JPH03146914A - Method for assembling optical component - Google Patents

Abstract

PURPOSE:To make the deviation of an optical axis hard to occur by interposing a metallic member which fuses thermally between a metallic base and a metallic surface, and then fusing the metallic member thermally with laser light and welding the metallic surface to the metallic base. CONSTITUTION:An optical lens 3 such as a Fresnel lens is assembled on the metallic base 1 where an optical element 2 such as a semiconductor is mounted. In a preprocessing stage, a vapor-depositing means deposits a metallic material on part of an optical lens 3 to form the metallic surface 7. Then the optical lens 3 is positioned in front of the optical element 2 and the optical axis is adjusted to set the metallic surface 7 opposite the front surface of the metallic base 1; and the metallic member which fuses thermally is interposed between the front surface of the base 1 and metallic surface 7. Then a laser light source (not shown in figure) is positioned in front of the optical lens 3 and driven to irradiate the metallic member 8 with laser light 9 through the lens 3 and fuse the member 8 thermally, and the fused metal is cooled and solidified to weld the metallic surface 7 and metallic base 1 to each other, thereby fixing the optical lens 3.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is an optical component for assembling an optical component such as a Fresnel lens onto a metal base on which an optical element such as a semiconductor laser or a light emitting diode is mounted. Regarding the assembly method.

<Prior Art> FIG. 2 shows a conventional method of assembling optical components. 1
is a metal base, and an optical element 2 such as a semiconductor laser or a light emitting diode is mounted on the upper surface of the base. The optical axis 4 is adjusted by positioning a flat optical lens 3 such as a Fresnel lens in front of the optical element 2. At this time, there is a gap between the optical lens 3 and the front surface of the metal base A cured resin 5 is interposed. Next, a light source (not shown) is driven in front of the optical lens 3 to irradiate the ultraviolet curing resin 5 with ultraviolet rays 6 to cure the resin, and the optical lens 3 is bonded and fixed to the metal base 1.

<Problems to be Solved by the Invention> However, in this method of assembling optical components, since the ultraviolet curing resin 5 has a large coefficient of thermal expansion after curing, the ultraviolet curing resin 5 expands with changes in ambient temperature. There is a possibility that the optical lens 3 will be displaced and the optical axis alignment will be shifted.

FIG. 3 shows a state in which the optical lens 3 is displaced and tilted due to this resin deformation, and its optical axis 4 is deviated from the proper position by an angle θ.

The present invention was made in view of the above problem, and an object of the present invention is to provide a method for assembling optical components with excellent temperature characteristics by bonding and fixing optical components onto a metal base by metal fusion. do.

<Means for Solving the Problems> The present invention provides a pretreatment step for forming a metal surface on a part of the optical component and a metal base when assembling the optical component on a metal base on which an optical element is mounted. positioning the optical component at a predetermined position of the stand with the metal surfaces facing each other, and interposing a heat-melting metal member between the metal base and the metal surface, and irradiating the metal member with laser light. The optical component is bonded and fixed by bonding the metal surface to the metal base by thermally melting the metal member.

<Function> Since the optical component is bonded and fixed to the metal base by metal fusion, the coefficient of thermal expansion of the bonded portion is smaller than that when ultraviolet curing resin is used. Therefore, even if the ambient temperature changes, the displacement of the optical component due to thermal expansion of the joint is small, and the optical axis is less likely to shift.

<Embodiment> FIG. 1 shows a method for assembling optical components according to an embodiment of the present invention.

The illustrated example is a method for assembling an optical lens 3 such as a Fresnel lens on a metal base l on which an optical element 2 such as a semiconductor laser or a light emitting diode is mounted, and includes a pretreatment process 2 and a positioning process.

Each step of the bonding process is performed in series.

In the pretreatment process, a metal material is deposited on a portion of the optical lens 3 by means such as vapor deposition or sputtering to form a metal surface 7. The metal material here is not limited to any type as long as it adheres to the lens base material.

Next, the positioning process is a process for positioning the optical lens 3 in front of the optical element 2 and adjusting the optical axis 4. In this embodiment, the metal surface 7 is placed in front of the metal base 1. At the same time, a thermally meltable metal member 8 is interposed between the front surface of the metal base I and the metal surface 7. Although solder is used as the metal member 8, the present invention is not limited to this, and other heat-melting metal members may be used.

In the next bonding process, a laser light source (not shown) is positioned in front of the optical lens 3, and by driving this laser light source, the laser light 9 is irradiated onto the metal member 8 through the optical lens 3. In this embodiment, a gas laser such as a carbon dioxide laser is used as the laser light source, but the invention is not limited to this, and a crystalline solid-state laser such as a YAG laser or an amorphous solid-state laser such as a glass laser may also be used. good.

By irradiating the metal member 8 with laser light 9, the metal member 8 is thermally melted, and then the molten metal is cooled and solidified to fuse the metal surface 7 and the metal base 1 to fix the optical lens 3. By performing this series of steps, the optical lens 3
is fixed onto the metal base 1 via a metal joint, and the degree of deformation due to heat (temperature) is smaller than that using ultraviolet curing resin, resulting in misalignment of the optical axis 4. It's hard to do.

The thermal expansion coefficient of ultraviolet curable resin is 6.4×10-5/
'The coefficient of thermal expansion of C1 metal (e.g. tin) is 2.3 Xl0
-'/'C1, and the effect of temperature can be reduced to about 1/3 in the joint made of metal compared to the joint made of ultraviolet curing resin.

<Effects of the Invention> As described above, the present invention is capable of assembling an optical component on a metal base on which an optical element is mounted, by aligning a metal surface formed on a part of the optical component with a predetermined position of the metal base. At the same time, a metal member that can be thermally melted is interposed between the metal base and the metal surface, and the metal surface is heated by irradiating the metal member with laser light and melting the metal member. Since the optical components are bonded and fixed by being fused to the base, the coefficient of thermal expansion of the metal joint is smaller than that of the joint made of ultraviolet curing resin, so even if the ambient temperature changes, the thermal expansion of the joint will not occur. The displacement of the optical components caused by this is small, which has the effect of making it difficult for the optical axis to shift.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a method for assembling optical components according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a conventional method for assembling optical components, and FIG. 3 is an explanatory diagram showing problems in the conventional method. It is a diagram.

Claims (1)

[Claims] A method for assembling an optical component on a metal base on which an optical element is mounted, comprising: a pretreatment step of forming a metal surface on a part of the optical component; and a predetermined position of the metal base. positioning the optical component with the metal surfaces facing each other, and interposing a thermally meltable metal member between the metal base and the metal surface; and irradiating the metal member with a laser beam to separate the metal member. 1. A method for assembling optical components, characterized by carrying out a series of bonding steps of bonding and fixing optical components by fusing a metal surface to a metal base by thermal melting.