KR20070026002A - Optical modulator module package - Google Patents

Abstract

An optical modulator module package is provided to embed a light transmissive cover separated from an optical modulator device by a predetermined gap, in a substrate and to prevent electric/optical characteristics from being concentrated on the light transmissive cover as the optical modulator device is not directly installed on the cover. An optical modulator module package is composed of a substrate(210) having a through-hole receiving and emitting the light and a circuit formed on at least one of the inner and outer sides; a light transmissive cover(250) contained in the through-hole to pass the light incident to an optical modulator device(230) and the diffracted light emitted from an optical modulator; and a metal connecting part attached on one surface of the substrate to install the optical modulator device and driver ICs(Integrated Circuit,220,240) on the substrate.

Description

Optical modulator 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.

2E is a cross-sectional view of an optical modulator module package according to a first preferred embodiment of the present invention.

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

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

Figure 5 is a comparison of the optical modulator module package according to a preferred embodiment of the present invention and the optical modulator module package according to the prior art.

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

210: substrate

220, 240: driver integrated circuit

230: light modulator element

250: light transmissive cover

FIELD OF THE INVENTION The present invention relates to light modulators and, more particularly, to light modulator module packages.

An optical modulator is a circuit or an apparatus that mounts a signal on light (optical modulation) in a transmitter when a free space of an optical fiber or 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 an injured portion on the substrate so as to be mechanically operated. 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 adopted and applied to information 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.

The size of a micromirror is about 10-1000 micrometers, and about 1-106 pieces of mirrors are produced and applied. A large image display device is small, as small as 10 to 50 µm, but requires about one million mirrors because the number of mirrors is required by the number of pixels. However, in the case of adaptive optics or optical signal splitters, the size of the mirror is somewhat larger, about a few hundred micrometers, but the number is reduced, requiring several hundreds. In the case of scanners or optical pickups, the mirrors can be as large as a few millimeters and one application is sufficient. In this way, the size and number are very different depending on the application, and the application varies depending on the motion direction and the dynamic or static motion. Of course, the manufacturing method of the micro mirror accordingly is also different. The mirror of a large image display apparatus is about tens of micrometers in size, but the response time is very fast, about tens of microseconds, and the mirror of an adaptive optical or optical signal distributor is about several hundred micrometers in size and several hundreds of micrometers. Mirrors of several millimeters in size are used for scanners, and the response time is several kilometres.

1A is an exploded perspective view of an optical modulator module package according to the prior art. Referring to FIG. 1A, the optical modulator module package 100 includes a substrate 110, a light transmissive substrate 120, a light modulator element 130, driver integrated circuits 140a to 140d, a heat dissipation plate 150, and a connector ( 160). Here, the light transmissive substrate 120 is a substrate capable of producing fine-pitch wiring and bump arrays, and not only a printed circuit board but also a glass substrate, a silicon substrate, an LTCC substrate, a multi-layer PCB, and the like. Can be.

The substrate 110 is a commonly used semiconductor substrate, and the lower surface of the light transmissive substrate 120 is attached on the substrate 110. The light modulator element 130 is attached to the upper surface of the light transmissive substrate 120 to correspond to the hole formed in the substrate 110.

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

The driver integrated circuits 140a to 140d are flip-chip connected to the periphery of the optical modulator element 130 to which the light transmissive substrate 120 is attached, and drive voltages to the optical modulator element 130 according to a control signal input from the outside. Serves to provide.

The heat dissipation plate 150 is provided to dissipate heat generated in the optical modulator element 130 and the driver integrated circuits 140a to 140d, and a metal material that emits heat well is used.

The method of manufacturing the optical modulator module package 100 shown in FIG. 1A includes attaching the connector 160 to the substrate 110, the optical modulator element 130 and the driver integrated circuit 140a to the light transmissive substrate 120. Attaching 140d), providing a heat sink 150, laminating the light transmissive substrate 120 on the substrate 110 and performing wire bonding, the optical modulator element 130 and the driver integrated circuits 140a to 140b). Attaching the heat dissipation plate 150 to 140d) and mounting the optical modulator element 130 and the driver integrated circuits 140a to 140d to form the optical modulator module package 100.

The optical modulator module package 100 shown in FIG. 1A has a large number of components, and therefore, a large number of components must be mounted in an appropriate space, thereby limiting the minimization of the module package. In addition, in order to directly mount the light modulator element 130 to the light transmissive substrate 120, the electrical / optical characteristics are concentrated on the light transmissive substrate 120, and the manufacturing cost of the light transmissive substrate 120 is increased to implement the light modulator element 130. There is a problem. In addition, since the optical modulator element 130 is directly mounted on the light transmissive substrate 120, there is a problem in that the effect of foreign matters is increased according to a narrow distance between the light modulator element 130 and the light transmissive substrate 120. In addition, during the process of directly mounting the light modulator element 130 to the light transmissive substrate 120, there is a problem that contamination by foreign matters, scratches may occur.

The present invention provides an optical modulator module package capable of minimizing a module package by accommodating an optically transmissive cover spaced apart from the optical modulator element at a predetermined interval in the substrate in an embedded form.

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

In addition, the present invention provides a light modulator module package in which the electrical / optical characteristics are not concentrated in the light transmissive cover and the manufacturing cost of the light transmissive substrate is low by using a standard semiconductor process.

In addition, the present invention provides a light modulator module package that can reduce the effect of foreign matter between the light modulator element and the light transmissive cover is not mounted directly on the light transmissive cover.

In addition, the present invention provides an optical modulator module package that can reduce the problem of contamination by foreign matter generated during the process of mounting the optical modulator element directly to the light transmissive substrate because the optical modulator element is not directly mounted on the light transmissive cover. .

In addition, the present invention provides a possible optical modulator module package that is easier on fine pitch applications by mounting the optical modulator element on a silicon substrate fabricated in a standard semiconductor process.

In addition, the present invention provides an optical modulator module package that can reduce optical noise by tilting a light transmissive substrate with respect to an optical modulator element.

According to an aspect of the present invention, a through hole through which light is allowed to enter and exit, a substrate having a circuit formed on at least one of an inner or outer surface, and received in a through hole, the incident light and the light modulator incident on the light modulator element An optical modulator module package including a light transmitting cover through which diffracted light emitted from the light is passed and a metal connection portion attached to one surface of a substrate to mount the optical modulator element and the driver integrated circuit on the substrate may be provided.

Here, the cross-section of the through hole has a '□' or '凸' shape, the light transmissive cover may be accommodated facing the light modulator element of the through hole.

In addition, the optical modulator module package according to the present invention is mounted on the substrate corresponding to the through hole of the substrate, the optical modulator device for modulating the incident light incident through the through hole of the substrate to emit diffracted light, in the vicinity of the optical modulator device The display device may further include at least one driver integrated circuit mounted on the substrate and configured to provide a driving voltage to the optical modulator device according to a control signal input from the outside.

Here, the light transmissive cover may be accommodated at a predetermined angle in the through hole.

Here, the inclination of the light transmissive cover may be 4 degrees with respect to the horizontal.

According to another aspect of the present invention, a first through hole through which light can enter and exit is formed, a substrate having a circuit formed on at least one of the inner or outer surface, the substrate is located on the substrate, and includes an open surface of the first through hole A housing having a second through-hole formed therein, a light-transmitting cover accommodated in the second through-hole and allowing incident light incident to the optical modulator element and diffracted light exiting the optical modulator to pass therethrough; An optical modulator module package can be provided that includes a metal connection for mounting an integrated circuit on a substrate.

Here, the cross section of the second through hole may have a '□' or '凸' shape, and the light transmissive cover may be accommodated to face the light modulator element among the second through holes.

In addition, the optical modulator module package according to the present invention is mounted on the substrate corresponding to the first through hole of the substrate, the optical modulator device for modulating the incident light incident through the first through hole of the substrate to emit diffracted light, optical modulator The device may further include at least one driver integrated circuit mounted on a substrate around the device and providing a driving voltage to the optical modulator device according to a control signal input from the outside.

Here, the optical modulator element and the driver integrated circuit may be flip chip connected to the substrate.

In addition, the light modulator element may be side sealed by an epoxy resin.

Here, the metal connection portion may be a metal bump or a metal pad.

Hereinafter, a preferred embodiment of the optical modulator 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 regardless of reference numerals and the same reference numerals Duplicate description thereof 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 a 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 the conduction of the ribbon (reflective surface of the ribbon serving as the first electrode) and the substrate (substrate serving as the second electrode). Film).

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 215, an insulating layer 225, a sacrificial layer 235, a ribbon structure 245, and a piezoelectric body 255 is shown.

The substrate 215 is a commonly used semiconductor substrate, and the insulating layer 225 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). The reflective layers 225 (a) and 225 (b) may be formed on the insulating layer 225 to reflect incident light.

The sacrificial layer 235 supports the ribbon structure 245 on both sides so that the ribbon structure can be spaced apart from the insulating layer 225 at regular intervals, and forms a space at the center.

The ribbon structure 245 serves to light modulate the signal by causing diffraction and interference of incident light as described above. The shape of the ribbon structure 245 may be configured in a plurality of ribbon shapes 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 255 controls the ribbon structure 245 to move up and down according to 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 225 (a) and 225 (b) are formed to correspond to the holes 245 (b) and 245 (d) formed in the ribbon structure 245.

For example, when the wavelength of light is λ, no voltage is applied or a predetermined voltage is applied to the upper reflective layers 245 (a) and 245 (c) and the lower reflective layer 225 (a) formed on the ribbon structure. ), The interval between the insulating layers 225 on which 225 (b) is formed is equal to nλ / 2 (n is a natural number). Therefore, in the case of the 0th order diffracted light (reflected light), the total path difference between the light reflected from the upper reflective layers 245 (a) and 245 (c) formed on the ribbon structure and the light reflected from the insulating layer 225 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 a proper voltage different from the applied voltage is applied to the piezoelectric material 255, the upper reflective layers 245 (a) and 245 (c) and the lower reflective layers 225 (a) and 225 (b) formed on the ribbon structure. The distance between the insulating layers 225, 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 245 (a) and 245 (c) formed in the ribbon structure and the light reflected from the insulating layer 225 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 245 and the insulating layer 225 on which the lower reflective layers 225 (a) and 225 (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 per screen 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 this embodiment, it is assumed that there are two holes 245 (b) -1 formed in the ribbon structure 245. Three upper reflective layers 245 (a) -1 are formed on the ribbon structure 245 due to the two holes 245 (b) -1. Two lower reflective layers are formed in the insulating layer 225 corresponding to the two holes 245 (b) -1. In addition, another lower reflective layer is formed on the insulating layer 225 corresponding to a portion of the gap between the first pixel (pixel # 1) and the second pixel (pixel # 2). Therefore, the number of upper reflective layers 245 (a) -1 and lower reflective layers per pixel is the same, and the luminance of modulated light is obtained by using zero-order diffraction light or ± first-order diffraction 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 horizontally on the screen 275. 285-1, 285-2, 285-3, 285-4, ..., 285- (k-3), 285- (k-2), 285- (k-1), 285-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).

According to the present invention, an optical modulator element and a driver integrated circuit for driving the optical modulator element are mounted on a substrate, and a light transmissive cover for transmitting incident light and diffracted light entering and exiting the optical modulator element is spaced apart from the optical modulator element by a predetermined distance. Prepared.

In the above description, a cross-sectional view of a general optical modulator device is described. Hereinafter, the optical modulator module package according to the present invention will be described with reference to specific embodiments with reference to the accompanying drawings. Embodiments according to the invention are largely divided into three as follows. It demonstrates in order below.

2E is a cross-sectional view of an optical modulator module package according to a first preferred embodiment of the present invention. Referring to FIG. 2E, the light modulator module package includes a substrate 210, driver integrated circuits 220 and 240, a light modulator element 230, and a light transmissive cover 250.

The substrate 210 has a through hole formed therein so that incident light may be incident on the optical modulator element 230 or diffracted light may be emitted, and a circuit is formed on at least one of an inner surface and an outer surface. Therefore, the substrate 210 transmits a control signal received from an external control circuit to the driver integrated circuits 220 and 240. In this case, electrical connection with the driver integrated circuits 220 and 240 may be made through flip chip bonding. Here, the substrate 210 may further include a metal bump (or pad: metal bumps and pads collectively referred to as a metal connection portion) attached to one surface thereof to mount the optical modulator element and the driver integrated circuit on the substrate. have. Here, the metal bumps and the metal pads may have a size difference that is generally used. Accordingly, the metal bumps formed on the substrate 210 may be flip chip connected to the metal pads formed on the optical modulator device or the driver integrated circuit. Alternatively, the metal pad formed on the substrate 210 may be flip chip connected to the metal bump formed on the optical modulator device or the driver integrated circuit. Here, the substrate 210 may be formed of a semiconductor silicon substrate capable of a fine pitch process, a low temperature cofired ceramic (LTCC) or a high temperature cofired ceramic (HTCC).

The optical modulator element 230 is formed on an upper surface of the light transmissive cover 250 corresponding to the hole of the substrate 210, and modulates incident light incident through the through hole formed in the substrate 210 to emit diffracted light. Play a role. Here, the optical modulator element 230 may be flip chip connected to the substrate 210.

In addition, the optical modulator element 230 is flip-chip connected to the substrate 210 in correspondence with the light transmissive cover 250, and has a rectangular cross section and one side is relatively longer. In addition, the light modulator element 230 is provided with an adhesive or the like around it to provide sealing from the external environment. Here, for sealing, a dam may be formed around the optical modulator element 230 and sealed using a predetermined dispensing liquid.

In addition, the light modulator element 230 may be side sealed by an epoxy resin. That is, the epoxy modulator 230 may be attached to the periphery of the optical modulator element 230 to protect the optical modulator element 230. That is, epoxy resins generally have excellent mechanical properties of the cured resin, very good dimensional stability, and good machinability, thereby protecting the optical modulator device 230 using the same.

The driver integrated circuits 220 and 240 are flip-chip connected to the periphery of the optical modulator element 230 to which the light transmissive cover 250 is attached, and drive voltages to the optical modulator element 230 according to a control signal input from the outside. Serves to provide. In addition, the driver integrated circuits 220 and 240 may have a rectangular cross section, and the number may be increased or decreased as necessary according to the size of the optical modulator element 230. That is, referring to FIG. 2E, two driver ICs 220 and 240 are illustrated, but the present invention is not limited thereto. Herein, the fine modulator device 230 and the driver integrated circuits 220 and 240 are not directly mounted on the light transmissive cover 250, thereby allowing fine pitch. That is, in general, when the circuit pattern is formed on the substrate 210 such as the silicon substrate rather than the light transmissive cover 250 such as glass, it is advantageous to form a fine circuit pattern.

The light transmissive lid 250 is accommodated in the through hole formed in the substrate 210, and is preferably formed of a high quality light transmissive material in order to allow the incident light and the diffracted light to pass well. For example, the light transmissive lid 250 can be glass. In addition, in order to efficiently transmit incident light and diffracted light on the upper surface of the light transmissive lid 250 in order to absorb light and absorb incident light, an absorption film coating or diffuse reflection structure is applied to an area where incident light and diffracted light are not transmitted. It can be fabricated and can be antireflective coated on one or both sides to reduce unwanted radiation and reflectivity. Herein, the black metal may be used as the absorbing film. In addition, the cross section of the through hole formed in the substrate 210 has a '凸' shape, and the light transmissive cover 250 faces a portion of the through hole facing the light modulator element 230, that is, a portion of the cross section of the through hole that is wide open. It can be located at Therefore, the light transmissive cover 250 may be supported by the substrate 210 formed in the narrowly open portion of the through hole. In addition, according to another embodiment, the cross-section of the through hole formed in the substrate 210 has a '□' shape, the light transmissive cover 250 may be accommodated facing the light modulator element of the through hole. Here, the light transmitting cover 250 may be accommodated in the through hole and fixed by using a predetermined adhesive.

Here, fine pitch is possible by not mounting the optical modulator element directly on the light transmissive lid. In general, a fine pitch wiring manufacturing process is possible on a glass substrate, but a dry etching process is required to manufacture the fine pitch wiring. However, glass substrates are generally subjected to anti-reflection coating (AR coating) to improve the transmittance. Therefore, there is a high possibility that the anti-reflective coating film will be damaged during the dry etching process, and the electrical, optical, and mechanical properties of the glass substrate will be increased. By concentrating, processing becomes difficult and the unit price increases. Therefore, it is advantageous in terms of production, price, or performance that the silicon substrate is responsible for the electrical / mechanical characteristics and the glass substrate is only responsible for the optical properties among the various functions of the light-transmissive substrate by using the silicon substrate as in the present invention. When the silicon substrate is used, the semiconductor process can be used as it is, so that fine pitch wiring can be manufactured and the adhesion of the film can be improved.

3 is a cross-sectional view of an optical modulator module package according to a second preferred embodiment of the present invention. Referring to FIG. 3, the light modulator module package includes a substrate 310, driver integrated circuits 320 and 340, a light modulator element 330, and a light transmissive cover 350. Hereinafter, the differences from the first embodiment will be mainly described.

The light transmissive lid 350 is inclined by a predetermined angle and accommodated in the substrate 310. That is, the shape of the through hole formed in the substrate 310 is manufactured so that the light transmissive cover 350 may be tilted and mounted. Here, if the predetermined angle at which the light transmissive cover 350 is inclined is an angle at which the amount of incident light and diffracted light reflected from the light transmissive cover 350 is minimal, there is no limitation in the value thereof. Therefore, this angle can be set by experiment, and preferably, the reflection loss can be reduced when the inclination is about 4 degrees with respect to the horizontal. Here, the optical communication device is used in a direction of reducing the optical signal reflection loss by giving an inclination of about 4 degrees. That is, since the light transmissive cover 350 is inclined at a predetermined angle to each other than in parallel with the light modulator element 330, the amount of incident light and diffracted light reflected from the light transmissive cover 350 may be reduced. The light transmissive cover 350 is inclined by a predetermined angle to accommodate the inside of the substrate 310.

Here, the shape in which the transparent cover 350 is accommodated in the through hole formed in the substrate 310 may be variously implemented. Referring to FIG. 3, the cross section of the through hole formed in the substrate 310 may have a '凸' shape, and the light transmissive cover 350 may be located at a wide open portion of the through hole. Here, the through hole formed in the substrate 310 is inclined to one side in the '凸' shape, so that the light transmissive cover 350 forms a constant angle with the light modulator element 330. In this case, the light transmissive cover 350 may be attached to the substrate 310 by an adhesive.

In addition, according to another embodiment, the cross-section of the through hole formed in the substrate 310 has a '+' shape, and the light transmissive cover 350 may be accommodated in the center cavity. In this case, a process of accommodating the transparent cover 350 may be added to the process of manufacturing the substrate 310. In addition, since the light transmissive cover 350 is trapped by the through hole formed in the substrate 310, a separate adhesive for attaching the light transmissive cover 350 to the substrate 310 is not required.

4 is a cross-sectional view of an optical modulator module package according to a third preferred embodiment of the present invention. Referring to FIG. 4, the light modulator module package includes a substrate 410, driver integrated circuits 420 and 440, a light modulator element 430, a light transmissive cover 450, and a housing 460. Hereinafter, the differences from the first embodiment will be mainly described.

The housing 460 is attached to one surface of the substrate 410, and a second through hole corresponding to the first through hole formed in the substrate 410 is formed. Accordingly, a first through hole is formed during the manufacturing of the substrate 410, and a second through hole having an open surface larger than that of the first through hole is formed during the manufacturing of the housing 460. Thereafter, a light transmissive cover 450 having a width larger than the open surface of the first through hole and smaller than the open surface of the second through hole is deposited on the substrate 410. Therefore, according to the third exemplary embodiment, the process of forming the first through hole in the substrate 410 may be performed simply and simply.

Figure 5 is a comparison of the optical modulator module package according to a preferred embodiment of the present invention and the optical modulator module package according to the prior art. 5, an optical modulator module package (a) according to the prior art and an optical modulator module package (b) according to a preferred embodiment of the present invention are shown. The optical modulator module package (a) according to the prior art includes a light transmissive substrate 510 and an optical modulator element 520. The optical modulator module package (b) according to the preferred embodiment of the present invention includes a substrate 530, Light transmissive cover 550 and light modulator element 540.

The distance between the light transmissive lid 550 and the light modulator element 540 is greater than the distance between the light transmissive substrate 510 and the light modulator element 520. Thus, according to the present invention, the influence on foreign matter that can be placed between the light transmissive cover 550 and the light modulator element 540 is small. For example, when incident light or incident diffracted light incident by the foreign material or the scratch attached on the light transmissive cover 550 is diffracted or scattered, the larger the distance between the light transmissive cover 550 and the light modulator element 540 is, The influence due to such diffraction or scattering becomes small. Therefore, according to the present invention, the influence on the foreign matter that can be placed between the light transmitting cover 550 and the light modulator element 540 can be reduced.

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 optical modulator module package according to the present invention has an effect of minimizing the module package by accommodating an optically transparent cover installed in a substrate spaced apart from the optical modulator element at a predetermined interval in an embedded form.

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

In addition, the optical modulator module package according to the present invention has an effect that the manufacturing cost of the light transmissive substrate is low because the electrical / optical properties are not concentrated in the light transmissive cover.

In addition, the optical modulator module package according to the present invention has an effect of reducing the effect of foreign matter between the optical modulator element and the light transmissive cover because the light modulator device is not directly mounted on the light transmissive cover.

In addition, the optical modulator module package according to the present invention has an effect of reducing the problem of contamination by foreign matter generated during the process of mounting the optical modulator element directly on the light transmissive substrate because the optical modulator element is not directly mounted on the light transmissive cover. There is.

In addition, the optical modulator module package according to the present invention has an effect of enabling fine pitch by not mounting the optical modulator element directly on the light transmissive cover.

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.

Claims (12)

A substrate having a through hole through which light can enter and exit, and a circuit formed on at least one of an inner and outer surface thereof; A light transmissive cover accommodated in the through hole and configured to pass incident light incident to the optical modulator element and diffracted light emitted from the light modulator; And And a metal connector attached to one surface of the substrate to mount the optical modulator element and the driver integrated circuit on the substrate. The method of claim 1, And the metal connection portion is a metal bump or a metal pad. The method of claim 1, The cross-section of the through hole has a '□' or '凸' shape, the light transmissive cover is characterized in that the optical modulator module package, characterized in that is accommodated facing the optical modulator element of the through hole. The method of claim 1, An optical modulator element mounted on the substrate corresponding to the through hole of the substrate and configured to emit diffracted light by modulating incident light incident through the through hole of the substrate; And And at least one driver integrated circuit mounted on the substrate around the optical modulator element and providing a driving voltage to the optical modulator element according to a control signal input from the outside. The method of claim 1, The light transmissive cover is an optical modulator module package, characterized in that accommodated inclined at a predetermined angle in the through hole. The method of claim 1, The inclination of the light transmissive cover is an optical modulator module package, characterized in that 4 degrees relative to the horizontal. A substrate having a first through hole through which light can enter and exit, and a circuit formed on at least one of an inner and outer surface thereof; A housing disposed on the substrate and having a second through hole including an open surface of the first through hole; A light transmissive cover accommodated in the second through hole and configured to pass incident light incident to the optical modulator element and diffracted light emitted from the light modulator; And And a metal connector attached to one surface of the substrate to mount the optical modulator element and the driver integrated circuit on the substrate. The method of claim 7, wherein And the metal connection portion is a metal bump or a metal pad. The method of claim 7, wherein The cross section of the second through hole has a '□' or '凸' shape, the light transmissive cover is the optical modulator module package, characterized in that is received facing the optical modulator element of the second through hole. The method of claim 7, wherein An optical modulator element mounted on the substrate corresponding to the first through hole of the substrate and configured to emit diffracted light by modulating incident light incident through the first through hole of the substrate; And And at least one driver integrated circuit mounted on the substrate around the optical modulator element and providing a driving voltage to the optical modulator element according to a control signal input from the outside. The method according to claim 4 or 10, And said optical modulator element and said driver integrated circuit are flip chip connected to said substrate. The method according to claim 4 or 10, And wherein the light modulator element is side sealed by an epoxy resin.

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