CONTACT SYSTEM WITH A JOINING AID ELEMENT

Description

State of the art

[0001] The invention relates to a contact system comprising a printed circuit board and at least one press-fit contact. The press-fit contact is designed to be pressed into a cutout in the printed circuit board, thereby making electrical contact with the printed circuit board.

[0002] Press-fit contacts, particularly in a contact system of the type mentioned above, can be inserted into a cutout in a printed circuit board (PCB) using an automated manufacturing machine, thereby making electrical contact with the PCB. The tolerance during the insertion process is small, provided the cutout creates a positive connection between the PCB's cutout wall and the press-fit contact.

[0003] US 4 265 508 A, DE 10 2018 000940 A1 and JP 4 111796 B2 show contact systems comprising a printed circuit board, at least one press-fit contact and an joining aid. Disclosure of the invention

[0004] According to the invention, the contact system of the type mentioned above comprises at least one joining aid element. The joining aid element is designed to be connected to the printed circuit board by frictional and / or positive locking. The joining aid element has a guide funnel for the at least one press-fit contact – in particular, at least two or more press-fit contacts. The guide funnel is arranged and designed to guide an end section of the press-fit contact, designed for pressing into the printed circuit board, into the opening in the printed circuit board.

[0005] Advantageously, a press-fit contact with a lateral tolerance corresponding to the guide funnel can be fed onto the printed circuit board (PCB) by an automated manufacturing system and pressed into the PCB. Preferably, the joining aid has a guide shaft adjoining the guide funnel, which is designed to define the insertion direction of the press-fit contact during the pressing process. Advantageously, the press-fit contact can thus be aligned within the guide shaft, particularly orthogonally to the PCB, even if it enters the funnel at an angle, and can be plastically shaped to indicate the opening.

[0006] In a preferred embodiment, the joining aid has at least one anchoring element, in particular a centering notch, wherein the anchoring element is configured to engage in a recess or opening in the printed circuit board and thus secure the joining aid against displacement or misalignment on the printed circuit board. The printed circuit board advantageously has an opening for receiving the anchoring element, in particular the centering notch. Advantageously, the joining aid can thus be positioned precisely over the opening in the printed circuit board.

[0007] The joining aid is designed for soldering to the printed circuit board. This allows the joining aid to be soldered to the circuit board along with other electronic components in a cost-effective manner.

[0008] The joining element has at least one or two solder pads, the solder pad being designed for soldering to a surface of the printed circuit board, in particular a conductor track of the printed circuit board. Advantageously, the joining element can thus be provided cost-effectively as an SMD component and soldered together with other electronic components in a soldering oven, in particular a reflow soldering oven. Advantageously, in the embodiment already mentioned, the joining element, which is anchored to the printed circuit board, in particular by a form-fit connection to prevent displacement or misalignment, can be secured in its position during reflow soldering by means of the anchoring element.

[0009] The soldering base is preferably formed by a piece or layer of metal, wherein the piece or layer of metal is connected to the joining aid. The joining aid is, for example, made of plastic. The metal layer can be bonded to the joining aid. Advantageously, the joining aid can thus be provided in a cost-effective manner. The metal piece can, for example, be molded into the plastic joining aid.

[0010] In a preferred embodiment, the soldering foot is formed by a sheet metal angle, one leg of which is connected to the joining aid, and the other leg of which is designed for soldering to the printed circuit board. Advantageously, the soldering foot can thus be connected to the joining aid in a cost-effective manner, for example, by simply pushing or pressing in the leg designed for connection to the joining aid.

[0011] In a preferred embodiment, the joining aid has a solder pin for soldering into a cutout in the printed circuit board. The solder pin can, for example, be molded into or inserted into the joining aid. The solder pin has an end section designed for soldering to the printed circuit board, which can be inserted into the cutout in the printed circuit board and soldered there.

[0012] Advantageously, the joining aid can be soldered to the circuit board together with other THT components (THT = Through-Hole Technology).

[0013] In a preferred embodiment, the capture funnel has a cone angle between 20 and 140 degrees, preferably between 40 and 60 degrees, more preferably between 45 and 50 degrees, or 48 degrees. Advantageously, an end section of the press-fit contact can be guided along the slope formed by the cone angle up to the guide shaft.

[0014] As previously described, the joining aid can have a collection funnel and a guide shaft adjoining the collection funnel. In another embodiment, the joining aid can have only a collection funnel and thus no guide shaft.

[0015] In a preferred embodiment, the joining aid is made of plastic. The plastic is, for example, a thermoplastic, in particular PEEK (PEEK = polyetheretherketone), PPS (PPS = polypropylene sulfide), LCP (LCP = liquid crystal polymer), a polyolefin, for example polyethylene or polypropylene, a polyamide or polycarbonate.

[0016] In a preferred embodiment, the joining aid has at least two trapping funnels arranged along a row. The joining aid 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 trapping funnels. The trapping funnels can, for example, be arranged along a straight line. In another embodiment, the trapping funnels can be arranged according to a press-fit pin arrangement of several press-fit pins. For example, an integrated component, in particular a molded component, on which press-fit contacts for pressing into the printed circuit board are formed, can thus be press-fitted to the printed circuit board with a tolerance by means of the joining aid.

[0017] In a preferred embodiment, the contact system comprises a semiconductor module with electrical connections. The electrical connections are each designed as press-fit contacts and are further configured to be pressed into the printed circuit board. For this purpose, the press-fit contacts have, for example, a needle-eye-shaped end section or a boat-shaped end section. The press-fit contacts are, for example, made of copper or a copper alloy. Figure 1 shows an embodiment of a contact system with an joining aid element configured to receive an end section of a press-fit contact and to guide a through-hole in a printed circuit board; Figure 2 This shows in Figure 1 The joining aid shown is in a top view.

[0018] Figure 1Figure 1 shows an embodiment of a contact system 1. The contact system 1 comprises a printed circuit board 2. In this embodiment, the printed circuit board 2 has four openings 3, 4, 5, and 6, spaced apart from each other and arranged in a row. The openings 3, 4, 5, and 6 are each designed to receive a press-fit contact. For this purpose, each opening has a metal layer or a metal cylinder formed on one wall of the opening. A metal layer 7 on the wall of opening 3 is designated by way of example.

[0019] The circuit board 2 also has a conductor track 8, which is electrically connected to the metal layer 7. This allows a press-fit contact inserted into the opening 3 to be electrically connected to other electronic components connected to the circuit board 2.

[0020] In this embodiment, the printed circuit board 2 also has two openings 9 and 10. Openings 9 and 10 are each designed to receive an anchoring element. The printed circuit board 2 has an electrically conductive layer 11 in the area of ​​opening 9 and an electrically conductive layer 13 in the area of ​​opening 10. The electrically conductive layers 11 and 13, in particular conductor tracks, each form a surface of the printed circuit board and are each designed for surface soldering, in particular SMD soldering (SMD = Surface-Mounted Device), with a solder pad.

[0021] The contact system 1 also includes a joining aid element 14. In this embodiment, the joining aid element is designed as a plastic element.

[0022] In this embodiment, the joining aid element 14 has a plastic body in which funnel-shaped recesses are formed for inserting a press-fit contact.

[0023] Figure 1 Figure 3 shows an exemplary mold module 30, in particular an inverter. In this embodiment, four press-fit contacts 31, 32, 33, and 34 are formed on the mold module 30, each projecting in the same direction. The press-fit contacts 31, 32, 33, and 34 each have a press-fit section for insertion into the circuit board 2, and there into a cutout, for example, cutout 3, 4, 5, or 6. In this embodiment, the press-fit contacts form control connections for the mold module 30.

[0024] In this embodiment, the joining aid 14 has a collection funnel 24 for the press-fit contact 31, a collection funnel 25 for the press-fit contact 32, a collection funnel 26 for the press-fit contact 33, and a collection funnel 27 for the press-fit contact 34. The collection funnels 24, 25, 26, and 27 each open into a guide shaft, which in this embodiment is cylindrical. A guide shaft 23, which connects to the collection funnel 24, is designated by way of example. The collection funnel 24, together with the guide shaft 23, forms a particularly tapered opening in the joining aid 14, especially in the plastic body of the joining aid 14.

[0025] In this embodiment, the cone angle 28 of the insertion funnel 24 is 48 degrees.

[0026] The joining element 14 is designed for soldering, in particular SMD soldering (SMD = Surface-Mounted Device), to the printed circuit board 2. For this purpose, the joining element 14 has two solder feet 19 and 20, each of which is attached to one of the mounting pins 17 and 18 of the joining element 14, respectively. The mounting pins 17 and 18 are each integrally formed with the plastic body of the joining element 14.

[0027] In this embodiment, the solder feet 19 and 20 are designed as sheet metal angles, in particular stamped grids or lead frames. Each solder foot 19 and 20 has an opening on one mounting leg for passing through or receiving the fastening element 17 or 18, respectively. Each solder foot 19 and 20 has a solder leg 22 or 21, respectively. In this embodiment, the solder leg 22 of the solder foot 19 is soldered to the metal layer 11 by means of a solder medium 12. In this embodiment, the solder leg 21 of the solder foot 20 is soldered to the metal layer 13 by means of a solder medium 12. In this embodiment, the solder leg contains a solder medium 12. Figure 2 The recess shown in more detail is designed for the insertion of an anchoring element.

[0028] In this embodiment, the mold module 30 has additional electrical connections. In this embodiment, the mold module 30 is designed as a semiconductor switch half-bridge. A ground connection 43, a power supply connection 44, and an output connection 42 are each designed as a die-cut grid and protrude from the mold module 30 together, extending in the same direction.

[0029] The functionality of the contact system 1 and a joining method for attaching a press-fit contact are explained below: The joining aid 14 can be plugged into the printed circuit board 2 using the anchoring elements 15 and 16, which in this embodiment are designed as pins. For this purpose, the anchoring elements 15 and 16 are inserted into the corresponding openings 9 and 10, respectively, in the printed circuit board 2. The printed circuit board 2 has previously been printed with solder paste 12. After the joining aid 14 is attached to the printed circuit board 2, the solder leg 22 rests on the metal layer 11, and the solder leg 21 then rests on the metal layer 13.

[0030] The circuit board 2 can then be, especially together with others, in Figure 1The electronic components (not shown) are soldered in a reflow soldering oven. The solder 12, which extends between the printed circuit board 2, in particular the metal layers 11 and 13, and the solder pads 19 and 20, in particular the solder legs 22 and 21, can then melt and bond the solder legs 21 and 22 to the printed circuit board 2. The openings formed by the traps 24, 25, 26 and 27 then open precisely into the corresponding openings 3, 4, 5 and 6 in the printed circuit board 2.

[0031] The mold module 30 can then be pressed into the circuit board 2. The mold module 30 has previously been screwed or plugged into other components of an inverter or an electric motor, for example. The circuit board 2 can then be plugged onto the mold module 30 – as indicated by arrows 36 and 37. The press-fit contacts 31, 32, 33, and 34 can then be captured by the corresponding capture funnels 24, 25, 26, and 27 – with a tolerance corresponding to the capture funnels – and guided into the respective guide shaft. During the subsequent pressing process of the circuit board 2 onto the mold module 30, the press-fit section 35 of the press-fit contacts can then be pressed into the respective opening in the circuit board 2.The press-fit contact 31 is then pressed into the opening 3, the press-fit contact 32 into the opening 4, the press-fit contact 33 into the opening 5, and the press-fit contact 34 into the opening 6 of the circuit board 2, and each makes electrical contact with the circuit board 2 at that point.

[0032] Figure 2 This shows in Figure 1The joining aid 14, as previously shown, is shown in a top view. The trapping funnels 24, 25, 26, and 27 are each arranged in a row along a longitudinal extension 40 of the joining aid 14. The soldering foot 19, which is attached to the mounting pin 17, has a recess 38 on the soldering leg 22. The soldering leg 20, which is attached to the mounting pin 18, has a recess 39 on the soldering leg 21. In this embodiment, the recesses 38 and 39 are each U-shaped. Thus, when attached to the plastic body 41 of the joining aid 14, the soldering legs 21 and 22 can... Figure 1 encompass the anchoring element 15 or 16 shown.

[0033] In this embodiment, the anchoring element 15 extends orthogonally to the fastening element 17. In this embodiment, the anchoring element 16 extends orthogonally to the fastening element 18.

Claims

1. Contact system (1) with a printed circuit board (2) and at least one press-fit contact (31, 32, 33, 34), wherein the press-fit contact (31, 32, 33, 34) is designed to be pressed into a cut-out (3, 4, 5, 6) in the printed circuit board (2) and to electrically contact the printed circuit board (2) in the process, wherein the contact system (1) has at least one joining aid element (14) which is designed to be connected to the printed circuit board (2) in a force-fitting and / or a materially integral manner, and which for the at least one press-fit contact (31, 32, 33, 34) has a funnel trap (24, 25, 26, 27) which is disposed and designed to guide an end portion (35) of the press-fit contact (31, 32, 33, 34), which is designed to be pressed into the printed circuit board (2), into the cut-out (3, 4, 5, 6) of the printed circuit board (2), characterized in that the joining aid element (14) has at least one soldering foot (19, 20) which is designed to be connected to a surface (11, 13) of the printed circuit board (2) by soldering.

2. Contact system (1) according to Claim 1, characterized in that the joining aid element (14) has a guide shank (23) which adjoins the funnel trap (24, 25, 26, 27) and is designed to define a joining direction of the press-fit contact (31, 32, 33, 34) during press-fitting.

3. Contact system (1) according to one of the preceding claims, characterized in that the soldering foot (19, 20) is formed by a sheet metal angle which by way of one leg is connected to the joining aid element, and the further leg (21, 22) thereof is designed to be connected to the printed circuit board (2) by soldering.

4. Contact system (1) according to one of the preceding claims, characterized in that the joining aid element (14) has a soldering pin for soldering in a cut-out in the printed circuit board.

5. Contact system (1) according to one of the preceding claims, characterized in that the funnel trap (24, 25, 26, 27) has a cone angle (28) between 20 and 140 degrees.

6. Contact system (1) according to one of the preceding claims, characterized in that the joining aid element (14) is formed from plastics material.

7. Contact system (1) according to one of the preceding claims, characterized in that the joining aid element (14) has at least two funnel traps (24, 25, 26, 27) disposed along a row.

8. Contact system (1) according to one of the preceding claims, characterized in that the contact system (1) has a semiconductor module (30) having electrical connections which are each formed as a press-fit contact (31, 32, 33, 34), and which are designed to be pressed into the printed circuit board (2).

9. Contact system according to one of the preceding claims, characterized in that the joining aid element (14) has at least one anchoring element (15, 16), in particular a centring pin, which is formed to engage in a recess (9, 10) or a cut-out in the printed circuit board (2) and thus secure the joining aid element (14) against being misplaced on the printed circuit board (2).