Hermetically gastight optoelectronic or electro-optical component and method for producing the same

Abstract

A method for producing a hermetically gastight optoelectronic or electro-optical component with great robustness to heat and moisture is described. A housing cap is connected to a carrier in a hermetically gastight manner. Orifices in the housing cap are closed in a hermetically gastight manner by a window element. An electronic component with a housing has a housing cap, a carrier as base plate of the housing, and an interior space enclosed by the housing cap and the carrier. An optoelectronic or electro-optical converter element is arranged in the interior space. The housing cap is closed in a hermetically gastight manner by the carrier through a bonding connection of fused metal. The orifice is connected to the housing cap in a hermetically gastight manner by a window element along an edge metallization of the window element by a circumferential first seam of a fused metallic material.

Claims

1. A method for producing a hermetically gastight optoelectronic or electro-optical component, the method comprising: a) providing a carrier for at least one optoelectronic or electro-optical converter element, the carrier also serving as a base plate of a housing; b) providing a housing cap having an opening at a bottom surface such that, after the housing cap is placed on the carrier, an interior space for receiving the at least one converter element is formed by the housing cap above the carrier; c) producing at least one orifice in the housing cap for passing through desired radiation through the at least one orifice in the housing cap along a desired beam path oriented substantially orthogonally to the carrier and having an axis that substantially centrally penetrates the at least one orifice and the at least one converter element; d) providing at least one window element transparent to the radiation, the at least one window element having a shape and a size adapted to the orifice of the housing cap and having an edge area with an edge metallization as a contact surface, the edge metallization of the edge area of the window element being made as a layer sequence of at least two layers, wherein the edge area of the window element is coated with a first layer of chromium or titanium and a second layer comprising one of iron-nickel, platinum or palladium, said second layer being deposited on top of the first layer and said edge metallization including a circumferential seam of fused metallic material; e) assembling the carrier, the converter element, the housing cap and the at least one window element to form a hermetically sealed gastight connection between the housing cap and the edge area of the at least one window element by fusing a metallic material between the edge metallization of the at least one window element and the housing cap, and to form a hermetically sealed gastight connection between the housing cap and the carrier by fusing a metallic material between the housing cap and the carrier, wherein positioning the housing cap on the carrier comprises aligning the at least one orifice along the beam path opposite the at least one converter element.

2. The method according to claim 1, further comprising producing the window element as a plate of transparent material selected from the group consisting of sapphire (Al.sub.2O.sub.3), magnesium fluoride (MgF.sub.2), magnesium oxide (MgO), lithium fluoride (LiF), calcium fluoride (CaF.sub.2), barium fluoride (BaF.sub.2), silicon (Si), silicon dioxide (SiO.sub.2), germanium (Ge), zinc selenide (ZnSe), zinc sulfide (ZnS), cadmium telluride (CdTe), gallium arsenide (GaAs), titanium dioxide (TiO.sub.2), Y-partially stabilized zirconia (ZrO.sub.2), a mixture of thallium bromide and thallium iodide (KRS 5; Tl(BrI)), flint glass, fused silica, and combinations thereof.

3. The method according to claim 1, wherein the edge metallization further comprises a third layer of gold or nickel as a protective or wetting layer.

4. The method according to claim 1, wherein the edge metallization is produced by a vapor deposition process or by an electrochemical process.

5. The method according to claim 1, wherein the interior space is either filled with a gas or a gas mixture or is evacuated before producing the hermetically gastight connection between the housing cap and the carrier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail in the following with reference to drawings and embodiment examples. In the drawings:

(2) FIG. 1 is a schematic illustration of a first embodiment of an electronic component according to the invention with a converter element in longitudinal section;

(3) FIG. 2 is a schematic diagram of a housing cap according to the invention;

(4) FIG. 3 is a schematic diagram of a window element according to the invention;

(5) FIG. 4 is a schematic illustration of a second embodiment of an electronic component according to the invention with two converter elements in longitudinal section;

(6) FIG. 5 is a schematic illustration of a third embodiment of an electronic component according to the invention with two converter elements in longitudinal section;

(7) FIG. 6 is a schematic illustration of a fourth embodiment of an electronic component according to the invention with a first embodiment of an inner reflector in longitudinal section;

(8) FIG. 7 is a schematic illustration of a fifth embodiment of an electronic component according to the invention with a second embodiment of an inner reflector in longitudinal section;

(9) FIG. 8 is a schematic illustration of a sixth embodiment of an electronic component according to the invention with an outer reflector in longitudinal section;

(10) FIG. 9 is a schematic illustration of a first embodiment of a measuring cell according to the invention;

(11) FIG. 10 is a schematic illustration of a second embodiment of a measuring cell according to the invention with a mirror unit; and

(12) FIG. 11 is a schematic illustration of a third embodiment of a measuring cell according to the invention with a plurality of mirror units.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(13) An electronic component 1 according to the invention has as essential elements a housing 2 which is formed by a housing cap 4 with an orifice 5 and a carrier 3 above which there is placed the housing cap 4, and a window element 10 and an optoelectronic or electro-optical converter element 7 (FIG. 1).

(14) The carrier 3 is formed as a plate of Kovar and serves as a base plate for the housing 2. The housing cap 4 is placed in a hood-like manner on a surface of one of the lateral surfaces of the carrier 3. An interior space 6 in which the converter element 7 is arranged is surrounded by the inner sides of housing cap 4 and areas of the lateral surface of carrier 3. Converter element 7 has contact elements 7.1 for electrically contacting the converter element 7 which are guided through contact holes 3.1 of carrier 3 and fused with glass in the contact holes 3.1 so as to be hermetically gastight.

(15) The housing cap 4 is made of nickel and has an opening 4.2 (see also FIG. 2) in its bottom surface 4.1. The wall of the housing cap 4 is bent outward around the opening 4.2 and accordingly forms a circumferential edge 4.3 bounding the opening 4.2. In a region of the housing cap 4 facing upward, an orifice 5 is provided opposite carrier 3 in the housing cap 4. The window element 10 is arranged outside interior space 6 over orifice 5 and completely covers orifice 5. An optical filter 11 is held in interior space 6 directly below orifice 5. A beam path 8 for radiation 9 which is relevant for converter element 7 is realized from orifice 5 to converter element 7. Optical filter 11 is arranged in this beam path 8. For the sake of simplicity, no holders for the above-described elements, e.g., optical filter 11, are shown in FIGS. 1 to 11.

(16) Window element 10 has greater dimensions than orifice 5 and has an edge area 10.1 which protrudes over orifice 5 on all sides (see also FIG. 2). An edge metallization 10.2 is provided on the edge area 10.1 on the lateral surface of the window element 10 facing the housing cap 4 (bottom lateral surface). A first seam 17 which is formed by fused filler material is provided between edge metallization 10.2 and the region of housing cap 4 around orifice 5. Window element 10 and housing cap 4 are connected with one another by first seam 17 so as to be hermetically gastight.

(17) Housing cap 4 is welded to carrier 3 in a hermetically gastight manner along circumferential edge 4.3 by a second seam 18.

(18) A housing cap 4 according to the invention is shown in FIG. 2. As was described with reference to FIG. 1, the housing cap 4 surrounds the interior space 6 on five sides. The bottom surface 4.1 has opening 4.2 which is bounded by circumferential edge 4.3. The window element 10 is arranged above orifice 5 by means of first seam 17 and is connected to housing cap 4 in a hermetically gastight manner.

(19) A perspective view of the bottom lateral surface of a window element 10 according to the invention in FIG. 3 shows edge area 10.1 and the edge metallization 10.2 which is formed circumferentially on the lateral surface. Edge metallization 10.2 comprises at least two metallic layers which are vapor deposited one above the other on a circumferential portion of the edge area.

(20) In further embodiments of the invention, edge metallization 10.2 can also be sputtered on by PVD.

(21) A second embodiment of the electronic component according to the invention shown in FIG. 4 is outfitted with a first converter element 7.2 and a second converter element 7.3. An orifice 5 is provided in housing cap 4 above first converter element 7.2 and second converter element 7.3. The two orifices 5 are covered and closed in a hermetically gastight manner by a common window element 10. There is a first beam path 8.1 between the first converter element 7.2 and the orifice 5 provided above the latter and there is a second beam path 8.2 between the second converter element 7.3 and the orifice 5 provided above the latter. An optical filter 11 is arranged in the two beam paths 8.1, 8.2 at a distance from orifices 5 such that an intermediate space 12 is formed between optical filter 11, orifices 5 and the window element. The intermediate space 12 communicates with the interior space 6 through a channel 13. Farther downstream along the two beam paths 8.1, 8.2, there is arranged in each instance a further optical filter 11 which is associated exclusively with the first beam path 8.1 and exclusively with the second beam path 8.2, respectively. While the further optical filter 111 in the first beam path 8.1 is oriented orthogonal to the first beam path 8.1, the further optical filter 111 in the second beam path 8.2 is tilted with respect to the second beam path 8.2. The first beam path 8.1 is a measurement beam path and the second beam path 8.2 is a reference beam path.

(22) In further embodiments of the electronic component according to the invention, the further filters 111 can also both be tilted relative to the first beam path 8.1 and relative to the second beam path 8.2, respectively, in order to adjust optical parameters of the two beam paths 8.1, 82, for example. To this end, the further filters 111 are designed to be adjustable, i.e., their tilt angles can be selectively varied and adjusted.

(23) Each converter element 7.2 and 7.3 has contact elements 7.1 which are guided through contact holes 3.1 of the carrier 3 and cast integral therein with glass so as to be hermetically gastight. Housing cap 4 is connected to carrier 3 by second seam 18. In this example, second seam 18 is produced by means of a pulse welding method. In this case, no weld filler material is used; rather, the material of housing cap 4 and of carrier 3 is partially fused in the region of circumferential edge 4.3 and of carrier 3 below circumferential edge 4.3.

(24) In a third embodiment example of the electronic component 1 according to the invention which is shown in FIG. 5, the construction basically corresponds to that shown in FIG. 4, but an optical filter 11 is associated with the first beam path 8.1 and the second beam path 8.2 in each instance. Further, a diaphragm 23 with a diaphragm aperture 23.1 is provided in beam paths 8.1 and 8.2. The diaphragms 23 have edges which extend up to the inner side of housing cap 4 and accordingly divide the interior space 6 horizontally. The radiation 9 can only pass through the respective diaphragm aperture 23.1. This prevents unwanted stray radiation from propagating along the first beam path 8.1 and second beam path 8.2. Stray radiation may be caused, for example, by radiation components exiting from the front sides of the optical filter 11 and/or further optical filter 111.

(25) In a fourth embodiment example of the electronic component 1 according to the invention, a converter element 7 is arranged in the interior space 6 (FIG. 6). Housing cap 4 has an orifice 5. The converter element 7 is an electro-optical converter element and is designed to emit radiation 9 in a wavelength range of infrared radiation between 0.8 and 25 m. An inner reflector 14 is arranged above converter element 7 in interior space 6 such that a first portion of the beam path 8 is surrounded in a rotationally symmetrical manner by the inner reflector 14. The inner reflector 14 has a conical shape and is provided on its inner side with a coating (not shown) which reflects IR radiation. Converter element 7, inner reflector 14 and orifice 5 are aligned with respect to one another such that radiation 9 emitted by converter element 7 is collected through the inner reflector 14 and emitted through orifice 5 as directed beam bundle. Inner reflector 14 is soldered to converter element 7. In further arrangements, inner reflector 14 is held by a holding device (not shown). The second seam 18 is formed by soldering.

(26) In further arrangements, inner reflector 14 can also have elliptical or parabolic shapes. Moreover, it can also be shaped in a freeform manner, for example, by a combination of elliptical and parabolic segments.

(27) In an alternative construction of the inner reflector 14, an inner side of housing cap 4 is shaped as an inner reflector 14 and is coated, as is shown schematically in FIG. 7.

(28) In a sixth embodiment of an electronic component 1 according to the invention, an outer reflector 15 is placed on housing cap 4 above window element 10 (FIG. 8). The outer reflector 15 has a reflector holder 16 on the side thereof. Housing cap 4 is laterally surrounded by the reflector holder 16. In order to achieve a highly accurate positioning of outer reflector 15, reflector holder 16 is on the upper side of the bent circumferential edge 4.3. In further embodiments, outer reflector 15 can be bondingly connected, particularly glued, soldered or welded, to housing cap 4 over the surface, over some areas or by spots.

(29) A first embodiment example of a measuring cell 19 using the optoelectronic and electro-optical converter element 7 according to the invention is shown schematically in FIG. 9. The measuring cell 19 has a tubular measuring cell housing 19.1 of aluminum, two through-holes 20 being provided in the side walls thereof for guiding in and guiding out a medium to be measured. The measuring cell housing 19.1 can be cylindrically tubular or can also have a tubular shape in the form of an n-sided prism (shown only in FIG. 11). An electro-optical converter element 7 functioning as emitter unit is arranged at a front end of the measuring cell housing 19.1. Another optoelectronic converter element 7 functioning as sensor is arranged at the other front end of the measuring cell housing 19.1. The two converter elements 7 face one another and are located opposite one another. The extensions of the beam paths 8 of the two converter elements 7 form a common optical axis and are indicated by a dashed line. A measuring path 22 is defined by the spacing between the converter elements 7.

(30) A second embodiment of a measuring cell 19 according to the invention is shown in FIG. 10. Two converter elements 7, one of which is formed as sensor and one as emitter unit, are arranged side by side at the front end of the measuring cell housing 19.1. The two converter elements 7 face in direction of the opposite end of the measuring cell housing 19.1. A mirror unit 21 is arranged at the opposite end of the measuring cell housing 19.1 such that a common optical axis which is folded once is defined between the two converter elements 7. By means of this step, the measuring path 22 (represented by a dashed line) is more than doubled with the length of the measuring cell housing 19.1 remaining the same.

(31) In order to lengthen the measuring path 22 even further with the length of the measuring cell housing 19.1 remaining the same, further mirror units 21 can be arranged as is shown in FIG. 11. In this third embodiment example of the measuring cell 19, two converter elements 7 are again arranged side by side, one converter element 7 being formed as sensor and the other converter element 7 being formed as emitter unit. At the opposite end of the measuring cell housing 19.1, four mirror units 21, i.e., a first mirror unit 21.1, a third mirror unit 21.3, a fifth mirror unit 21.5 and a seventh mirror unit 21.7 are arranged side by side. A second mirror unit 21.2, a fourth mirror unit 21.4 and a sixth mirror unit 21.6 are provided adjacent to the two converter elements 7. A common optical axis of the two converter elements 7 is folded seven times and extends from the one converter element 7 to the first mirror unit 21.1, then to the second mirror unit 21.2 and further successively until the seventh mirror unit 21.7 and then to the other converter element 7. As a result of this arrangement, the measuring path 22 (dashed line) is more than eight times as long as the measuring path 22 in the first embodiment example according to FIG. 9.

REFERENCE NUMERALS

(32) 1 electronic component 2 housing 3 carrier 3.1 contact hole 4 housing cap 4.1 bottom surface 4.2 opening 4.3 circumferential edge 5 orifice 6 interior space 7 converter element 7.1 contact elements 7.2 first converter element 7.3 second converter element 8 beam path 8.1 first beam path 8.2 second beam path 9 radiation 10 window element 10.1 edge area 10.2 edge metallization 11 optical filter 111 further optical filter 12 intermediate space 13 channel 14 inner reflector 15 outer reflector 16 reflector holder 17 first seam 18 second seam 19 measuring cell 19.1 measuring cell housing 20 through-hole 21 mirror unit 21.1 first mirror unit 21.2 second mirror unit 21.3 third mirror unit 21.4 fourth mirror unit 21.5 fifth mirror unit 21.6 sixth mirror unit 21.7 seventh mirror unit 22 measuring path 23 diaphragm 23.1 diaphragm aperture