Method for applying at least one solder deposit to at least one solder pad

Abstract

A method for applying at least one solder deposit (1) to at least one solder pad (2) of at least one, in particular electronic, component (3) is proposed, wherein the solder deposit (1) is applied electrochemically to the solder pad (2).

Description

[0001] The invention relates to a method for applying at least one solder deposit to at least one solder pad. Furthermore, the invention relates to a component comprising the solder pad with the solder deposit. Furthermore, the invention also relates to a use of a corresponding component and to a component system.

[0002] Methods for applying solder deposits to solder pads are known from the prior art. The solder is typically applied to the solder pad in the form of a solder paste, particularly consisting of solder balls and flux, using a printing process. This approach limits the precision with which the solder quantity and distribution can be controlled. An inaccurately applied solder deposit can then lead to defects, solder spatter, and short circuits in the subsequent soldering process.

[0003] A method for applying at least one solder deposit to at least one solder pad of at least one, particularly electronic, component is proposed. The solder deposit is applied galvanically to the solder pad.

[0004] The solder deposit is, in particular, a solder reservoir that is in a non-molten form. In particular, the solder deposit applied to the solder pad can be melted in a soldering process, in particular to contact the component with another component. The solder pad is, in particular, intended to receive the solder deposit. The solder pad is, in particular, an electrically conductive surface on the component to which the component can be soldered. In particular, the solder pad is connected to at least one conductor track of the component. “Intended” should be understood to mean, in particular, specially programmed, specially equipped, and / or specially designed. The fact that an object is intended for a function should be understood to mean, in particular, that the object performs the function in at least one operating state.

[0005] The component is preferably designed as an electronic component, such as a flexible film, a circuit board, a sensor, or the like. In particular, the component is intended to be electrically and materially connected to at least one other, in particular electronic, component by means of the solder of the solder deposit in a soldering process. The component can preferably have a plurality of solder pads. Preferably, at least one solder deposit can be applied to each solder pad of the component using the method.

[0006] Preferably, the solder deposit is applied to the solder pad galvanically, in particular not chemically. In particular, galvanic application allows a greater layer thickness of the solder deposit to be achieved than chemical application. The solder deposit can preferably be applied to the solder pad using a bath plating process, a barrel plating process, or a pin plating process.

[0007] The inventive design of the method advantageously allows for the precise control and adjustment of the solder quantity applied to the solder pad and the distribution of the solder across the solder pad. Advantageously, the component can be prepared for a soldering process, in particular a thermode soldering process, in which the number of defects, solder splashes, and short circuits can be minimized. Advantageously, this enables the soldering of components with a small distance between the solder pads.

[0008] Furthermore, it is proposed that the solder deposit contain tin. The solder preferably consists of pure tin. Alternatively, it is conceivable that the solder be formed from an alloy containing tin. In addition to tin, the alloy can in particular comprise at least one other metal, such as lead, zinc, silver, or copper. In particular, the solder pad is electroplated with tin in the process. This advantageously enables particularly precise tinning of the solder pad.

[0009] It is further proposed that the component be designed as a flexible film. The flexible film is, in particular, a film-like flexible printed circuit board. The flexible film can also be referred to, in particular, as an FPC (Flexible Printed Circuits) connector. The flexible film preferably has at least one degree of freedom. The flexible film comprises, in particular, at least one flexible carrier element, in particular made of a plastic. The carrier element can be designed, for example, as a polyester film. Conductor tracks, electronic circuits, or the like, and in particular the soldering pad, are preferably constructed on the carrier element. A flexible film provided with particularly precise solder deposits can advantageously be provided.

[0010] It is further proposed that the flexible film have a fine pitch of less than 500 µm. Pitch refers in particular to the distance between the centers of two adjacent connections on the flexible film. A pitch of less than 500 µm is in particular a fine pitch. The smaller the fine pitch, i.e. the closer components can be arranged on the flexible film, the higher the demands on the precision of the solder application. The flexible film has in particular a fine pitch of less than 500 µm, preferably less than 400 µm and particularly preferably less than 300 µm. Soldering of fine pitch flexible films can advantageously be enabled.

[0011] Furthermore, a component, in particular an electronic component, is proposed. The component comprises at least one solder pad to which at least one solder deposit has been applied using a method according to the invention. Advantageously, a component with at least one particularly precise solder deposit can be provided. Advantageously, a component that is particularly well suited for use in a thermode soldering process can be provided.

[0012] Furthermore, the use of a component according to the invention in a thermode soldering process is proposed. In the thermode soldering process, the component is preferably soldered to another, in particular electronic, component. In particular, the solder from the solder deposit, preferably from multiple solder deposits on multiple solder pads, is used to create the solder connection. This advantageously enables a particularly reliable thermode soldering process.

[0013] It is further proposed that the solder deposit is melted and soldered by means of at least one thermode. The thermode is designed in particular as a stamp or bracket. The thermode is preferably provided to exert mechanical pressure on the component, in particular in a region of the solder deposit and in particular from a surface of the component facing away from the solder deposit. In particular, the thermode is provided to press the component against the further component, in particular such that the solder deposit comes into contact with a solder pad of the further component. The thermode is preferably designed to be heatable. The hot thermode, which is in contact with the component, heats in particular the solder deposit until it melts. The liquid solder connects the solder pads of the component and the further component, in particular to one another.Preferably, the thermode is then cooled so that the solder solidifies and creates a bonded, particularly electrically conductive, connection between the two components, especially the solder pads of the components. The thermode is preferably removed once the components have been soldered. This advantageously enables particularly precise melting and soldering of the solder deposit, both in terms of location and quantity.

[0014] It is further proposed that the component be contacted with at least one further, in particular electronic, component. In particular, the component is electrically contacted with the further component, so that electrical currents can flow between the components. The further component can be designed, in particular, as a flexible film, a circuit board, a sensor, or the like. This advantageously enables particularly precise contacting.

[0015] It is also proposed that the additional component be designed as a printed circuit board. In particular, the component can be designed as a flexible foil that is connected to the printed circuit board in the thermode soldering process. In particular, the flexible foil can be intended to connect the printed circuit board to an additional printed circuit board, an electronic device, or the like. This advantageously enables particularly precise soldering of a printed circuit board.

[0016] Furthermore, a component system is proposed. The component system comprises at least one component according to the invention. The component system comprises at least one further, in particular electronic, component that is contacted with the component, in particular by a thermode soldering process. Preferably, the component is designed as a flexible film, and the further component as a printed circuit board. Advantageously, a particularly robust and precisely contacted component system can be provided.

[0017] The invention is illustrated by an exemplary embodiment in the following figures. They show: Fig. 1 a component according to the invention, in particular an electronic component, during a method according to the invention in a schematic representation, Fig. 2 the component according to the invention Fig. 1 according to the method according to the invention in a schematic representation and Fig. 3 a sectional view of a component system according to the invention during contacting in a schematic representation.

[0018] Fig. 1 shows a component 3, in particular an electronic component, during a method for applying at least one solder deposit 1 to at least one solder pad 2 of the component 3 in a schematic representation. The solder deposit 1 is galvanically applied to the solder pad 2. In the present exemplary embodiment, the component 3 comprises, for example, four solder pads 2, with one solder deposit 1 being applied to each solder pad 2. The solder pads 2 are each connected to at least one conductor track 7 of the component 3 (cf. Fig. 2).

[0019] Component 3 is designed as a flexible film. The flexible film has a fine pitch of less than 500 µm.

[0020] In the present exemplary embodiment, the solder deposits 1 are applied to the solder pads 2 using a bath electroplating process, for example. Alternatively, it is conceivable that the solder deposits 1 are applied to the solder pads 2 using a barrel electroplating process or a pin electroplating process. The component 3 is arranged in an electrolyte bath 8. The component 3 is arranged between two anodes 9, 10. The component 3, in particular the solder pads 2, functions / function as a cathode. Depending on a voltage applied to the electrodes 3, 9, 10, metallic solder material is deposited on the solder pads 2 and forms the solder deposits 1. The component 3 can, for example, be masked in order to control the distribution of the solder deposits 1.

[0021] The solder deposits 1 contain tin. The electrolyte is a tin electrolyte. The solder pads 2 are electroplated with tin during the process.

[0022] Fig. 2 shows component 3 from Fig. 1, in particular temporally, according to the method in a schematic representation. In the present exemplary embodiment, the component 3 comprises, for example, four solder pads 2, onto each of which at least one solder deposit 1 is applied in the manner shown in Fig. 1 was applied.

[0023] Fig. Figure 3 shows a schematic sectional view of a component system 6 during contacting. The component system 6 includes the component 3. The component system 6 includes at least one further, in particular electronic, component 4, which is contacted with the component 3, in particular by a thermode soldering process. Fig. 3 shows the component system 6 during the thermode soldering process.

[0024] Component 3 is used in the thermode soldering process. In the thermode soldering process, component 3 is soldered to the other component 4. The solder from the solder deposits 1 is used to create the solder connection. The other component 4 is designed as a printed circuit board.

[0025] The solder deposits 1 are melted and soldered by means of at least one thermode 5. The thermode 5 is intended to exert a mechanical pressure on the component 3, in particular in a region of the solder deposits 1 and in particular from a surface of the component 3 facing away from the solder deposits 1. In Fig. 3, a force direction of the thermode 5 is indicated by an arrow 11. The thermode 5 is intended to press the component 3 against the further component 4, in particular such that the solder deposits 1 each come into contact with a solder pad 12 of the further component 4. For the sake of clarity, Fig. 3, only one solder deposit 1, one solder pad 2 of the component 3, and one solder pad 12 of the further component 4 are identified by reference numerals. The thermode 5 is designed to be heatable. The hot thermode 5, which is in contact with the component 3, heats the solder deposits 1 until they melt. The liquid solder connects the solder pads 2, 12 of the component 3 and the further component 4 to one another. The thermode 5 is then cooled so that the solder solidifies and creates a material-locking, in particular electrically conductive, connection between the two components 3, 4, in particular the solder pads 2, 12 of the components 3, 4. The thermode 5 is removed when the components 3, 4 are soldered. Fig. Figure 3 shows the thermode soldering process shortly before the removal of the thermode 5.

[0026] Component 3 is contacted with the further, particularly electronic, component 4. Component 3 is electrically contacted with the further component 4, so that electrical currents can flow between components 3, 4. Reference symbol 1 solder depot 2 solder pads 3 Component 4 component 5 thermode 6 Component system 7 Conductor track 8 Electrolyte bath 9 Anode 10 Anode 11 Arrow 12 solder pad

Claims

[1] Method for applying at least one solder deposit (1) to at least one solder pad (2) of at least one, in particular electronic, component (3), wherein the solder deposit (1) is applied galvanically to the solder pad (2). [2] Method according to claim 1, wherein the solder deposit (1) contains tin. [3] Method according to claim 1 or 2, wherein the component (3) is designed as a flexible film. [4] Method according to claim 3, wherein the flex film has a fine pitch of less than 500 µm. [5] Component, in particular electronic component, comprising at least one solder pad (2) to which at least one solder deposit (1) has been applied in a method according to one of the preceding claims. [6] Use of a component (3) according to claim 5 in a thermode soldering process. [7] Use according to claim 6, wherein the solder deposit (1) is melted and soldered by means of at least one thermode (5). [8] Use according to claim 6 or 7, wherein the component (3) is contacted with at least one further, in particular electronic, component (4). [9] Use according to claim 8, wherein the further component (4) is designed as a printed circuit board. [10] Component system comprising at least one component (3) according to claim 5 and at least one further, in particular electronic, component (4) which is contacted with the component (3), in particular by a thermode soldering process.

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