KR100423186B1 - Module for packaging optical modulating chip and optical modulating device using the same - Google Patents

Abstract

The present invention relates to a module for packaging an optical modulator chip and an optical modulator using the same, comprising: a first substrate having an optical modulator chip mounted thereon and an outer lead terminal provided on an outer circumferential surface of the optical modulator chip; And a second substrate bonded to the first substrate and electrically connected to an optical modulator chip and an externally-connected connection terminal of the first substrate, wherein the first substrate or the second substrate is an optical modulator chip as an optical modulator chip. By constructing an optical path that emits light at, the refractive index of the light can be independently controlled and diffracted, and the long wire bonding produces an effect of preventing the sagging of the wire loops and the occurrence of shorts and breaks of the wires.

Description

Module for packaging optical modulating chip and optical modulating device using the same

The present invention relates to a module for packaging an optical modulator chip and an optical modulator using the same. More particularly, the optical modulator chip can be diffracted by independently adjusting the refractive index of light. An optical modulator chip packaging module capable of preventing occurrence of breakage and an optical modulator using the same.

In general, optical signal processing is capable of high-speed processing of large-capacity information by parallel processing, unlike conventional digital information processing, which cannot process a large amount of data in real time, and design and manufacture a binary phase filter using circuit spatial optical modulation theory. Researches on optical logic gates, optical amplifiers, optical elements, and optical modulators, etc. are being conducted. In particular, research on the development of display devices using optical modulators is being actively conducted.

1 is a configuration diagram of a laser display using a conventional optical modulator, the optical modulators (11, 12, 13) for modulating the amount of light by receiving red, green, and blue laser, respectively, and the optical modulators (11) Reflectors 15, 16, and 17 reflecting the output light of the light beams 12 and 13, respectively, and a focusing lens focused to display the light reflected from the reflectors 15, 16, and 17 on the screen 40. It consists of 30.

In the conventional laser display, the light emitted through the red, green, and blue lasers is modulated by using the acoustic optical effect in the light modulators 11, 12, and 13, respectively, according to an image to be displayed on the screen 40. The intensity of the light is controlled, and the red, green, and blue light implements one pixel of the image, and the reflectors 15, 16, and 17 are installed to correspond to the light modulators 11, 12, and 13. By focusing on the focusing lens 30 and irradiating the screen 40, an image is realized.

Such a light modulator of a conventional laser display may not allow the generated optical wave to be limited to a desired area and may proceed in a predetermined direction in the entire area of the piezoelectric substrate of the light modulator, thereby forming an array form. There are no drawbacks.

In addition, since the miniaturization of the light source and the development of a suitable optical modulator have not been completed, they are not practically used at present.

Accordingly, the present invention has been made to solve the problems described above, by using a ferroelectric that generates polarization reversed by 180 ° by the applied voltage, by selectively applying a voltage to a plurality of electrodes spaced apart from each other, An object of the present invention is to provide an optical modulator packaged with an optical modulator chip capable of independently adjusting the refractive index of light incident on a ferroelectric.

Another object of the present invention is to provide a module for packaging an optical modulation chip that can prevent sagging of wire loops and short and broken wires due to long wire bonding.

In order to achieve the above object of the present invention, a plurality of upper electrodes spaced apart from each other are formed on an upper portion of a ferroelectric substrate, and a lower electrode is formed on a lower portion of the ferroelectric substrate, so as to apply an applied voltage. An optical modulator chip generating polarization reversed by 180 degrees;

Comprising a substrate to which the optical modulator chip is bonded,

The substrate includes a plurality of electrode pads electrically connected to the plurality of upper electrodes of the optical modulator chip, and optically modulated terminals connected to the electrode pads and drawn out to the outside. An apparatus is provided.

According to another aspect of the present invention, there is provided an optical modulator chip, comprising: a first substrate provided with an external lead-out terminal on an outer circumferential surface on which the optical modulator chip is mounted; And a second substrate bonded to the first substrate and electrically connected to an optical modulator chip and an externally-connected connection terminal of the first substrate, wherein the first substrate or the second substrate is an optical modulator chip as an optical modulator chip. The optical modulation chip packaging module is provided, characterized in that the optical path is provided in the light emitting.

According to another preferred aspect of the present invention, a plurality of upper electrodes, ferroelectric substrates, and lower electrodes spaced apart from each other so as to generate 180 ° reversed polarization by an applied voltage are sequentially formed. The formed optical modulator chip may be bonded to each other, and grooves may be formed on the upper surface of the optical modulator chip to guide light incident and emitted from the optical modulator chip, and the plurality of electrode pads may be connected to the electrode pads on the upper surface of the optical modulator chip. A first substrate on which the terminals are drawn out;

A second surface having a top surface and a bottom surface, the top surface having a plurality of bonding pads capable of performing electrical connection in correspondence with a plurality of upper electrodes of the optical modulator chip and a plurality of electrode pads of the first substrate; Provided is a module for packaging an optical modulation chip, comprising a substrate.

1 is a block diagram of a laser display using a conventional optical modulator.

2 is a conceptual diagram illustrating a rotation principle of an optical modulator according to the present invention.

3A and 3B are cross-sectional views of an optical modulator chip inserted into an optical modulator chip packaging module according to the present invention.

4 is a perspective view of an optical modulator chip according to the present invention.

5 is a perspective view of an optical modulation device according to a first embodiment of the present invention.

6 is a perspective view of an optical modulation device according to a second embodiment of the present invention.

FIG. 7 is an enlarged view of region 'A' of FIG. 6.

8A to 8F are process flow charts of manufacturing a second substrate according to the present invention.

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

100: ferroelectric 111,112,113, 120: upper electrode

110: lower electrode 125: silicon oxide film

126: polyimide layer 130: passivation layer

131: electrode pad 150: optical modulator chip

200: second substrate 210: bonding pad

280: wire 300: first substrate

320: external withdrawal terminal 400: home

410: light incidence furnace 411: light emission furnace

450: chip mounting hole 500: silicon substrate

501,502: silicon nitride film 510: electrode pad

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a conceptual diagram illustrating a rotation principle of an optical modulator according to the present invention, and a plurality of electrodes 111, 112, and 113 spaced apart from each other is formed on an upper portion of the ferroelectric 100, and from the power supply 115 to the electrodes 111, 112, and 113. When a voltage is applied, the polarization phenomenon in which the ferroelectrics 101, 103, and 105 are positioned below the electrode to which the voltage is applied is reversed 180 degrees from the spontaneous polarization of the ferroelectric. When light is irradiated to the ferroelectric reversely polarized in the 180 ° direction in a direction perpendicular to the polarization direction, the refractive index changes at an angle inversely proportional to the lattice period of the ferroelectric, and the incident light is diffracted and output.

In the ferroelectrics 102 and 104 to which no voltage is applied, light irradiated with spontaneous polarization inherent to the ferroelectric is transmitted.

An optical modulator using such a ferroelectric selectively diffracts incident light by applying a voltage, selectively transmits the diffracted light by a blocking unit, condenses the light in the focusing lens, and then scans the screen onto a two-dimensional surface. It can serve as a projector to display the screen.

Here, the ferroelectric is preferably formed of LiNbO ₃ ,

The optical modulation device of the present invention can selectively apply a voltage to a plurality of electrodes spaced apart from each other to independently adjust the refractive indices of light incident on the ferroelectric, that is, only light incident on the ferroelectrics of the corresponding electrodes to which the voltage is applied In addition, by simultaneously applying a voltage to a plurality of electrodes, it is possible to diffract light incident on the ferroelectrics of the electrodes.

Of course, in such an optical modulation device, it would be possible if a switching device and a control device of the power supply for which of the electrodes are to be applied.

3A and 3B are cross-sectional views of an optical modulator chip inserted into an optical modulator chip packaging module according to the present invention. First, a lower electrode 110 is deposited below the ferroelectric 100, and the ferroelectric 100 is disposed. An upper electrode pattern 120 of each of the electrodes spaced apart from each other is deposited on the upper portion of the substrate, and a passivation layer 130 protecting the upper electrode pattern 120 is formed on the upper electrode pattern 120. The passivation layer 130 is provided with openings for forming electrode pads 131 corresponding to the upper electrodes.

As shown in FIG. 3B, the passivation layer 130 may have a stacked structure of a silicon oxide film 125 and a polyimide layer 126.

4 is a perspective view of an optical modulator chip according to an embodiment of the present invention, in which a passivation layer 130 is formed on an upper surface of the ferroelectric 100, and the respective electrodes of the upper electrode pattern 120 are formed on the surface of the passivation layer 130. A plurality of electrode pads 131 which are electrically connected are exposed.

The plurality of electrode pads 131 are electrically connected to the lower electrode patterns, that is, the electrodes spaced apart from each other. When a voltage is applied to the plurality of electrode pads 131, the ferroelectrics below the plurality of electrode pads 131 are electrically connected. The polarization phenomenon reversed in the 180 ° direction from the spontaneous polarization is generated.

The present invention proposes an optical modulation device for mounting the above-described optical modulator chip, and applied to a projector or an optical display, and a module for mounting the optical modulator chip.

Accordingly, in the basic optical modulation device of the present invention, a plurality of upper electrodes spaced apart from each other are formed on the upper portion of the ferroelectric substrate, and a lower electrode is formed on the lower portion of the ferroelectric substrate, and the polarization is inverted by 180 ° by an applied voltage. An optical modulator chip to generate; The substrate is formed of a substrate to which the optical modulator chip is bonded. The substrate includes a plurality of electrode pads electrically connected to the upper electrodes of the optical modulator chip, and connected to the electrode pads. Consisting of terminals.

The above-described optical modulation device and packaging module will be described in more detail with reference to the drawings.

5 and 6, the module for packaging the optical modulator chip of the present invention is basically a light modulator chip is mounted, the first substrate having an external lead-out terminal on the outer peripheral surface on which the optical modulator chip is mounted ( 300); And a second substrate 200 adhered to the first substrate 300 and electrically connected to an optical modulator chip and an external lead-out connection terminal of the first substrate 300. The first substrate 300 or the second substrate 200 is electrically connected to the first substrate 300. The substrate 200 is characterized in that the optical path is provided with an optical modulator chip and the light emitted from the optical modulator chip.

5 is a perspective view of an optical modulation device according to a first embodiment of the present invention, in which the above-described optical path is formed as a groove 400 in the first substrate 300.

Accordingly, in the first embodiment of the present invention, there is provided a groove 400 for mounting an optical modulator chip and receiving and emitting light, and including a first substrate 300 having an outer lead terminal on an outer circumferential surface of the groove; The second substrate 200 is attached to the first substrate 300 and electrically connected to an optical modulator chip and an external lead-out connection terminal of the first substrate 300.

In more detail, the first substrate 300 has an upper surface and a lower surface, and the groove 400 for guiding the adhesion of the optical modulator chip 150 and the light incident and emitted to the optical modulator chip 150 on the upper surface. Is formed, and the upper surface of the groove 400 is provided with a plurality of electrode pads 320 and terminals 310 connected to the electrode pads and drawn out to the outside.

In addition, the second substrate 200 may have an upper surface and a lower surface, and the upper surface may include a plurality of upper electrodes 111 and 112 of the optical modulator chip 150 and a plurality of electrode pads 320 of the first substrate. A plurality of bonding pads 211 may be provided to correspond to each other.

The module for packaging the optical modulator chip is mounted in the groove 400, and then the plurality of upper electrodes 111 and 112 of the optical modulator chip and the plurality of electrode pads of the second substrate 200. The wire bonding is performed in a one-to-one correspondence, and the plurality of electrode pads 210 and the plurality of electrode pads 211 and the first substrate 300 of the second substrate 200 are extended. When the electrode pads 320 are wire bonded, the optical modulation device of the present invention is completed.

Here, the ground metal 380 is provided in the mounting area of the optical modulator chip 150 of the first substrate 300, and the external lead terminals 350 connected to the ground metal are connected by a metal pattern. .

In the optical modulation device of the present invention configured as described above, when a voltage is applied through the external lead terminal 310 formed on the first substrate 300, the optical modulator chip generates polarization reversed 180 ° from the spontaneous polarization. When light is incident on the groove 400, the light is diffracted in a region where a voltage is applied to the light modulator chip, and light is transmitted through a region where no voltage is applied.

FIG. 6 is a perspective view of an optical modulator device according to a second exemplary embodiment of the present invention, in which an optical path incident to the modulator chip and an optical path emitting light from the optical modulator chip have portions of both sides of the second substrate 200 removed. (In Fig. 6, it is a light incident path 410 and a light emission path 411.).

Therefore, the module for packaging the optical modulator chip according to the second embodiment of the present invention has a mounting surface of the optical modulator chip 150, and the external drawing terminal is provided on the outer circumferential surface of the mounting surface of the optical modulator chip 150. 1 substrate 300; There is a hole (that is, a chip mounting hole 450 in FIG. 6) attached to the first substrate 300 to expose the top surface of the optical modulator chip 150, and a part of both sides ('B' region) There is a groove (refer to FIG. 6, the light incidence path 410 and the light emission path 411) that is removed to expose opposite sides of the light modulator chip, the outside of the light modulator chip and the first substrate 300. The second substrate 200 is electrically connected to the lead connection terminal.

In more detail, the first substrate 300 includes external lead terminals 310 and bonding pads 320 connected to the external lead terminals 310, and a mounting area of the optical modulator chip 150. It is provided.

In addition, the second substrate 200 has chip mounting holes 450 penetrating at the centers of the upper and lower surfaces thereof, and opposing first and second sides ('B' region) and second and second sides ('C'). A portion of the first both side surfaces 'B' region may be removed to the chip mounting hole 450 based on a lower surface thereof so that the light incident path 410 may be formed in the first both side surfaces 'B' region. ), A light emitting path 411 and a protrusion 250 are formed, and a plurality of bonding pads are formed on the upper surface of the optical modulator chip 150 to electrically connect with the upper electrodes 111 and 112. The protrusions 250 of the second substrate are adhered to the first substrate 300 outside the mounting area of the optical modulator chip.

Also in the second embodiment of the present invention, when the optical modulator chip 150 is mounted and wire bonding is performed, the manufacture of the optical modulation device is completed.

In the optical modulation device according to the second embodiment of the present invention thus completed, when a voltage is applied through the external lead terminal 310 formed on the first substrate 300, the optical modulator chip generates 180 ° reversed polarization. When light enters the light incident path 410, light is diffracted in a region where voltage is applied to the light modulator chip, and light is transmitted through a region where no voltage is applied, thereby causing light emission path 411. ) Is released.

FIG. 7 is an enlarged plan view of the 'A' region of FIG. 6, wherein the plurality of bonding pads 210 formed on the upper surface of the second substrate 200 surround the area where the optical modulator chip 150 is mounted. The number of bonding pads arranged on the upper surface ('E' region) in the 90 ° direction in which light is incident and arranged is cheaper than that of the bonding pads formed on the upper surface ('D' region) in the direction in which light is incident. The bonding pads 213 formed on the upper surface (the 'D' region) in the incident direction are selected from the bonding pads 210 and 215 formed on the upper surface (the 'E' region) in the 90 ° direction to which light is incident. Are electrically connected to the metal patterns 216.

When the external lead terminals are formed on the upper surface of the first substrate in the direction in which the light is incident, the lead terminals and the bonding pads of the first substrate should be electrically connected by wire bonding. At this time, the wire in the direction in which the light is incident to block the incident light, it is impossible to obtain the desired output from the optical modulator chip.

For this reason, the number of bonding pads formed on the upper surface ('D' region) of the second substrate 200 in the direction in which light is incident is the bonding formed in the upper surface ('E' region) in the 90 ° direction in which light is incident. Formed to be larger than the number of pads, the bonding pads formed on the upper surface ('D' region) of the second substrate in the direction in which light is incident and formed on the upper surface ('E' region) in the 90 ° direction to which light is incident The bonding pads 215 that are not wire bonded are electrically connected to each other by metal lines.

Therefore, the bonding pads 213 formed on the upper surface ('D' region) of the second substrate 200 in the direction in which the light is incident are bonded to the optical modulator chip 150 and the wire 280, and the light is incident at 90 °. The bonding pads 215 formed on the upper surface ('E' region) in the direction are connected by metal lines and wire-bonded with the external lead terminals, so that a voltage can be applied to the optical modulator chip.

Here, the number of bonding pads formed on the upper surface ('E' region) in the 90 ° direction in which light is incident is most preferably formed twice the number of bonding pads formed on the upper surface ('D' region) in the direction in which light is incident. desirable.

On the other hand, the first and second substrates can be produced by applying a semiconductor substrate, the use of silicon is most preferred because of the low cost and ease of the process.

Therefore, in the packaging of the optical modulator module, the second substrate applied in the first and second embodiments of the present invention can prevent the sagging of the wire loop and the occurrence of shorts and breaks of the wires by long wire bonding.

8A to 8F are process flowcharts of manufacturing a second substrate according to the present invention. First, silicon nitride films (Si _x N _y ) 501 and 502 are formed on and under a silicon (Si) substrate 500 (FIG. 8a), a plurality of bonding pads 503 are formed on the upper silicon nitride layer 501, and the inside of the lower silicon nitride layer 502 is etched (FIG. 8B).

Then, a part of silicon is etched in the KOH solution using the etched remaining silicon nitride film 502 'as a mask (FIG. 8C).

After part of the silicon is etched, the silicon nitride film 502 'is removed, another silicon nitride film 504 is deposited to the inner portion of the etched silicon (FIG. 8D), and the silicon nitride film 504 is masked. Then, silicon is etched to the upper silicon nitride film 501 (Fig. 8E).

Finally, the silicon is removed in the process of FIG. 8E to remove the upper silicon nitride film exposed in the lower surface direction, thereby forming the chip mounting groove 450 shown in FIG. 6 (FIG. 8F).

As described in detail above, the present invention can be diffracted by independently adjusting the refractive index of light, and the long wire bonding can prevent the sagging of the wire loop and the occurrence of shorts and breaks of the wires. It can be effective.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (12)

A first substrate having an optical modulator chip mounted thereon and having an outer lead terminal on an outer circumferential surface on which the optical modulator chip is mounted; And a second substrate bonded to the first substrate and electrically connected to an optical modulator chip and an externally-connected connection terminal of the first substrate, wherein the first substrate or the second substrate is an optical modulator chip as an optical modulator chip. Module for packaging an optical modulator chip, characterized in that the optical path for emitting light from the. The method of claim 1, And the optical path is a groove for mounting the optical modulator chip formed on the first substrate, or a groove in which opposing side surfaces formed on the second substrate are removed. A plurality of upper electrodes, a ferroelectric substrate, and a lower electrode, which are spaced apart from each other, may be bonded to each other to sequentially generate 180 ° inverted polarization by an applied voltage, and light incident and emitted to the light modulator chip. A groove for guiding the first surface, the first substrate including a plurality of electrode pads and terminals connected to the electrode pads and drawn out to the upper surface other than the groove; A second surface having a top surface and a bottom surface, the top surface having a plurality of bonding pads capable of performing electrical connection in correspondence with a plurality of upper electrodes of the optical modulator chip and a plurality of electrode pads of the first substrate; Module for packaging an optical modulator chip, characterized in that consisting of a substrate. The method of claim 3, wherein The first substrate is further provided with bonding pads connected to external lead-out terminals and is provided with a mounting area of the optical modulator chip; The second substrate has a chip mounting hole penetrating at a center of an upper surface and a lower surface thereof, and a part of the first both sides of the opposing first side surfaces and the second side surfaces extends to the chip mounting hole from the bottom surface. A substrate having light incident paths, light emission paths, and protrusions formed on the second side surfaces, and a plurality of bonding pads formed on the upper surface thereof to be electrically connected to upper electrodes of the optical modulator chip; The protrusions of the second substrate are bonded to the first substrate outside the mounting area of the optical modulator chip. The method according to claim 3 or 4, The plurality of bonding pads formed on the upper surface of the second substrate are arranged to surround the area where the optical modulator chip is mounted. And the number of bonding pads formed on the upper surface in the 90 ° direction in which light is incident is twice the number of bonding pads formed on the upper surface in the direction in which light is incident. The method according to claim 3 or 4, The plurality of bonding pads formed on the upper surface of the second substrate are arranged to surround the area where the optical modulator chip is mounted. The number of bonding pads formed on the upper surface in the 90 ° direction in which light is incident is greater than the number of bonding pads formed on the upper surface in the direction in which light is incident, The bonding pads formed on the upper surface of the light incident direction is electrically coupled in a metal pattern to the bonding pads selected from the bonding pads formed on the upper surface in the 90 ° direction incident light, modulator chip packaging module. The method according to claim 3 or 4, And the first substrate and the second substrate are semiconductor substrates. The method according to claim 4, The ground modulator chip mounting region of the first substrate is provided with a ground metal, and the ground metal further comprises an external lead terminal connected to the metal pattern. An optical modulator chip having a plurality of upper electrodes spaced apart from each other on an upper portion of the ferroelectric substrate, and a lower electrode formed on the lower portion of the ferroelectric substrate to generate polarization reversed by 180 ° by an applied voltage; Comprising a substrate to which the optical modulator chip is bonded, The substrate includes a plurality of electrode pads electrically connected to the plurality of upper electrodes of the optical modulator chip, and terminals connected to the electrode pads and drawn out to the outside. . The method of claim 9, The substrate to which the optical modulator chip is bonded is composed of a first substrate and a second substrate; The first substrate may adhere to the optical modulator chip, and grooves may be formed on the upper surface of the first substrate to guide light incident and emitted to the optical modulator chip. Terminals connected to the electrode pads and drawn out to the outside are provided; The second substrate has an upper surface and a lower surface, and a plurality of bonding pads may be electrically connected to the upper surfaces of the optical modulator chip and the plurality of electrode pads of the first substrate. The optical modulation device characterized by the above-mentioned. The method of claim 9, The substrate to which the optical modulator chip is bonded is composed of a first substrate and a second substrate; The first substrate further includes an external lead terminal and bonding pads connected to the external lead terminals, the substrate having a mounting area of an optical modulator chip; The second substrate has a chip mounting hole penetrating at the center of an upper surface and a lower surface thereof, and a part of the first both sides of the first and second sides opposite to the bottom surface is removed to the chip mounting hole. The second sides are formed with light incident paths, light emitting paths, and protrusions, and a top surface of the substrate having a plurality of bonding pads formed therein for electrical connection with upper electrodes of the optical modulator chip; The protrusions of the second substrate are bonded to the first substrate outside the mounting area of the optical modulator chip. The method according to any one of claims 9 to 11, And a ground metal is provided in the optical modulator chip mounting area of the first substrate, and the ground metal further includes an external lead terminal connected to the metal pattern.