Method for manufacturing an electrical device

Abstract

The present invention relates to a method for manufacturing an electrical device based on a circuit board, wherein the circuit board has a first conductor circuit structure with a conductor circuit on one side of the circuit board, which is hereinafter referred to as the primary side; a second conductor circuit structure with a conductor circuit, which is arranged on the other side of the circuit board, which is hereinafter referred to as the secondary side, and / or is arranged in an intermediate layer of the circuit board as an internally located conductor circuit structure; and a plurality of metallized through-holes, through which the conductor circuits of the first conductor circuit structure can be electrically connected to the conductor circuits of the second conductor circuit structure. At least one first electrical component is arranged on the primary side, and the at least one first electrical component is welded to the first conductor circuit structure by a first welding step. According to the present invention, before the at least one first electrical component is arranged on the primary side and welded by the first welding step, at least one of these metallized through-holes is closed only on the primary side by means of a protective layer.

Description

[0001] The invention relates to a method for manufacturing an electrical device and the electrical device.

[0002] In addition, the present invention relates to a method for manufacturing an electrical device based on a circuit board, wherein the circuit board has: a first conductor circuit structure having a conductor circuit on one side of the circuit board, which is referred to as the primary side below; a second conductor circuit structure having a conductor circuit, which is arranged on the other side of the circuit board, which is referred to as the secondary side below, and / or is arranged as an internally located conductor circuit structure in an intermediate layer of the circuit board; and a plurality of metallized through-holes, through which the conductor circuits of the first conductor circuit structure can be electrically connected to the conductor circuits of the second conductor circuit structure respectively, wherein at least one first electrical component is arranged on the primary side, and the at least one first electrical component is welded to the first conductor circuit structure by a first welding step.

[0003] This type of circuit board is generally known in the technical field of circuit boards. It is also known that at least one electrical component, for example in the form of a surface mounted component (also known as SMD, English Surface Mounted Device, surface mounted component) or a plug-in component also known as a THD component (Through-Hole Device, through-hole component) is arranged on the primary side and soldered to the first or second conductor track structure.

[0004] The object of the present invention is to provide a method which provides better results with respect to the corrosion protection of plated through-holes than known methods.

[0005] This object is achieved according to the invention by a method having the features of claim 1. Advantageous embodiments of the method according to the invention are given by the dependent claims.

[0006] According to the invention, provision is therefore made that at least one of the plated through-holes is closed only on the primary side by means of a protective layer before the at least one first electrical component is arranged on the primary side and soldered in the first soldering step.

[0007] One major advantage of the method according to the invention is that by closing the metallized channels that have not yet been mounted with the aid of a protective layer, reliable corrosion protection is ensured also for the primary side. If, for example, the metallized channels that have not yet been mounted are obscured by components to be mounted on the circuit board or subsequently mounted on the circuit board, it cannot be ensured that reliable corrosion protection can still be ensured subsequently in the context of subsequent steps. By coating the metallized channels with a protective layer on the primary side before the components are attached to the primary side according to the invention, it is ensured that no obscured metallized channels remain that are not protected on the primary side by a suitable protective layer.

[0008] According to an extended design of the method according to the invention, any corrosion-resistant material that can withstand subsequent processing steps, such as welding steps, can be used for the protective layer. However, it is considered particularly advantageous that the protective layer is composed of a welding protection layer, which plays a role of welding protection in particular in the first welding step. In order to protect the conductor circuit that should not be in contact with the welding material from being wetted by the welding material, it is known to apply the so-called welding protection varnish to the conductor circuit before the first welding step. This welding protection varnish coating step can be used in an advantageous manner to achieve a synergistic effect so as to also close the metallized channel that has not yet been assembled on the primary side. In other words, the welding protection varnish performs a dual function in this case: on the one hand, the welding protection varnish coats and protects the conductor circuit from the influence of the welding material, which may wet the conductor circuit in the next welding step, and on the other hand, the welding protection varnish serves as a closed structure above the metallized channel that has not yet been assembled or on the primary side; both protection functions can be achieved by this coating step.

[0009] Epoxy resins are preferably used as solder varnishes.

[0010] According to another embodiment, after the circuit board has been populated with electrical components, the primary side of the circuit board is coated with a covering layer at least in the region with the metallized through-holes, the covering layer being composed in particular of an acrylic resin or a lacquer containing an acrylic resin. The resulting device can be coated with such a covering layer on both sides of the circuit board, either completely or at least in partial regions.

[0011] As the material for the covering layer, any material suitable for the electrical operation of the device and providing good corrosion protection can be used, for example silicon or a silicon-containing lacquer. However, with regard to particularly good protection properties, in particular particularly good corrosion protection, it is considered advantageous to apply a covering layer in the form of an acrylic resin or a lacquer containing acrylic resin on both sides of the circuit board or at least in the area provided with the metallized channels after the circuit board is populated with electrical components. Acrylic resins or lacquers containing acrylic resins are strong and not very permeable to air, at least stronger and less permeable than silicon.

[0012] According to another embodiment, after the printed circuit board is installed, the secondary side is coated over the entire surface or at least in the region having the metallized plated through-holes with a covering layer, which in particular consists of an acrylic resin or a lacquer containing an acrylic resin.

[0013] It is considered advantageous here if, before the first electrical components are fixed to the primary side and soldered in a first soldering step, all non-assembled metallized vias which are located below the first electrical components after mounting and are concealed by them after fixing and soldering are closed on the primary side by means of a protective layer.

[0014] In a first soldering step, the first electrical component is soldered to one or more conductor tracks of the conductor track arrangement.

[0015] According to another embodiment, after the first welding step, at least one second electrical component is arranged on the primary side and is welded to, in particular to one or more conductor tracks of, the second conductor track structure by a second welding step.

[0016] According to another embodiment, metallized plated through holes for arranging the at least one second electrical component are excluded from the coating and remain unsealed by means of the protective layer.

[0017] All the conductive metallized paths on the inner wall side, which are particularly used for mounting one or more second electrical components on the primary side after mounting and soldering one or more first electrical components and soldering one or more second electrical components to at least one second conductor circuit of a second conductor circuit structure, are kept excluded from the coating and remain unsealed by means of the protective layer.

[0018] According to another embodiment, before the at least one first electrical component is mounted on the primary side and soldered in the first soldering step, a plated through hole located below at least one second electrical component after the second component has been arranged is closed on the primary side by means of the protective layer.

[0019] If the second conductor track structure is an inner conductor track structure arranged in an intermediate layer of the printed circuit board, it is advantageous if the electrically conductive metallization paths on the inner wall or at least some of the metallization paths extend to the intermediate layer and electrically connect the primary side and the intermediate layer to one another.

[0020] If a second conductor track structure with second conductor tracks is located on the secondary side, the metallized through-holes or at least some of them can extend through the printed circuit board and electrically connect the primary side to the secondary side.

[0021] According to another embodiment, the at least one second electrical component has a plurality of connecting contacts which are introduced into metallized vias excluded from the coating by the protective layer when the second component is arranged, and the connecting contacts are welded to the second conductor track structure by the second welding step.

[0022] According to another embodiment, the diameter of the plated through hole is designed such that, by the second soldering step, solder material is drawn from the secondary side in the direction of the primary side due to a capillary effect and the plated through hole is completely or at least partially filled with solder material.

[0023] According to another embodiment, a reflow soldering method is preferably carried out in the first soldering step and / or a wave soldering or wave soldering method is preferably carried out in the second soldering step.

[0024] The first component is preferably a surface-mount component and / or the second component is preferably a plug-in component.

[0025] In addition, the present invention also relates to an electrical device having a circuit board, wherein the circuit board has: a first conductor circuit structure having a conductor circuit on one side of the circuit board, which is referred to as the primary side below; a second conductor circuit structure having a conductor circuit, which is arranged on the other side of the circuit board, which is referred to as the secondary side below, and / or is arranged as an internally located conductor circuit structure in an intermediate layer of the circuit board; and a plurality of metallized through-holes, through which the conductor circuits of the first conductor circuit structure can be electrically connected to the conductor circuits of the second conductor circuit structure respectively, and wherein at least one electrical component is arranged on the primary side and the at least one electrical component is soldered to the first and / or second conductor circuit structures.

[0026] According to the invention, it is provided that at least one of the metallized plated vias arranged below the at least one electrical component is closed only on the primary side by means of a protective layer.

[0027] With regard to the advantages of the device according to the invention and advantageous embodiments of the device according to the invention, reference is made to the embodiments described above in conjunction with the method according to the invention.

[0028] According to one embodiment of the device, the protective layer is a soldering protective layer.

[0029] According to another extended design of the device, the primary side of the circuit board is coated with a covering layer, in particular consisting of an acrylic resin or a lacquer containing an acrylic resin, in the area having the metallized through-holes, and / or the secondary side of the circuit board is coated with a covering layer, in particular consisting of an acrylic resin or a lacquer containing an acrylic resin, all over or at least in the area having the metallized through-holes.

[0030] The invention also relates to a rail vehicle, in particular a rail vehicle having a traction converter. According to the invention, the rail vehicle, in particular a traction converter of the rail vehicle or one of the traction converters of the rail vehicle, has the above-described electrical device and / or an electrical device produced according to the above-described method.

[0031] The present invention is described in detail below based on embodiments;

[0032] Figure 1 shows an embodiment of a circuit board which can be used to produce an embodiment of the device according to the invention,

[0033] Figure 2 An embodiment of the device according to the invention is shown, which can be based on Figure 1 The circuit board shown is manufactured

[0034] Figure 3 The method for manufacturing the Figure 2 The method steps of the embodiment of the method of the device shown, and

[0035] Figure 4 An exemplary embodiment of a rail vehicle according to the invention is shown.

[0036] In the drawings, the same reference numbers are used throughout to refer to the same or like parts.

[0037] Figure 1 Schematic diagram of a section of a circuit board 10, which can be further processed to produce an electrical device. The circuit board 10 has a first conductor track structure 11a on its side, which is referred to below as the primary side 11, which comprises a plurality of conductor tracks. A second conductor track structure 12a is located on the opposite side, which is referred to below as the secondary side 12, which also comprises a plurality of conductor tracks.

[0038] In addition, according to Figure 1In the view of FIG. 1 , the inner wall side is coated with a conductive material B and thus there are conductive metallized vias as metallized through-holes on the inner wall side, wherein the metallized vias 21 to 25 are used to electrically connect the conductor tracks of the first conductor track structure 11 a with the conductor tracks of the second conductor track structure 12 a. The metallized vias 21 to 25 are thus not yet populated and are not used to accommodate connecting contacts of components to be mounted on the circuit board 10.

[0039] The metallized vias 26 and 27 are used to allow the connection contacts of so-called plug-in elements to pass through. Such plug-in elements can be placed on the primary side 11 of the circuit board 10 and the connection contacts of the plug-in elements are guided through the metallized vias 26 and 27 in order to connect them to the second conductor track structure 12a.

[0040] The conductor track structures 11a and 12a are usually relatively thin. Figure 1 The illustration is not true to scale but is shown much thicker than actual thickness in order to illustrate the interaction with the metallization vias.

[0041] Figure 2 Shown based on Figure 1 An embodiment of an electrical device 50 manufactured by a circuit board 10 according to Figure 1 The circuit board 10 and the first component 100 and the second component 200. The first component 100 is preferably a surface mounted component, also known as an SMD component (Surface Mounted Device); the second component 200 is preferably a plug-in component, also known as a THD component (Through-Hole Device).

[0042] The circuit board 10 can naturally also have more surface-mount components and more plug-in components than shown here. Figure 2 For reasons of clarity of the illustration, the elements 100 and 200 are limited to the drawings. Figure 2 The view omits the Figure 1 The two conductor track structures 11a and 12a shown in FIG. 1 and having a very small thickness.

[0043] according to Figure 2 The device is preferably manufactured by Figure 3 The method steps are implemented in the form of a flowchart. Therefore, the following reference is made to Figure 2 and Figure 3 .

[0044] In order to manufacture according to Figure 2 In a first method step 1000, a circuit board 10 is first defined as generally known, for example by etching. Figure 1 The printed circuit board 10 provided with the conductor track structures is therefore used as a base material to be further processed for the following configurations.

[0045] In the following method step 1100, a protective layer in the form of a solder resist 30 is first applied to the primary side 11 provided with the conductor track structures 11a and 12a. The solder resist 30 preferably covers all sections of the first conductor track structure 11a that are not to be covered by solder in the following first soldering step. In addition, within the scope of coating the printed circuit board 10, all sections on the primary side 11 that are to be soldered according to the solder resist 30 are protected. Figure 2 The manufacture of the device should not be equipped with or equipped with plug-in components and metallized channels. Figure 2 In the illustration of FIG. 2 , metallized vias 21 to 25 that are not to be mounted are closed.

[0046] Only the metallization vias 26 and 27 remain free of the solder resist 30 , since these are intended to be used for the connecting contacts 210 and 220 of the plug-in element 200 .

[0047] In the following method step 1200, the printed circuit board 10 is populated with the first component 100 or all surface-mounted components on the primary side 11. The assembly of the components according to method step 1200 preferably includes applying solder paste to the conductor track sections of the first conductor track structure 11a to which the connecting contacts 110 and 120 of the first component 100 are to be soldered.

[0048] The first component 100 is subsequently “reflow” soldered to the first conductor track structure 11 a of the printed circuit board 10 within the scope of a first soldering step 1300 , preferably in a reflow oven.

[0049] In the following component assembly step 1400, the second component 200 is placed on the primary side 11 of the circuit board 10 with its connecting contacts 210 and 220, wherein the connecting contacts 210 and 220 are inserted into and preferably pass through the metallized vias 26 and 27. Advantageously, the connecting contacts 210 and 220 extend to the second conductor track structure 12a on the secondary side 12.

[0050] In the following second welding step 1500, the second component 200 is connected to the second conductor track structure 12a (see FIG. 1 ) on the secondary side 12 of the circuit board 10 via its connecting contacts 210 and 220. Figure 1) soldering, the second soldering step is preferably wave soldering or wave soldering. The solder 35 can enter the channel contact means 26 and 27 upwards by capillary effect from below or from the secondary side wetted by the solder 35; this also applies to the metallized channels 21 to 25 open at the bottom if the cross-sectional dimensions are designed to be large enough, even if this is Figure 1 Not explicitly shown.

[0051] After the second welding step 1500 has been completed, the resulting assembly is preferably cleaned on both sides within the scope of a cleaning step. In a subsequent drying step 1700 , the assembly is dried.

[0052] After drying is complete, the entire assembly is provided with a cover layer 40 in the form of a protective lacquer, which can be a silicone lacquer or a lacquer containing silicon, all over the primary side 11 and the secondary side 12 of the circuit board 10 in the context of a lacquering step 1800. However, it is considered particularly advantageous if the cover layer 40 is an acrylic resin or at least contains an acrylic resin, i.e. forms an acrylic resin lacquer.

[0053] By painting in the painting step 1800, a closure of the unassembled metallized channels 21 to 25 is also formed on the secondary side 12, so that all unassembled metallized channels 21 to 25 of the circuit board 10 are protected or closed on both sides, namely on the primary side 11 by the solder protection layer 30 and the covering layer 40 located on the solder protection layer and on the secondary side 12 individually by the covering layer 40.

[0054] After painting, the Figure 2 The device 50 is dried in a drying step 1900 .

[0055] In summary, by combining Figure 2 and Figure 3 The described method steps ensure that the unmounted metallized vias, ie the metallized vias 21 to 25 , are closed on both sides and thus reliably prevent corrosion of the metallized structures on the inner wall side.

[0056] Figure 4 An embodiment of a rail vehicle 500 according to the present invention is shown, which has one or more traction converters 510. The traction converters 510 each have one or more of the above-mentioned Figures 1 to 3 The device 50 is described.

[0057] Reference numerals list

[0058] 10 Circuit Board

[0059] 11 Primary side

[0060] 11a First conductor circuit structure

[0061] 12 Secondary side

[0062] 12a Second conductor circuit structure

[0063] 21-27 Metallized Through Holes

[0064] 30 Welding protective layer / protective layer

[0065] 35 Solder

[0066] 40 Overlay

[0067] 50 Electrical installations

[0068] 100 First Components / Surface Mount Components

[0069] 110 Connector contacts

[0070] 120 Connector contacts

[0071] 200 Second component / plug-in component

[0072] 210 Connector contacts

[0073] 220 Connector contacts

[0074] 500 Rail vehicles

[0075] 510 Traction Converter

[0076] 1000 Methods and Steps

[0077] 1100 Methods and Steps

[0078] 1200 Methods and Steps

[0079] 1300 First welding step

[0080] 1400 Component Assembly Steps

[0081] 1500 Second welding step

[0082] 1600 Cleaning Steps

[0083] 1700 Drying Step

[0084] 1800 Painting Steps

[0085] 1900 Drying step

[0086] B Conductive Materials

Claims

1. A method for manufacturing an electrical device (50) based on a circuit board (10), wherein: The circuit board has: a first conductor track structure (11a) having conductor tracks on a side of the printed circuit board (10), referred to below as the primary side (11), a second conductor track structure (12a) having a conductor track, which is arranged on the other side of the printed circuit board (10), hereinafter referred to as the secondary side (12), and / or as an inner conductor track structure in an intermediate layer of the printed circuit board (10), and - a plurality of metallized through holes (21-25), through which the conductor circuit of the first conductor circuit structure (11a) can be electrically connected to the conductor circuit of the second conductor circuit structure (12a), respectively; wherein at least one first electrical component (100) is arranged on the primary side (11), and the at least one first electrical component is welded to the first conductor circuit structure (11a) through a first welding step (1300), Characterized in that, before the at least one first electrical component (100) is arranged on the primary side (11) and soldered by the first soldering step (1300), only at least one of the metallized through-holes (21-25) is closed on the primary side (11) by means of a protective layer (30), After the circuit board (10) is assembled with a first electrical component (100), the primary side (11) of the circuit board (10) is coated with a covering layer (40) at least in the area with the metallized through-holes, and after the circuit board (10) is assembled, the secondary side (12) is coated with a covering layer (40) all over or at least in the area with the metallized through-holes.

2. The method according to claim 1, characterized in that The protective layer (30) is a welding protective layer (30).

3. The method according to claim 2, characterized in that The protective layer (30) plays a role of welding protection in the first welding step (1300).

4. The method according to claim 1, characterized in that: The covering layer of the primary side (11) is composed of acrylic resin or a lacquer containing acrylic resin.

5. The method according to claim 1, characterized in that The cover layer of the secondary side (12) consists of acrylic resin or a lacquer containing acrylic resin.

6. The method according to claim 1, characterized in that After the first welding step (1300), at least one second electrical component (200) is arranged on the primary side (11) and is welded to the second conductor track structure (12a) by a second welding step (1500).

7. The method according to claim 6, characterized in that By means of the protective layer (30), metallized through-holes (26, 27) for arranging the at least one second electrical component (200) are excluded from the coating and remain unsealed.

8. The method according to claim 7, characterized in that Before the at least one first electrical component (100) is arranged on the primary side (11) and soldered through the first soldering step (1300), a metallized through hole (25) located below the at least one second electrical component (200) after the second electrical component (200) is arranged is closed on the primary side (11) by means of the protective layer (30).

9. The method according to claim 7, characterized in that: The at least one second electrical component (200) has a plurality of connecting contacts (210, 220), which are introduced into metallized through-holes (26-27) excluded from the coating by the protective layer (30) when the second electrical component (200) is arranged, and the connecting contacts (210, 220) are welded to the second conductor circuit structure (12a) by the second welding step (1500).

10. The method according to claim 7, characterized in that The diameter of the metallized through-hole (21-27) is designed so that, through the second welding step (1500), the welding material is pulled from the secondary side (12) toward the primary side (11) due to the capillary effect and the metallized through-hole (21-27) is completely or at least partially filled with the welding material.

11. The method according to claim 6, characterized in that - performing a reflow soldering method in the first soldering step (1300), and / or - In the second welding step (1500), wave welding or wave soldering is performed.

12. The method according to claim 6, characterized in that - the first electrical component (100) is a surface mounted component, and / or - The second electrical component (200) is a plug-in component.

13. An electrical device (50) having a circuit board (10), wherein: The circuit board (10) has: a first conductor track structure (11a) having conductor tracks on a side of the printed circuit board (10), referred to below as the primary side (11), a second conductor track structure (12a) having a conductor track, which is arranged on the other side of the printed circuit board (10), hereinafter referred to as the secondary side (12), and / or as an inner conductor track structure in an intermediate layer of the printed circuit board (10), and - a plurality of metallized through holes (21-25), through which the conductor circuit of the first conductor circuit structure (11a) can be electrically connected to the conductor circuit of the second conductor circuit structure (12a), respectively; and wherein at least one electrical component is arranged and soldered on the primary side (11), Characterized in that at least one of the metallized through-holes (21) arranged below the at least one electrical component is closed only on the primary side (11) by means of a protective layer (30), The primary side (11) of the circuit board (10) is coated with a covering layer (40) in a region having metallized through-holes, and the secondary side (12) of the circuit board (10) is coated with a covering layer (40) over the entire surface or at least in a region having metallized through-holes.

14. The device (50) according to claim 13, characterized in that The protective layer (30) is a welding protective layer.

15. The device (50) according to claim 13, characterized in that The covering layer (40) of the primary side (11) is made of acrylic resin or a lacquer containing acrylic resin, and / or the covering layer (40) of the secondary side (12) is made of acrylic resin or a lacquer containing acrylic resin.

16. A rail vehicle (500), characterized in that: The rail vehicle (500) comprises an electrical device (50) according to one of claims 13 to 15 and / or an electrical device (50) produced according to the method of one of claims 1 to 12.

17. The rail vehicle (500) according to claim 16, characterized in that The rail vehicle (500) is a rail vehicle having a traction converter (510).

18. The rail vehicle (500) according to claim 16, characterized in that The traction converter (510) of the rail vehicle (500) or one of the traction converters (510) of the rail vehicle has the electrical device (50).

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