JP2000236103A - Package for housing optical semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speed up the conversion of optical signals to electrical signals in an optical semiconductor element and transmit the electrical signals correctly to an outside electrical circuit. SOLUTION: A package for housing an optical semiconductor element, consists of a substrate 1 having in an upper face a recessed section 1a for housing an optical semiconductor element 3, a through-hole 1b formed on the side part of the substrate 1 to allow the recessed section 1a for communicating with the outside, a plurality of interconnection layers 4 which are formed from the inner surface of the recessed section 1a over the outer surface of the substrate 1 and which are connected by electrodes of the optical semiconductor element 3, a plurality of external lead terminals 6 attached to the interconnection layers 4 formed on the outer surface of the substrate 1, and a cover 2 for closing the recessed section 1a. The substrate 1 is formed of an insulating material, having a relative permittivity of 6 (at room temperature and 1 MHz) or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor element housing package for housing an optical semiconductor element.

[0002]

2. Description of the Related Art Conventionally, an optical semiconductor device housing package for housing an optical semiconductor device is generally made of an aluminum oxide sintered body, and has a base having a concave portion for housing the optical semiconductor device on an upper surface thereof. A through-hole formed on the side of the base, through which the recess communicates with the outside, and through which an optical fiber for transmitting an optical signal to the optical semiconductor element housed in the recess is inserted,
A plurality of wiring layers made of a refractory metal powder such as tungsten, molybdenum, and manganese formed from the inner surface of the concave portion to the side surface of the base and connected to the electrodes of the optical semiconductor element, and wiring formed on the side surface of the base A plurality of external lead terminals made of a metal material such as an iron-nickel-cobalt alloy attached to the layer, and a lid attached to the upper surface of the base and closing the recess. The optical semiconductor element is bonded and fixed in the concave portion of the base via an adhesive such as glass, resin, brazing material and the like, and each electrode of the optical semiconductor element is electrically connected to a wiring layer via a bonding wire. A lid is bonded to the upper surface of the base via a sealing material made of glass, resin, brazing material, or the like, and the optical semiconductor element is hermetically housed inside a container formed of the base and the lid, and the base is penetrated. The optical semiconductor device as a product by inserting fixing the optical fiber in the hole.

Such an optical semiconductor device irradiates an optical semiconductor element with an optical signal transmitted from an optical fiber, causes the optical semiconductor element to transmit and receive the optical signal, and converts the optical signal into an electric signal. It is used for high-speed communication and the like by transmitting a signal to an external electric circuit via a wiring layer and an external lead terminal.

[0004]

However, in this conventional package for housing an optical semiconductor element, a large number of wiring layers are provided side by side on a side surface of the substrate with an aluminum oxide sintered body forming a substrate therebetween. That the relative permittivity of the aluminum oxide sintered body is 10 (room temperature, 1 MH
z), there is a disadvantage that a large capacitance is formed between adjacent wiring layers, and the conversion of an optical signal into an electric signal in the optical semiconductor element becomes slow due to the large capacitance. Was. Particularly in optical communication, the optical signal transmitted from the optical fiber to the optical semiconductor device is extremely high speed. Cannot be transmitted to the optical communication, which is a fatal drawback for optical communication.

The present invention has been made in view of the above-mentioned drawbacks, and has as its object to increase the speed of converting an optical signal into an electrical signal in an optical semiconductor device, and to convert an optical signal into an electrical signal to provide a predetermined external electrical circuit. It is an object of the present invention to provide an optical semiconductor element housing package that can accurately transmit an optical semiconductor device.

[0006]

According to the present invention, there is provided a base having a concave portion for accommodating an optical semiconductor element on an upper surface, a through hole formed in a side portion of the base and communicating the concave portion to the outside,
A plurality of wiring layers formed from the inner surface of the concave portion to the outer surface of the base and connected to the electrodes of the optical semiconductor element, and a plurality of external layers attached to the wiring layer formed on the outer surface of the base. A lead terminal, attached to the upper surface of the base,
A package for housing an optical semiconductor element comprising a lid for closing the recess, wherein the substrate has a relative dielectric constant of 6 (room temperature, 1M
Hz) or less.

According to the package for housing an optical semiconductor element of the present invention, since the base on which a plurality of wiring layers are formed is formed of an insulating material having a relative dielectric constant of 6 (room temperature, 1 MHz) or less, adjacent substrates are formed. The capacitance between the wiring layers becomes a small value,
As a result, the conversion speed of the optical signal to the electric signal in the optical semiconductor element is no longer high, and the optical signal transmitted through the optical fiber can be surely converted into the electric signal by the optical semiconductor element. The converted electric signal can be accurately transmitted to a predetermined external electric circuit.

[0008]

Next, the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of the package for housing an optical semiconductor element according to the present invention, wherein 1 is a base, and 2 is a lid. The base 1 and the lid 2 constitute a container for housing the optical semiconductor element 3 therein.

The base 1 is provided on its upper surface with a recess 1a forming a space for accommodating the optical semiconductor element 3,
The optical semiconductor element 3 is mounted and fixed on the bottom surface of the concave portion 1a.

The substrate 1 has a relative dielectric constant of 6 (room temperature, 1 MH
z) The following insulating materials, for example, a glass ceramic sintered body, specifically, silicon oxide 44% by weight, aluminum oxide 28% by weight, magnesium oxide 11% by weight, zinc oxide 8
A glass component consisting of 75% by weight of boron oxide and 9% by weight of boron oxide, and a sintered body of 25% by weight of aluminum oxide. While adding and mixing to form a slurry, the slurry is formed into a ceramic green sheet (ceramic green sheet) by employing a doctor blade method or a calendar roll method,
Thereafter, the ceramic green sheet is subjected to an appropriate punching process, and a plurality of the green sheets are laminated to form a ceramic green sheet.
It is manufactured by firing at a temperature of ° C.

A plurality of wiring layers 4 are formed on the substrate 1 from the inner surface of the concave portion 1a to the outer surface of the substrate 1, and a region of the wiring layer 4 exposed in the concave portion 1a has an optical semiconductor element. 3 are electrically connected to each other through bonding wires 5, and external lead terminals 6 connected to an external electric circuit are made of a brazing material such as silver brazing in a region formed on the outer surface of the base 1. It is attached via brazing.

The wiring layer 4 functions as a conductive path for connecting each electrode of the optical semiconductor element 3 to an external electric circuit, and is formed of a metal powder such as copper or silver.

The wiring layer 4 is formed by applying a metal paste obtained by adding a suitable organic binder, a solvent, and the like to a metal powder of copper, silver, or the like to a ceramic green sheet serving as the substrate 1 by a conventionally well-known screen printing method. By printing and applying the pattern on the substrate 1,
Is formed over the outer side surface.

The wiring layer 4 has a relative permittivity of the substrate 1 of 6
(Wiring room temperature, 1 MHz)
As a result, the conversion speed of the optical signal to the electrical signal in the optical semiconductor element 3 can be increased, and the optical signal transmitted through the optical fiber 7 described later can be converted into a smaller value. The optical semiconductor element 3 can reliably convert the electric signal into an electric signal, and the converted electric signal can be accurately transmitted to a predetermined external electric circuit.

When the relative permittivity of the substrate 1 exceeds 6 (room temperature, 1 MHz), the capacitance value between the adjacent wiring layers 4 increases, and the optical signal in the optical semiconductor element 3 is converted into an electric signal. Conversion speed becomes slow. Therefore, the base 1 is specified as an insulating material having a relative dielectric constant of 6 (room temperature, 1 MHz) or less.

The wiring layer 4 is preferably provided with a metal having excellent corrosion resistance such as nickel and gold and excellent wettability with a brazing material to a thickness of 1 μm to 20 μm by a plating method on the exposed surface. In addition, the oxidation corrosion of the wiring layer 4 can be effectively prevented, and the brazing of the external lead terminals 6 to the wiring layer 4 can be firmly performed. Therefore, it is preferable that a metal having excellent corrosion resistance, such as nickel and gold, and excellent in wettability with a brazing material is applied to the exposed surface of the wiring layer 4 to a thickness of 1 μm to 20 μm.

Further, external lead terminals 6 are brazed and attached to the wiring layer 4 via a brazing material such as silver brazing, and the external lead terminals 6 are attached to each of the optical semiconductor elements 3 housed in the container. Acts to electrically connect the electrodes to an external electrical circuit,
By connecting the external lead terminal 6 to an external electric circuit, the optical semiconductor element 3 housed in the container is connected to the external electric circuit via the wiring layer 4 and the external lead terminal 6.

The external lead terminal 6 is made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy.
For example, an ingot made of a metal material such as an iron-nickel-cobalt alloy is formed into a predetermined shape by applying a conventionally known metal working method such as a rolling method or a punching method.

The external lead terminal 6 is coated with a metal having excellent corrosion resistance such as nickel and gold and excellent wettability with a brazing material to a thickness of 1 μm to 20 μm by a plating method on the exposed surface. In addition, when the external lead terminal 6 is connected to an external electric circuit, the connection can be reliably prevented.
It can be made strong. Therefore, the external lead terminal 6 is made of a metal having excellent corrosion resistance such as nickel and gold and excellent wettability with a brazing material of 1 μm to 2 μm on the exposed surface.
Preferably, it is applied to a thickness of 0 μm.

The base 1 to which the external lead terminals 6 are attached
Also, a through-hole 1b is formed on the side portion thereof.

The through hole 1b is formed in a concave portion 1a provided in the base 1.
The optical fiber 7 is inserted into the through hole 1b, and functions as an insertion hole for inserting the optical fiber 7 from the outside to the inside of the container.

The through-holes 1b are formed in the ceramic green sheet serving as the base 1, for example, by forming holes in the ceramic green sheet in advance by a punching method, or by forming a hole in a side portion of the base 1. It is formed in a predetermined shape on the side.

A frame-like base member 8, for example, is brazed around the through hole 1b on the outer surface of the base 1, and a metal flange attached to the optical fiber 7 is attached to the base member 8. 9 is welded using a laser beam such as YAG.

The base member 8 includes the optical fiber 7 and the base 1.
Acts as a base metal material when attaching to steel. For example, it is made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy. It is formed into a predetermined shape by applying a conventionally known metal working method such as a working method.

The base member 8 has a metal layer made of a high melting point metal powder such as tungsten, molybdenum, manganese or the like or a metal layer made of an active metal powder such as titanium on the outer surface of the base 1 and around the through hole 1b. The metal layer is brazed and attached to the metal layer via a brazing material such as silver brazing, so that the metal layer is attached to the outer surface of the base 1 around the through hole 1b.

A metal flange 9 attached to the optical fiber 7 is welded to the base member 8 by using a laser beam such as YAG, so that the optical fiber 7 for transmitting an optical signal to the optical semiconductor element 3 is formed on the base member. It will be fixed to 1.

On the other hand, a lid 2 made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy is joined to the upper surface of the base 1, thereby forming the base 1 and the lid 2. The optical semiconductor element 3 is hermetically sealed inside the container.

The lid 2 is formed into a predetermined shape by subjecting an ingot such as an iron-nickel-cobalt alloy to a conventionally known metal working method such as a rolling method or a punching method. .

Thus, according to the package for housing an optical semiconductor element of the present invention, the optical semiconductor element 3 is mounted and fixed on the bottom surface of the concave portion 1 a of the base 1, and each electrode of the optical semiconductor element 3 is connected to the external lead terminal via the bonding wire 5. 6 and electrically connected to the brazed wiring layer 4
The lid 2 is bonded to the upper surface of the substrate 1, the optical semiconductor element 3 is accommodated in a container formed of the base 1 and the lid 2, and finally the optical fiber 7 is attached to the through hole 1 b formed in the base 1. It becomes an optical semiconductor device as a product.

Such an optical semiconductor device transmits an optical signal from the outside to the optical semiconductor element 3 via the optical fiber 7, converts the optical signal into an electric signal in the optical semiconductor element 3, and converts the converted electric signal into the wiring layer 3 and It is used for optical communication or the like by transmitting it to an external electric circuit via the external lead terminal 6.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. Although formed from a sintered body, the present invention is not limited to this, and may be formed from an organic resin or the like having a relative dielectric constant of 6 (room temperature, 1 MHz) or less.

[0032]

According to the package for housing an optical semiconductor element of the present invention, the base on which a plurality of wiring layers are formed is formed of an insulating material having a relative dielectric constant of 6 (room temperature, 1 MHz) or less. The capacitance between adjacent wiring layers has a small value. As a result, the speed of converting an optical signal into an electrical signal in the optical semiconductor device is no longer high, and the optical signal transmitted via the optical fiber is reliably transmitted to the optical semiconductor device. The electric signal can be converted to an electric signal, and the converted electric signal can be accurately transmitted to a predetermined external electric circuit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a package for housing an optical semiconductor element of the present invention.

FIG. 2 is a side view of the package for storing an optical semiconductor element shown in FIG. 1;

FIG. 3 is a plan view of the package for storing an optical semiconductor element shown in FIG. 1 in a state where a lid is removed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 1a ... Depression 1b ... Through-hole 2 ... Lid 3 ... Optical semiconductor element 4 ... Wiring layer 6 ... External lead terminal 7 ... Optical fiber

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Keitaro Okazaki 1-1, Yamashita-cho, Kokubu-shi, Kagoshima F-term in the Kokubu Plant of Kyocera Corporation (reference) 2H037 BA01 BA11 DA35 5F041 AA02 DA12 DA72 EE06 FF14 5F088 BA02 BB01 GA02 JA05

Claims (1)

[Claims] 1. A base having a concave portion for accommodating an optical semiconductor element on an upper surface, a through hole formed in a side portion of the base and communicating the concave portion to the outside, and formed from an inner surface of the concave portion to an outer surface of the substrate. A plurality of wiring layers to which electrodes of the optical semiconductor element are connected, a plurality of external lead terminals attached to a wiring layer formed on an outer surface of the base, and a plurality of external lead terminals connected to an upper surface of the base. An optical semiconductor element storage package comprising: a cover attached to the semiconductor device; and a lid closing the recess, wherein the substrate is formed of an insulating material having a relative dielectric constant of 6 (room temperature, 1 MHz) or less. Package for element storage.