with the lower substrate.

Here, the sealing cap may accommodate only the optical modulator element or together with the driver IC.

The lower substrate may be any one of a light transmissive substrate such as a glass substrate, a semiconductor substrate such as silicon, an LTCC, an HTCC, and a multilayer printed circuit board.

In addition, in the optical modulator module package according to an embodiment of the present invention, the lower substrate has a hole in which the optical signal is transmitted in a portion corresponding to the optical modulator, and seals the hole and allows light transmission. It may further include a transparent cover.

The electrical connection between the lower substrate and the printed circuit board may be made by any one of wire bonding or TAB.

Here, when the electrical connection between the lower substrate and the printed circuit board is made of wire bonding, the bonding wire may be protected by an epoxy resin.

Here, the printed circuit board may include a flexible substrate integrally.

Here, the printed circuit board may include a connector for connection with an external circuit.

The optical modulator and driver IC may be mounted on the lower substrate by one adhesive.

The adhesive may be an anisotropic conductive film (ACF) or a non-conductive film (NCF).

Here, the light modulator may be side sealed by an epoxy resin.

In addition, the optical modulator module package according to an embodiment of the present invention may further include a sealing dam for protecting the driving region of the optical modulator formed in the region where the optical modulator is connected to the lower substrate.

According to another aspect of the invention, the lower substrate; Located on the lower substrate, a micro electro mechanical system (MEMS) device for transmitting a signal to or receive a signal from the outside; A driver IC mounted around the MEMS device to drive the MEMS device; And a printed circuit board positioned on the MEMS device and the driver IC to face the lower substrate and having a signal connection function with an external circuit.

In addition, the MEMS package according to an embodiment of the present invention may further include a sealing cap positioned between the printed circuit board and the MEMS device to perform a sealing function of the MEMS device.

The sealing cap may have a groove formed therein to accommodate the MEMS element and the driver IC, and may be sealed with the lower substrate.

The sealing cap may accommodate only the MEMS device or the driver IC together.

The lower substrate may be any one of a light transmissive substrate such as a glass substrate, a semiconductor substrate such as silicon, an LTCC, an HTCC, and a multilayer printed circuit board.

The electrical connection between the lower substrate and the printed circuit board may be made by any one of wire bonding or TAB.

Here, when the electrical connection between the lower substrate and the printed circuit board is made of wire bonding, the bonding wire may be protected by an epoxy resin.

Here, the printed circuit board may include a flexible substrate integrally.

Here, the printed circuit board may include a connector for connection with an external circuit.

Here, the MEMS device and the driver IC may be mounted on the lower substrate by one adhesive.

Here, the MEMS device may be side sealed by an epoxy resin.

In addition, the MEMS package according to an embodiment of the present invention may further include a sealing dam for protecting the driving region of the MEMS device formed in a region where the MEMS device is connected to the lower substrate.

Hereinafter, preferred embodiments of the MEMS module package according to the present invention will be described in detail with reference to the accompanying drawings, and in the following description with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals. Duplicate explanations will be omitted. In addition, an embodiment of the present invention may be generally applied to a MEMS package for transmitting a signal to or receiving a signal from the outside, and among the MEMS packages applied to the present invention before describing preferred embodiments of the present invention in detail. The optical modulator will be described first.

Optical modulators are largely divided into a direct method of directly controlling the on / off of light and an indirect method using reflection and diffraction, and the indirect method may be divided into an electrostatic method and a piezoelectric method. Herein, the optical modulator is applicable to the present invention regardless of the manner in which the optical modulator is driven.

The electrostatically driven grating light modulator disclosed in US Pat. No. 5,311,360 includes a plurality of regularly spaced deformable reflective ribbons having reflective surface portions and suspended above the substrate.

First, an insulating layer is deposited on a silicon substrate, followed by a deposition process of a sacrificial silicon dioxide film and a silicon nitride film. The silicon nitride film is patterned with a ribbon and a portion of the silicon dioxide layer is etched so that the ribbon is held on the oxide spacer layer by the nitride frame. To modulate light with a single wavelength [lambda] 0, the modulator is designed such that the thickness of the ribbon and the thickness of the oxide spacers are [lambda] 0/4.

The lattice amplitude of this modulator, defined by the vertical distance d between the reflective surface on the ribbon and the reflective surface of the substrate, is determined by the ribbon (reflective surface of the ribbon serving as the first electrode) and the substrate (substrate serving as the second electrode). By applying a voltage between the conductive films).

Figure 2a is a perspective view of one type of diffractive light modulator module using a piezoelectric of the indirect light modulator applicable to the present invention, Figure 2b is another type of diffractive light modulator module using a piezoelectric applicable to a preferred embodiment of the present invention Perspective view. 2A and 2B, an optical modulator including a substrate 210, an insulating layer 220, a sacrificial layer 230, a ribbon structure 240, and a piezoelectric material 250 is shown.

The substrate 210 is a commonly used semiconductor substrate, and the insulating layer 220 is deposited as an etch stop layer, and an etchant for etching a material used as a sacrificial layer, where the etchant is an etching gas or an etching solution. Solution). The reflective layers 220 (a) and 220 (b) may be formed on the insulating layer 220 to reflect incident light.

The sacrificial layer 230 supports the ribbon structure 240 at both sides so as to be spaced apart from the insulating layer 220 at regular intervals, and forms a space at the center.

As described above, the ribbon structure 240 causes diffraction and interference of incident light to optically modulate the signal. The shape of the ribbon structure 240 may be configured in the form of a plurality of ribbons according to the electrostatic method as described above, or may be provided with a plurality of open holes in the center of the ribbon according to the piezoelectric method. In addition, the piezoelectric member 250 controls the ribbon structure 240 to move up and down in accordance with the degree of contraction or expansion of up and down or left and right caused by the voltage difference between the upper and lower electrodes. Here, the reflective layers 220 (a) and 220 (b) are formed to correspond to the holes 240 (b) and 240 (d) formed in the ribbon structure 240.

For example, when the wavelength of light is λ, no voltage is applied or a predetermined voltage is applied to the upper reflective layers 240 (a) and 240 (c) and the lower reflective layer 220 (a) formed on the ribbon structure. )) Is formed, the interval between the insulating layer 220 is equal to nλ / 2 (n is a natural number). Therefore, in the case of the zero-order diffracted light (reflected light), the total path difference between the light reflected from the upper reflective layers 240 (a) and 240 (c) formed on the ribbon structure and the light reflected from the insulating layer 220 is equal to nλ, which is reinforced. By interfering, the diffracted light has maximum brightness. Here, in the case of + 1st and -1st diffraction light, the brightness of light has a minimum value due to destructive interference.

In addition, when an appropriate voltage different from the applied voltage is applied to the piezoelectric member 250, the upper reflective layers 240 (a) and 240 (c) and the lower reflective layers 220 (a) and 220 (b) formed on the ribbon structure. The gap between the insulating layers 220 on which? Is formed is equal to (2n + 1) λ / 4 (n is a natural number). Therefore, in the case of zero-order diffracted light (reflected light), the total path difference between the upper reflective layers 240 (a) and 240 (c) formed on the ribbon structure and the light reflected from the insulating layer 220 is (2n + 1) λ / 2. As shown in FIG. 8, the diffracted light has minimum luminance due to destructive interference. Here, in the case of + 1st and -1st diffraction light, the brightness of light has a maximum value due to constructive interference. As a result of this interference, the light modulator can adjust the amount of reflected or diffracted light to carry the signal on the light.

In the above, the case in which the distance between the ribbon structure 240 and the insulating layer 220 on which the lower reflective layers 220 (a) and 220 (b) are formed is nλ / 2 or (2n + 1) λ / 4 has been described. Naturally, various embodiments that can be driven at intervals that can adjust the intensity interfered by the diffraction and reflection of incident light can be applied to the present invention.

Hereinafter, the optical modulator of the type shown in FIG. 2A will be described.

Referring to FIG. 2C, the optical modulator includes a first pixel (pixel # 1), a second pixel (pixel # 2),. And m micromirrors 100-1, 100-2,..., 100-m that are responsible for the m-th pixel (pixel #m). The optical modulator is responsible for the image information of the one-dimensional image of the vertical scanning line or the horizontal scanning line (assuming that the vertical scanning line or the horizontal scanning line is composed of m pixels), and each micromirror 100-1, 100-2. , ..., 100-m) is in charge of any one of m pixels constituting the vertical scan line or the horizontal scan line. Thus, the reflected and diffracted light in each micro mirror is then projected on the screen as a two dimensional image by the light scanning device. For example, in the case of VGA 640 * 480 resolution, 640 modulations are performed on one side of an optical scanning device (not shown) for 480 vertical pixels, thereby generating one frame of one screen per side of the optical scanning device. The optical scanning device may be a polygon mirror, a rotating bar, a galvano mirror, or the like.

Hereinafter, the principle of light modulation will be described based on the first pixel (pixel # 1), but the same may be applied to other pixels.

In the present embodiment, it is assumed that there are two holes 240 (b) -1 formed in the ribbon structure 240. Due to the two holes 240 (b)-1, three upper reflective layers 240 (a)-1 are formed on the ribbon structure 240. Two lower reflective layers are formed in the insulating layer 220 corresponding to the two holes 240 (b)-1. In addition, another lower reflective layer is formed on the insulating layer 220 corresponding to the portion of the gap between the first pixel (pixel # 1) and the second pixel (pixel # 2). Accordingly, the number of upper reflective layers 240 (a) -1 and lower reflective layers per pixel is the same, and the luminance of modulated light is obtained by using zero-order diffracted light or first-order diffracted light as described above with reference to FIG. 2A. It is possible to adjust.

Referring to FIG. 2D, there is shown a schematic diagram in which an image is generated on a screen by a diffractive light modulator array applicable to a preferred embodiment of the present invention.

Light reflected and diffracted by the m micromirrors 100-1, 100-2,..., 100-m arranged vertically is reflected by the optical scanning device, and is generated by scanning the screen 270 horizontally. 280-1, 280-2, 280-3, 280-4, ..., 280- (k-3), 280- (k-2), 280- (k-1), 280-k) are shown. When rotated once in the optical scanning device, one image frame may be projected. Here, the scanning direction is shown in a left to right direction (arrow direction), but it is obvious that the image may be scanned in another direction (for example, the reverse direction).

Embodiments in accordance with the present invention relate to a technique in which a printed circuit board is positioned above an optical modulator, thereby forming an overall small size optical modulator module package. That is, the printed circuit board is located on the upper part of the optical modulator, and the wiring of the printed circuit board to which a signal for driving the optical modulator is input to the driver IC is coupled to the lower substrate by wire bonding or tape automated bonding (TAB). . In the present invention, the lower substrate is applicable to the present invention as long as the substrate can have a fine pitch such as a light transmissive substrate, a semiconductor substrate, LTCC and HTCC. Here, in the case of substrates other than the light transmissive substrate, holes are formed in the center thereof to allow the movement of light, and the holes may be sealed by the light transmissive cover.

The optical modulator has been described above with reference to a perspective view and a plan view, in general, with reference to the accompanying drawings, a MEMS module package according to the present invention will be described with reference to specific embodiments. Embodiments according to the present invention are divided into four categories, which will be described in turn below.

3 is a perspective view of an optical modulator module package protecting a light modulator using a cap according to a first preferred embodiment of the present invention, and FIG. 4A is a light modulator using a cap according to a first preferred embodiment of the present invention. A cross-sectional view of a protecting optical modulator module package. 3 and 4A, the lower substrate 310, the driver IC 320 (1), 320 (2), the adhesive 325 (1), and 325 (2), the optical modulator 330, and the sealing cap 340, printed circuit board 350, bonding wire 360, flexible PCB 370, and bonding wire protection epoxy 380 are shown. 4B is a cross-sectional view of an optical modulator module package for protecting an optical modulator when a predetermined hole is formed in the lower substrate 310 by using a cap according to a second exemplary embodiment of the present invention. Hereinafter, the above-described first and second embodiments will be described in detail.

The lower substrate 310 is formed of a through hole H or a transparent material so that incident light may be incident to the light modulator 330 or diffracted light may be emitted, and a circuit may be formed on at least one of an inner surface and an outer surface. . The lower substrate 310 may be a general semiconductor substrate, and at least a portion thereof may be transparent or holes may be formed to transmit light. Accordingly, the lower substrate 310 transmits a control signal input from an external control circuit (not shown) to the driver ICs 320 (1) and 320 (2). Here, electrical connection with the driver ICs 320 (1) and 320 (2) may be made through flip chip bonding. The lower substrate 310 may further include a metal bump attached to one surface of the lower substrate 310 to mount the optical modulator and the driver IC on the substrate. The metal bumps may be in a flip chip connection with metal pads formed in an optical modulator or driver integrated circuit. The lower substrate 310 may include a low temperature cofired ceramic (LTCC), a high temperature cofired ceramic (HTCC), a light transmissive substrate, a semiconductor substrate, and a printed circuit board (multilayer). Printed circuit boards), or any other suitable structure.

Referring to FIG. 4A, when the lower substrate 310 is a light transmissive substrate, the light transmissive substrate may be antireflective optically coated on both surfaces thereof to allow light transmission. Here, the light transmissive substrate may be a glass substrate.

Referring to FIG. 4B, when the lower substrate 310 is any one of the semiconductor substrate, the LTCC, the HTCC, and the printed circuit board, the lower substrate 310 may not be transparent, and thus the light modulator 330 may be disposed on the lower substrate 310. A hole through which incident light and incident light emitted by the light modulator 330 may pass may be formed in a region corresponding to the light modulator 330. Here, the hole formed in the lower substrate 310 may be sealed by a light transmissive cover (for example, glass) (not shown) capable of transmitting light. The position at which the light transmissive cover seals the hole may be at various positions such as the center portion of the hole, the top / bottom portion, and the like.

The driver ICs 320 (1) and 320 (2) are flip-chip connected to the periphery of the optical modulator 330, and serve to provide a driving voltage to the optical modulator 330 according to a control signal input from the outside. . In addition, the driver ICs 320 (1) and 320 (2) may be increased or decreased as needed in accordance with the size and / or other requirements of the optical modulator 330. That is, referring to FIG. 3, two driver ICs 320 (1) and 320 (2) are illustrated, but the exemplary embodiment is not limited thereto.

The light modulator 330 modulates incident light incident through the through hole formed in the lower substrate 310 or the transparent lower substrate 310 to emit diffracted light. Here, the optical modulator 330 may be flip chip connected to the lower substrate 310. In addition, the optical modulator 330 has a rectangular cross section and is formed to be relatively longer in one direction.

In addition, the optical modulator 330 and the driver IC 320 (1) and 320 (2) may be mounted on the lower substrate 310 by one adhesive. That is, the light modulator 330 and the driver ICs 320 (1) and 320 (2) are divided into areas mounted on the lower substrate 310, and one adhesive is applied to the lower substrate 310 in one process. The optical modulator 330 and the driver ICs 320 (1) and 320 (2) may be mounted on the lower substrate 310. Herein, any suitable adhesive that can electrically and mechanically attach the chip to the substrate can be applied to the present invention regardless of its form. For example, any one of an anisotropic conductive film (ACF), a non-conductive film (NCF), a non-conductive paste (NCP), and an anisotropic conductive paste (ACP) Or an adhesive prepared from a combination thereof may be applied to the present invention.

The sealing cap 340 is positioned between the lower substrate 310 and the printed circuit board 350 to accommodate the optical modulator 330 (which may include driver ICs 320 (1) and 320 (2)). A groove is formed therein, where the sealing cap 340 is sealed by the lower substrate 310 and the adhesive medium, wherein the adhesive medium is epoxy, solder, fritglass, and liquid crystal polymer (LCP). It may be a hermetic mounting material such as a crystal polymer, and in this case, the sealing cap 340 may be sealed to the lower substrate 310. Accordingly, the sealing cap 340 may include the optical modulator 330 and the driver IC 320 ( 1), 320 (2) serves to protect from external moisture, pressure, etc. That is, the sealing cap 340 is located between the printed circuit board 350 and the optical modulator 330 and the optical modulator 330 ) Performs a sealing function.

Here, the material of the sealing cap 340 may be a metal. In addition, as described below, the sealing cap 340 may be omitted so that the printed circuit board 350 may be directly positioned on the optical modulator 330 and the driver ICs 320 (1) and 320 (2). When the sealing cap 340 according to the present invention is not provided, an epoxy side sealing around the optical modulator 330 or a sealing dam is formed inside the optical modulator 330 to thereby form the optical modulator 330 and the driver IC 320 (1). ), 320 (2)) can be protected from external moisture, pressure, and the like.

The material of the sealing cap 340 is a Fe53%, Ni29%, Co17% master alloy in the case of a cobar having a small coefficient of thermal expansion, and in the case of Invar, a Fe63%, Ni36% master alloy material, and the shape of the cross section of the sealing cap 340 Is hat-shaped, and may protect the optical modulator 330 from external moisture. Here, the sealing cap 340 can effectively prevent the penetration of moisture compared to the epoxy resin which is a mounting material according to the prior art, in particular, when the sealing cap 340 is a metal can exhibit an excellent effect in terms of preventing moisture penetration. . Here, the coefficient of thermal expansion of the sealing cap 340 may be similar to that of the bottom glass substrate or light modulator 330 to be bonded. As described above, the material of the sealing cap 340 may be Kovar or Invar. The Kovar or Invar may have the same or similar thermal expansion coefficient as that of the optical modulator 330 because the thermal expansion coefficient is relatively small. Here, the coefficient of thermal expansion of the sealing cap 340 is 5.86ppm / ℃, invar is 1.3ppm / ℃ Koba.

The printed circuit board 350 is positioned on the optical modulator 330 and the driver ICs 320 (1) and 320 (2) to face the lower substrate 310, and the driver ICs 320 (1) and 320 ( 2)), a circuit wiring for transmitting a signal for driving the optical modulator 330 is formed, and is electrically connected to the circuit wiring formed on the lower substrate 310. Here, the printed circuit board 350 may be wire bonded 360 to the lower substrate 310 or bonded using tape (TAB: tape automated bonding). When the printed circuit board 350 is wire bonded 360 to the lower substrate 310, the wire 360 bonding the lower substrate 310 and the printed circuit board 350 to each other is protected by the epoxy resin 380. passivation).

The flexible PCB 370 may be bent to flexibly receive an electrical signal from an external circuit (eg, a mother board). That is, the optical modulator module package may be accommodated using the flexible PCB 370 even in a narrow space. In this case, a connector (not shown) for coupling with an external circuit may be formed at one end of the flexible PCB 370. Here, the printed circuit board 350 may be detachable or integral with the rigid substrate and the flexible substrate (flexible substrate) 370. That is, when the printed circuit board 350 is a rigid substrate, the printed circuit board 350 may be integrally formed with the flexible substrate (flexible substrate) 370 electrically coupled with an external circuit (an external control substrate, where the external control substrate may be a rigid substrate). It may be a removable substrate that can be detached and attached to the flexible substrate (flexible substrate) 370. Bonding wire protection epoxy 380 may be formed to surround the wire 360 used for wire bonding to protect from external humidity, pressure, and the like.

5 is a cross-sectional view of an optical modulator module package in which an optical modulator is side sealed according to a second exemplary embodiment of the present invention. Referring to FIG. 5, a lower substrate 510, driver ICs 520 (1) and 520 (2), adhesives 525 (1) and 525 (2), an optical modulator 530, and an epoxy resin 535 ( 1), 535 (2)), printed circuit board 540, bonding wires 550 (1), 550 (2), and bonding wire protection epoxy 560 is shown. The differences from the first embodiment described above will be mainly described.

The light modulator 530 may be side sealed by epoxy resins 535 (1) and 535 (2). That is, the epoxy modulators 535 (1) and 535 (2) may be coated around the light modulator 530 to protect the light modulator 530. That is, the epoxy resins 535 (1) and 535 (2) generally have excellent mechanical properties of the cured resin, very good dimensional stability, and good machinability, so that the optical modulator 530 may be protected by using the same. Can be. Here, the heights of the optical modulator 530 and the driver ICs 520 (1) and 520 (2) may be substantially the same. Therefore, the printed circuit board 540 may be directly positioned on the optical modulator 530 and the driver ICs 520 (1) and 520 (2).

6 is a cross-sectional view of an optical modulator module package having a dam according to a third exemplary embodiment of the present invention. Referring to FIG. 6, a lower substrate 610, driver ICs 620 (1), 620 (2), adhesives 625 (1), 625 (2), an optical modulator 630, and an optical modulator pad 633. 1, 633 (2), lower substrate bumps 635 (1), 635 (2), sealing dams 637 (1), 637 (2), printed circuit boards 640, bonding wires 650 (1), 650 (2) and epoxy 660 for bonding wire protection are shown. The differences from the first embodiment described above will be mainly described.

Sealing dams 637 (1) and 637 (2) may be formed and sealed around the optical modulator 630. That is, the sealing dams 637 (1) and 637 (2) to protect the fine driving region of the light modulator 630 formed inside the region where the light modulator 630 is connected to the lower substrate 610 by an adhesive or the like. It may be provided. Here, the optical modulator 630 and the lower substrate 610 are electrically coupled to each other by the optical modulator pads 633 (1) and 633 (2) and the lower substrate bumps 635 (1) and 635 (2). .

The sealing dam 637 may be a metal such as eutectic solder or gold (Au). Here, the eutectic solder may be a fluxless solder such as AuSn, a solder having a low melting point in a solder alloy such as InSn or Sn, and the process may be performed at a low temperature when applied to the present invention. There is an advantage to proceed. When metal is used as the sealing dam 637, the signal wires of the optical modulator element 630 may be protected by an insulator, and the sealing dams 637 (1) and 637 (2) may be disposed on the lower substrate 610. An adhesive film may be formed at a portion to be bonded.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, the MEMS module package according to the present invention has an effect of reducing the overall size by changing the interlayer configuration.

In addition, the MEMS module package according to the present invention does not directly mount the light modulator to the light transmissive cover, so that the electrical / optical characteristics are not concentrated on the light transmissive cover.

In addition, the MEMS module package according to the present invention has an effect of reducing the overall size by using a cap, a sealing method of various shapes for protecting the optical modulator.

Although the above has been described with reference to a preferred embodiment of the present invention, those of ordinary skill in the art to the present invention without departing from the spirit and scope of the present invention and equivalents thereof described in the claims below It will be understood that various modifications and changes can be made.

In addition, although the above-described embodiments have been described in connection with an optical modulator package, other types of MEMS components may be packaged together with the above-described embodiment. Such MEMS devices or components may include, for example, rotational sensors or gyroscopic or acceleration sensors used in motor devices or airplanes. Other types of MEMS devices may include inertia sensors or Lorentz (magnetic) for sensors. In these additional types of MEMS components the substrate must be transparent or have holes formed to allow light transmission. In addition, in the case of the MEMS device, side sealing, chip sealing, etc. may be possible for hermetic mounting. In addition, adhesives such as ACF can be shared between MEMS devices and related devices for fine-pitch interconnection. Except for this, the embodiments according to the invention described above can be used with these additional MEMS components or other MEMS components.

Claims (30)

Lower substrate; An optical modulator positioned on the lower substrate and transmitting an optical signal through the lower substrate; A driver IC mounted around the light modulator to drive the light modulator; Circuit wiring formed on the lower substrate to transmit a signal for driving the optical modulator; And And a printed circuit board positioned on the optical modulator and the driver IC to face the lower substrate, the printed circuit board serving as a signal connection with an external circuit. The method of claim 1, The lower substrate is a light modulator module package, characterized in that the portion corresponding to the light modulator is transparent to allow light transmission. The method of claim 2, And a portion corresponding to the light modulator of the lower substrate is formed of an anti-reflective optical coating glass to enable light transmission. The method of claim 1, And a sealing cap positioned between the printed circuit board and the optical modulator to perform a sealing function of the optical modulator. The method of claim 4, wherein The sealing cap has a groove formed therein to accommodate the optical modulator element and the driver IC, the optical modulator module package, characterized in that sealed with the lower substrate. The method of claim 4, wherein And the sealing cap accommodates the optical modulator element and the driver IC. The method of claim 4, wherein And the sealing cap receives the light modulator element. The method of claim 1, The lower substrate is an optical modulator module package, characterized in that any one of a semiconductor substrate, LTCC, HTCC and multilayer printed circuit board. The method of claim 8, The lower substrate is a light modulator module package, the hole corresponding to the optical signal is formed in a portion corresponding to the light modulator, the optical modulator module package, characterized in that it further comprises a light transmissive cover for sealing the hole and capable of transmitting light. The method of claim 1, And the electrical connection between the lower substrate and the printed circuit board is made by any one of wire bonding or TAB. The method of claim 10, And the bonding wire is protected by an epoxy resin when the electrical connection between the lower substrate and the printed circuit board is made of wire bonding. The method of claim 1, The printed circuit board is an optical modulator module package, characterized in that it comprises a flexible substrate integrally. The method of claim 1, The printed circuit board is an optical modulator module package, characterized in that it comprises a connector for connection with an external circuit. The method of claim 1, And said optical modulator and driver IC are mounted on said lower substrate by a single adhesive. The method of claim 14, The adhesive is an optical modulator module package, characterized in that an anisotropic conductive film (ACF) or non-conductive film (NCF). The method of claim 1, And wherein the light modulator is side sealed by an epoxy resin. The method of claim 1, And a sealing dam for protecting the driving region of the optical modulator formed in the region where the optical modulator is connected to the lower substrate. Lower substrate; Located on the lower substrate, a micro electro mechanical system (MEMS) device for transmitting a signal to or receive a signal from the outside; A driver IC mounted around the MEMS device to drive the MEMS device; And And a printed circuit board positioned on the MEMS device and the driver IC to face the lower substrate, and having a function of connecting a signal to an external circuit. The method of claim 18, The MEMS package further comprises a sealing cap positioned between the printed circuit board and the MEMS device to perform a sealing function of the MEMS device. The method of claim 19, The sealing cap has a groove formed therein to accommodate the MEMS element and the driver IC, characterized in that the MEMS package is sealed with any one of the lower substrate and epoxy, solder, fritted glass and LCP. The method of claim 19, The sealing cap is a MEMS package, characterized in that for receiving the MEMS device and the driver IC. The method of claim 19, The sealing cap is a MEMS package, characterized in that for receiving the MEMS element. The method of claim 18, The lower substrate is a MEMS package, characterized in that any one of a semiconductor substrate, LTCC, HTCC and a multilayer printed circuit board. The method of claim 18, MEMS package, characterized in that the electrical connection between the lower substrate and the printed circuit board is made by any one of wire bonding or TAB. The method of claim 24, And a bonding wire is protected by an epoxy resin when the electrical connection between the lower substrate and the printed circuit board is made of wire bonding. The method of claim 18, The printed circuit board MEMS package, characterized in that it comprises a flexible substrate in one piece. The method of claim 18, The printed circuit board MEMS package, characterized in that it comprises a connector for connection with an external circuit. The method of claim 18, The MEMS device and the driver IC is mounted on the lower substrate by a single adhesive. The method of claim 18, The MEMS device is characterized in that the side sealing by epoxy resin package. The method of claim 18, The MEMS package further comprises a sealing dam for protecting the driving region of the MEMS device formed in the region where the MEMS device is connected to the lower substrate.

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