Method for mounting an electrical component on a printed circuit board and electrical component

Abstract

The invention relates to a method for mounting an electrical component on a printed circuit board and an electrical component, comprising at least the following steps: a) Establishing an electrical and mechanical connection between at least one terminal pin (6) of the electrical component (1) and a component side (5) of the printed circuit board (2), b) Establishing a mechanical connection between at least one empty pin (7) of the electrical component (1) and the component side (5) of the printed circuit board (2).

Description

[0001] The invention relates to a method for mounting an electrical component on a printed circuit board and to an electrical component.

[0002] Various methods are known for assembling electrical printed circuit boards (PCBs), which are also referred to as printed circuits or circuit boards, or may be designed as such, with electrical components, including the THT method (Through the hole technology method) and the SMD method (Surface mounted device method).

[0003] The SMD process can include, in particular, the following steps: 1. PCB preparation: The circuit board is cleaned and prepared for the assembly process. Any solder residue or contamination from previous processing is removed. 2. Applying the solder paste: If necessary, using a stencil, solder paste, which may be a mixture of fine solder and flux, is applied precisely to the solder pads of the circuit board. 3. Place components (pick-and-place): Typically using an automatic pick-and-place machine, the SMD components are precisely placed onto the circuit board, with the connection pins of the electrical component positioned in the area of ​​the solder pads. 4. Soldering: The assembled circuit board is placed in a soldering oven, specifically a reflow oven. There, it is heated in a controlled manner so that the solder paste melts and the components are firmly soldered onto the board. 5. Inspection and rework: After the soldering process, the circuit board is inspected and tested.

[0004] Additional bonding of components to a printed circuit board (PCB) is generally done when mechanical stability is important, especially with double-sided PCBs or when components need to be fixed during the soldering process. It is particularly common when large or heavy components are to be mounted on the PCB. Such components can include transformers, power supplies, and larger capacitors or inductors that, due to their weight and / or dimensions, cannot be mounted on the PCB with the desired mechanical stability using surface-mount technology (SMD) and are therefore at higher risk of detachment, for example, during transport of the assembled PCB or due to other vibrations. Components with a greater weight or those subject to mechanical stress (e.g.,(In case of vibrations), they are additionally bonded to stabilize their position and reduce the risk of damage or displacement during processing or operation. Bonding is usually done before soldering, and the components are then fixed in place during the soldering process. The adhesive can cure under heat, ensuring that the components remain securely in position.

[0005] EP 2 031 945 A2 discloses a method for mounting electronic components or electromechanical components, hereinafter also referred to as electrical components, on a printed circuit board.

[0006] DE 195 43 765 A1 discloses an electrical component with axially extended connecting pins for contacting a printed circuit board.

[0007] The previously described gluing process leads to additional costs and an additional step in the assembly process, which undesirably increases the manufacturing time.

[0008] The technical problem therefore arises of creating a method for mounting an electrical component on a printed circuit board and an electrical component that enables a mechanically stable fastening of a particularly heavy electrical component to a printed circuit board, thereby reducing manufacturing costs and manufacturing time.

[0009] The solution to the technical problem is provided by the objects having the features of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0010] A method for mounting an electrical component on a printed circuit board is proposed. An electrical component within the meaning of this disclosure can also be an electronic component or an electromechanical component. Exemplary electrical components were described above. Preferably, the electrical component is a transformer. The printed circuit board can, in particular, be a control board of a pulse inverter of a vehicle, especially an electric or hybrid vehicle. The mounting can be carried out according to the steps of an SMD process described above, in particular steps 2 to 4.

[0011] The electrical component, designed as an SMD component, has at least one electrical connection pin, but preferably several electrical connection pins, which is / are designed for electrical and mechanical contact with a component side of the printed circuit board (PCB). The component side refers to the side of the PCB on which the electrical component is mounted. A connection pin is made of an electrically conductive material. It can be pin-shaped or wire-shaped. The connection pin, in particular a free end, is positioned in the area of ​​a solder pad on the PCB and then soldered to it. This achieves mechanical and electrical contact. Through the electrical contact thus established, the electrical component is integrated into an electrical circuit in a predetermined manner. The connection pin therefore forms an element for the electrical connection to the circuit.The electrical connection of the electrical component with other components or sections of the circuit can then be established via conductor tracks on / in the circuit board.

[0012] In addition to at least one electrical connection pin, the electrical component has at least one empty pin designed for mechanical contact with the component side of the printed circuit board. An empty pin is a pin that is not required, or not necessarily required, for electrical connection to the circuit. In other words, electrical contact with the printed circuit board, particularly according to predetermined contact parameters, is possible even without the empty pin. Preferably, but not necessarily, the empty pin serves exclusively for mechanical contact. However, it is also conceivable that the empty pin serves for redundant electrical contact.

[0013] It is possible that the connecting pin and / or the empty pin is / are bent or angled.

[0014] In the first manufacturing step of the proposed process, an electrical and mechanical connection is established between the at least one terminal pin of the electrical component and a component side of the printed circuit board. This can be achieved, in particular, by soldering in the area of ​​a solder pad on the printed circuit board, as previously explained.

[0015] In a further manufacturing step, a mechanical connection is established between the at least one empty pin of the electrical component and the component side of the printed circuit board (PCB). This can also be achieved by soldering in the area of ​​a solder pad on the PCB. A solder pad on a PCB is a conductive area on the PCB surface used to connect electrical components. These are small, usually round, rectangular, or other geometrically shaped copper areas or areas made of another conductive material, arranged at predetermined positions on the PCB. Solder pads serve as contact points for the soldering process and the electrical circuit.

[0016] The manufacturing steps do not necessarily have to be carried out sequentially. Rather, they can also be performed at least partially simultaneously. For example, both the at least one connecting pin and the at least one empty pin can each be positioned in the area of ​​a solder pad, e.g., using a pick-and-place machine, and then soldered together with the circuit board.

[0017] The proposed method advantageously enables a reliable and stable mechanical fastening of a particularly heavy electrical component to a printed circuit board (PCB), eliminating the need for (additional) adhesive bonding and thus reducing manufacturing costs and production time. In particular, the creation of the mechanical connection between the empty pin and the component side can be easily integrated into the SMD manufacturing process. Specifically, the PCB can be provided with at least one additional solder pad compared to a configuration without an empty pin. This additional solder pad can be positioned such that at least a portion of the empty pin is located within the area of ​​the additional solder pad when the electrical component is positioned in its intended placement orientation.

[0018] In another embodiment, the at least one empty pin is attached to a single solder pad on the printed circuit board. The single solder pad can be a pad designed for attaching a single empty pin. In particular, the dimensions of the single solder pad can be chosen such that only a single empty pin can be soldered to it. This advantageously results in a high degree of configuration freedom in the design of the printed circuit board, since such single solder pads generally require little space on / in the board and can therefore be easily integrated into a design for creating a predetermined circuit.

[0019] In another embodiment, several empty pins are attached to individual solder pads on the circuit board. In this embodiment, the electrical component therefore has multiple empty pins. This advantageously increases the mechanical stability of the attachment while simultaneously maintaining the configuration freedom described above.

[0020] In another embodiment, several empty pins are attached together to a single solder pad on the printed circuit board. The solder pad can be a pad designed for the simultaneous attachment of multiple empty pins. In particular, the dimensions of the solder pad can be chosen such that several empty pins can be soldered to it. This advantageously simplifies the manufacturing of the printed circuit board, as only one additional solder pad is required for attaching multiple pins.

[0021] In another embodiment, mounting sections of the solder pad are provided via a solder mask clearance. This clearance refers to an area on the printed circuit board (PCB) that is left uncovered by the solder mask layer. The solder mask, or solder resist, is a protective layer applied to the PCB to prevent solder from adhering to unwanted areas. This mask typically covers most of the copper traces and areas of the PCB. The clearances are targeted cutouts in this mask that leave uncovered the areas where soldering is to take place, such as the solder pads for surface-mount devices (SMDs). In these areas, no solder mask is applied, allowing the solder to make contact with the metallic pads of the PCB during assembly and soldering.This advantageously results in a simple manufacturing process for the printed circuit board, as the areas for attaching multiple connection pins can be provided in a known and proven manner.

[0022] In another embodiment, the mounting section of the circuit board for the at least one empty pin is provided as a potential-free area. This can mean that the single or surface solder pad used to mount the empty pin is electrically insulated on the circuit board side. It is also possible that the empty pin is electrically insulated on the component side.

[0023] Alternatively, the mounting area of ​​the circuit board for the at least one empty pin is provided with a reference potential. This can mean that the single or flat solder pad used to mount the empty pin is electrically connected to a reference potential, e.g., ground, on the circuit board side. It is also possible that the empty pin is connected to a reference potential, e.g., ground, on the component side.

[0024] In particular, the circuit board-side mounting sections and / or component-side mounting sections for multiple solder pins are arranged in such a way that electrical operational safety is ensured and, in particular, requirements for leakage and / or creepage current safety are met.

[0025] This advantageously results in a simple and reliable electrical connection of the electrical component to the circuit board via the at least one empty pin.

[0026] A further proposal is an electrical component for mounting on a printed circuit board, wherein the electrical component has at least one electrical connection pin designed for electrical and mechanical contacting of the component side of a component side of the printed circuit board, wherein the electrical component has at least one empty pin designed for mechanical contacting of the printed circuit board.

[0027] According to the invention, the at least one empty pin is designed for mechanical contact with the component side of the printed circuit board. This and the corresponding advantages of such a component have already been explained above.

[0028] The at least one connecting pin and / or the at least one empty pin can be located on the underside of the electrical component. A pin (connecting pin and / or empty pin) can extend away from the electrical component. In particular, a pin can have at least one section that, when mounted on the printed circuit board, extends parallel to the surface on the component side. Additionally, a pin can have at least one section that, when mounted on the printed circuit board, extends perpendicular to the surface on the component side.

[0029] An electrical connection pin can be electrically connected to at least one electrical element of the component. This electrical element can be located within a housing of the component, for example, encapsulated in a housing body. A section of the connection pin can also be encapsulated in a housing body. An empty pin is preferably not electrically connected to an electrical element of the component. However, a section of the empty pin can also be encapsulated in the housing body.

[0030] In a further embodiment, the electrical component has several electrical connection pins and several empty pins, which are arranged relative to each other with a predetermined minimum distance. If the electrical component has several connection pins, these are preferably arranged relative to each other in such a way that a predetermined minimum distance between the connection pins is ensured. Such a minimum distance can be selected such that the described requirements for leakage and / or tracking current safety are met, even if contamination occurs (whereby dirt particles may impair the leakage and / or tracking current safety).

[0031] The predetermined minimum distance between empty pins and connection pins advantageously ensures operational reliability even in the presence of empty pins, in particular compliance with the specified requirements for leakage and / or creepage current safety. Preferably, connection pins and empty pins, especially their component-side end sections, are arranged alternately along a spatial direction, wherein the pins can maintain at least the minimum distance from each other along this spatial direction. In the printed circuit board (PCB) configuration, this spatial direction can extend parallel to the surface on the component side.

[0032] In another embodiment, the empty pins are connected at a free end, which can also be referred to as the PCB-side end, via a connecting bridge, the connecting bridge being designed for mechanical contact with the component side of the PCB. The connecting bridge can be made of a conductive material, preferably the same material as the empty pin. In particular, the empty pins can be designed as prongs of a comb-like structural element extending away from the connecting bridge. This advantageously enables simple and mechanically stable fastening.

[0033] In another embodiment, the empty pin forms a section of the connection pin. Along a direction of extension of the connection pin oriented from the PCB-side end of the connection pin towards the component, this section can be a segment that follows a connection section of the connection pin with at least one electrical element of the component. In other words, the connection pin can continue after the connection with the electrical element and then form the empty pin. This advantageously results in a simple manufacturing process for the electrical component with an empty pin.

[0034] A printed circuit board with an electrical component according to one of the embodiments described in this disclosure is further described, wherein at least one electrical connection pin electrically and mechanically contacts a component side of the printed circuit board, and wherein at least one empty pin mechanically contacts the component side of the printed circuit board. A vehicle with such a printed circuit board is further described.

[0035] The invention is explained in more detail using exemplary embodiments. The figures show: Fig. 1. A schematic side view of an electrical component on a printed circuit board, Fig. 2 a schematic top view of a pin header of an electrical component in a first embodiment, Fig. 3 a schematic top view of a partial area of ​​a surface of a printed circuit board in a first embodiment, Fig. 4 a schematic top view of a partial area of ​​a surface of a printed circuit board in a further embodiment, Fig. 5 a schematic top view of a pin header of an electrical component in a further embodiment, Fig. 6 a schematic top view of a partial area of ​​a surface of a printed circuit board in a further embodiment, Fig. 7 a schematic top view of a pin header of an electrical component in a further embodiment, Fig. 8 a schematic top view of a partial area of ​​a surface of a printed circuit board in a further embodiment and Fig. 9 a schematic flowchart of a method according to the invention.

[0036] In the following, identical reference symbols denote elements with the same or similar technical characteristics.

[0037] Fig. Figure 1 shows a schematic side view of an electrical component 1 on a printed circuit board 2. The electrical component 1 has a cuboid-shaped base 3 and two pin headers 4 on its underside, which, when the electrical component 1 is mounted on the printed circuit board 2, are arranged on a component side 5. The electrical component 1 can, in particular, be a transformer. In this case, electrical elements of the transformer, e.g., a primary coil and at least one secondary coil, can be arranged in the base 3. The design of the component 1 as a transformer is purely exemplary. The electrical component 1 can also be an electrical or electronic component other than a transformer.

[0038] The electrical component 1 has electrical connection pins 6, which serve for the electrical and mechanical contacting of the printed circuit board 2 in the area of ​​the component side 5. Furthermore, the electrical component 1 has empty pins 7, which also serve for the electrical and mechanical contacting of the printed circuit board 2 in the area of ​​the component side 5. The connection pins 6 and the empty pins 7, in particular their component-side ends, can each be embedded in the material of the pin headers 4.

[0039] Also shown are solder pads 8 of circuit board 2, which serve to connect to the connection pins 6. Circuit board 2 also includes additional solder pads 9, which serve to connect to the connection pins 6. The connection pins 6 and the empty pins 7 are soldered to circuit board 2 in the area of ​​solder pads 8 and 9 for mounting.

[0040] The in Fig. The depicted embodiment of the electrical component 1 is exemplary. It is conceivable that the electrical component 1 has no pin strips 4 and that the connection pins 6 and the empty pins 7 are attached to / in the base body 3.

[0041] Fig. Figure 2 shows a schematic top view of a pin header 4 of an electrical component 1 in a first embodiment. The electrical component 1 is shown to have three connecting pins 6a, 6b, 6c and three empty pins 7a, 7b, 7c in the area of ​​the pin header 4. These pins 6a, 6b, 6c, 7a, 7b, 7c are oriented along a spatial direction x, which in the illustrated embodiment represents a longitudinal direction of the pin header 4 and, in the assembled state of the component 1, is parallel to the surface of the printed circuit board 2 (see Figure 2). Fig. 1) is oriented, alternating, and arranged with a predetermined minimum distance from each other. It can be seen that the connection pins 6a, 6b, 6c are galvanically isolated from the empty pins 7a, 7b, 7c. This allows compliance with leakage and creepage current safety requirements.

[0042] Fig. Figure 3 shows a schematic top view of a partial area of ​​a surface of a component side 5 of a printed circuit board 2 in a first embodiment, which is used to attach an electrical component 1 with the Fig. The pin strip 4 shown in the diagram is used.

[0043] The diagram shows individual solder pads 8a, 8b, 8c, each designed for connection to the PCB-side (free) end of exactly one of the connection pins 6a, 6b, 6c. Along a connecting line of the centers of these individual solder pads 8a, 8b, 8c, these centers are spaced apart from each other at a predetermined minimum distance, where this predetermined minimum distance corresponds to the distance between two pads along the spatial direction x (see Fig. 2) adjacent connection pins 6a, 6b, 6c. Also shown are individual solder pads 9a, 9b, 9c, each designed for connection to the PCB-side (free) end of exactly one of the empty pins 7a, 7b, 7c. Along a connecting line of the centers of these individual solder pads 9a, 9b, 9c, these centers are spaced apart from each other with a predetermined minimum distance, where this predetermined minimum distance corresponds to the distance between two adjacent connection pins 7a, 7b, 7c along the spatial direction x. The geometric dimensions of the individual solder pads 8a, 8b, 8c, 9a, 9b, 9c, in particular their area requirements, their length and / or their width, can be selected such that predetermined requirements regarding creepage and leakage currents are met. Thus, it is conceivable that the in Fig. The 3 individual solder pads 8a, 8b, 8c, 9a, 9b, 9c shown may also have other, especially larger, dimensions than those shown.

[0044] Along the spatial direction x, the single solder pads 9a, 9b, 9c for connection to the empty pins 7a, 7b, 7c are arranged alternately with the single solder pads 8a, 8b, 8c for connection to the connecting pins 6a, 6b, 6c.

[0045] Fig. Figure 4 shows a schematic top view of a partial area of ​​a surface of a component side 5 of a printed circuit board 1 in a further embodiment, which is used to attach an electrical component 1 with the Fig. The pin strip shown in section 2 serves as the basis for pin 4. Unlike the one in Fig. In the embodiment shown in Figure 3, the solder pad 9 for connection to the empty pins 7a, 7b, 7c is designed as a flat solder pad. This pad is designed for connection to the PCB-side (free) ends of all empty pins 7a, 7b, 7c. Mounting sections 10a, 10b, 10c of the flat solder pad 9 are provided by a solder mask relief. The remaining areas of the surface of the flat solder pad 9 are thus coated with a solder mask.

[0046] Along a connecting line of the centers of these fastening sections 10a, 10b, 10c, these centers are spaced apart from each other at a predetermined minimum distance, wherein this predetermined minimum distance corresponds to the distance between two adjacent connection pins 7a, 7b, 7c along the spatial direction x (see Fig. 2) corresponds. Along the spatial direction x, the mounting sections 10a, 10b, 10c for connection to the empty pins 7a, 7b, 7c are arranged alternately with the single solder pads 8a, 8b, 8c for connection to the terminal pins 6a, 6b, 6c.

[0047] Fig. Figure 5 shows a schematic top view of a pin header 4 of an electrical component 1 in a further embodiment. In this embodiment, the empty pins 9a, 9b, 9c each form a section of a connection pin 8a, 8b, 8c. Along a direction of extension of a connection pin 8a, 8b, 8c, which is oriented from the circuit board-side end of the connection pin 6a, 6b, 6c to the component 1, the section forming the empty pin 9a, 9b, 9c is arranged after a connecting section 11a, 11b, 11c of the respective connection pin 9a, 9b, 9c with at least one electrical element of the component. Thus, the connection pin 8a, 8b, 8c is extended after the connection with the electrical element to form an empty pin 9a, 9b, 9c in each case.

[0048] Fig. Figure 6 shows a schematic top view of a partial area of ​​a surface of a component side 5 of a printed circuit board 2 in a further embodiment, which is used to attach an electrical component 1 with the in Fig. The pin header 4 shown in Figure 5 serves as the connection point. In this embodiment, the circuit board has two solder pads 12, each serving for connection to a terminal pin 6a, 6b, 6c and the empty pin 7a, 7b, 7c formed by the respective terminal pin 6a, 6b, 6c. Mounting sections 8a, 8b, 8c for the terminal pins 6a, 6b, 6c and mounting sections 9a, 9b, 9c for the empty pins 7a, 7b, 7c of a solder pad 12 are provided by a solder mask relief. The remaining areas of the surface of the solder pad 12 are thus coated with a solder mask. Along the spatial direction x, the mounting sections 9a, 9b, 9c for connection to the empty pins 7a, 7b, 7c are arranged at the same height as the single solder pads 8a, 8b, 8c for connection to the connection pins 6a, 6b, 6c.

[0049] Fig. Figure 7 shows a schematic top view of a pin header 4 of an electrical component 1 in a further embodiment. The empty pins 7a, 7b, 7c are connected at one free end via a connecting bridge 13. This connecting bridge 13 serves for the mechanical contact of the component side 5 of the printed circuit board 2. The empty pins 7a, 7b, 7c are designed as teeth of a comb-like structural element and extend away from the connecting bridge 13.

[0050] Fig. Figure 8 shows a schematic top view of a partial area of ​​a surface of a component side 5 of a printed circuit board 2 in a further embodiment, which is used to attach an electrical component 1 with the in Fig. The pin strip shown in section 5 serves as the basis for pin 4. Unlike the one in Fig. In the embodiment shown in Figure 3, the solder pad 9 for connection to the empty pins 7a, 7b, 7c is designed as a flat solder pad. This pad is designed for connection to the connecting bridge 13, which in turn connects all empty pins 7a, 7b, 7c. The connecting bridge 13 can be soldered to the flat solder pad. Due to the resulting full-surface soldering, no areas of the flat solder pad need to be exposed with solder mask.

[0051] Fig. Figure 9 shows a schematic flowchart of a method according to the invention for mounting an electrical component 1 on a printed circuit board 2 (see Figure 9). Fig.1) In a first step S1, an electrical and mechanical connection is established between at least one terminal pin 6 of the electrical component 1 and a component side 5 of the printed circuit board 2. In a second step S2, a mechanical connection is established between at least one unused pin 7 of the electrical component 1 and the component side 5 of the printed circuit board 2. Steps S1 and S2 can be performed at least partially simultaneously. Reference symbol list 1 electrical component 2 circuit boards 3 basic shapes 4 Pin strips 5 Component side 6, 6a, 6b, 6c connection pin 7, 7a, 7b, 7c Empty pin 8, 8a, 8b, 8c solder pad 9, 9a, 9b, 9c solder pad 10a, 10b, 10c fastening sections 11a Connecting sections 12 surface solder pads 13 Connecting bridge S1, S2 process steps QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 2 031 945 A2

[0005] DE 195 43 765 A1

[0006]

Claims

[1] Method for mounting an electrical component (1) on a printed circuit board (2), comprising at least the steps of: a) Establishing an electrical and mechanical connection between at least one terminal pin (6) of the electrical component (1) and a component side (5) of the printed circuit board (2), b) Establishing a mechanical connection between at least one empty pin (7) of the electrical component (1) and the component side (5) of the printed circuit board (2). [2] Method according to claim 1, characterized by , that at least one empty pin (6) is attached to a single solder pad (9) of the circuit board (1). [3] Method according to claim 2, characterized by , that several empty pins (7a, 7b, 7c) are each attached to a single solder pad (9a, 9b, 9c) of the circuit board (2). [4] Method according to claim 1, characterized by , that several empty pins (7a, 7b, 7c) are attached together to a surface solder pad (9) of the circuit board (2). [5] Method according to claim 4, characterized by , that mounting sections (10a, 10b, 10c) of the surface solder pad (9) are provided via a solder mask relief. [6] Method according to any of the preceding claims, characterized by , that the mounting section (10a, 10b, 10c) of the printed circuit board (2) is provided with a potential-free or reference potential for the at least one empty pin (6). [7] Electrical component for mounting on a printed circuit board (2), wherein the electrical component (1) has at least one electrical connection pin (6) designed for electrical and mechanical contacting of a component side (5) of the printed circuit board (2), wherein the electrical component (1) has at least one empty pin (7) designed for mechanical contacting of the printed circuit board (2), characterized by, that the at least one empty pin (7) is designed for mechanical contacting the component side (5) of the printed circuit board (2). [8] Electrical component according to claim 7, characterized by , that the electrical component (1) has several electrical connection pins (6a, 6b, 6c) and several empty pins (7a, 7b, 7c), wherein these are arranged with a predetermined minimum distance relative to each other. [9] Electrical component according to claim 7 or 8, characterized by , that the empty pins (7a, 7b, 7c) are connected at a free end via a connecting bridge (13), wherein the connecting bridge (13) is designed for mechanical contacting the component side (5) of the printed circuit board (2). [10] Electrical component according to claim 7, characterized by , that the empty pin (7) forms a section of the connecting pin (6).

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