Abstract:
The invention relates to an optoelectronic module with at least one carrier element, at least one optoelectronic component that is connected to the carrier element and can emit and/or receive light, and at least one adjusting opening arranged in the carrier element for receiving at least one adjusting means. An exact positioning of the optoelectronic module can be achieved through the adjusting opening arranged in the carrier element. The invention also relates to an optoelectronic system with at least one said optoelectronic module, at least one base part and at least one adjusting means that is arranged in the base part and passes through the at least one adjusting opening of the carrier element of the optoelectronic module.

Description:
FIELD OF THE INVENTION 
   The invention relates to an optoelectronic module according to the preamble of claim  1  and to an optoelectronic system. 
   BACKGROUND OF THE INVENTION 
   In view of the increasing requirements for fast and reliable optical data transmission paths, optoelectronic components are becoming ever more important. The coupling of these optoelectronic components to optical transmission paths, such as light-conducting fibers or optical printed circuit boards for example, requires a high degree of accuracy of the spatial adjustment of the optoelectronic components in relation to the respective optical data transmission paths in order to achieve a low-loss coupling between the optical components. 
   In the case of known optical connector systems, as shown for example in  FIG. 4 , a first connector  100  and a second connector  200  are joined to one another. The end regions of light-conducting fibers  110 ,  210  are respectively introduced into the connectors  100 ,  200 , so that the respective coupling surfaces of the light-conducting fibers  110 ,  210  are arranged on the respective front side  120 ,  220  of the respective connectors  100 ,  200 . An exact adjustment of the respective coupling surfaces in relation to one another is achieved in the case of this shown connector system by means of adjusting pins  250 , these adjusting pins  250  being held in the one connector  200  and the other connector  100  having corresponding clearances receiving the adjusting pins  250 . 
   When the two connector parts  100 ,  200  of the connector system shown in  FIG. 4  are joined together, the respective coupling regions of the light-conducting fibers  110 ,  210  are in this way aligned with one another. After joining together, this connector system can be locked with a clip  300 , which has resilient engaging regions  350 , which engage behind the respective rear side of the connectors. 
   Such an alignment of two optical connectors by adjusting pins is also described for example in the article “The MT-RJ connector—how it all fits together” by Eric Leichter, Corning Cable Systems. 
   Furthermore, in the article from Agilent Technologies: “Agilent Technologies singlemode small form factor (SFF) module incorporates micromachined silicon, automated passive alignment, and non-hermetic packaging to enable the next generation of low-cost fiber optic transceivers”, it is shown how such a connector with two adjusting pins may be constructed. 
   However, as described at the beginning, the requirement for exact adjustment does not only arise in the case of connectors, but in particular also in the case of the connection of active electrooptical components to corresponding optical transmission paths, for example light-conducting fibers or optical printed circuit boards. 
   SUMMARY OF THE INVENTION 
   The invention provides an optoelectronic module with at least one carrier element, at least one optoelectronic component which is connected to this carrier element and can emit and/or receive light and at least one adjusting opening arranged in the carrier element for receiving at least one adjusting means. 
   The integration of the at least one adjusting opening in the carrier element allows the optoelectronic module to be positioned exactly. In this case, the adjusting opening can be precisely produced in the carrier element, it then being possible for the optoelectronic component that is connected to the carrier element to be aligned in relation to this adjusting opening exactly in relation to a further optical component, in that, with the aid of the adjusting openings and an adjusting means arranged on the further optical component, in particular with an adjusting pin passing through the adjusting opening of the electrooptical module, the optoelectronic module is positioned exactly. 
   In one example, there is a definable spatial relationship between the adjusting opening and the optoelectronic component. Therefore, in the case of connection to an optical printed circuit board for example, the optoelectronic module can be exactly aligned by means of further adjusting means, in that the optoelectronic module is merely fitted onto these adjusting means. In this way, a self-adjustment of the electrooptical module is possible, so that low-cost and quick assembly is possible. Further, cost-intensive steps for adjustment are then not necessary. 
   The carrier element and the optoelectronic component are advantageously surrounded at least partly by a plastic, a clearance being provided in the plastic at least in the region of the at least one adjusting opening. Simple to handle optoelectronic modules which have the customary forms of housing or packages for electronic modules can be achieved in this way. 
   A low-cost optoelectronic module is produced in this case if the clearance in the plastic has a greater extent in the plane of the carrier element than the adjusting opening. Among the ways in which the cost saving is achieved here is that the respective injection mold can be made relatively imprecisely in the region of the adjusting opening, since the actual adjustment of the optoelectronic module in relation to its respective counterpart, in one example, is only performed by means of the adjusting opening in the carrier element. This configuration of the invention also achieves the effect that the adjustment is performed exclusively via the adjusting opening arranged in the carrier element, whereby the accuracy of the adjustment is increased. Any inaccuracies in the plastic molding then have no effect. 
   To allow adjusting pins of different lengths to be used, and to obtain independence from the respective arrangement of the optoelectronic module, the clearance in the plastic together with the adjusting opening form a continuous channel. The respective adjusting means, in particular an adjusting pin, can then be inserted through this continuous channel, so that it enters the optoelectronic module at one end of the channel and leaves the optoelectronic module again at the other end of the channel. 
   To be able to shield light-sensitive optoelectronic components or avoid the emission of stray radiation, the plastic is advantageously non-transparent, at least to the light emitted and/or received by the at least one optoelectronic component. 
   A simple to handle and electrically simple to contact optoelectronic module can be obtained by forming the carrier element as a leadframe which has at least one contactable contact surface, the leadframe together with the plastic forming a surface-mountable component, in particular an SMD, TSSOP or VQFN component. 
   A leadframe is understood here as meaning a metal or metallized carrier element which has at least one contact surface which can be contacted from the outside, which can be electrically contacted from the outside after production of the optoelectronic module has been completed, in particular after encapsulation with plastic, and by means of which an optoelectronic component located inside the optoelectronic module can be electrically contacted. 
   Simple contacting of the optoelectronic module and dissipation of heat can be achieved by the carrier element having at least one surface on which no plastic is arranged. The contactings can then be carried out on this surface of the carrier element and, for example, a heat sink can be arranged on it. 
   A simple arrangement of the optoelectronic component on the carrier element can be performed by the optoelectronic component being arranged on at least one intermediate carrier connected to the carrier element, the intermediate carrier being substantially transparent to the light emitted and/or received by the optoelectronic component. This allows the light emitted or received by the optoelectronic component to be received or emitted through the intermediate carrier. 
   In order to obtain a completely functional optoelectronic module, at least one further electronic component, in particular a passive and/or active component, is connected to the carrier element. The optoelectronic component is advantageously electrically connected to the carrier element by means of at least one bonding wire. 
   The invention also provides an optoelectronic system with at least one optoelectronic module of the specific type described above, at least one base part and at least one adjusting means which is arranged in the base part and passes through at least one adjusting opening of the carrier element of the optoelectronic module. 
   The system is designed for the optoelectronic module to be adjusted as simply and precisely as possible. 
   In order to achieve good heat dissipation, the base part is advantageously formed as a heat sink. 
   The electrical contacting of the optoelectronic module can be achieved by the provision of a printed circuit board, which is connected to the optoelectronic module and which has at least one adjusting opening which is passed through by the adjusting means of the at least one base part. In this way, the electrically conducting printed circuit board is also adjusted in relation to the optoelectronic module by the adjusting means, so that the electrical contacting is likewise performed in a substantially self-adjusting manner. The printed circuit board or the optoelectronic module may in this way be simply fitted onto the adjusting means, without further adjusting steps being necessary. 
   The printed circuit board is in this case advantageously formed such that it is flexible and is connected to further electronic components, in particular active components. 
   In a development of the invention, the base part is an optical printed circuit board and the at least one adjusting means is arranged on this printed circuit board in such a way that at least one optical channel arranged in the optical printed circuit board can be optically coupled to at least one optical component of the optoelectronic module. A simple, quick and precise adjustment of the optoelectronic module on the optical printed circuit board is achieved as a result. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described in more detail below on the basis of the figures of the drawings, in which: 
       FIG. 1  shows a plan view of an optoelectronic module with adjusting openings, 
       FIG. 1A  shows a sectional representation through the optoelectronic module of  FIG. 1  along the section A—A, 
       FIG. 1B  shows a sectional representation through the optoelectronic module of  FIG. 1  along the section B—B, 
       FIG. 2  shows a sectional representation through an optoelectronic system with an optoelectronic module, a base part and an adjusting means, 
       FIG. 2A  shows a sectional representation of the optoelectronic system shown in  FIG. 2  along the sectional line A—A, 
       FIG. 3  shows an optoelectronic system with an optoelectronic module and an optical printed circuit board, and 
       FIG. 4  shows a connector system according to the prior art. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the detailed description of the figures which follows, the same reference numerals are used for the same components, even if different embodiments are concerned. 
   The plan view of  FIG. 1  and the respective sectional representations in  FIGS. 1A and 1B  show an optoelectronic module  1  with a carrier element  2 , optoelectronic components  31 ,  32  arranged on the carrier element  2  and also adjusting openings  4 , which are arranged in the carrier element  2 . 
   The carrier element  2  is a leadframe, which has contact regions (leads)  21 , in one example, on its outer periphery has inside a carrier area  22  (die pad) for an optoelectronic component  31 ,  32  or an intermediate carrier (substrate)  33 , on which such a component is arranged. The contact regions  21  have on their underside contact surfaces  20 , which serve for the electrical contacting of the finished optoelectronic module  1 . As can be seen in the plan view of  FIG. 1 , the contact regions  21  of the leadframe  2  are not electrically connected to those of the carrier area  22 . 
   During the production of such an optoelectronic module  1 , at first all the parts of the leadframe  2  are held in a larger outer frame, which is punched away after production of the optoelectronic module has been completed. Also arranged in the leadframe  2  are optical windows  25 , through which light can enter or leave the optoelectronic components  31 ,  32 . The optoelectronic components are formed here as a light-emitting VCSEL laser  31  and as a photodetector chip  32 . Four active regions are respectively provided in this case, so that the optoelectronic module  1  has four transmitting channels and four receiving channels. 
   Arranged on the leadframe  2 , in the leadframe region  22  arranged in the inner area, there is firstly an intermediate carrier  33 , on which the respective optoelectronic component  31 ,  32  is arranged. The intermediate carrier  33  is in this case substantially transparent to the light emitted or received by the respective optoelectronic component  31 ,  32 . The intermediate carrier may in this case be a silicon substrate, for example, or some other semiconductor or a glass substrate. Arranged here as optoelectronic components on the intermediate carrier  33  are on the one hand a laser chip  31  and on the other hand a photodetector chip  32 . The respective active regions of the respective optoelectronic component  31 ,  32  are in this case arranged over the optical window  25  of the leadframe  2 , so that light can enter and leave through this optical window  25  through the leadframe  2 . 
   As can be further seen in the plan view of  FIG. 1 , further electronic components  38 ,  39 , which serve for controlling the respective optoelectronic component  31 ,  32 , are arranged on the leadframe  2 . Electrical connections between the individual contact portions  21  of the leadframe, between the additional electronic components  38 ,  39  and the intermediate carrier  33  or the optoelectronic components  31 , 32  are performed in the embodiment shown here by means of bonding wires  35 . The electrical connection of the optoelectronic component  31 ,  32  to the intermediate carrier  33  may also take place by means of flip-chip mounting. 
   As shown in  FIGS. 1 and 1B , adjusting openings  4 , which in the embodiment shown here are formed as circles, are also arranged in the leadframe  2 . The adjusting opening can in this case be precisely introduced into the leadframe  2 , either by punching or by etching. 
   The entire arrangement is surrounded by a preferably non-transparent plastic  5 . As shown in  FIG. 1B , a clearance  55  is provided in the plastic in the region of the adjusting opening  4 , so that a continuous channel  4 ,  55 , comprising the clearance  55  and the adjusting opening  4 , is formed. As shown in  FIG. 1  and  FIG. 1B  for example, the clearance has in this case a greater extent in the plane of the leadframe  2  than the adjusting opening  4  itself. In this embodiment, the clearance  55  is also formed as a square, as shown in  FIG. 1  for example, whereas the adjusting opening  4  is round. However, any other forms may also be used here. 
   Here, the plastic  5  forms the actual outer form of the module housing or the package, so that the optoelectronic module shown in  FIGS. 1 ,  1 A and  1 B is substantially a VQFN (very thin profile quad flat non leaded package), that is to say a package without contact leads. The plastic may also be formed here as non-transparent plastic, so that the optoelectronic components  31 , 32  are optically shielded. 
   Shown in  FIG. 2  is an optoelectronic system in which an optoelectronic module  1 , which substantially corresponds to that shown in  FIGS. 1 ,  1 A and  1 B, is connected to a base part  60 , which is formed as a heat sink. 
   A section through the optoelectronic system of  FIG. 2  along the sectional direction A—A is shown in  FIG. 2A . Here it can clearly be seen that two adjusting pins  6  are connected to the heat sink  60 , the adjusting pins being respectively fixed in a blind-hole bore  61  of the heat sink  60 . The optoelectronic module  1  is in this case fitted with its adjusting openings  4  onto the adjusting pin  6 . In  FIG. 2A  it can be clearly seen that the region  55  with a clearance in the plastic  5  is passed through by the adjusting pin, without the adjusting pin coming into contact with the plastic  5 . The adjustment of the optoelectronic module  1  therefore takes place exclusively via the adjusting openings  4  arranged in the leadframe  2 , since there is no contact with the plastic  5  by the adjusting pins  6 . 
   Also provided is a flexible printed circuit board  7 , arranged on which are further active components  65 , which adjoin the heat sink  60 . Here, the flexible printed circuit board is made in a rectangular form, so that the further active components  65  are arranged in a region of the printed circuit board  7  which is perpendicular to the region assigned to the electrooptical module  1 . 
   In the region of the adjusting pins  6 , the flexible printed circuit likewise has openings  74 , with which the printed circuit board  7  is adjusted in relation to the optoelectronic module  1 . This also allows the electrical contacting to be performed in a simple and virtually self-adjusting manner. 
   Openings  75  in the flexible printed circuit board  7  make it possible for light  310 ,  320  to pass directly through to the optical windows  25  in the leadframe. 
   Here, the adjusting pins  6  are of a great length, so that an optical connector can still be pushed onto the adjusting pins  6  for the optical connection of the electrooptical module  1  to a light-conducting fiber. Such an optical connector is not shown here, but can be adjusted with respect to the electrooptical components  31 ,  32  of the electrooptical module  1  by means of the adjusting pins  6 . 
     FIG. 3  shows an electrooptical system with an electrooptical module  1  in a further configurational variant. Provided here as the basis of the system is an optical printed circuit board  70 , in which optical channels or optical waveguides  73  run. In the optical printed circuit board  70 , adjusting pins  6  are also arranged in blind-hole bores  71 . The optoelectronic module  1  is pushed with its adjusting openings  4  onto the adjusting pins  6 . As a result, the optoelectronic components  31 ,  32  of the optoelectronic module  1  are adjusted with the coupling regions of the optical channels  73  in such a way that a coupling of light into the electrooptical components  31 ,  32  or out of the electrooptical components into the optical channels  73  of the optical printed circuit board  70  is exactly possible. 
   The electrooptical module  1  is in this case mounted at its contact surfaces  20  on the optical printed circuit board  70  by means of solder points  74 . Electrical conductor tracks  72 , which run on the optical printed circuit board  70 , can in this case also be contacted with respect to the electrooptical module  1  by means of the solder points  74 .