JP2588517Y2 - Semiconductor laser device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a semiconductor laser device using a semiconductor laser chip as a light emitting element of a laser. It is about improvement.

[0002]

2. Description of the Related Art A can-seal type semiconductor laser device of this type comprises a block formed integrally with a metal stem.
A semiconductor laser chip is die-bonded, a metal cap body provided with a transparent plate such as a glass plate is fitted to the semiconductor laser chip portion, and the cap body is fixed to the stem and sealed. This prevents the semiconductor laser chip from deteriorating due to atmospheric humidity and the like, protects the semiconductor laser chip from external impacts and the like, and furthermore, leads the lead terminal from the through hole formed in the stem to the inside of the cap. It is well known that the lead terminal is fixed to the stem in an insulating sealing state.

Conventionally, as a means for fixing the lead terminal to the stem in an insulating sealing state, a glass sealing material is formed in a cylindrical shape, and this is inserted into a through hole of the stem while being fitted to the lead terminal. Then, a method of heating and firing at about 900 ° C. (a so-called hermetic sealing method) has been adopted.

[0004]

However, this sealing method has an advantage that the through-hole can be securely sealed, but on the other hand, it requires a great deal of steps for manufacturing a cylindrical glass sealing material and firing at a high temperature. In addition to the need for labor, the post-processing step of applying nickel plating after pickling the stem that has been discolored by baking at a high temperature is required, so the cost required for fixing the lead terminals to the stem is required. However, there has been a problem that the cost of the semiconductor laser device is significantly increased.

In order to solve this problem, it is conceivable to bond the lead terminals to the stem with an adhesive such as a synthetic resin or the like. Since the process and the pickling and plating steps as post-processing are not required, the manufacturing cost can be significantly reduced. However, in order to increase the bonding strength of the lead terminal to the stem, a hard adhesive that cures by drying must be used as the adhesive. However, if a hard adhesive is used, this hard adhesive is used. Infinite number of minute cracks or gaps occur due to the difference in thermal expansion between the adhesive and the stem and the difference in thermal expansion between the adhesive and the lead terminal. However, there is a problem that the hermetic state is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a can-seal type semiconductor laser device which maintains the fixing strength of a lead terminal and the sealing property of a through hole in a stem in a form which can be manufactured at low cost. Things.

[0007]

In order to achieve the above object, the present invention provides a stem having a semiconductor laser chip provided on an upper surface side and a cap body fixed on the upper surface of the stem so as to cover the semiconductor laser chip. A semiconductor laser device comprising a lead terminal inserted into a cap body through a through hole formed in the stem, wherein the lead terminal is connected to a hard adhesive layer with respect to a position of the through hole in the stem. A moisture-permeable and soft adhesive layer is filled with a hard adhesive layer in an opening on the upper surface side of the stem and a soft adhesive layer in an opening on the lower surface side of the stem in the through hole. In this manner, the two adhesive layers are superposed one on the other, and the hard adhesive layer is raised from the upper surface of the stem. "

[0008]

With this configuration, the lead terminals are firmly bonded to the stem with a hard adhesive layer, while the lead terminals are finely cracked due to a difference in thermal expansion or the like to the hard adhesive layer. Or even if many gaps occur, the soft adhesive layer,
By deforming following the thermal expansion of the hard synthetic resin, the through hole in the stem can be maintained in a sealed state, so that the inside of the cap body can be lengthened regardless of the occurrence of cracks or gaps in the hard adhesive layer. By maintaining the sealed state for a period, the durability of the semiconductor laser chip can be improved.

In this case, in addition to filling the hard adhesive layer into the opening in the through hole toward the upper surface of the stem, the hard adhesive layer is configured to rise from the upper surface of the stem. By doing so, the upper surface side of the stem of the lead terminal, that is, the portion protruding to the cap body can be firmly supported by the hard adhesive layer which swells at the base portion as described above. When performing wire binding between the lead terminal and the semiconductor laser chip with a metal wire, it is possible to reliably reduce deformation and swinging of the lead terminal,
Poor bonding of the metal wire to the lead terminal, that is, occurrence of a wire binding error can be reliably reduced.

Therefore, according to the present invention, the lead terminal can be firmly fixed to the stem by a simple process of applying an adhesive to the portion of the through hole in the stem. Can be reliably sealed, the durability of the semiconductor laser chip can be reliably ensured at low cost, and the wire bonding error can be reduced, so that the cost can be further reduced.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 3 show a first embodiment. In these figures, reference numeral 1 designates a disk-shaped stem 2 made of metal such as carbon steel, and a cap having a window hole formed at the upper end. 5 shows a semiconductor laser device including a body 3, and a transparent plate 4 made of glass or the like that closes the window hole is fixed to an inner surface of the cap body 3.

A block 5 is integrally provided on the upper surface of the stem 2. A semiconductor laser chip 6 and a semiconductor substrate 7 with a monitoring photodiode (not shown) are provided on the side of the block 5. And one of the three lead terminals 8, 9, 9 for the semiconductor laser chip 6 is fixed to the lower surface of the stem 2 by welding, and the other two are bonded. The lead terminals 9, 9 are inserted into the inside of the cap body 3 through the through holes 10, 10 formed in the stem 2, and are fixed to the stem 2 by the following means.

That is, a large-diameter hole 10a is partially formed in the through-hole 10 on the upper surface side of the stem 2, and a thermosetting resin such as an epoxy resin is formed in the large-diameter hole 10a. A hard adhesive layer 11 made of a hard synthetic resin such as UV or UV resin is filled so that the hard adhesive layer 11 swells on the upper surface of the stem 2, and the lower surface side of the stem 2 in the through hole 10. A soft adhesive 12 made of a material having non-moisture-permeable and adhesive properties without being cured, such as a silicone resin or a fluorine resin or rubber.
And the lead terminal 9 is bonded to the stem 2 by two soft and hard adhesive layers 11 and 12 which are overlapped in the axial direction of the lead terminal 9.

In the case of this embodiment, the thin metal wires 13 are provided between the semiconductor laser chip 6 and the semiconductor substrate 7 and between the semiconductor substrate 7 and the tips of the lead terminals 9 and 9, respectively. , 14 are connected by wire bonding. After the cap body 3 is fitted to the block body 5, the entire periphery of the outward flange portion 3 a formed at the lower end of the cap body 3 is resistance-welded to the upper surface of the stem 2, thereby forming the stem 2. It is stuck to. In fixing the transparent plate 4 to the cap body 3,
A hard adhesive layer 11 is formed annularly between the outer peripheral surface of the transparent plate 4 and the inner peripheral surface of the cap body 3, and
A soft adhesive layer 12 is provided between the inward flange 3b of the transparent plate 4 and the upper surface of the transparent plate 4.
Adhered at 1,12.

As described above, the lead terminal 9 is connected to the stem 2
Adhesive layer 1 of two layers of soft and hard
When the lead terminals 8 are adhered to each other, the lead terminals 8 can be firmly fixed to the stem 2 with the hard adhesive layer 11, while the lead terminals 8 are finely bonded to the hard adhesive layer 11 by a difference in thermal expansion or the like. Even if many cracks or gaps occur, the soft adhesive layer 12 is deformed following the thermal expansion of the hard adhesive layer 11, so that the through hole 10 is maintained in a sealed state. The inside of the body 3 can be reliably maintained in a highly airtight state.

Moreover, in addition to filling the hard adhesive layer 11 into the opening in the through hole toward the upper surface of the stem 2, the hard adhesive layer 11 is raised from the upper surface of the stem 2. By virtue of this configuration, the upper side of the stem 2 of the lead terminal 9, that is, the portion protruding to the cap body 3, is firmly supported by the hard adhesive layer 11 bulging as described above at the base thereof. When wire bonding is performed between the lead terminal 9 and the semiconductor substrate 7 with the metal wire 14, deformation and swinging of the lead terminal 9 can be reliably reduced. This makes it possible to reliably reduce the occurrence of poor bonding of the metal wire 14 to the metal wire 9, that is, the occurrence of a wire binding error.

In the second embodiment shown in FIG. 4, an opening in the through hole 10 on the upper surface side of the stem 2 is formed by a tapered hole 10b.
And the hard adhesive layer 11 is filled in the tapered hole 10b so that the hard adhesive layer 11 is raised on the upper surface of the test 2, while the stem 2 of the stem 2 in the through hole 10 is filled. The opening on the lower surface side is filled with a soft adhesive layer 12, and the same effect as described above can be obtained with this configuration. In this embodiment, the notch 13 is formed in a portion of the lead terminal 9 which is in close contact with the hard adhesive layer 11 to prevent the lead terminal 9 from coming off. However, in other embodiments, It goes without saying that the notch 13 may be formed in the lead terminal 9.

In each of the above embodiments, the lead terminals are formed in a pin shape having a circular cross section.
It is needless to say that may be square in cross section.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is a front sectional view showing a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser device 2 Stem 3 Cap body 4 Transparent plate 6 Semiconductor laser chip 7 Semiconductor substrate 8, 9 Lead terminal 10 Through hole 11 Hard adhesive layer 12 Soft adhesive layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-196291 (JP, A) JP-A-1-143284 (JP, A) JP-A 63-167766 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) H01S 3/18 H01L 33/00 H01L 23/02

Claims (1)

(57) [Scope of request for utility model registration] [1 claim: a stem having a semiconductor laser chip on the upper surface side, and a cap member which is fixed so as to cover the semiconductor laser chip on the upper surface of the stem, from the through hole in the cap body which is formed in the stem in the semiconductor laser device formed by inserting the lead terminals, the lead terminals, to sections of the through-holes in the stem, soft in the adhesive layer and the moisture impermeable hard and adhesive layer, the through hole Of the opening on the upper side of the stem
Adhesive layer of soft adhesive at the opening on the bottom side of the stem
Into two adhesive layers that are stacked to fill
And bonding the hard adhesive layer to the upper surface of the stem.
A semiconductor laser device characterized in that the semiconductor laser device is configured to swell .