JP2004235379A - Optical package and optical module using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact optical package suitable for the mounting of a face receiving light emission type optical semiconductor element such as a VCSEL, and capable of achieving excellent mass production, miniaturization, high frequency characteristics, and highly reliable assembly and an optical module using the optical package. <P>SOLUTION: This optical package P1 consists of a base body 1 of a dielectric layer laminate structure, a through-hole conductor 10 accessory to the base body 1, conductor patterns 11, 12 and 13, and an external electrode lead 14. The external electrode lead 14 is mounted on the side face 19 of a recessed part 18 on the back face of the base body 1, and the conductor pattern 12 and the through-hole conductor 10 are formed as an optical package P1 arranged like a ladder in order to make the interval of the connecting parts short so that the conductor pattern 11 can be smoothly connected to the conductor pattern 13. The optical package P1 is mounted with a face receiving light emission type optical semiconductor element so that an optical module M1 can be constituted. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technology relating to mounting of a surface emitting / receiving optical semiconductor element such as a surface emitting laser (hereinafter, VCSEL), a PIN photodiode (hereinafter, PIN-PD), an avalanche photodiode (hereinafter, APD), and the like. For example, it is suitable for mounting such a surface light emitting / receiving type optical semiconductor element, or further mounting electronic components for operating it, and is excellent in mass productivity, small in size, excellent in high frequency characteristics and highly reliable. The present invention relates to an optical package that can be assembled and an optical module using the same.
[0002]
[Prior art]
In recent years, large-capacity optical fiber communication has been widely spread and developed in the field of public communication and private communication (LAN). Accordingly, the transmission speed has been increased, and high-speed optical transmission using an optical fiber is required. In addition to the conventionally used optical transmission at a distance of several kilometers to several hundreds of kilometers, a very short reach (very short reach) is used. VSR), and applications called Gigabit Ethernet (R) (GbE) are becoming increasingly important. In these applications of VSR and GbE, an optical transmission speed of 10 gigabits per second is being required. In such transmission, an unspecified number and various kinds of uses are assumed, and the size of the device is greatly reduced as compared with the conventional one. It is considered that industrialization and improvement of mass productivity are industrially important.
[0003]
In the optical communication system, a 0.85 μm band surface light emitting element called VCSEL is frequently used as a new optical semiconductor device having excellent mass productivity, stable characteristics, and high-speed optical transmission. Also, VCSEL devices in the 1.31 μm band and 1.55 μm band are under development, and commercialization is expected.
[0004]
Further, in the light receiving element, a surface light receiving element such as a PIN-PD or an APD is used for electrically converting a high-speed optical signal as in the related art.
[0005]
The inventor of the present invention has provided a VCSEL element on which a waveguide for optically connecting to a surface-type optical semiconductor element is attached to a substrate on which wiring for supplying electricity to the VCSEL element is formed. The surface excluding the installation surface and the back surface was fixed to an external circuit board on which external wiring for supplying current to the surface-type optical semiconductor element was formed, and the external wiring formed on the external circuit board and the base were formed on the base. An optical module that can be electrically connected to wiring has already been proposed (see Patent Document 1). This proposal is that the optical module can have a simple configuration, assembling is simple, and good optical connection can be efficiently performed.
[0006]
In a LAN or the like using Gigabit Ethernet (R), for example, a form of an optical transceiver in which a transmitter and a receiver are packaged in one is generally used, and the size is standardized (see Patent Document 2). reference).
[0007]
In recent years, optical transceivers have been reduced in size in order to reduce the size of the entire device, and have been changed to a form called an SFF (Small Form Factor) which is about half the size of a conventional one.
[0008]
Conventionally, these optical semiconductor elements are generally mounted on a conventional optical package as shown in FIG. The conventional optical package shown in FIG. 11 is called a TO-CAN package, and has a cylindrical stem 30 made of metal, a cylindrical glass feedthrough 33 provided on the stem 30, and an optical semiconductor from outside through the glass feedthrough 33. It comprises a cylindrical lead pin 32 for supplying current to the element and a cap 31 attached to the stem 30 for hermetically sealing the optical semiconductor element. The VCSEL device 40, which is an optical semiconductor device, is mounted on the stem 30 and is electrically connected to the lead pins 32 by gold wires 41. Thereafter, the cap 31 is fixed to the stem 30 and sealed, thereby completing the VCSEL module. A transparent window 31a is attached to an upper portion of the cap 31, and the VCSEL element 40 is optically connected to an external optical waveguide through the transparent window 31a. The VCSEL module is used by being mounted and fixed on an external electronic circuit board.
[0009]
[Patent Document 1]
Japanese Patent Application No. 2002-204682
[Patent Document 2]
JP-A-2000-214351
[0010]
[Problems to be solved by the invention]
However, in the optical module using the TO-CAN package, when the optical module is fixed to the electronic circuit board on which the electronic circuit is mounted with the lead pins 32, the lead pins 32 are connected to the aerial wiring between the package and the electronic circuit board. As a result, the discontinuity of the characteristic impedance of the wiring greatly increases, and the high-frequency characteristics deteriorate.
[0011]
In order to solve this problem, it is conceivable that the lead pins 32 are mounted on an electronic circuit board with the shortest possible length so that the lead pins 32 are not exposed to the air. However, it is difficult to ensure the reliability for a long period of time, and the high frequency characteristics are not stable due to the variation in the length of the lead pins 32 and the variation in the amount of solder at the time of mounting and fixing the optical module. In addition, the size of the TO-CAN package is standardized, for example, φ5.6 mm. However, if the size is further reduced, the TO-CAN package is required to keep the characteristic impedance of the glass feedthrough 33 constant. Variations in the size of the lead pins 32 need to be reduced and more strictly controlled, making fabrication difficult.
[0012]
In addition, since the signal line is bent at the connection between the lead pin 32 and the gold wire 41 in the package, the characteristics of the package alone are not sufficient. 12 and 13 show frequency response characteristics of electric wiring of the TO-CAN package alone. That is, the input end of the lead pin 31 was not protruded from the stem 30 at all, the output end was taken at one end of the gold wire 41 as a terminal for input to the VCSEL element 9, and a signal line model was formed by the lead pin 31 and the gold wire 41. The reflection characteristics (FIG. 12) and the transmission characteristics (FIG. 13) of the frequency response are shown. In the characteristic shown by the broken line in the case where the resistance is terminated near the VCSEL element 9 so as to match the characteristic impedance of the glass feedthrough 33, the signal reflection at a high frequency is large as shown in FIG. As shown, since almost no signal is transmitted, it is difficult to use it for signal transmission, for example, at 10 Gbps.
[0013]
Further, even when a substrate such as a microstrip line whose characteristic impedance is controlled is used instead of the gold wire 41, there is a problem that a high-frequency signal is deteriorated at a bent portion in a connection portion between the lead pin 32 and the microstrip line substrate. is there.
[0014]
Further, since the lead pins 32 are arranged concentrically from the center of the package, in order to mount them on an electronic circuit board, the pins are bent in the middle of the lead pins 32, and holes are made in the electronic circuit board to insert the lead pins 32. The structure had poor mass productivity, such as soldering, which was unsuitable for the electronic component mounting process.
[0015]
Therefore, the present invention has been proposed in view of the above-described problems, and is particularly suitable for mounting a light emitting / receiving type optical semiconductor element, and is excellent in mass productivity, small in size, excellent in high frequency characteristics and highly reliable. It is an object to provide a package and an optical module using the same.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, an optical package according to the present invention includes a substrate on which an optical semiconductor element is mounted, a laminated structure including a plurality of dielectric layers, a conductor pattern formed on the front and back surfaces of the laminated structure, A stepped conductor formed inside the laminated structure and including a conductor pattern and a through-hole conductor, and a lead conductor for wiring to an external circuit board; the lead conductor is provided in the laminated structure; The conductive pattern formed on the surface of the multilayer structure is electrically connected to the conductor pattern formed on the surface of the multilayer structure via the step-shaped conductor, and the conductive pattern formed on the surface of the multilayer structure is electrically connected to the optical semiconductor element mounted on the surface of the base. Signals can be input and output.
[0017]
Further, in the above configuration, an interval between the through-hole conductors adjacent to each other is set to １ ／ or less of a wavelength of the electric signal.
[0018]
Further, the step-shaped conductor is formed of a coplanar line, and a distance between the through-hole conductors adjacent to each other is gradually reduced as approaching a conductor pattern formed on the surface of the laminated structure.
[0019]
Further, the lead conductor is held on at least three surfaces.
[0020]
Further, a capacitor is formed in a part of the laminated structure.
[0021]
Further, an electronic element for driving the optical semiconductor element is mounted on a front surface or a back surface of the laminated structure.
[0022]
Further, a radiation fin is attached to a surface except for the surface of the laminated structure.
[0023]
Further, the radiation fin is connected to a conductor pattern for mounting the electronic element or the optical semiconductor element.
[0024]
Further, an optical module according to the present invention is obtained by mounting at least an optical semiconductor element on any one of the optical packages described above. Specifically, an optical semiconductor element alone, or an optical semiconductor element and an electronic element are mounted on an optical package, an optical waveguide is fixed above the optical semiconductor element, and the side surface of the concave portion and the lead conductor are connected to an external electronic device. It is fixed to the side end of the circuit board, converts the electric signal on the external electronic circuit board into an optical signal, and takes out the optical signal to the side end through the waveguide, or faces the side end. Thus, the optical signal guided through the waveguide is converted into an electric signal, and the electric signal is extracted on the external electronic circuit board.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of an optical package and an optical module using the same according to the present invention will be described in detail with reference to the drawings schematically showing the embodiments.
[0026]
1 to 4 are views for explaining an optical package P1 according to the present invention. FIG. 1 is a perspective view of the front side of the optical package P1, FIG. 2 is a perspective view of the rear side of the optical package P1, and FIG. 2 is a perspective view from another angle, and FIG. 4 is a perspective view showing the internal wiring structure in FIG. 5 and 6 are views for explaining a state where the VCSEL is mounted on the optical package P1, FIG. 5 is a perspective view of the front side of the optical package P1, and FIG. 6 is a sectional view of FIG. FIG. 7 is a cross-sectional view (a conductor pattern for electric wiring and a through-hole conductor are omitted from the drawing) for explaining a state in which a radiation fin is attached to the optical package P1. FIG. 8 is a perspective view illustrating an optical module M1 according to the present invention. FIG. 9 is a side view illustrating a state in which the optical transceiver assembly A1 is configured by mounting the light M1 together with a receiving module and other electronic components on an external electronic circuit board.
[0027]
The optical package P1 of the present invention has a substrate 1 having a laminated structure composed of a plurality of dielectric layers, a conductor pattern 11 formed on a surface 16 of the substrate 1, and a conductor pattern 12 (12a, 12b) formed on an inner layer of the substrate 1. , 12c), the conductor pattern 13 formed in the concave portion 18 on the back surface of the base and the through-hole conductor 10 connecting them, and the mounting surface 19 (described later) of the optical module on the external electronic circuit board (the side surface of the concave portion 18 on the back surface of the base). It is a lead conductor attached, which comprises an external electrode lead 14 held on at least three surfaces, and a metal fitting 2 bonded to a surface 16, and a VCSEL element 9 and other VCSELs are formed in a cavity 15 formed on the surface 16. The driver 23 and the like are mounted so that the gold ribbon 20 can be electrically connected to one end of the conductor pattern 10. Here, the conductor pattern 12 and the through-hole conductor 10 constitute a step conductor, and the external electrode lead 14 and the conductor pattern 11 formed on the surface of the laminated structure are electrically connected via the step conductor. To allow an electrical signal to be input and output from the conductor pattern 11 formed on the surface of the laminated structure to the optical semiconductor element mounted on the surface of the base 1.
[0028]
In the optical module M1 of the present invention, the VCSEL element 9 and other VCSEL drivers 23 and the like are mounted in the cavity 15 of the optical package P1, and are electrically connected to one end of the conductor pattern 10 of the optical package P1 by the gold ribbon 20. Above 16, an optical waveguide (mainly an optical fiber 22 and a ferrule 21 accommodating the optical fiber 22, a lens (not shown)) optically connected to the VCSEL element 9 is supported by a metal fitting 2 as a support, a transparent window fitting 3, The first metal protection body 4 and the second metal protection body 5 are attached to each other, and the mounting surface 19 of the optical module to the external electronic circuit board is fixed to the mounting surface of the mounting base 8. And the external electrode leads 14 can be electrically connected.
[0029]
First, the configuration of the optical package P1 will be described in detail.
[0030]
The electrical wiring of the optical package P1 is composed of a high-frequency signal line used for optical modulation of the VCSEL element 9 and a DC line used for applying a bias voltage to the VCSEL element 9, and is provided with a through-hole conductor 10, conductor patterns 11, 12, 13 and an external circuit, respectively. It is configured using a part of the electrode lead 14.
[0031]
The high-frequency signal line of the electric wiring of the optical package P1 is such that the signal conductors 10c, 11c, 12c, 13c, 14c are sandwiched between the ground conductors 10a, 11a, 12a, 13a, 14a and the ground conductors 10b, 11b, 12b, 13b, 14b. To form a coplanar electrode. The high-frequency signal line adjusts the size of the signal conductor and the distance between the signal conductor and the ground conductor so as to match the characteristic impedance (for example, 25Ω or 50Ω) of the external wiring formed on the external circuit board.
[0032]
In the mounting method shown here, the VCSEL element 9 is mounted so as to transmit a high-frequency signal incident from the rear and rear thereof to an electrode formed on the surface for miniaturization. is necessary. However, the bent portion causes deterioration of reflection characteristics, transmission characteristics, and group delay characteristics in transmission characteristics, which are transmission characteristics of a high-frequency signal, due to impedance mismatching or the like.
[0033]
Therefore, the conductor pattern 12 and the through-hole conductor 10 are arranged in a step-like manner, and the conductor pattern 11 and the conductor pattern 13 are smoothly connected. In addition, the distance between the signal conductor and the ground conductor is gradually increased from the conductor pattern 13 to the conductor pattern 11 so that an electrode (not shown) formed on the surface of the VCSEL element 9 and one end of the conductor pattern 10 can be shortly electrically wired. Spread or narrow.
[0034]
The connection point between the conductor pattern 12 and the through-hole conductor 10 forms a bent portion (bent portion). The interval between the connection points, that is, the interval between the centers of the through-hole conductors 10 adjacent to each other, is a high-frequency signal transmitted. By making the wavelength shorter than ４ (λ / 4), the change in the characteristic impedance of the high-frequency signal line acting on the high-frequency signal can be reduced.
[0035]
Actually, even if the characteristic impedance changes at intervals of λ / 4, the transmission characteristics of the high-frequency signal are deteriorated to a considerable extent. Therefore, it is preferable that the interval between the connection points is made 1/4 or less of λ / 4.
[0036]
For example, when transmitting a high-frequency signal having a bandwidth of 15 GHz into a dielectric material having a relative dielectric constant of 9, the highest frequency of the high-frequency signal is 15 GHz and its wavelength λ _15G Is about 6.7 mm. In this case, the length of the through-hole conductor 10 and the conductor patterns 11, 12, and 13 is λ _15G / 16, which is shorter than about 0.42 mm, and each contact is arranged so as to be smoothly connected from the conductor pattern 11 to the conductor pattern 13.
[0037]
By configuring the high-frequency signal line of the optical package P1 in this manner, a high-frequency electric signal is incident on the surface of the VCSEL element 9 perpendicularly from the rear side of the VCSEL element 9 and the optical signal is emitted forward of the surface. Can be configured in a small size and in a wide band. For example, an optical module is mounted on a side end and can be suitably used for an optical module assembly of a thin card type or the like inserted into a slot. Further, since the base 1 is a dielectric, many fine wirings can be formed, and it can be used for a complicated circuit handling a large number of signals.
[0038]
The DC line of the electric wiring of the optical package P1 is constituted by a part of each of the through-hole conductor 10, the conductor patterns 11, 12, and 13, and the external electrode lead 14. Part of the DC line is connected to a comb-shaped parallel plate conductor 12d constituting a capacitor.
[0039]
By configuring the DC line of the optical package P1 in this manner, the fluctuation of the DC voltage applied to the VCSEL element 9 can be reduced with a simple structure, and the operation of the VCSEL element 9 can be stabilized. Further, since the base 1 is a dielectric, many fine wirings can be formed, and it can be used for a complicated circuit handling a large number of signals.
[0040]
A part of the through-hole conductor 10 and the conductor pattern 12 is further provided with a heat-dissipating through-hole conductor 10 e and a heat-dissipating conductor pattern 12 e for heat dissipation of the VCSEL element 9 or the VCSEL driver 23, and provided with a heat dissipation fin 24. The heat dissipation through-hole conductor 10e, the heat dissipation conductor pattern 12e, and the heat dissipation fins 24 are thermally connected to secure a heat dissipation path.
[0041]
By configuring the heat radiating structure of the optical package P1 in this manner, a wide heat radiating surface is easily secured on a surface other than the surface 16 of the base 1, and the VCSEL element 9, the VCSEL driver 23, etc. mounted on the optical package P1 are cooled. And has the effect of making them operate stably.
[0042]
Next, another configuration of the optical package P1 will be described in detail.
[0043]
As a dielectric material used for the base 1, a ceramic material such as alumina, aluminum nitride, or glass ceramic can be used.
[0044]
The conductor patterns 11, 12, and 13 are formed by printing a conductor film containing any of Au, Ni, Cu, W, Mo, and the like, and are connected by through-hole conductors 10 made of Cu, W, and the like.
[0045]
One end of the external electrode lead 14 is accommodated in a recess called a castellation provided on a mounting surface 19 of the optical module on an external electronic circuit board, and one end of the external electrode lead 14 is brazed with silver.
[0046]
Thus, the external electrode lead 14 is fixed to the base 1 on the three surfaces at one end of the external electrode lead 14, so that the base 1 can be firmly fixed to the mounting base 8. In addition, since the mounting surface 19 of the optical module on the external electronic circuit board can be tightly attached to the mounting base 8 without any gap or with a small gap, stable mounting of high-frequency signal transmission characteristics can be achieved.
[0047]
In the present embodiment, the external electrode leads 14 are used as connection terminals with the mounting base 8, but instead of these external electrode leads 14, a terminal electrode group composed of a plurality of grid-shaped terminal electrodes is formed in at least three regions. May be formed.
[0048]
By using a ball-shaped grid array to which solder balls are added instead of the external electrode leads 14 as electrode terminals, convenience in mounting the optical module M1 using the optical package P1 is improved.
[0049]
Further, in this embodiment, the mounting of the VCSEL element 9 has been described. However, the same effects as described above can be obtained when the optical package P1 is used for mounting a surface light emitting / receiving optical semiconductor element such as a PIN-PD or an APD. Can be played.
[0050]
By taking measures to secure an optical path vertically above the surface 16, edge-emitting optical semiconductor elements such as a Fabry-Perot laser diode (FP-LD) and a distributed feedback laser diode (DFB-LD), a waveguide type The present invention can also be used for an end face light receiving type optical semiconductor element such as a photodiode (WG-PD), and can provide the same effects as described above.
[0051]
When mounting the VCSEL, the VCSEL driver, and the electronic elements for the peripheral circuit, a part of them may be mounted in another cavity formed on the back surface 17 in addition to mounting all of them in the cavity 15.
[0052]
When mounting a transimpedance and its peripheral circuit electronic elements as a PIN-PD or APD and a preamplifier in the same manner as the mounting of the VCSEL, a part of them is formed on the back surface 17 except that all are mounted on the cavity 15. It may be mounted in another cavity.
[0053]
The same applies to the implementation of the FP-LD, DFB-LD, or WG-PD.
[0054]
By mounting in this way, a large mounting area can be taken with the same optical package size, many elements can be mounted, and an optical semiconductor element and peripheral circuits for driving the same can be integrated. Thus, a high-performance optical module that is small and capable of performing complicated processing can be realized. Further, since the optical semiconductor element and the peripheral circuit for driving the optical semiconductor element are close to each other, deterioration of electric signals in electric wiring connecting them is small.
[0055]
Next, the configuration of the optical module M1 in which the VCSEL element 9 is assembled as a module using the optical package P1 will be described in detail.
[0056]
In the optical module M1, the VCSEL element 9 is mounted on the optical package P1 together with the VCSEL driver 23 and the like, and after the electrical wiring is performed, the VCSEL element 9 and the optical waveguide are optically aligned, and the optical waveguide is supported. To complete the optical package P1.
[0057]
Specifically, first, the VCSEL element 9 is mounted together with the VCSEL driver 23 and the like in the cavity 15 of the base 1 which is a mounting base, and the electrode (not shown) of the VCSEL element 9 or the VCSEL driver 23 and one end of the conductor pattern 11 are provided. Are electrically connected by a gold ribbon 20.
[0058]
Next, the transparent window fitting 3 is disposed on the metal fitting 2 of the base 1 so as to cover the VCSEL element 9. A transparent sapphire window (not shown) is provided in an upper opening of the transparent window fitting 3. Then, a first metal protector 4 having a cylindrical shape and a flange 4a formed on one end side is disposed on the transparent window fitting 3 such that the flange 4a is on the base 1 side. A lens (not shown) is accommodated inside the first metal protector 4 and is fixedly adhered with a transparent adhesive. Further, a cylindrical ferrule 21 in which an optical fiber 22 to be optically connected to an LD is housed in a cylindrical second metal protector 5 in the same manner as the first metal protector 4 is provided. The second metal protector 5 is accommodated in the first metal protector 4. As described above, the first and second metal protectors 4, 5 are provided with the flanges 4a, 5a, so that an optical connector receptacle (not shown) can be fitted.
[0059]
If necessary, an optical isolator for removing reflected return light propagating through the optical fiber 22 is provided inside the metal protection body 4.
[0060]
The metal fitting 2 is made of Kovar or the like, and is brazed to the base 1. Further, after mounting the VCSEL element 9 on the transparent window metal member 3 made of Kovar or stainless steel and having a sapphire window and provided with a sapphire window, the VCSEL element 9 is seam-welded to the VCSEL element 9. It is tightly sealed. Thereby, the VCSEL element 9 can be protected for a long life.
[0061]
The first metal protector 4 and the second metal protector 5 are made of Kovar or stainless steel.
[0062]
Finally, mounting of the optical module M1 on an external electronic circuit board will be described.
[0063]
The optical module M1 is mounted on a side end 8a of a mounting base 8 which is an external electronic circuit board. At the same time, an IC 6 for driving the optical module M1 and electronic elements 7 such as a capacitor and a resistor constituting a peripheral circuit thereof are also mounted on the mounting base 8, thereby completing the optical module assembly A1.
[0064]
With the structure in which the external electrode leads 14 are attached to the mounting surface 19 of the optical module on the external electronic circuit board, solder such as cream solder is applied to the mounting electrodes of the mounting substrate in advance on the surface of the mounting substrate 8, The M1, the IC 6, and the electronic element 7 can be packaged together through a solder reflow process at about 260 ° C.
[0065]
As described above, according to the present embodiment, the optical module can be assembled together with the components constituting the peripheral circuit on the external electronic circuit board in an automated batch by solder reflow or the like, and the mountability is excellent.
[0066]
Thus, according to the optical package P1 and the optical module M1 using the same, the optical package P1 is suitable for mounting an optical semiconductor element of a surface light emitting / receiving type such as a VCSEL, is excellent in mass productivity, is small, has excellent high-frequency characteristics, and has high reliability. An optical package and an optical module using the same can be provided.
[0067]
【Example】
An embodiment of the optical package P1 according to the present invention will be described below.
[0068]
The substrate 1 was formed by laminating six layers of sheet-like alumina ceramics having a size of 3.9 mm square, a thickness of 0.25 mm, and a relative dielectric constant of 9.4. Conductor patterns 11, 12, and 13 were formed in each layer, and the layers between the conductor patterns 11, 12, and 13 in each layer were connected by through-hole conductors 10 having a diameter of 0.1 mm to form electric wiring. At this time, the conductor pattern 13 and the through-hole conductor 10 were arranged in a stepwise manner, and the conductor pattern 11 and the conductor pattern 13 were smoothly connected.
[0069]
Further, the cavity 15 was formed by forming a hole in one layer of the surface 16 on the surface 16 of the base 1. Also, a concave portion 18 on the rear surface of the substrate is formed on the rear surface 17 of the substrate 1 by the same method, and the mounting surface 19 (the side surface of the concave portion 18 on the rear surface of the substrate) of the optical module is 0.3 mm wide and deep. A castellation having a thickness of 0.2 mm was formed.
[0070]
Further, an external electrode lead 14 having a width of 0.2 mm, a thickness of 0.15 mm, and a length of 1.98 mm was fixed to the castellation with a silver solder. A gap of 0.05 mm between the castellation and the external electrode lead 14 was filled with silver solder over a length of 0.48 mm in the length direction of the external electrode lead 14 so that three surfaces of the external electrode lead 14 were in contact with the silver solder.
[0071]
Finally, a metal fitting 2 made of a FeNiCo alloy having a width of 0.4 mm and a thickness of 0.5 mm was silver-brazed on the surface 16 of the base 1 to complete the optical package P1.
[0072]
The optical package P1 is mounted on the side end 8a of the mounting substrate 8 on which the coplanar line having the characteristic impedance of 50Ω is formed, and the coplanar line on the mounting substrate 8 and the external electrode leads 14 are electrically connected. As a result of inputting and outputting an electric signal between one end of the coplanar line and one end of the conductor pattern 11 and measuring the frequency response characteristics, the characteristics shown in FIG. 10 were obtained. From this result, it was confirmed that the reflection characteristics were significantly improved by arranging the conductor pattern 13 and the through-hole conductor 10 in a stepwise manner and smoothly connecting the conductor pattern 11 and the conductor pattern 13.
[0073]
【The invention's effect】
According to the optical package of the present invention and the optical module using the same, the following remarkable effects can be obtained.
[0074]
According to the optical package of the first aspect, the optical module can be configured in a small size and in a wide band. For example, the optical module is suitably used for a photoelectric conversion module assembly of a thin card type or the like in which the optical module is mounted at an end portion and inserted into a slot. Becomes possible. Further, a large number of fine wirings can be formed, and it can be used for a complicated circuit handling a large number of signals.
[0075]
According to the optical package of the second aspect, the electric wiring of the optical package can be further widened.
[0076]
According to the optical package of the third aspect, it is possible to broaden the total high-frequency characteristics of converting optical to light in the optical package in which the optical semiconductor element is mounted.
[0077]
According to the optical package of the fourth aspect, the base can be firmly fixed to the external electronic circuit board. In addition, since the mounting surface of the optical module can be closely attached to the external electronic circuit board without any gap or with a small gap, mounting with stable transmission characteristics of a high-frequency signal can be performed.
[0078]
According to the optical package of the fifth aspect, the fluctuation of the DC voltage applied to the optical semiconductor element or the electronic element can be reduced with a simple structure, and the operation of the optical semiconductor element or the electronic element mounted on the optical package can be stabilized. it can.
[0079]
According to the optical package of the sixth aspect, deterioration of a signal for operating the optical semiconductor element is small. Further, a module including an electronic circuit for operating the optical semiconductor element can be downsized.
[0080]
According to the optical package of the seventh aspect, it is possible to easily secure a wide heat radiation surface on a surface other than the surface of the base, cool the optical semiconductor element or the electronic element mounted on the optical package, and operate them stably. Can be.
[0081]
According to the optical package of the eighth aspect, since the radiation fin is connected to the conductor pattern for mounting the electronic element or the optical semiconductor element, the cooling effect can be further enhanced.
[0082]
According to the optical module of the ninth aspect, it is excellent in mountability on an external electronic circuit board, and exhibits excellent effects in miniaturization, broadening of the band, high reliability, and improvement in mass productivity.
[Brief description of the drawings]
FIG. 1 is a front perspective view schematically illustrating an embodiment of an optical package according to the present invention.
FIG. 2 is a perspective view on the back side schematically illustrating an embodiment of the optical package according to the present invention.
FIG. 3 is a perspective view schematically illustrating the embodiment of the optical package according to the present invention from another angle on the back surface side.
FIG. 4 is a perspective view showing an internal state schematically illustrating an embodiment of the optical package according to the present invention.
FIG. 5 is a diagram schematically illustrating an embodiment of the optical package according to the present invention, and is a perspective view illustrating a state where a surface emitting laser (VCSEL) is mounted on the optical package.
FIG. 6 is a diagram schematically illustrating an embodiment of the optical package according to the present invention, and is a cross-sectional view illustrating a state where a surface emitting laser (VCSEL) is mounted on the optical package.
FIG. 7 is a diagram schematically illustrating another embodiment of the optical package according to the present invention, in which a conductor pattern for heat dissipation is formed inside the optical package, and the heat dissipation fin is mounted on the outside of the package; FIG. 6 is a cross-sectional view showing a structure when the connection is made to the.
FIG. 8 is a perspective view schematically illustrating an embodiment of the optical module according to the present invention.
FIG. 9 is a side view schematically illustrating a state where the optical module according to the present invention is mounted on an external electronic circuit board.
FIG. 10 is a graph illustrating frequency response characteristics of electric wiring of the optical package according to the present invention.
FIG. 11 is a cross-sectional view schematically illustrating an example of an optical package and an optical module using the same according to the related art.
FIG. 12 is a diagram illustrating frequency response characteristics of electric wiring of the optical package according to the related art, and is a graph illustrating reflection characteristics (S11).
FIG. 13 is a diagram illustrating frequency response characteristics of electric wiring of the optical package according to the related art, and is a graph illustrating transmission characteristics (S21).
[Explanation of symbols]
1: Substrate
2: Metal fittings (constituting support)
3: Transparent window fitting (constituting support)
4: First metal protector (constituting support)
5: Second metal protector (constituting support)
6: IC
7: Electronic element
8: Mounting base (external electronic circuit board)
8a: Side end (external electronic circuit board)
9: VCSEL device (surface emitting laser device; optical semiconductor device)
10: Through-hole conductor (configured with ground conductors 10a and 10b and signal conductor 10c)
10e: Heat dissipation through-hole conductor
11: Conductor pattern (configured with ground conductors 11a and 11b and signal conductor 11c formed on the surface of the base)
12: Conductor pattern (configured with ground conductors 12a and 12b and signal conductor 12c formed in the inner layer of the base)
12d: comb-shaped parallel plate conductor (constituting a capacitor)
12e: Heat dissipation conductor pattern
13: Conductor pattern (configured with ground conductors 13a and 13b and signal conductor 13c formed on the back surface of the base)
14: External electrode lead (lead conductor)
15: Cavity
16: Surface of base
17: Back of base
18: recess on the back of the base
19: Mounting surface of optical module on external electronic circuit board (side surface of 18)
20: Au wire
21: Ferrule (constituting optical waveguide)
22: Optical fiber (constituting optical waveguide)
23: VCSEL driver (electronic element)
24: Heat radiation fin
30: stem (constituting TO-CAN package)
31: Cap (constitutes TO-CAN package)
31a: Transparent window
32: Lead pin
33: Glass feedthrough
40: VCSEL device (surface emitting laser device)
41: Gold wire
P1: Optical package
M1: Optical module
A1: Optical module assembly

Claims (9)

A substrate on which an optical semiconductor element is to be mounted includes a laminated structure including a plurality of dielectric layers, a conductor pattern formed on the front and back surfaces of the laminated structure, and a conductor pattern and a through-hole conductor formed inside the laminated structure. A stepped conductor, and a lead conductor for wiring to an external circuit board, the lead conductor being provided in the laminated structure, and the lead conductor and a conductor pattern formed on a surface of the laminated structure being combined with the stepped conductor. An optical package electrically connected to the optical semiconductor element mounted on the surface of the base from a conductor pattern formed on the surface of the laminated structure. . 2. The optical package according to claim 1, wherein a distance between the through-hole conductors adjacent to each other is set to １ ／ or less of a wavelength of the electric signal. 3. The light according to claim 2, wherein the stepped conductor is formed of a coplanar line, and a distance between the adjacent through-hole conductors is gradually reduced as approaching a conductor pattern formed on a surface of the multilayer structure. 4. package. The optical package according to claim 1, wherein the lead conductor is held on at least three surfaces. The optical package according to claim 1, wherein a capacitor is formed in a part of the laminated structure. The optical package according to claim 1, wherein an electronic element for driving the optical semiconductor element is mounted on a front surface or a rear surface of the stacked structure. 7. The optical package according to claim 1, wherein a radiation fin is attached to a surface of the laminated structure other than the surface. The optical package according to claim 7, wherein the heat radiation fin is connected to a conductor pattern for mounting the electronic element or the optical semiconductor element. An optical module comprising at least an optical semiconductor element mounted on the optical package according to claim 1.

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