JPH06103780B2 - Method for manufacturing laser diode unit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a laser diode unit having a novel structure.

<Prior Art> FIG. 11 shows a conventional laser diode unit 100, and a stem 101 has three lead terminals 102, 104, 106.
Are provided so as to penetrate in the thickness direction of the stem 101.
The protruding end of the lead terminal 102 is electrically connected to the laser diode 108 and has a function of supplying a current to the laser diode 108, and the lead terminal 104 has a function of extracting a current output from the photodiode.

That is, the laser light emitted from the laser diode 108 is received by the photodiode 110, and a current proportional to the amount of the received light is output from the photodiode 110 to the lead terminal 104. Therefore, it becomes possible to automatically control the light emission power of the laser diode 108 based on the value of the current. The lead terminal 106 has a function of connecting the laser diode 108 and the photodiode 110 to the ground.

A ring-shaped connecting member 112 is attached to and integrated with the stem 101, and a closed-end cylindrical cap 113 having one end opened for enclosing the laser diode 108 and the like is attached to the connecting member 112. Has been. The stem 101 and the connecting member 112, and the connecting member 112 and the cap 1
13 and 13 are integrated by resistance welding or the like.

Further, since the opening window 113A is formed on the bottom surface of the cap 113 and the opening window 113A is closed by the glass cover 114, the laser light of the laser diode 108 is emitted from the opening window 113A.
It is emitted from A to the outside. The inside of the laser diode unit 100 configured as described above is generally filled with an inert gas such as nitrogen gas, and in particular, oxidation of the light emitting end surface of the laser diode 108 is prevented.

<Problems to be Solved by the Invention> As described above, the conventional laser diode unit has a complicated structure, and the work of each process such as arrangement of lead terminals, laser diodes, photodiodes and bonding wire connection is complicated. I had to do it in a complicated structure. In the prior art, many such difficult working steps are performed for each individual laser diode unit, so that there is a problem that the production efficiency is particularly low when a large number of laser diode units are to be manufactured.

The present invention has been made in view of the above conventional circumstances, and an object of the present invention is to provide a method of manufacturing a laser diode unit, which enables efficient mass production of the laser diode unit.

<Means for Solving the Problems> A method for manufacturing a laser diode unit according to the present invention,
A step of providing a plurality of sections forming one laser diode unit on the substrate, a step of providing a first lead section and a second lead section on the board for each section, and a photodiode for detecting laser light output are provided. A step of mounting the submount base that has been provided on the substrate for each section, a step of mounting a laser diode chip on each submount base, and a first step for supplying current to each laser diode chip in the section. And a second lead portion for detecting the current of the photodiode, and a step of dividing the substrate into each section.

<Operation> In the present invention, one substrate is divided into a plurality of sections, a laser diode unit is assembled in each section, and when the laser diode is assembled, the substrate is divided into each section to manufacture a plurality of laser diode units. . That is,
The manufacturing process of each laser diode unit is simultaneously performed on one substrate, and when the laser diode units are finally assembled, the laser diode units are separated from each other.

<Example> First, a laser diode unit (hereinafter simply referred to as a unit) manufactured by a manufacturing method according to an example of the present invention will be described.

FIG. 1 shows an overall schematic view of the unit 1, and FIG. 2 shows a sectional view taken along the line II-II in FIG.

As shown in the drawing, a submount conductive base 3 formed in a plate shape with a conductive material such as silicon is attached and fixed onto the substrate 9.

The substrate 9 is a so-called high thermal conductivity type printed circuit board, and has lead portions (first function having a function of supplying a current to the laser diode) formed of a copper film 9B on a plate-shaped member 9A such as aluminum via an insulating film 9C. A lead portion 11, a lead portion (second lead portion having a function of detecting a current output from the photodiode) 13, and a lead portion (having a function of connecting the laser diode and the photodiode to the ground) 15 are formed. ing.

On the other hand, a laser diode 5 is attached and fixed on the base 3, and the laser diode 5 and the base 3 are connected by a wire 17
Connected by.

Further, in the embodiment, the base 3 is made of silicon Si, and in the region 2 shown by the dotted line in FIG. 1, when the base 3 is the N region, impurities are diffused so as to become the P region. As a result, a PN junction is formed, and as a result, the base 3 itself has a function as a photodiode. Alternatively, another photodiode may be formed and embedded in the region 2 of the base 3 with the light receiving surface of the photodiode exposed.

Then, one side surface 3A of the base 3 on which the laser diode chip 5 is provided is covered with silicon dioxide SiO2, and the aluminum wiring 4 for supplying a current to the laser diode chip 5 and the base 3 are formed. Aluminum wiring 6 for taking out a current is provided.

A laser diode chip 5 is connected to one end of the aluminum wiring 4, and one end of a wire 19 is connected to the other end of the aluminum wiring 4.
The other end of 19 is connected to the lead 11.

One end of the aluminum wiring 6 is joined to the region 2 and the other end of the aluminum wiring 6 is connected to the wire 21.
Of the wire 21, and the other end of the wire 21 is connected to the lead portion 13.

The laser diode 5, except for the portions where the lead portions 11, 13, 15 are connected to other electric circuits (not shown),
The photodiode 7, the base 3, the wires 17, 19, 21 and part of each of the lead portions 11, 13, 15 are covered with a protective film 26 such as aluminum oxide A1203 having a dielectric property. The light emitting end surface of the device, the lead portions 11, 13, 15 and the like are prevented from being oxidized, and the moisture resistance of the unit 1 is improved.

Further, the substrate 9 is provided with a protective cover 23 for preventing mechanical destruction or the like of the laser diode 5. The protective cover 23 is formed in a substantially U-shaped cross section, and the light emitting end surface of the laser diode 5 is left. The main functional parts of the unit 1 are set to be protected. It should be noted that both end surfaces of the protective cover 23 are closed by a member such as glass that allows laser light to pass therethrough, and an inert gas such as nitrogen gas is sealed in the protective cover 23 to prevent oxidation of the end surface of the laser diode 5. It is also suitable for the configuration of the unit 1 to further improve

The protective cover 23 is formed of a highly reflective resin in which a metal having a high reflectance such as rutile is contained in an appropriate transparent resin, and is provided at a position corresponding to the position of the photodiode 7 on the back surface side thereof. The reflecting portion 25 having the tapered surface 25A is integrally formed. The inclination of the tapered surface 25A of the reflecting portion 25 is set so that the laser light of the laser diode 5 is efficiently reflected toward the light receiving surface of the photodiode 7.

Therefore, according to the laser diode unit 1 having the above-described configuration, the lead portions 11 and 15 are connected to a power source (not shown) to supply a current to the laser diode 5, whereby one of the light emitting end faces (second Laser light can be oscillated from the left end face in the figure). Along with this, laser light is also emitted from the other light emitting end surface (right end surface in FIG. 2) of the laser diode 5 and is received by the photodiode 7 via the reflecting portion 25, and the output of this photodiode 7 is read. The intensity of the laser light oscillated from the laser diode 5 is stabilized by controlling the supply current to the laser diode 5 detected by the section 13.

Next, a method according to an embodiment of the present invention for manufacturing the laser diode unit 1 having the above structure will be described.
This will be described with reference to FIGS.

First, as shown in FIG. 3, partition grooves 9E are formed on the substrate 9 at equal intervals to partition the substrate 9 into a plurality of partitions, and
Lead sections 11, 13, and 15 are provided in each of the sections partitioned by 9E. As shown in FIG. 2, these lead portions 11, 13, 15 have an insulating film 9C formed on the upper surface of the plate-shaped member 9A, and a conductive thin film 9B formed on the insulating film 9C. It is formed by removing the excess conductive thin film 9B by means. The lead portions 11, 13, 15 are formed at appropriate intervals with respect to each other in order to prevent an electrical short circuit.

Next, after coating the tip portion 15A of the lead portion 15 for each section with a bonding material (indium or the like) 30, the submount base 3 is placed on each bonding material 30, as shown in FIG. . Then, the submount base 3 is mounted on the substrate 9
While pressing to the side, the melting point of the bonding material 30 (about 16 for indium)
It is once heated to 3 ° C.) and mounted on the substrate 9 in a state where the submount base 3 is connected to the lead portion 15. The submount base 3 is provided with the photodiode 2 in advance, and the upper surface 3A of the submount base 3 is previously covered with silicon dioxide SiO2. Furthermore, a wiring 4 for supplying a current to the laser diode and a wiring 6 connected to the region 2 are provided in advance on the SiO2 film, and a bonding material connected to the wiring 6 is provided at the tip of the base 3. 32 (such as an alloy of gold and tin) is pre-coated. A part of the SiO2 film is peeled off for later wire bonding.

Next, as shown in FIG. 5, the laser diode chip 5 is placed on the bonding material 32 for each section by using a known vacuum carrier or the like. Then, while pressing the laser diode chip 5 toward the base 3 side, it is once heated to the melting point of the bonding material 32 (about 230 ° C. for an alloy of gold and tin), and the submount with the laser diode chip 5 connected to the wiring 6. Attach it on the base 3.

Then, as shown in FIG. 6, under heating conditions (for example, 120
Bonding with wires 17, 19 and 21 for each section at (° C). That is, the upper surface of the laser diode chip 5
The base 3 exposed at the peeled portion of the SiO2 film is connected by the wire 17, the lead portion 11 and the wiring 4 are connected by the wire 19, and the lead portion 13 and the wiring 6 are connected by the wire 21.

Then, as shown in FIG. 7, the lead portions 11, 1 of each section are
The tape 36 covers the rear ends of the tapes 3, 15.

Next, as shown in FIG. 8, after the protective film 26 is formed by sputtering, the tape 36 is removed to expose a part of the lead parts 11, 13, 15 from the protective film 26 for connection with other electric circuits. Let

Next, as shown in FIG. 9, after forming through-holes 9D in the substrate 9 in each section, the embossments 23A protruding from the protective cover 23 are inserted into the through-holes 9D, respectively, and the tip of the embossing 23A is attached to the substrate 9. Embossed from the back, this embossed
The protective cover 23 is attached to each section by crimping the tip of 23A.

Through the series of steps described above, a plurality of laser diode units 1 partitioned by the groove 9E are formed on the substrate 9. Then, in this state, the elements of each section are exposed to 5mW for 20 hours at 70 ° C
Current is supplied to perform the operation test and the optical characteristic test to select a stable and high-quality element.

Next, as shown in FIG. 10, the substrate 9 is divided by the partition grooves 9E, and each laser diode unit 1 is separated to complete the manufacturing process.

<Effect> According to the method for manufacturing a laser diode unit of the present invention, a plurality of units can be manufactured simultaneously on one substrate by a simple operation process, and therefore a large number of laser diode units can be manufactured efficiently. It is possible,
Significant cost reduction can also be realized.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram of a laser diode unit according to an embodiment of the present invention, and FIG. 2 is II-II in FIG.
Sectional views taken in the direction of the arrows, FIGS. 3 to 10 are conceptual diagrams each showing a manufacturing method according to one embodiment of the present invention for each step, and FIG. 11 is a schematic configuration diagram of a conventional laser diode unit. 1 is a laser diode unit, 2 is a region (photodiode), 3 is a submount base, 5 is a laser diode chip, 9 is a substrate, 9E is a partition groove, 11 is a first lead portion, 13 is a second It is a lead part.

Claims (1)

[Claims] 1. A step of providing a plurality of sections forming one laser diode unit on a substrate, a step of providing a first lead section and a second lead section on the substrate for each section, and a laser beam output. A step of mounting a submount base having a photodiode for detection on a substrate for each section,
Attaching the laser diode chip to each submount base, and connecting each laser diode chip to the first lead portion for current supply in the section and the second lead portion for current detection of the photodiode. A method of manufacturing a laser diode unit, comprising: a step of connecting to a substrate; and a step of dividing the substrate into sections.