JPH07128550A - Optical module package - Google Patents

Abstract

PURPOSE:To provide the optical package having joined parts which are excellent in solder joinability and are high in reliability by specifying the thickness of an Au plating layer to be formed in the joining parts on main constituting members to be solder joined by using a solder material consisting essentially of at least >=1 kinds of a group consisting of Pb, Sn, In and Bi. CONSTITUTION:This hermetic optical module package consists of a heath radiating plate 4, a case 1, a case cap 2, a ceramic introducing terminal 3 and a window as its main constituting members and is internally mounted with a light emitting element. The Au plating layers of a thickness of <=0.77mum are formed on the joining parts on the main constituting members to be solder joined by using the solder material consisting essentially of at least >=1 kinds of the group consisting of Pb, Sn, In and Bi. The thickness of the Au plating layers formed in the joining parts on the main constituting members is confined to <=0.7mum in such a manner and, therefore, the formation of the brittle layers by reaction of the solder material and the Au plating layers is suppressed even if the parts are solder joined by using such solder material. The secure solder joining is thus executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package member constituting an optical module using a semiconductor used in an optical communication device using an optical fiber.

[0002]

2. Description of the Related Art FIG. 1 shows a butterfly type optical module package as an example of an optical module package used in an optical communication device or the like. Usually, this butterfly type optical module package is composed of a case 1, a case lid 2, a ceramic introduction terminal 3, a heat sink 4 and a window as main components, and this package is hermetically sealed.
A window (not shown) is mounted inside the window mounting cylinder 5, and the light generated from the light emitting element mounted inside the optical module package is extracted to the outside from the window. The heat radiating plate plays a role of releasing heat generated during use to the outside of the optical module package.

The ceramic lead-in terminal 3 has a circuit formed of Au or the like on an insulating ceramic. One end of each circuit is inside the optical module package and the other end is outside. It is arranged to be located. Then, the end of the circuit located inside and the light emitting element mounted in the optical module package are connected via a bonding wire, and the other end located outside is connected to a lead wire, The lead wire outside the optical module package and the light emitting element inside are electrically connected.

Usually, Kovar or the like is used for the case 1 and the case lid 2, Cu-W alloy or the like is used for the heat dissipation plate 4, and sapphire or the like is used for the window. In the optical module package consisting of these main components, the case 1, the ceramic introduction terminal 3, and the heat sink 4 among the above components are usually joined by Ag brazing, and Ni and further A
After u or the like is plated, a window is formed by soldering with a solder material such as Au—Sn alloy. Although the wettability of the solder material is improved by forming the Au plating layer, the thickness of the Au plating formed improves the bonding bondability when bonding to the circuit formed on the ceramic introduction terminal 3. Therefore, the thickness is usually 1 μm or more. The case lid 2 is usually joined by seam welding after the light emitting element and the like are mounted in the optical module package.

In addition to the main components described above, various components such as a Peltier cooler are mounted inside the optical module package. Since these are solder-joined in several stages, a solder material having a lower melting point is selected step by step. Of course, the solder material used last among the solder materials used has a melting point higher than the heating temperature due to the heat generated during the use of the optical module.

[0006]

As described above, after the case 1, the ceramic lead-in terminal 3 and the heat sink 4 are assembled, Ni, Au, etc. are added to them in order to improve the wettability with the solder material. After plating, the window and other parts (Peltier cooler, etc.) are soldered. Figure 3
FIG. 3 is an explanatory view showing an example of a heat sink, in which a Peltier cooler is provided with Pb, Sn,
Soldering is performed using a solder material containing In or Bi as a main component, and these solder materials and A formed on the heat dissipation plate are used.
It was easy to form a brittle layer by reacting with the u plating layer. As described above, since the formed Au plating has a thickness of usually 1 μm or more, a large amount of the fragile layer is generated, which causes a problem that the Peltier cooler easily peels off from the heat sink. It was In addition, there has been a problem that the reliability of the joint portion where the components other than the Peltier cooler are soldered using the same solder material as described above is deteriorated.

[0007]

The present invention has been made as a result of various studies in view of the above problems of the prior art.
An optical module package having high reliability by improving the joint strength of a joint portion to be solder-joined by using a solder material containing at least one or more of Pb, Sn, In, and Bi as a main component for the main constituent members. It is the one we are trying to provide. That is, it is an airtight optical module package in which a heat dissipation plate, a case, a case lid, a ceramic introduction terminal, and a window are main constituent members, and a light emitting element is mounted inside, which is a group of Pb, Sn, In, and Bi. An optical module, wherein an Au plating layer having a thickness of 0.7 μm or less is formed at a joint portion on the main constituent member to be solder-joined by using a solder material containing at least one of the above as a main component. It is a package.

[0008]

In the present invention, Pb, Sn, and the like on the main constituent members constituting the optical module package such as the heat sink, the case, the case lid, the ceramic introduction terminal, and the window.
Au formed in a joint portion to be solder-joined by using a solder material containing at least one of In and Bi as a main component
Since the thickness of the plating layer is 0.7 μm or less, even if the components are soldered using the solder material, the generation of a brittle layer due to the reaction between the solder material and the Au plating layer is suppressed. Therefore, soldering can be firmly performed.

[0009]

EXAMPLES The present invention will be described in detail below with reference to examples. As shown in FIG. 2, the heat dissipation plate 4, the case 1, the case ring 6, and the ceramic introduction terminal 3 are assembled, and the JIS BA
Brazing was performed in a hydrogen atmosphere using a g-8 Ag brazing material.

After assembling in this way, the heat sink 4, the case 1, the case ring 6 and the ceramic introduction terminal 3 are made of Ni.
It was plated (thickness: about 3 μm) and further Au-plated (thickness is shown in Table 1). Next, after masking the portion of the heat dissipation plate 4 where the Peltier cooler is soldered (A portion in FIG. 3), Au plating is further performed, and then 0.2 μm of the previously plated A
Together with the u plating layer, the thickness was set to 1.5 μm.

After that, the masking was washed away. The Au plating thickness of the masking A portion is as shown in Table 1. Next, a Peltier cooler was soldered to the portion A. Table 1 shows the solder materials used. Comparative example No. 1
No. 4 does not mask the A portion, and the thickness of the Au plating layer of the A portion is 1.5 μm, and Comparative Example No. 5 is different in that the Au plating thickness of the A portion is 0.8 μm. This is similar to the example of the present invention.

The optical module package (case cover 2 not yet attached) thus manufactured is provided with JIS C7021.
A vibration test was performed under condition D of test method A-7 (the number of tests is 10 each). The number of peeled Peltier coolers generated by this vibration test is also shown in Table 1.

[0013]

[Table 1]

As shown in Table 1, peeling of the Peltier cooler did not occur in the examples of the present invention. On the other hand, in all the comparative examples, peeling of the Peltier cooler occurred. In the present embodiment, the case where the Peltier cooler is solder-joined by using the solder material containing at least one kind or more of the group of Pb, Sn, In, and Bi as the main component is described as an example. The parts to be joined may be other than the Peltier cooler. Even in this case, as in the case of the present embodiment, it is natural that peeling of the solder joint portion is less likely to occur.

[0015]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, an optical package having an excellent solder joint property and a highly reliable joint portion can be obtained, which contributes to high performance of an optical module, and has industrially remarkable effects. It is a thing.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an example of an optical module package of the present invention.

FIG. 2 is a perspective view showing a state in which a case lid of the optical module package of the present invention in FIG. 1 is not attached.

FIG. 3 is an explanatory diagram showing an example of a heat sink of the present invention. In the figure, A is a portion where the Peltier cooler is soldered.

[Explanation of symbols]

 1 case 2 case lid 3 ceramic introduction terminal 4 heat sink 5 window mounting tube 6 case ring

Claims (1)

[Claims] 1. An airtight optical module package in which a light-emitting element is mounted inside, which comprises a heat sink, a case, a case lid, a ceramic introduction terminal and a window as main components, and which is Pb, Sn, In, Bi. At least one of the group
A having a thickness of 0.7 μm or less at a joint portion on the main constituent member to be solder-joined by using a solder material containing at least one kind as a main component.
An optical module package having a u-plated layer.