JP2619523B2 - LD chip carrier fixing structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding an LD chip carrier fixing structure, a metal member is embedded on a ceramic substrate of a Peltier device, and the metal member is interposed therebetween, so that the LD chip carrier and the Peltier device can be easily laser-welded. An LD chip carrier made of a metal material on which an LD chip is mounted and a ceramic substrate of a Peltier element with the object of providing an LD chip carrier fixing structure that enables secure fixing and further improves the adhesion between the two. In the structure for fixing the LD chip carrier, a metal member is embedded in a region on the ceramic substrate close to a contact surface between the LD chip carrier and the ceramic substrate and a predetermined gap is provided between the LD chip carrier and the metal member. And by irradiating the laser over the metal member to weld them, A ceramic substrate of the Peltier element configured to closely fixed.

[Industrial applications]

The present invention relates to a structure for fixing an LD chip carrier made of a metal material on which an LD chip is mounted to an insulating ceramic substrate of a Peltier device.

[Conventional technology]

Laser diode (hereinafter, LD) on the light emitting side for optical communication
In the module, proper temperature control of the LD chip is performed to ensure stable performance and the like (for example, the oscillation wavelength changes when the temperature changes). For example, as shown in FIG. 3, an LD chip carrier 51 made of a metal material on which an LD chip (not shown) is mounted is closely fixed to an insulating ceramic substrate 52a of a Peltier element 52.
Control the temperature of the LD chip. The fixing between the LD chip carrier 51 and the ceramic substrate 52a is performed in consideration of heat transfer (mainly cooling characteristics) and mounting strength.
After metallizing (Au) 53 the mounting upper surface of the 52a, the LD chip carrier 51 is entirely adhered thereon, and is mounted and fixed with solder.

[Problems to be solved by the invention]

However, in the conventional fixing method by soldering, work must be performed in an inert gas atmosphere in order to improve the reliability of the soldering, and the desired mounting of the LD chip carrier 51 due to the creep phenomenon of the solder 54. There is a disadvantage that it is difficult to maintain accuracy. For this reason, it is desirable that work in an inert gas atmosphere is unnecessary and that the LD chip carrier 51 can be fixed by laser welding having excellent mounting strength. However, since the ceramic material cannot be laser-welded, not only the ceramic substrate 52a but also the metallized ceramic substrate 52a and the LD
It is practically impossible to directly perform laser welding with the chip carrier 51.

In addition, if there is a gap between the LD chip carrier and the Peltier element, the heat insulating space causes the LD by the Peltier element.
Since the cooling (heating) efficiency of the chip is reduced, it is desired that the LD chip carrier and the ceramic substrate (Peltier element) be in close contact with each other.

In view of the above, in the present invention, a metal member is embedded on a ceramic substrate,
It is an object of the present invention to provide an LD chip carrier fixing structure that enables laser welding between a chip carrier and a ceramic substrate and further improves the adhesion between the two.

[Means for solving the problem]

According to an LD chip carrier fixing structure according to the present invention for solving the above object, according to a structure for fixing an LD chip carrier made of a metal material on which an LD chip is mounted and a ceramic substrate of a Peltier element, the LD chip carrier and the ceramic are fixed. By embedding a metal member in a region on the ceramic substrate close to the contact surface with the substrate and providing a predetermined gap between the LD chip carrier and the metal member, and performing laser irradiation across the LD chip carrier and the metal member. These are welded, and the LD chip carrier and the ceramic substrate of the Peltier element are adhered and fixed to each other by a structural feature.

(Operation)

The Peltier element, the metal member embedded on the ceramic substrate, and the LD chip carrier are welded by laser irradiation.
Thereby, the LD chip carrier and the Peltier element are securely fixed. In addition, since there is a predetermined gap between the metal member and the LD chip carrier, an adhesion force due to a condensing force acts on this portion after welding, and the adhesion between the two members is improved.

〔Example〕

 Hereinafter, the present invention will be described based on illustrated embodiments.

1 and 2 show an embodiment of the present invention, wherein 1 is a LD chip carrier made of stainless steel on which an LD chip (not shown) is mounted, and 2 is a Peltier element. Generally, a Peltier element is used to mainly cool a small-capacity element by utilizing an endothermic / heat-generating phenomenon that occurs when two types of conductors are connected to each other at both ends and an electric current flows. 2a is a ceramic substrate for Peltier element 2 insulation.

As described above, the LD chip carrier 1 and the ceramic substrate 2a
Since it is difficult to directly fix by welding with a laser, a low heat conductive metal, for example, stainless steel is first embedded in the ceramic substrate 2a by a method such as sintering (in this case,
(Embedded in, for example, an inverted T-shape as shown in the figure so that it is difficult to come out upward). Is provided. Then, laser irradiation is performed over the LD chip carrier 1 and the embedded member 5. As a result, the laser irradiation portions of both members 1 and 5 are melted and integrated, and the LD chip carrier 1 can be fixed to the embedded member 5 and thus to the ceramic substrate 2a of the Peltier element 2. That is, laser welding can be performed, and the disadvantages associated with the conventional soldering operation can be eliminated. Moreover, the step H
Is provided, a tensile force is inherent between the two members 1 and 5 due to solidification shrinkage after welding at the laser welded portion (irradiated portion) A, and the LD chip carrier 1 and the ceramic substrate
As a result of the increase in the contact force of the contact surface 2a at the contact surface S, the Peltier element 2
It is possible to maintain and improve the cooling (or heating) efficiency of the LD chip (not shown).

The laser welding portion A may be discontinuous as shown in the drawing or may be continuously formed along a line.

〔The invention's effect〕

As described above, according to the present invention, it is possible to eliminate the disadvantages of the above-described prior art associated with soldering, to easily and reliably fix the LD chip carrier to the Peltier element by laser welding, and to improve the adhesion between the two. The cooling (heating) efficiency can be maintained and improved.

[Brief description of the drawings]

1 is a perspective view of one embodiment of an LD chip carrier fixing structure according to the present invention, FIG. 2 is a front view of the embodiment shown in FIG. 1, and FIG. 3 is a front view of a conventional LD chip carrier fixing structure. It is. 1 ... LD chip carrier, 2 ... Peltier element, 2a ... Ceramic substrate, 5 ... Embedded member, A ... Laser welded part, H ... Step, S ... Contact surface.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsushi Higaki 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (56) References JP-A-62-137174 (JP, A) (JP, U)

Claims (1)

(57) [Claims] In a structure for fixing an LD chip carrier (1) made of a metal material on which an LD chip is mounted and a ceramic substrate (2a) of a Peltier element (2), the LD chip carrier (1) and the ceramic substrate (2a) are fixed. The metal member (5) is embedded in the region on the ceramic substrate (2a) close to the contact surface (S) with the LD chip carrier (1) and the metal member (5).
A predetermined gap (H) is provided between the LD chip carrier (1) and the metal member (5), and these are welded by irradiating a laser beam over the LD chip carrier (1) and the metal member (5). An LD chip carrier fixing structure, wherein the LD chip carrier is fixed to the ceramic substrate (2a) in (2).