Transistor outline housings for distributed feedback lasers

Abstract

A transistor outline (TO) housing comprising a base part having a mounting area for a thermoelectric cooler, wherein the base part has at least two feedthroughs for connecting an optoelectronic component. A support extends from the upper surface of the base part, which support has at least two conductor traces arranged thereon, each of which is connected to a respective one of the feedthroughs for connecting the optoelectronic component.

Claims

1. A transistor outline housing for connecting to an optoelectronic component, comprising: a base part having an upper surface, the upper surface having a cooler mounting area; two feedthroughs configured to be connected to the optoelectronic component; a support that extends from the upper surface of the base part, wherein the support has two conductor traces arranged thereon, each of the two conductor traces being connected to a respective one of the two feedthroughs; and a ground conductor trace arranged on the support between the two conductor traces a trace sub-mount on a front side of the support, a thermoelectric cooler, the optoelectronic component, and a component sub-mount, wherein the thermoelectric cooler is arranged on the cooler mounting area of the base part, the component sub-mount extending above at least portions of the thermoelectric cooler and extending perpendicular to the upper surface of the base part, and wherein the component sub-mount adjoins the trace sub-mount.

2. The TO housing of claim 1, wherein the housing is a TO-56 style housing.

3. The TO housing of claim 1, further comprising the optoelectronic component connected to the two feedthroughs.

4. The TO housing of claim 1, wherein the two conductor traces extend along an angle to a lateral end face of the support.

5. The TO housing of claim 1, further comprising a trace sub-mount on a front side of the support, the two conductor traces being disposed on the trace sub-mount.

6. The TO housing of claim 5, wherein the trace sub-mount has through-holes with side walls that are metallized.

7. The TO housing of claim 1, wherein the two feedthroughs and the two conductor traces define signal paths having an impedance from 20 to 30 each.

8. The TO housing of claim 1, wherein the support has at least one of a height between 2.0 and 3.5 mm, a thickness between 0.3 and 1 mm, and a width between 1.0 and 2.0 mm, and/or wherein the base part has at least one of a diameter between 5 and 7 mm and a thickness between 0.5 and 2.5 mm.

9. The TO housing of claim 1, wherein the base part and the support are gold-plated.

10. The TO housing of claim 1, wherein the cooler mounting area in a central region of the upper surface of the base part and wherein the support is provided only on one side of the cooler mounting area.

11. The TO housing of claim 1, wherein the optoelectronic component is a DFB laser.

12. The TO housing of claim 1, wherein the thermoelectric cooler has an L-shaped portion, wherein the component sub-mount is arranged on a surface of the L-shaped thermoelectric cooler, the surface being oriented perpendicularly to the upper surface of the base part.

13. The TO housing of claim 1, wherein the component sub-mount is connected to the trace sub-mount by bonding wires.

14. The TO housing of claim 13, wherein the bonding wires have a length of less than 1 mm each.

15. The TO housing of claim 1, further comprising a driver circuit connected to the two feedthroughs, wherein the driver circuit has an impedance from 20 to 30.

16. The TO housing of claim 1, wherein the base part and the support are stamped as a single piece.

17. The TO housing of claim 1, wherein the base part and the support are each stamped parts that are joined to each other soldering or welding.

18. A transistor outline housing for connecting to an optoelectronic component, comprising: a base part having an upper surface, the upper surface having a cooler mounting area; two feedthroughs configured to connect to the optoelectronic component; a support that extends from the upper surface of the base part, wherein the support has two conductor traces arranged thereon, each of the two conductor traces being connected to a respective one of the two feedthroughs; a ground conductor trace arranged between the two conductor traces; and a trace sub-mount on a front side of the support, the two conductor traces being disposed on the trace sub-mount, wherein the trace sub-mount has through-holes with side walls that are metallized.

19. A transistor outline housing for connecting to an optoelectronic component, comprising: a base part having an upper surface, the upper surface having a cooler mounting area; two feedthroughs configured to connect to the optoelectronic component; and a support that extends from the upper surface of the base part, wherein the support has two conductor traces arranged thereon, each of the two conductor traces being connected to a respective one of the two feedthroughs, wherein the cooler mounting area in a central region of the upper surface of the base part and wherein the support is provided only on one side of the cooler mounting area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject-matter of the invention will now be explained in more detail by way of an exemplary embodiment as illustrated in the drawings of FIGS. 1 to 4.

(2) FIG. 1 is a perspective view of a TO housing according to the invention.

(3) FIG. 2 is a perspective view of the TO housing equipped with the optoelectronic component and the TEC.

(4) FIG. 3 is a detailed view of the sub-mount arranged on a support, the sub-mount having the conductor traces that lead to the mounting area of the optoelectronic component.

(5) FIG. 4 is a schematic sectional view of a detail in the region of a through hole of a sub-mount.

DETAILED DESCRIPTION

(6) FIG. 1 is a perspective view of a TO housing 1 according to a preferred exemplary embodiment of the invention.

(7) It will be understood that the completed TO housing will additionally be provided with a cap that includes a window. The cap is not illustrated in this view, nor in the further views.

(8) TO housing 1 comprises a stamped base part 2 having an upper surface 7 from which the support 3 protrudes, which is provided with the conductor traces 5a and 5b that are used as signal conductor traces.

(9) Base part 2 and support 3 may have a plate-like shape. In particular, base part 2 and support 3 may be produced by stamping.

(10) Base part 2 and/or support 3 are made of a metal, in particular a steel.

(11) Preferably, base part 2, support 3, and the connection pins 9, 12a to 12c, 11a to 11b are coated, in particular gold-plated.

(12) Support 3 is arranged on the upper surface 7 of base part 2 offset from a central axis thereof and projects vertically upwards.

(13) A lateral end face 6 of the support 3 substantially faces the central axis of base part 2.

(14) In the present exemplary embodiment, a sub-mount 15 is arranged on a front side of support 3, which sub-mount is made of a dielectric material, in particular a ceramic sub-mount 15, on which the conductor traces 5a and 5b are arranged, which serve as signal conductor traces for the optoelectronic component.

(15) Conductor traces 5a and 5b are routed along an angle.

(16) Conductor traces 5a and 5b are connected to the feedthroughs 8a and 8b.

(17) Feedthroughs 8a and 8b as well as the further feedthroughs consist of a connection pin 9 accommodated in a glass seal 10 which hermetically seals the TO housing 1.

(18) Next to the support 3, a mounting area 4 for a thermoelectric cooler is provided on the upper surface 7 of the base part 2.

(19) The angled conductor traces 5a and 5b extend from the connection pins 9 (RF pins) to the end face 6 of the support 3 in an area above this mounting area 4, which area in turn serves as a mounting area (23 in FIG. 2) for the optoelectronic component.

(20) Furthermore, a ground conductor 13 is located between the conductor traces 5a and 5b, which is also provided in the form of a conductor trace on sub-mount 15.

(21) Sub-mount 15 is preferably provided in the form of a ceramic plate with a thickness of preferably less than 0.3 mm.

(22) Above and below the component-side ends of the conductor traces 5a and 5b, a respective ground conductor 14a, 14b is located, which serves as a shield and which can be connected to the sub-mount of the optoelectronic component (19 in FIG. 2).

(23) Conductor traces 5a, 5b and ground conductor traces 13, 14a, 14b are provided in the form of a metal layer, in particular a gold-containing metal layer, for example as a gold-nickel layer.

(24) The signal paths to the optoelectronic component are defined by the connection pins 9, the conductor traces 5a, 5b, and the bonding wires and conductor traces on the sub-mount of the thermoelectric component (not illustrated here).

(25) The signal paths preferably have an impedance of 20 to 30 within the high frequency range.

(26) In addition to connection pins 9, the housing of this exemplary embodiment furthermore comprises the three connection pins 12a to 12c arranged in a row, which are used, for example, to connect a thermoelectric cooler (DC pins).

(27) Connection pins 11a to 11b opposite the support 3 are projecting further upwards than the connection pins 12a to 12c and are used in particular for connecting a thermistor which is arranged on the sub-mount of the optoelectronic component (19 in FIG. 2).

(28) The feedthroughs of connection pins 11a to 11b and 12a to 12c also include a glass seal.

(29) FIG. 2 shows the equipped TO housing, again in a perspective view.

(30) A thermoelectric cooler 16 is mounted on the upper surface 7 of the base part. Thermoelectric cooler 16 has an L-shaped portion 17. The mounting area 23 for the optoelectronic component is located above the lower leg of L-shaped portion 17.

(31) The optoelectronic component is a DFB laser diode 18.

(32) DFB laser diode 18 sits on a ceramic sub-mount 19 which is aligned vertically and preferably arranged substantially centrally in the TO housing 1.

(33) For this purpose, the sub-mount 19 is applied to the vertical leg of L-shaped portion 17.

(34) Next to the DFB laser diode 18, a thermistor 36 is arranged, which is used to control the thermoelectric cooler 16.

(35) Conductor traces 5a, 5b of support 3 are connected to the connection pins 9 by a solder 22, in particular by a gold-tin solder.

(36) The sub-mount 15 of conductor traces 5a, 5b and the sub-mount 19 of the optoelectronic component are aligned in a plane such that conductor traces 5, 5b and 25, 26 thereof are directly facing each other. The conductor traces 5a, 5b which are used as signal conductor traces are connected to the conductor traces 25 and 26 of the sub-mount 19 of the DFB laser diode 18 by a plurality of bonding wires 20a, 20b, preferably gold bonding wires.

(37) Conductor trace 26 leads directly to the DFB laser diode 18.

(38) Below conductor trace 26, the ground conductor trace 14b is connected to a ground conductor trace 37 on the sub-mount 19 of the DFB laser diode 18 by bonding wires 21b.

(39) A ground conductor trace 24 which is connected, by bonding wires 21a, to the ground conductor trace 14a and to the conductor trace 13 lying between conductor traces 5a and 5b, encloses the conductor trace 25 which is used as a signal conductor trace on the sub-mount 19 of the DFB laser diode 18. In this manner, conductor trace 25 is also shielded.

(40) Conductor trace 25 is connected to the DFB laser diode 18 by a bonding wire 27.

(41) FIG. 3 is a plan view of sub-mount 15 which is used to route the conductor traces 5a and 5b that serve as signal conductor traces to the mounting area (23 in FIG. 2) of the optical component.

(42) Sub-mount 15 is preferably made of a ceramic, and the conductor traces 5a and 5b are preferably made of gold or a gold-containing alloy.

(43) Conductor traces 5a and 5b are used to extend the signal path coming from the connection pins that are extended through the base part of the TO housing, upwards and towards the center of the housing.

(44) For this purpose, conductor traces 5a and 5b are routed along an angle.

(45) The connection area 34 for the optoelectronic component leads towards a lateral end face 6 of the sub-mount 15 or of the support with sub-mount 15.

(46) In connection area 34, the conductor traces 5a and 5b and the ground conductor traces 14a, 13, and 14b can be connected to the sub-mount of the optoelectronic component, by bonding wires.

(47) Within the range of ground conductor trace 13, which is arranged between conductor traces 5a and 5b and has a smaller width than the conductor traces 5a and 5b, there are a plurality of through-holes 28, preferably at least five, which have metallized side walls thereby providing a shielding which extends through the sub-mount 15. Metallized through-holes 28 are used to electrically connect the ground conductor trace to the support.

(48) The corner region 30 of the middle ground conductor trace 13 is chamfered and has an enlarged width. This avoids sharp edges and the associated signal loss.

(49) The corner regions 31 and 29 of conductor traces 5a and 5b are cut off at the edge so that the width of conductor traces 5a and 5b is reduced in the respective corner region 31, 29.

(50) Conductor trace 5a includes an enlarged area 33 between corner region 29 and connection area 34. This serves to tune the impedance profile of the signal path.

(51) The ground conductor traces 14a and 14b above and below the connection area of conductor traces 5a and 5b serve to shield the conductor traces 5a and 5b on the one hand, and on the other hand for connection to the sub-mount of the optical component.

(52) Ground conductor traces 14a and 14b each have at least one, preferably exactly one through-hole 32a, 32b with metallized side walls, thereby connecting the ground conductor traces 14a and 14b to the support.

(53) FIG. 4 is a sectional view through one of the through-holes 28 of a ground conductor trace.

(54) Through-hole 28 which is formed into the sub-mount 15, in particular etched, has inclined side walls. More particularly, the through-hole 28 has a frusto-conical shape with a cone angle from 5 to 90, preferably from 20 to 40. The side walls are provided with a metal layer 35, in particular with a gold-containing metal layer 35. Metallization within the meaning of the invention also refers to complete filling of the openings, in particular through-holes 28.

(55) By using the sub-mount shown in FIGS. 3 and 4, it was possible to achieve an impedance of approximately 25 of the signal path starting form a connected driver circuit and extending as far as to an electronic component.

(56) The TO housing of the invention enables high transmission rates in the high-frequency range when using DFB laser diodes. At the same time, the TO housing is robust and easy to manufacture.

(57) TABLE-US-00001 LIST OF REFERENCE NUMERALS 1 TO housing 2 Base part 3 Support 4 Mounting area 5a, 5b Conductor traces 6 End face 7 Upper surface 8a, 8b Feedthrough 9 Connection pin 10 Glass seal 11a-11c Connection pin 12a-12c Connection pin 13 Ground conductor trace 14a, 14b Ground conductor trace 15 Sub-mount 16 TEC 17 L-shaped portion 18 DFB laser diode 19 Sub-mount 20a, 20b Bonding wires 21a, 21b Bonding wires 22 Solder 23 Mounting area 24 Ground conductor trace 25 Conductor trace 26 Conductor trace 27 Bonding wire 28 Through-hole 29 Corner region 30 Corner region 31 Corner region 32a, 32b Through-hole 33 Enlargement 34 Connection area 35 Metal layer 36 Thermistor