JP3128206B2 - Semiconductor laser unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser unit which is incorporated in an optical disk or other various optical devices to constitute a pickup, and more particularly, to a hologram type pickup in a laser diode chip (hereinafter, referred to as an LD) for a light source. The present invention relates to an improvement of a semiconductor laser unit in which a light receiving element for signal reading is arranged in one package.

[0002]

2. Description of the Related Art Recently, music CDs and other CD-ROs have been developed.
In various optical disk systems such as M and MD, a hologram type pickup employing a hologram element (HOE) having functions such as beam generation, light branching, and error signal generation as an optical system has been proposed. This pickup includes a semiconductor laser unit in which an LD chip for a light source and a light receiving element for signal reading are arranged in one package, and a hologram element bonded and fixed to the upper surface of the semiconductor laser unit. Such a hologram type pickup can achieve various advantages, such as reduction in the number of parts, improvement in environmental resistance, reduction in size and weight, reduction in cost, and high-speed access. FIG. 8 shows a conventional semiconductor laser unit in which a stem (metal) made of a metal such as Kovar is used as a base (island) 1 and the base 1
The LD chip 100 and the light receiving element 200 are mounted above, and the lead pins 2 for the terminals are inserted and set in a plurality of holes 42 formed in the base 1.
Numerals 0 are electrically connected to predetermined lead pins 2 by wire bonding 3, respectively. Light receiving element for optical reasons
200 is fixed to the upper surface of the base 71 protruding from the base 1,
The LD chip 100 is fixed to the side surface of the mounting surface 81 erected on the base 1 so that the laser emitting point is located above the light receiving element 200 and the laser emission point is directed upward.
The D chip 100 is maintained substantially vertical, and the light receiving element 200 is maintained substantially horizontal. In this prior art, after the lead pin 2 is inserted into the hole 42 of the base (island) 1, the hole 42 is filled with a glass sealant 52 or the like to fix and insulate the lead pin 2, so that the pitch of the lead pin 2 is narrowed. Is naturally limited, it is difficult to further reduce the size of the base (island) 1, and CD-ROM drives for notebook PCs, CDs for music, MDs, etc. There was a problem that it was not possible to immediately respond to the need for further reduction in size and weight of applied equipment.

[0003]

In order to meet such needs, the applicant of the present invention has proposed FIG. 9 (Japanese Patent Application No. 9-8486).
Has already been proposed. In this prior art, an island 1, which is a base having an LD chip 100 and a light receiving element 200, a lead frame 2 'having lead pins 2,..., A resin mold 7 for fixing and insulating the lead pins 2' to the island 1 or Are formed, and the lead pins 2 forming the periphery of the island 1 are used as electrical connection terminals. Each of the lead pins 2 is inserted into a plurality of holes 42 formed in the island 1 and further filled. Filled with material and lead pin 2 ...
The base island 1 can be made as small as possible as compared with the above-described prior art which fixes and insulates the semiconductor device, and further miniaturization can be achieved. Since multiple products can be molded on a strip-shaped metal plate, multiple products can be molded at once or continuously when molding resin or molding resin, reducing the number of parts and achieving high accuracy without variation. Products can be mass-produced. By the way, in the prior art in which the inner lead portion 2 "is drawn in from the periphery of the island 1 to fix and insulate the lead pins 2..., The inner lead portion 2" results in the space for mounting the LD chip 100 and the light receiving element 200 in the island 1 being reduced. The layout will be occupied. Therefore, the size of the island 1 is slightly increased, thereby increasing the LD chip 100 and the light receiving element.
There was no choice but to design enough space to mount the 200, and there was still room for development in minimizing the size to a minimum. In addition, it is necessary to bend the inner lead portion 2 ″ in the lead frame 2 ′, or to put the preformed island 1 and the lead frame 2 ′ together in a mold and fix the resin mold 7 or the molding resin. In addition, the molding is complicated, and there is room for contrivance in providing at low cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional circumstances, and a technical problem of the present invention is that a semiconductor laser unit in which an LD chip for a light source and a light receiving element for signal reading are arranged in a single package has a smaller size. It is to realize the cost reduction at low cost.

[0005]

According to a first aspect of the present invention, a laser diode chip for a light source and a light receiving element for reading a signal are mounted on an island. and a semiconductor laser unit which is in a single package the light receiving element is electrically connected to a predetermined lead pin, said laser diode
Parallel leads electrically connected to the
Dopin is dispersed in multiple thin resin molding parts to
And hold it in a skewered shape,
Together with the resin molding part or separate from the resin molding part
Connect the resin molded part and the island and fix the parts together
The point is that they are assembled together . According to a second aspect, the resin molded portion according to the first aspect is mounted on a lead frame.
Preformed with resin mold on parallel lead pins
The gist is that The claim 3 or claim 1
Or a pair of the resin molded parts described in
The land is preformed with a metal material separate from the resin molding and
The gist is that it is fixed in a sandwiched manner by a pair of resin molded portions . Further, claim 4 is the same as claim 1 to claim 3.
Do not use the tip of the lead pin as an electrical connection surface.
And summarized in that that. Furthermore, claim 5 is claim 3.
With the protruding end of the ground lead pin facing the joint,
Inside the recess for storage provided on the island
The tip is crimped and fixed in the position
Is the gist.

According to the above technical means, the following effects are obtained. (Claim 1) The semiconductor laser unit is provided with leads arranged side by side.
A plurality of thin pins with pins skewered in the vertical direction
It consists of a resin molded part and an island.
Is integrated with or separate from the resin molded part.
The lands are fixed to each other to secure the joint and are assembled together. So
Because of the laser diode on the island to the lead pin
Inner space occupying space for mounting chips and light receiving elements
Preform resin molded parts and islands without forming
Assembled by the assembly method using molded products. (Claim 2) The present semiconductor laser unit is the same as that of the first embodiment.
Island molding and island
The pin is fixed in a skewered shape with the vertical direction of the pin.
The lead frame is used as the core, and one lead pin
Eliminates the complexity of molding when inserting and positioning in a mold
I do. (Claim 3) The semiconductor laser unit according to claim 1 or 2, wherein the mounting surface of the laser diode chip and the light receiving element has a highly accurate flatness and squareness of the metal island formed by cold casting or the like. (Horizontal plane and vertical plane). (Claim 4) The semiconductor laser unit according to claims 1 to 3
In addition to the above, the loop distance of wire bonding for connecting the lead pin to the laser diode chip and the light receiving element is minimized, and the wire bonding is positioned in the plane view area of the semiconductor laser unit. (Claim 5) The semiconductor laser unit according to claim 3
Ground without expensive plating on islands
A simple method of crimping and fixing the lead pin
Forming a base means and fixing the caulking and fixing with the resin molding part.
Effectively used to increase the fixing strength with Iland
You.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show a half as a reference example .
FIGS. 4 to 7 show an embodiment of a semiconductor laser unit according to the present invention .
Each of the embodiments of such a semiconductor laser unit is shown.

First, a reference embodiment shown in FIGS. 1 to 3 will be described. Reference numeral A denotes a semiconductor laser unit as a reference example . The semiconductor laser unit A includes an LD chip 100 for a light source and a light receiving element for signal reading. 200 are arranged in one package, and together with a hologram element (not shown) fixed to the upper surface of the package, constitutes a hologram type pickup.
The D chip 100 and the light receiving element 200 are mounted on the island 1, and the LD chip 100 and the light receiving element 200 are electrically connected by wire bonding 3 to the lead pins 2 provided in a skewered manner in the island 1 in the vertical direction. ing.

The island 1 is a resin-molded product, as shown in FIG. 1, a main body 11 having an arc shape on both left and right sides in plan view, and an LD chip 100 protruded upward from a longitudinal central region of the main body 11. It is formed from the mounting portion 21 of the light receiving element 200.

As shown in FIG. 1, the mounting portion 21 is
The vertical upright surface 21a of the central portion raised from the
0, and the LD chip 100 is mounted on the vertical surface 21a via the monitor photodiode 300.
Are fixed by bonding or the like.

As shown in FIG. 1, the mounting portion 21 has a horizontal upper surface 21b near the right side of the LD chip 100 as an actual mounting portion of the light receiving element 200, and the light receiving element 200 is bonded to the horizontal upper surface by bonding or the like. It is fixed.

The lead pins 2 electrically connected to the LD chip 100, the light receiving element 200 and the like are integrated with the island 1 when the island 1 is formed by resin molding.

The lead pins 2 are integrated using a lead frame (not shown). Although not shown, this lead frame has a plurality of lead pins 2 arranged in parallel at a desired pitch by applying a known means such as press molding or etching to a strip-shaped ultra-thin metal plate, for example, a 42 alloy plate or a copper plate as a substrate. The required number of lead frames are simultaneously set in a predetermined molding die, and are molded in a resin. Then, all the lead pins are vertically and skewered with respect to the island 1 on which the lead pins are molded. (See FIG. 2). Note that, when setting in the molding die, the protruding end portion 12 of the predetermined lead pin 2 is set so as to be separated from the LD chip 100 and the light receiving element 200 by a predetermined distance (distance for performing wire bonding).

Lead pin 2 integrated with island 1
After the mold is released, it is cut from the lead frame and is electrically connected to the LD chip 100 and the light receiving element 200 by wire bonding 3 connected to the protruding end surface 12a (see FIGS. 2 and 3).
Since the protruding end surface 12a of the lead pin 2 is a cut surface, it is preferable to perform a lapping process to improve conductivity and connection reliability.

Reference numeral 4 denotes a cover, which covers the entire upper surface of the island 1 from above after the electrical connection is made, and a hologram element (not shown) is attached to the center window hole 14. It is completed (see FIG. 3). The cover 4 may be fixed by fitting or engaging. However, it is also free to use an adhesive to strengthen the fixing.

As described above, in the semiconductor laser unit A of this embodiment , the island 1 and the parallel lead pins 2 which are vertically skewed on the island 1 and electrically connected to the LD chip 100 and the light receiving element 200 are provided.
Are integrated at the time of island molding (resin molding), so that it is not necessary to form an inner lead portion occupying the mounting space for the LD chip 100 and the light receiving element 200 on the island 1 on the lead pins 2. Hereinafter, in detail, it was possible to reduce the size of the island itself to a width of about 3.6 mm or less. In addition, the lead pins 2 can be formed at a higher density with the manufacturing accuracy of the lead frame, and the lead frames can be formed once or continuously for a plurality of products on a strip-shaped metal plate. Highly integrated and highly accurate island 1 without using bonding or fixing means
Can be provided in a skewered shape in the vertical direction, which simplifies the forming operation and process as compared with the case where the inner lead portion is bent and formed on the tip side of the lead pins 2. Not at all,
A highly reliable semiconductor laser unit A can be provided.

Next, an embodiment of the present invention shown in FIGS. 4 to 7 will be described. In this embodiment, the parallel lead pins 2 electrically connected to the LD chip 100 and the light receiving element 200 are used.
Are dispersed in a plurality of thin resin molding portions 5 and provided in a skewered shape in the vertical direction to separate the island 1 from the resin molding portion 5 and to join the resin molding portion 5 and the island 1 together. 1 shows an assembling type semiconductor laser unit in which the semiconductor laser units are fixed and integrally assembled.

As shown in FIGS. 6 and 7, the resin molded portion 5 is a pair of front and rear two pieces.

The two resin molded parts 5 are both resin molded parts, and the front resin molded part (described below with reference numeral 15) and the rear resin molded part (described below with reference numeral 25). 7) except for a small difference, as shown in FIG. 7, an elongated rectangular portion 35 having a step 35a at both ends and a horizontal portion provided on the upper surface of the elongated rectangular portion 35 so that both ends face each other. Is formed from the bent U-shaped part 45. For example, when the two are combined (when they are matched), the tips of the U-shaped parts 45, 45 Are configured to create a mating relationship.

The island 1 is formed with high precision by cold casting or the like. As shown in FIG. 7, the island 1 has left and right ear-shaped portions 31, 31 having an arcuate shape and having a concave recess 31a extending halfway from the lower end, and the left and right ear-shaped portions 31, 31.
Rectangular part 41 communicating the central part of
The LD chip 100, the light-receiving element 20, which is raised from 41
0 mounting part 51. As shown in FIG. 7, the island 1 is provided with a concave portion 61 for accommodating the ground lead pin 22 described later on a fitting surface (outer surface) serving as the fitting portion 6 with the resin molding portion 15 on the front side. I have.

As shown in FIGS. 4 and 7, the mounting portion 51 for the LD chip 100 and the light receiving element 200 has a resin molding portion 25 on the rear side.
The vertical upright surface 51a recessed at the portion facing the
0, and the horizontal upper surface 51b on the right side of the vertical standing surface 51a is the actual mounting portion of the light receiving element 200.

Reference numeral 25a denotes a V-groove provided in the rear resin molding portion 15 at a position opposed to the vertical upright surface 51a which is the mounting portion 51 of the LD chip 100.

The lead pins 2 are dispersed and integrated into the resin molding portions 15 and 25 when the front resin molding portion 15 and the rear resin molding portion 25 are molded by a resin mold.

As the lead pins 2, a lead frame 2 'is used as in the above-described embodiment . Of course, as shown in FIG. 6, the lead frame 2 'is formed by applying a known means such as press molding or etching to a strip-shaped ultra-thin metal plate 32, for example, a 42 alloy plate or a copper plate.
The lead frame 2 'is set in a predetermined mold (a mold for molding a resin molding portion on the front side or the rear side), and is molded with a resin. By molding the lead pin 2
Are dispersed and integrated into the respective resin molded portions 15, 25 in a vertical direction and in a skewered manner. This lead pin 2
Are cut from the lead frame 2 'after the front and rear resin molded portions 15, 25 are released from the mold.

Reference numeral 22 denotes a ground lead pin, which is shown in FIG.
As shown in FIG. 7, the protruding end portion 22a protrudes from the joint portion (specifically, a corresponding surface) of the front resin molding portion 15 with the island 1 so as to engage with the concave portion 61 for accommodation provided in the island 1. It is like that.

The three parts are joined (assembled) with the front resin molding portion 15 and the rear resin molding portion 25 having the island 1 and the lead pins 2 in a vertically skewered manner with the island 1 disposed in the middle. The lower step portions of the resin molding portions 15 and 25 are arranged such that the horizontal step surface 35a 'of the front resin molding portion 15 and the rear resin molding portion 25 comes into contact with the upper surface of the concave portion 31a of the island 1. 35a ", 35a" are inserted into the recessed portions 31a, 31a from the front and rear directions to assemble the three members, and the joint surfaces serving as the joint portions 6 are fixed by bonding or the like to form the island 1 into the front and rear resin molding. It is carried out by sandwiching between the parts 15, 25.

Thus, the island 1 and the resin molding portion 1 on the front side
5. The three-part assembly of the resin molding portion 25 on the rear side is a protruding end 22a of the ground lead pin 22 housed in the housing recess 61.
While cutting from above, the halves 22a 'and 22
After a ′ is crimped and fixed to the edge of the concave portion 61 to increase the fixing strength, the protruding end surface 12a of the lead pin 2 and the vertical upright surface 51a,
LD chip 100 and light receiving element 200 fixed to horizontal upper surface 51b
Are electrically connected to each other by wire bonding 3, the cover 4 is covered from above so as to cover the entire upper surface of the assembly, and a hologram element (not shown) is attached to the center window hole 14 to complete the assembly. The protruding end surface 12 of the lead pin 2 is similar to the above-described embodiment.
a is preferably subjected to a lapping treatment, and the cover 4 may be fixed by using an adhesive in combination.

In this embodiment thus constructed, a plurality of preformed thin resin molding portions 5 (15, 2) having vertically arranged lead pins 2 in a skewered shape in the vertical direction.
It is possible to provide an assembly type semiconductor laser unit in which the connection portions 6 between the 5) and the island 1 are fixed. The vertical skewing of the lead pins 2 with respect to the resin molding portion 5 is performed by resin molding using the lead frame 2 ', and the resin molding coating layer (resin molding portion) for the lead pins 2 is formed by a molding die. By setting the precision to the necessary optimum limit, the size can be reduced to the same extent as in the above-described embodiment even though the assembly method is used. Further, since the island 1 is formed of a metal material and has excellent surface accuracy in flatness and squareness, it is possible to stably and accurately mount components such as the LD chip 100 and the like which require mounting accuracy. In addition, the grounding means is formed by caulking and fixing the ground lead pin 22, and the caulking and fixing is performed by the resin molded portion 5 (15, 25).
It is effectively used as a means for increasing the fixing strength of the island 1 and the plating process, and the crimping fixation is used to increase the bonding strength at the time of assembling the resin molded part 5 (15, 25) with the island 1. In spite of being a semiconductor laser unit of an assembling method, the earth means and the fixing strength increasing means can be combined with a simple structure. And other excellent advantages.

Although not described in detail in this embodiment, in an assembly type semiconductor laser diode, the island may be integrated with one of the resin molding portions, or the resin molding portion may be further subdivided to form a pair. By combining the above, a metal or resin island may be fixed in a sandwiched manner. Further, the assembly (assembly) of the resin molded portion and the island does not need to be engaged as described above, and the resin molded portion may be tightly fitted, fitted and adhered, engaged or fitted and ultrasonically welded, or the like. , The molding material of the island, and the structure of the connection portion.

[0030]

As described above, the present invention has the following advantages. (Claim 1) A vertically arranged lead pin is skewed in a vertical direction.
A plurality of preformed thin resin moldings having a stab shape;
Since the joints with the island are fixed,
Laser diode chip on island with lead pin,
The inner lead that occupies the mounting space for the light receiving element
No islands are formed and the island itself is reduced in size
To meet today's needs for ultra-miniaturization
It is possible to assemble and form a conductor laser unit using an assembly method.
Wear. In this assembly method, the resin molded part and the island
Since they are manufactured and assembled later, productivity can be significantly improved.
Can be up. (Claim 2) In addition to claim 1, a lead for a resin molded portion is provided.
The vertical skewering of the dopin uses a lead frame.
This is performed at the time of resin molding of all resin molded parts
From the manufacturing accuracy of the lead frame and the manufacturing accuracy of the mold
Density of lead pins depends on the degree
The minimum thickness of the resin coating layer is reached by the accuracy of the mold
And therefore higher density and
Producing smaller semiconductor laser units
It is possible. (Claim 3) The island made of a metal material is a tree.
High accuracy flatness and squareness compared to oil-made islands
Can be Therefore, high mounting like LD chip
Stable and accurate mounting of parts that require precision
And release of the LD chip, which generates heat by emitting laser light.
Excellent heat resistance and improved response to dimensional changes due to thermal deformation
As a result, dimensional stability is improved and the error rate during operation is low.
To provide a highly reliable semiconductor laser unit.
You. Of course, will it be possible to support high output LD chips?
Can respond to a wide range of requests. (Claim 4) Further, the protruding end surface of the lead pin is wire bonded.
Wire bonding surface, so wire bonding
Promising cheaper offerings with minimum loop distance
Semiconductor laser
Do not protrude outward from the unit's planar view.
It is not easy, and it is convenient for miniaturization. (Claim 5) Also, the earth lead pin is crimped and fixed to
Base means, and the caulking fixation is made with the resin molding part.
Effectively used as a means to increase the fixing strength with islands
For ground bonding to the island
No plating process is required, further reducing cost
In addition, the crimping and fixing
To increase the bonding strength during assembly, the semiconductor laser
Despite being a unit, it has a simple structure and grounding hands
Combination of step and fixing strength increasing means to strengthen assembly
You.

[Brief description of the drawings]

FIG. 1 is a perspective view of a reference example of a semiconductor laser unit with a cover removed.

FIG. 2 is a sectional view taken along line (X)-(X) of FIG.

FIG. 3 is an enlarged perspective view of a reference example of a semiconductor laser unit.

FIG. 4 is a perspective view of the semiconductor laser unit according to the embodiment of the present invention, with a cover removed.

FIG. 5 is a sectional view taken along line (Y)-(Y) of FIG. 4;

FIG. 6 is a perspective view showing a state in which a resin molded portion is preformed on a parallel lead pin of a lead frame by a resin mold.

FIG. 7 is an exploded perspective view showing a state in which the island is held and fixed by the resin molded portion.

FIG. 8 is a sectional view of a conventional semiconductor laser unit.

FIG. 9 is a perspective view of a conventional semiconductor laser unit, showing a state in which a resin mold for fixing and insulating a lead pin to an island is used.

[Explanation of symbols]

A: Semiconductor laser unit 100: Laser diode chip (LD chip) 200: Light receiving element 2: Lead pin 1: Island 5: Resin molded part 6: Joining part 2 ': Lead frame 12a: Tip end face of lead pin 22: Earth lead pin 15 ： Front resin molded part 25 ： Rear resin molded part 22a ： Protrusion of ground lead pin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-137580 (JP, A) JP-A-4-96390 (JP, A) JP-A-6-203403 (JP, A) 4772 (JP, U) Real opening 63-167766 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01S 5/00-5/50 H01L 33/00 H01L 31/02- 31/0224

Claims (5)

(57) [Claims] 1. A semiconductor laser unit in which a laser diode chip for a light source and a light receiving element for signal reading are mounted on an island, and the laser diode chip and the light receiving element are electrically connected to predetermined lead pins to form a single package. In the above, the laser diode chip and the light receiving element
The parallel lead pins electrically connected to the
Dispersed in a flexible resin molding and kept in a skewered shape in the vertical direction.
And the island is integrated with any resin molded part.
Or separate from the resin molded part and the resin molded part
Fixing the joints with Iland and assembling them together
The semiconductor laser unit, characterized in that. 2. The resin molded part is mounted on a lead frame.
Preformed with resin mold on parallel lead pins
The semiconductor laser unit according to claim 1, wherein 3. A pair of said resin molded parts is used,
The island is preformed with a metal material separate from the resin molding.
And fixed in a sandwiched manner by a pair of resin molded portions.
3. The semiconductor laser unit according to claim 1 , wherein: 4. The electrical connection between the protruding end faces of the lead pins.
4. The method according to claim 1, wherein the surface is used as a surface.
5. The semiconductor laser unit according to claim 1. 5. A joint portion of the ground lead pin, wherein
And the tip of the
With its protruding end fixed in the recessed part for caulking
4. The semiconductor laser according to claim 3, wherein:
unit.