Contact system with a joining aid and method for joining
Technical Field
The invention relates to a contact system having a printed circuit board and at least one press-in contact. The press-in contact is designed to be pressed into a through-hole of the printed circuit board and to electrically contact the printed circuit board there.
Background
In particular, press-in contacts in contact systems of the type mentioned at the outset can be inserted into a through-hole of a printed circuit board, for example, by means of a processing robot, and in this case electrically contact the printed circuit board. The tolerances during the insertion are small, and for this reason the through-hole produces a force-fitting connection between the wall of the through-hole of the printed circuit board and the press-in contact.
Disclosure of Invention
According to the invention, a contact system of the type mentioned at the outset has at least one auxiliary joining element. The auxiliary engagement element is designed for a force-fitting and/or form-fitting connection to the printed circuit board. The auxiliary joining element has a catching funnel for at least one press-in contact, in particular at least two or more press-in contacts. The catch funnel is arranged and designed to guide the end section of the press-in contact, which is designed to be pressed into the printed circuit board, into the aperture of the printed circuit board.
Advantageously, the press-in contact can then be introduced with lateral tolerances corresponding to the guide funnel by the machining robot onto the printed circuit board and pressed there into said printed circuit board.
Preferably, the engagement aid element has a guide rod section connected to the catch funnel, which guide rod section is designed to predetermine the engagement direction of the press-in contact during the press-in. Advantageously, the press-in contact can then be oriented, in particular oriented plastically, in particular toward the through-hole, in the guide rod part, in particular perpendicularly to the printed circuit board, even when obliquely reaching the funnel.
In a preferred embodiment, the auxiliary engagement element has at least one anchoring element, in particular a centering pin, wherein the anchoring element is designed to engage in a recess or a bore in the printed circuit board and then to fix the auxiliary engagement element against displacement or displacement on the printed circuit board. The printed circuit board advantageously has a through-hole for receiving an anchoring element, in particular a centering pin. Advantageously, the auxiliary joining element can then be placed in the printed circuit board precisely through the through-opening.
Preferably, the auxiliary joining element is designed for a soldered connection to a printed circuit board. The auxiliary joining element can then be soldered to the printed circuit board together with the other electronic components in a cost-effective manner.
In a preferred embodiment, the auxiliary joining element has at least one or two solder feet, wherein the solder feet are designed for a solder connection to a surface of a printed circuit board, in particular to a conductor track of the printed circuit board. Advantageously, the auxiliary joining element can then be provided cost-effectively as an SMD component and soldered together with the other electronic components in a soldering furnace, in particular a reflow soldering furnace. Advantageously, in the embodiment with an anchoring element already mentioned, the joining aid element, which is anchored together with the printed circuit board, in particular in a form-fitting manner, to prevent displacement or displacement, can be fixed in its position during reflow soldering.
The soldering foot is preferably formed by a metal part or a metal layer, wherein the metal part or the metal layer is connected to the auxiliary joining element. The coaptation assistance element is formed, for example, from plastic. The metal layer can be glued to the auxiliary joining element. Advantageously, the auxiliary joining element can then be provided cost-effectively. The metal part can be molded into the plastic-joining auxiliary element, for example. In a preferred embodiment, the solder foot is formed by a corner of the plate which is connected with one leg to the auxiliary joining element and whose other leg is designed for a solder connection to the printed circuit board. The soldering foot can then be connected to the auxiliary joining element in a cost-effective manner, for example, by inserting or pressing in the leg designed for connection to the auxiliary joining element.
In a preferred embodiment, the auxiliary joining element has a soldering pin for soldering in a through-hole of the printed circuit board. The soldering plug can be molded or inserted into the joining aid, for example. The soldering pin has an end section configured for soldering to the printed circuit board, which end section can be inserted into a through-opening of the printed circuit board and soldered there.
Advantageously, the auxiliary joining element can then be soldered together with other THT components (Through-Hole Technology) to the printed circuit board.
In a preferred embodiment, the catch funnel has a cone angle of between 20 and 140 degrees, preferably between 40 and 60 degrees, further preferably between 45 and 50 degrees or 48 degrees. Advantageously, the end section of the press-in contact can then be guided all the way to the guide rod section on the bevel formed by the cone angle.
The coupling aid element can have a catch funnel and a guide rod connected to the catch funnel, as already described. In another embodiment, the coaptation assistance element can have only one catch funnel and thus no guide shaft.
In a preferred embodiment, the coaptation assistance element is formed from plastic. Examples of such plastics are thermoplastics, in particular PEEK (Poly-Ether-ketone), PPS (Poly-Propylen-Sulfid), LCP (Liquid-crystal Polymer), polyolefins, for example polyethylene or polypropylene, polyamides or polycarbonates.
In a preferred embodiment, the coaptation assistance element has at least two catch funnels arranged along a row. The coaptation assistance element can have at least two, only two, at least three, only three, at least four, only four, at least five, only five, or at least six, or only six jamming funnels. The catch funnels can for example be arranged along a straight line. In another embodiment, the catch funnel can be arranged according to a press-pin arrangement of a plurality of press-pins. For example, the integrated component, in particular the molded component, at which the press-in contact is formed for pressing into the printed circuit board, can then be press-connected to the printed circuit board with a certain tolerance by means of the auxiliary joining element.
In a preferred embodiment, the contact system has a semiconductor module with electrical connections. The electrical connections are each designed as press-in contacts and are each further designed for being pressed into a printed circuit board. For this purpose, the press-in contact has, for example, a pin-hole-shaped end section or a boat-shaped end section. The press-in contact is formed, for example, from copper or a copper alloy, respectively.
The invention also relates to a mating aid element for mating a press-in contact with a printed circuit board, in particular for a contact system of the type described above. The auxiliary joining element has a shaped body and at least one catch funnel for centering an end section of the press-in contact. The catch funnel is configured as a tapering cavity in the shaped body. Preferably, the auxiliary joining element has at least one solder tail configured for solder connection to a surface of the printed circuit board.
The invention also relates to a method for joining together a printed circuit board and a semiconductor module. In the method, the printed circuit board is plugged onto press-in contacts of the semiconductor module, wherein the end sections of the press-in contacts, which are designed to contact the printed circuit board, are guided through the latching funnels, preferably subsequently through the guide rods, all the way to the perforations in the printed circuit board. The press-in contact is further pressed into a through-hole of the printed circuit board and there electrically contacts the printed circuit board.
Drawings
The invention will now be described below with the aid of further embodiments. Further advantageous embodiments result from the combination of the features described in the figures and in the dependent claims. Wherein:
fig. 1 shows an embodiment for a contact system with an engagement aid element, which is designed to receive an end section of a press-in contact and to guide it into a through-opening of a printed circuit board;
fig. 2 shows the coaptation assistance element shown in fig. 1 in a top view.
Detailed Description
Fig. 1 shows an exemplary embodiment for a contact system 1. The contact system 1 comprises a printed circuit board 2. The printed circuit board 2 has in the present exemplary embodiment four openings 3, 4, 5 and 6, which are spaced apart from one another in a row in common. The bores 3, 4, 5 and 6 are each designed to receive a press-in contact. For this purpose, the perforations each have a metal layer formed on the perforation wall of the perforation or a metal cylinder. The metal layer 7 at the perforation wall of the perforation 3 is exemplarily marked.
The printed circuit board 2 also has a conductor track 8, which is electrically conductively connected to the metal layer 7. The press-in contact introduced into the through-opening 3 can then be electrically connected to a further electronic component connected to the printed circuit board 2.
In the present embodiment, the printed circuit board 2 also has two through holes 9 and 10. The bores 9 and 10 are each designed to receive an anchoring element. The printed circuit board 2 has an electrically conductive layer 11 in the region of the through-opening 9 and an electrically conductive layer 13 in the region of the through-opening 10. The electrically conductive layers 11 and 13, in particular the conductor tracks, each form a Surface of the printed circuit board and are each designed for a Surface-soldered connection, in particular an SMD-soldered connection, to a soldering foot (SMD).
The contact system 1 also has an engagement aid 14. The joining aid element is configured in the present exemplary embodiment as a plastic element.
In the present exemplary embodiment, the auxiliary engagement element 14 has a plastic body in which a funnel-shaped recess is formed for the introduction of the press-in contact.
Fig. 1 shows a molding module 30, in particular an inverter, for this purpose. In the present exemplary embodiment, four press-in contacts 31, 32, 33 and 34 are formed at the molding module 30, each of which projects in the same direction, from the molding module 30. The press-in contacts 31, 32, 33 and 34 each have a press-in section for pressing into the printed circuit board 2 and there into a through-hole, for example the through-hole 3, 4, 5 or 6. In the present embodiment, the press-in contacts form control contacts for the molding module 30.
In the present exemplary embodiment, the auxiliary joining element 14 has a catch funnel 24 for the press-in contact 31, a catch funnel 25 for the press-in contact 32, a catch funnel 26 for the press-in contact 33 and a catch funnel 27 for the press-in contact 34. The press-in funnels 24, 25, 26 and 27 each open into a guide rod part, which is of cylindrical design in the present exemplary embodiment. The guide rod portion 23 connected to the catch funnel 24 is exemplarily marked. Together with the guide rod 23, the catch funnel 24 forms a particularly conically formed perforation in the auxiliary joining element 14, in particular in the plastic body of the auxiliary joining element 14.
In the present example, the cone angle 28 of the introduction funnel 24 is 48 degrees.
The auxiliary joining element 14 is designed for a soldered connection, in particular an SMD soldered connection (SMD) component, to the printed circuit board 2. For this purpose, the auxiliary joining element 14 has two brazements 19 and 20, which are each inserted into one of the fixed journals 17 and 18 of the auxiliary joining element 14. The fixed journals 17 and 18 are each molded onto the plastic body of the auxiliary joining element 14.
In the present exemplary embodiment, the solder feet 19 and 20 are configured as plate corners, in particular as punched grids or lead frames. The soldering feet 19 and 20 each have a bore at the fastening leg for the insertion or reception of the fastening element 17 or 18. The soldering feet 19 and 20 each have a soldering leg 22 or 21. In the present exemplary embodiment, the soldering leg 22 of the soldering foot 19 is soldered to the metal layer 11 by means of the solder 12. In the present exemplary embodiment, the soldering leg 21 of the soldering foot 20 is soldered to the metal layer 13 by means of a solder 12. In the present exemplary embodiment, a recess for the passage of an anchoring element, which is shown in detail in fig. 2, is formed in the brazing leg.
In this embodiment, the molding module 30 also has additional electrical contacts. In the present exemplary embodiment, the mold module 30 is embodied as a semiconductor half bridge. The ground connection 43, the supply connection 44 and the output connection 42 are each designed as a punched grid and project together, in particular extending in the same direction, from the molding module 30.
The principle of operation of the contact system 1 and the joining method for joining press-in contacts will now be explained below.
The auxiliary engagement element 14 can be plugged into the printed circuit board 2 with the anchor elements 15 and 16, which are each embodied as a pin in the present exemplary embodiment. For this purpose, the anchoring elements 15 and 16 are inserted into the corresponding openings 9 and 10 in the printed circuit board 2. The printed circuit board 2 is previously printed with solder paste 12. The soldering leg 22 rests on the metal layer 11 after the joining of the auxiliary joining element 14 to the printed circuit board 2, and the soldering leg 21 rests on the metal layer 13.
Subsequently, the printed circuit board 2 can be soldered, in particular together with other electronic components not shown in fig. 1, in a reflow soldering oven. The solder 12 extending between the printed circuit board 2, in particular the metal layer 11 or 13, and the solder feet 19 and 20, in particular the solder legs 22 and 21, can then melt and connect the solder legs 21 and 22 to the printed circuit board 2 in a cohesive manner. The perforations formed by the catch funnels 24, 25, 26 and 27 then pass precisely into the corresponding perforations 3, 4, 5 and 6 in the printed circuit board 2.
The molding module 30 can then be pressed into the printed circuit board 2. The molding module 30 is already screwed or plugged to another component of the inverter or the electric motor, for example. The printed circuit board 2 can then be inserted into the molding module 30, as is outlined by the arrows 36 and 37. The press-in contacts 31, 32, 33 and 34 can then be clamped and guided into the respective guide rod sections by means of the respective clamping funnels 24, 25, 26 and 27, which are each assigned to a press-in contact, with a tolerance corresponding to the clamping funnels. During the pressing of the printed circuit board 2 further onto the molding module 30, the press-in sections 35 of the press-in contacts can then be pressed into corresponding openings in the printed circuit board 2. The press-in contact 31 is then pressed into the through-hole 3 of the printed circuit board 2, the press-in contact 32 is pressed into the through-hole 4 of the printed circuit board, the press-in contact 33 is pressed into the through-hole 5 of the printed circuit board and the press-in contact 34 is pressed into the through-hole 6 of the printed circuit board, and there is electrical contact with the printed circuit board 2 in each case.
Fig. 2 shows the coaptation assistance element 14 already shown in fig. 1 in a top view. The catch funnels 24, 25, 26 and 27 are each arranged in a row along the longitudinal extension 40 of the coaptation assistance element 14. The soldering foot 19 inserted onto the fastening journal 17 has a recess 38 at the soldering leg 22. The soldering foot 20 inserted onto the fixed journal 18 has a recess 39 at the soldering leg 21. In the present exemplary embodiment, the recesses 38 and 39 are each U-shaped. The soldering legs 21 and 22 can then enclose the anchoring element 15 or 16 shown in fig. 1 when inserted onto the plastic body 41 of the auxiliary joining element 14.
In the present exemplary embodiment, the anchoring element 15 extends orthogonally to the fastening element 17. In the present exemplary embodiment, the anchoring element 16 extends orthogonally to the fixing element 18.