JPH06112585A - Manufacture of submount - Google Patents

Abstract

PURPOSE:To obtain a submount excellent in conductive characteristics in which resistance from one side to the other side is lowered while exhibiting sufficient heat dissipation effect by applying a coating on one side of a wafer and then cutting the wafer into band members thereafter applying a coating on the other side. CONSTITUTION:A wafer 1 is sequentially coated 1a, on one side thereof, with Ti, Pt, and Au through sputtering and further coated with Pb-Sn through wet plating. The water 1 is then cut into band members 2 which are subjected to ultrasonic cleaning and subsequently coated, on the other side thereof, with Ti, Pt, and Au through sputtering. Thereafter, the band member 2 is cut into a submount 3. Since the wafer 1 is applied with coating on one side thereof and cut off and then applied with coating on the other side thereof, coating 1c on the other side spreads onto the cutting face, i.e., the side face. Consequently, electrical conduction from one side to the other side is achieved through connection of side faces thus realizing a submount excellent in conductive characteristics and exhibiting sufficient heat dissipation effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a submount used for an electronic component, especially a laser diode, and more particularly to a method of manufacturing a submount excellent in conductive characteristics.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a submount, one side of a wafer is coated, then the other side is coated, and then the wafer is cut into chips.

By the way, according to the conventional method for manufacturing the submount, the heat dissipation effect is excellent, and burrs are less likely to occur during cutting.
Although a wafer whose temperature does not rise easily is used, since it is cut after coating, the conductivity from one surface to the other is poor, and a sufficient heat dissipation effect was not obtained. Therefore, when this submount was used for a laser diode, the laser characteristics deteriorated.

For this reason, although the conductivity is covered by the connection (wire bonding) from one surface to the other surface, the man-hour for manufacturing the submount is increased and the productivity is lowered.

[0005]

Therefore, the present invention is intended to provide a method of manufacturing a submount having excellent conductive characteristics.

[0006]

A method of manufacturing a submount according to the present invention for solving the above problems is characterized in that one side of a wafer is coated, then cut, and then the other side is coated. Is.

[0007]

As described above, in the submount manufacturing method of the present invention, one side of the wafer is coated and then cut, and then the other side is coated, so that the coating on the other side wraps around to form a cut surface. The sides are also coated. As a result, electrical connection from one side to the other side can be obtained by the connection of the side surfaces, the conductive characteristics become excellent, and a sufficient heat dissipation effect can be obtained.

[0008]

EXAMPLE An example of a method of manufacturing a submount according to the present invention and a conventional example will be described. First, the first embodiment will be described. One surface of a wafer 1 made of AlN having an outer diameter of 100 mm and a thickness of 0.6 mm shown in FIG.
Å, Pt2000Å and Au500Å were coated 1a, and Pb-Sn 40% was further coated to a thickness of 3 μm by a wet plating method. Next, as shown in FIG. 2, this wafer 1 was sequentially cut into a strip 2 having a width of 2 mm. Next, this strip 2 is ultrasonically cleaned with isopropyl alcohol, and Ti1000 is sputtered on the other surface as shown in FIG.
Å, Pt2000Å and Au500Å were coated 1c.
Thereafter, the strip 2 was cut into a length of 2 mm to form a chip-shaped submount 3 as shown in FIG. 4, and then ultrasonic cleaning was performed with isopropyl alcohol.

Next, the second embodiment will be described with reference to FIG.
On one side of a wafer 1 made of AlN having an outer diameter of 100 mm and a thickness of 0.6 mm shown in FIG.
2000 Å, Au 500 Å coated 1a, then Pb
-Sn 40% coating 3μm by wet plating 1
b. Next, as shown in FIG. 6, this wafer 1 was cut into a rectangular shape having a length and a width of 2 mm to obtain a large number of chips 4. Next, the large number of chips 4 are ultrasonically cleaned with isopropyl alcohol, and the other surface is sputtered with Ti1000Å, P
The submount 5 shown in FIG. 7 was obtained by coating t2000Å and Au500Å.

Finally, a conventional example will be described. On one surface of a wafer 1'made of Si having an outer diameter of 100 mm and a thickness of 0.6 mm shown in FIG. 8, Ti1000Å, Pt2000Å, A by a vapor deposition method.
u 500Å was coated 1a. Next, as shown in FIG. 9, Ti1000Å and Pt were deposited on the other surface of the wafer 1'by vapor deposition.
2000 Å, Au 500 Å coated 1c, and Pb
-Sn 40% coating 3μm by wet plating 1
b. Next, as shown in FIG. 10, this wafer 1'is cut into a square with a length and width of 2 mm to form a chip-like submount 6
After being obtained, ultrasonic cleaning was performed with isopropyl alcohol.

When the V (voltage) -I (current) characteristics of the first, second and conventional submounts thus obtained were examined, the results shown in FIGS. 11, 12 and 13 were obtained. It was

As can be seen by comparing FIGS. 11, 12, and 13, the submounts of the first and second embodiments have significantly lower resistance and superior conductive characteristics than the submounts of the conventional example. I understand. In particular, the submount of the second embodiment is
Since the other side was coated after cutting into chips, the coating wraps around the surrounding four side surfaces, and the electric conduction from one side to the other side becomes extremely good. Therefore, the coating wraps around the two side surfaces of the first embodiment. However, it has lower resistance and better conductivity than the submount.

In the above embodiment, the Ti, Pt, and Au coatings are formed by the sputtering method having a strong adhesive force, but the vapor deposition method, the wet plating method, and the dry plating method may be used.

[0014]

As described above, according to the method of manufacturing a submount of the present invention, it is possible to easily obtain a submount having a low resistance from one surface to the other surface, excellent conductive properties, and sufficient heat dissipation effect. it can.

[Brief description of drawings]

FIG. 1 is a diagram showing a process of a first embodiment of a method of manufacturing a submount according to the present invention.

FIG. 2 is a diagram showing a process of a first embodiment of a method of manufacturing a submount according to the present invention.

FIG. 3 is a diagram showing a process of the first embodiment of the method of manufacturing a submount according to the present invention.

FIG. 4 is a diagram showing a process of the first embodiment of the method of manufacturing a submount according to the present invention.

FIG. 5 is a diagram showing steps of a second embodiment of the method of manufacturing a submount according to the present invention.

FIG. 6 is a diagram showing a process of a second embodiment of the method of manufacturing a submount according to the present invention.

FIG. 7 is a diagram showing a process of a second embodiment of the method of manufacturing a submount according to the present invention.

FIG. 8 is a diagram showing steps of a conventional submount manufacturing method.

FIG. 9 is a diagram showing steps of a conventional submount manufacturing method.

FIG. 10 is a diagram showing steps of a conventional submount manufacturing method.

FIG. 11 is a graph showing VI characteristics of a submount obtained by the first example of the method for manufacturing a submount according to the present invention.

FIG. 12 is a graph showing VI characteristics of a submount obtained according to a second example of the method for manufacturing a submount of the present invention.

FIG. 13 is a graph showing VI characteristics of a submount obtained by a conventional submount manufacturing method.

[Explanation of symbols]

 1 Wafer 2 Band material 3, 5 Submount 4 Chip

Claims (1)

[Claims] 1. A method of manufacturing a submount, which comprises coating one surface of a wafer, cutting the wafer, and then coating the other surface.