Method for establishing electrical connections to electronic components and chip assemblies - Patents.com

Abstract

The present application is directed to a method for establishing an electronic connection to an electronic component and chip assembly. The method includes the following steps: an electronic component having a first weld is provided; a first electrical contact is also provided; the first weld and the first electrical contact are in mechanical contact with each other; then, while the mechanical contact is maintained, a welding current is applied capable of welding the electrical contact and the weld together.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present application is directed to methods for establishing electronic connections to electronic components and chip assemblies. [Background technology]

[0002] The electrical connection of electronic components such as semiconductor components, electronic chips, varistors or thermistors is relevant throughout the entire technical field of electronics.

[0003] In particular, there is a demand in this field to provide a reliable electrical connection to electronic components in as simple a process as possible. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the patent invention is therefore to provide a method which at least partially solves the above-mentioned problems, as characterized in claim 1. Furthermore, a chip assembly is provided. Advantageous embodiments can be found in the further claims. [Means for solving the problem]

[0005] In a first aspect, a method for establishing an electrical connection is provided, the method comprising the steps of: providing an electronic component having a first weld; providing a first electrical contact portion; providing the first weld portion and the first electrical contact portion in mechanical contact with each other; and applying a welding current capable of welding the electrical contact portion and the weld portion together while maintaining the mechanical contact.

[0006] The welding method according to the invention is preferably resistance welding, since an electric current is used to weld the first electrical portion and the first weldment together.

[0007] As used herein, the first weld may be any resistance weldable part that can be assembled onto an electronic component. Preferably, the weld is made of a material that can be melted by resistance welding. Preferably, the first weld includes a metal.

[0008] The first electrical contact may be any type of electrical contact that can electrically contact the electronic component and is suitable for being welded to the first weld. An example of the first electrical contact may be a wire-shaped, block-shaped, or platelet-shaped contact that can be in mechanical contact with the first weld.

[0009] Since the first weld and the first contact are both suitable for being welded together by resistance welding, they are preferably electrically conductive. Preferably, during the mechanical contact, an electrically conductive contact is also established. In the resistance welding according to the invention, the highest resistance point in the welding circuit is at the interface between the first weld and the first contact. Thus, the interface or a point within the interface is the hottest when the maximum voltage drop of the electric circuit occurs there. Thus, at the interface the materials can melt and fuse together.

[0010] Preferably, the electronic component is a microchip sized electronic component, e.g., 0.09 mm 2 ~9mm 2 Preferably, the electronic component may be any varistor, or even more preferably an NTC thermistor.

[0011] This method has the advantage that an electrical connection can be easily established between the first electrical contact portion and the first weld.

[0012] The welding step may be performed by attaching a welding electrode to the component electrically connected with the first weld and the first electrical contact. The welding current of the electronic component may be in the range of 10 A to 200 A. The voltage may be in the range of 0.1 V to 10 V. Furthermore, the process does not require additional material at the interface between the first electrical contact and the first weld. Thus, the process has advantages over other techniques, such as, for example, soldering or wire bonding, which add additional materials or components to form the electrical joint.

[0013] Preferably, the first welded portion is a part of a terminal electrode of the electronic component.

[0014] In other words, this means that the weld may preferably be a region of the terminal electrode of the electronic component.

[0015] For example, the terminal electrode may be connected to an internal electrode, but is not limited thereto, and refers to any electrode that is attached to the outer surface of an electronic component and is suitable for incorporating an electronic device into an electronic circuit.

[0016] Preferably, the electronic component may have two terminal electrodes, in which case the first weld may be present on the first terminal electrode and the second weld may be present on the second terminal electrode, in which case the contact portion may be applied to both terminal electrodes according to the method described above.

[0017] More preferably, the first electrical contact portion is a first contact pad or a part of a first contact pad arranged on the carrier substrate.

[0018] Preferably, the electronic components may be attached or fixed to a carrier substrate. The carrier substrate is preferably an insulating substrate that may include or consist of a polymer or ceramic. In the case of ceramic, for example, a highly insulating alumina or aluminum nitride plate may be used.

[0019] This means that the method as described above can be applied to weld electronic components with welds to contact pads on a carrier substrate.

[0020] For this reason, the welding current needs to flow between the terminal electrode and the contact pad. In principle, according to the present application, the method of applying the welding current is not limited. For example, it is generally possible for the welding current to flow through the electronic component to the external electrode, then to the contact pad and then out of the contact pad via the welding contact. This allows easy access from the side of the electronic component opposite the welding interface. However, this approach is only suitable if the electronic component can withstand the welding current and voltage. However, in many cases, this approach is not preferred because the welding current may damage the electronic component or generate heat, which may damage the electronic component. Therefore, it is more preferable to make the welding contact only to the terminal electrode that is in mechanical and conductive contact with the contact pad, either directly or indirectly.

[0021] The application of this method on a carrier substrate having contact pads is particularly preferred, since the contact pads can have a size that allows them to be easily contacted for welding. If the top surface is defined as the surface of the substrate on which the electronic components are assembled, in a preferred configuration the electronic components only partially overlap the contact pads when viewed against the top surface. This allows the parts of the contact pads that do not overlap the electronic components to be contacted with reduced steric hindrance from the top surface.

[0022] Additionally, mechanical contact is preferably supported during welding by pressing the weld and electrical contact together.

[0023] Preferably, this means that the electronic component is at least lightly pressed onto the substrate, thereby pressing the terminal electrodes onto the contact pads on the substrate. Here and below, this pressing may be referred to by the term "pressure". Pressing force is any pressure or force capable of keeping the contact parts and the welds in contact. This may include, for example, the weight of the electronic component. However, it is preferred to apply an additional force or pressure as the pressing force. This additional pressing force is preferably in the range of 0.1N to 50N.

[0024] The application of pressure can ensure good electrical contact that ensures efficient flow of current during welding. Furthermore, it can support or guarantee that the materials of the first contact portion and the first weld are in firm mechanical contact with each other that allows for a weld spot that also has high mechanical durability. This not only provides an electrical connection, but also an efficient mechanical connection of the contact element to the weld.

[0025] Furthermore, it is preferred that the first electrical contact portion and / or the first weld portion comprises at least one weld bump or several weld bumps, the at least one weld bump or several weld bumps being capable of passing a welding current therethrough to form a localized weld spot.

[0026] The weld bump is most preferably provided on the contact part. This is particularly preferred if the contact part is part of or is a contact pad, since the contact pad can be formed by an etching technique that also allows the weld bump to be formed. The weld bump can therefore be formed during the structuring of the contact pad without requiring additional process steps.

[0027] In the context of this invention, a "weld bump" is any extrusion on the surface to be welded through which a welding current can be passed to create a heat spot that becomes the weld spot.

[0028] In the sense of the present application, "flow of welding current" refers to a welding current that has to flow through a relatively narrow spot, in particular an area with a very small cross-sectional diameter. By passing the welding current through the welding spot, the area of ​​the interface in electrical contact is much smaller than if the surface did not have a weld bump. This has the advantage that on the one hand the welding heat is only very localized, ensuring efficient heating of the metal that is melted and therefore efficiently welded, and on the other hand that the thermal stresses of the electronic component are reduced. If a large area is in contact, a high welding current may be required, which increases the overall heat transferred to the electronic component.

[0029] Preferably, the weld bump has a size of up to 1 / 10 of a millimeter as its average diameter.

[0030] Even more preferably, the weld bump may be pointed, i.e. have a conical or pyramidal shape pointing outwards from the surface to be welded, such a shape reducing the contact area and thus allowing efficient flow of the welding current.

[0031] Furthermore, according to a preferred embodiment, the first and second welding spots are simultaneously formed by the same welding current. "Formed by the same welding current" may specifically mean that the first and second welding spots are connected in series with respect to the welding current.

[0032] This configuration is particularly preferred because it allows the welding current to be conducted to the weld and then away from the weld again by the contact portion that is welded to the weld. In such a configuration, the welding electrode that only applies the welding current during the process does not need to directly access the terminal electrode that faces the contact portion and may be difficult to access directly. Instead, a first contact portion can be used to create a first weld spot and a second contact portion can be used to create a second weld spot.

[0033] This can be preferably achieved, in particular, when the first contact pad comprises or consists of two electrically isolated subpads, which can be contacted simultaneously with the first weld and the second weld. The first weld and the second weld are preferably electrically connected to each other. Both are preferably part of the same terminal electrode. When a welding current is applied between the first subpad and the second subpad, a weld spot is formed on each subpad and each weld. In this configuration, the current can be conducted from one subpad to the other by the terminal electrode. In other words, two subpads that are otherwise electrically and spatially separated can be bridged by one terminal electrode of the electronic component.

[0034] Preferably, the welding step can be performed such that the welding contact of the welder can be applied only to the subpad. Most preferably, the welding contact is applied to an area of ​​the subpad that does not overlap with the electronic component. This allows easy three-dimensional access of the welding contact to the subpad. Furthermore, this makes it possible to avoid the three-dimensionally difficult procedure of directly contacting the terminal electrode.

[0035] Additionally, the non-overlapping areas of the subpads may be used to contact electronic components by wire bonding or other methods.

[0036] According to one embodiment, the above-mentioned method can be subsequently or simultaneously applied, in particular during welding of a flip-chip electronic component to a carrier substrate, where two terminal electrodes are welded to two separate contact pads on the same carrier substrate, the two terminal electrodes being preferably terminal electrodes of the electronic component.

[0037] Here and below, "chip" refers to a configuration in which terminal electrodes are arranged on both sides of an electronic component. Thus, a "chip configuration" refers to a chip welded or connected to a carrier substrate at one of the terminal electrodes. The term "flip chip" refers to an electronic component in which two separate terminal electrodes are arranged on one side of the electronic component. This allows an electronic component with both terminal electrodes to be welded to a substrate with contact pads arranged accordingly. Thus, the term "flip chip configuration" refers to a configuration in which a flip chip is welded with at least two terminal electrodes on the same side of the flip chip to contact pads on a carrier substrate.

[0038] The materials of the welds and the electrical contacts may be different, in particular the materials of the outer layers of the welds and the electrical contacts may be different.

[0039] However, it is preferred that the outermost metal of the weld and the electrical contact be the same.

[0040] This preferably means that the overall material of each of the welds and electrical contacts is the same, or, in the case of layered electrodes such as layered terminal electrodes or layered contact pads, the outermost layers are the same material.

[0041] The advantage of having the same material is that both materials will heat and melt equally and a homogenous connection, and therefore a good electrical and mechanical connection, can be established.

[0042] Preferably, the contact parts and / or welds comprise silver, gold, copper, nickel, molybdenum or tungsten. Among these, silver, gold, copper and nickel are particularly preferred. Layered contact pads are particularly preferred, with a copper layer in direct contact with the carrier substrate, a nickel layer on top of the copper layer and a gold termination layer. For electronic components, gold termination electrodes are preferred. Alternatively, silver or a silver-gold alloy or layered electrodes comprising these materials are also preferred.

[0043] The method may further comprise providing an insulating carrier substrate and applying a metal layer on the insulating carrier substrate. The method of applying the metal layer may be selected from any suitable method, including printing or laminating the metal layer on the substrate. Alternatively, the metal layer may be sintered with the substrate or applied by physical vapor deposition, sputtering, galvanic deposition or chemical electroplating. Then, an etching step is applied that structures the metal layer. As an etching method, dry or wet etching may be applied. In particular, during the etching step, several contact pads or subpads may be formed on the substrate. Furthermore, during the etching or preferably in a separate etching step, at least one welding bump is formed for each subpad.

[0044] As a further aspect, there is provided a chip assembly that can be formed by the above-described method, and therefore all features and advantages disclosed for the method also apply to the chip assembly, and vice versa.

[0045] The chip assembly comprises an electronic component assembled on a carrier substrate, with first contact pads of the substrate welded to first terminal electrodes of the component to form electrical connections.

[0046] This means that it is possible to identify in the assembly weld spots, preferably produced by resistive welding, which electrically and preferably also mechanically connect the terminal electrodes and the contact pads, which is particularly advantageous since such a connection is formed by an advantageous method.

[0047] According to a further aspect of the assembly, the contact pad includes two separate subpads, and the terminal electrode is welded to both subpads.

[0048] In some cases, having two subpads electrically bridged by a terminal electrode is not essential to incorporating an electronic component in an assembly into a larger electronic circuit. In some cases, only one contact to one of the subpads is sufficient to electrically access an electronic component in an assembly. This means that one of the subpads may be redundant to incorporate the electronic component into an electronic circuit. However, the inventors have found that having two separate subpads is particularly advantageous for the welding method.

[0049] Furthermore, the electronic component may include a second terminal electrode that is welded to a second contact pad on the carrier substrate.

[0050] This arrangement is preferably realized in a flip-chip configuration, which allows, for example, electronic components with two terminal electrodes that can be fully contacted via the carrier substrate.

[0051] Of course, the second contact pad also preferably consists of two separate sub-pads.

[0052] Preferably, the first contact pads are connected to connection means for incorporating the chip assembly into an electronic circuit.

[0053] "Connecting means" in the sense of the present application refers to any electrical or electronic connection that can integrate a chip assembly, or more specifically an electronic component, into an electronic circuit. For example, connecting means includes any internal or external connection on a substrate. This can include, for example, conductive paths printed or otherwise applied to the substrate surface. Furthermore, it also includes vias that pass through the substrate, for example to an opposing surface. It also includes any internal electrodes in the substrate that can be directly or indirectly connected. Bonding wires as connecting means are particularly preferred for the present application. The preferred size of the subpad is between 1 and 0.5 mm. 2At such dimensions contact by wire bonding is particularly suitable.

[0054] For the reasons mentioned above, it is also preferable that the outermost metal of the first terminal electrode and the first contact pad be the same.

[0055] Also, as mentioned above, in this process, both the terminal electrode and the first contact pad can comprise silver, gold, copper, nickel, molybdenum or tungsten, of which silver, gold, copper or nickel are preferred.

[0056] Further, in another aspect, the use of the electronic component or the incorporation of the electronic component into an electronic circuit is described. Preferably, the connection for incorporation of the chip assembly or electronic component into an electronic circuit is made by only one sub-pad of the first contact pad.

[0057] As explained in more detail above, this has particular advantages for applying welding methods other than for electronic connections.

[0058] The present invention will be described in more detail below using exemplary embodiments. These exemplary embodiments are shown in the following figures, which are not to scale. Therefore, lengths as well as relative and absolute dimensions cannot be obtained from the figures. Furthermore, the following embodiments do not limit the present invention. [Brief description of the drawings]

[0059] [Figure 1] 1 illustrates a first embodiment of a welding assembly in a top view. [Diagram 2] 1 illustrates a first embodiment of a welding assembly in side view. [Diagram 3] 1 illustrates a first embodiment of a contact welding assembly in a top view. [Figure 4] 1 illustrates a first embodiment of a contact welding assembly in side view. [Diagram 5] 1 illustrates a second embodiment of a welding assembly in side view. [Figure 6] 1 illustrates a third embodiment of a welding assembly in side view. [Figure 7] 13 illustrates a fourth embodiment of a welding assembly in a top view. [Figure 8] 13 illustrates a fourth embodiment of a welding assembly in side view. [Figure 9] 1 illustrates a second embodiment of a contact welding assembly in a top view. [Figure 10] 1 illustrates a second embodiment of a contact welding assembly in side view. [Figure 11] 1 illustrates a first embodiment of a chip assembly in side view. [Figure 12] 1 illustrates a first embodiment of a chip assembly in a top view. [Figure 13] 1 illustrates a third contact welding assembly in top view. [Figure 14] 1 illustrates a second embodiment of a chip assembly in side view. [Figure 15] 4 illustrates process steps for forming contact pads. [Figure 16] 4 illustrates process steps for forming contact pads. [Figure 17] 4 illustrates process steps for forming contact pads. [Figure 18] 4 illustrates process steps for forming contact pads. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] A first embodiment of a welding assembly 1 is shown in a top view in Fig. 1. Fig. 2 shows a side view of the first embodiment of the welding assembly 1.

[0061] This first embodiment of a welding assembly 1 illustrates an intermediate step in one embodiment of a process for establishing an electrical connection.

[0062] The welding assembly 1 is provided with a carrier substrate 2, on which a first contact pad 3 is arranged. Furthermore, an electronic component 4 is provided, which has a first terminal electrode 5 and a second terminal electrode 6. The electronic component 4 is assembled on the contact pad 3, with the first terminal electrode 5 in mechanical contact with the first contact pad 3.

[0063] In general, the electronic component 4 can be any electronic component. Preferably, it is an NTC thermistor.

[0064] The carrier substrate 2 may be any suitable insulating substrate. Preferably, the material of the carrier substrate 2 comprises or consists of alumina.

[0065] The first contact pads 3 are made of metal and are suitable for welding. They preferably contain silver, gold, copper, nickel, molybdenum or tungsten. In particular, layered first contact pads 3 with a copper layer in direct contact with the carrier substrate 2 are preferred. A nickel layer may be assembled on top of the copper layer. Furthermore, a terminating gold layer is assembled on top of the nickel layer.

[0066] A gold terminated electrode is preferred for the first terminal electrode 5 and a gold terminated electrode is also preferred for the second terminal electrode 5. For example, the electrodes may be layered electrodes with the outermost layer being gold.

[0067] The first terminal electrode 5 is in mechanical contact with the first contact pad 3. This allows electrical contact to be established as well. The area of ​​the first terminal electrode 5 in contact with the first contact pad 3 is therefore an example of a weld.

[0068] Preferably, providing and maintaining mechanical contact also includes or is supported by pressing together the first terminal electrode 5 and the first contact pad 3. This can preferably be performed by pressing the electronic component 4 against the fixed carrier substrate 2 with a force or pressure.

[0069] The area where the first contact pad 3 is in contact with the first terminal electrode 5 can be considered as a contact portion.

[0070] As can be seen in Fig. 1, the electronic component 4 overlaps only a portion of the first contact pads 3. The determined non-overlapping areas can be referred to as non-overlapping. This allows the first contact pads 3 to be contacted in the non-overlapping areas for a different means than the top surface, where the top surface is the surface of the carrier substrate 2 on which the electronic component 4 is assembled.

[0071] A first embodiment of a contact welding assembly 1' is shown in Figures 3 and 4. The configuration of the first embodiment of the contact welding assembly 1' is basically the same as the first embodiment of the welding assembly 1 shown in Figures 1 and 2.

[0072] Since the electronic component 4 overlaps only a portion of the contact pad 3, a first welding contact 101 can be applied to the non-overlapping portion of the first contact pad 3. And a second welding contact 102 makes electrical contact with the terminal electrode 5. Both are connected to a welding machine 100.

[0073] This establishes a welding circuit. The welding circuit allows a welding current to be applied by the welder 100 while maintaining mechanical contact between the first contact pad 3 and the first terminal electrode 5. The welding current can generally be, but is not limited to, welding the first terminal electrode 5 to the first contact pad 3. Preferably, a welding voltage in the range of 0.1 V to 10 V and a welding current in the range of 10 A to 200 A are used.

[0074] These welding conditions are suitable for the preferred size of assemblies or chip assemblies that can be produced by this method. Preferably, the contact pads are 0.05 to 3 mm 2 Electronic components have sizes ranging from 0.05 to 1 mm. 2The size of the weld contact can range from 0.05 to 1 mm. 2 The range may be:

[0075] After the welding step, ie, application of the welding current, the weld contacts 101 and 102 are removed from the components of the welded assembly.

[0076] 4, even in a schematic and not to scale drawing, attaching the second welding contact 102 to the first terminal electrode 5 may be difficult due to steric hindrances. If the electronic component can withstand the welding current, the second welding contact 102 can be attached to the second terminal electrode.

[0077] 5 shows a second embodiment of the welding assembly 1. The second embodiment of the welding assembly 1 is generally equivalent to the first embodiment of the welding assembly shown in FIGS. 1 and 2, except that a weld bump 7 is provided on or as part of the contact pad 3. The weld bump 7 is oriented in a direction away from the contact pad 3. Also, the weld bump 7 is in contact with the first terminal electrode 5. The average diameter of the weld bump 7 is 0.1 mm or less.

[0078] As can also be seen in the schematic diagram when comparing FIG. 5 with FIG. 2, the weld bump can significantly reduce the contact area between the first terminal electrode and the first contact pad. This allows the weld bump 7 to carry the welding current. This allows the material of the first contact pad 3 and also the material of the first terminal electrode 5 to be heated only within this small contact area. This allows the material at the weld contact point to be efficiently melted and thus a mechanical and electrical welded connection to be established.

[0079] The weld bump 7 is preferably part of the first contact pad 3. The weld bump 7 generally refers to any extrusion of a contact pad through which a welding current can flow. Preferably, the weld bump 7 has a pyramidal or conical shape. This provides a tip that is narrow and through which a welding current can flow. Preferably, the tip is significantly smaller than the average diameter of the weld bump 7. The tip has at least half the average diameter of the weld bump 7.

[0080] A variation of this embodiment is shown in FIG. 6 as a third embodiment of the welding assembly 1. FIG. 6 shows that a plurality of weld bumps 7 can be provided on the first contact pad 3. As a representation of this, a diagram of two weld bumps 7 is shown, both in contact with the first terminal electrode 5. Equivalently, a roughened surface can also be used. By roughening the surface of the first contact pad, several weld bumps 7 can be formed through which the welding current can flow. It should be noted that in a configuration such as that shown in FIG. 6, the weld bumps 7 form parallel joints for the welding current.

[0081] 7 shows a top view of a fourth embodiment of the welding assembly 1. Moreover, the fourth embodiment of the welding assembly 1 can be seen in a side view in FIG.

[0082] The components of the fourth embodiment of the welding assembly 1 are generally equal to those of the first embodiment of the welding assembly, except that the first contact pad 3 consists of two subpads, a first subpad 31 and a second subpad 32. Each of the subpads is modified by at least one weld bump 7, which is advantageous but not essential to the principles of this assembly. In the fourth embodiment of the welding assembly 1, the first subpad 31 and the second subpad 32 are spatially and electrically isolated from each other, except that they are electrically bridged by the first terminal electrode 5.

[0083] This advantage is best seen in Figures 9 and 10, where a second embodiment of a contact welding assembly 1' is shown in a top view in Figure 9 and a side view in Figure 10. Here, a fourth embodiment of a welding assembly 1, shown in Figures 7 and 8, makes contact by means of welding contacts 101 and 102 in a partially similar manner to that shown in Figures 3 and 4.

[0084] In this configuration, a first weld contact 101 contacts the first subpad 31. A second weld contact 102 contacts the second subpad 32. Both weld contacts are assembled to the non-overlapping portions of each subpad, and each subpad is preferred for weld access from the top surface.

[0085] Assuming that a DC welding current is applied by the welding machine 100 with both welding contacts connected, the welding current can flow from the first welding contact 101 through the first subpad 31 to the first terminal electrode 5. From there, the welding current can flow to the second subpad 32 and then back to the welder via the second welding contact 102. Thus, a welding circuit is established. Naturally, the current direction cannot be defined as it depends on the type of current, i.e., AC or DC, but in this exemplary description it is emphasized that the contact point, i.e., weld bump 7, is a series connection since the first terminal electrode bridges the otherwise unconnected subpads 31 and 32.

[0086] This configuration has the advantage that it is not necessary to apply the welding contact directly to the first terminal electrode 5. On the other hand, the welding contact can be applied to the non-overlapping area, which is the area of ​​the subpad that is not overlapped by the electronic component 4 in top view. In this way, easy access from the top for the welding process step can be achieved.

[0087] FIG. 11 shows a first embodiment of a chip assembly 11 in a side view. In the first embodiment of the chip assembly 11, the electronic component 4 has a chip configuration with a first terminal electrode 5 and a second terminal electrode 6 on two opposite sides. This first embodiment of the chip assembly 11 can be preferably manufactured by a method including a configuration as shown in FIGS. 7 and 8 and 9 and 10. From the weld bumps, weld spots 8 are formed by welding. The weld spots 8 electrically and mechanically connect the terminal electrodes 5 to the subpads 31 and 32.

[0088] Additionally, one of the subpads, in this case the first subpad 31, can serve as a means for further electrical connection to incorporate the chip assembly 11 into an electronic circuit. As shown in Figure 11, this can be accomplished by wire bonding, with bonding wires 10 shown in Figure 11. Alternatives not shown include those discussed in the introduction.

[0089] A top view of the first embodiment of the chip assembly can be seen in Figure 12. Figure 12 shows that wire bonding can also be performed on the non-overlapping areas of the first contact pads 3.

[0090] 11, the second subpad 32 may not contribute to incorporating the electronic component 4 into an electronic circuit. The second subpad 32 may be redundant for incorporating the electronic component 4 into an electronic circuit. The second subpad 32 may have the sole purpose of applying a preferred welding process.

[0091] Figure 13 shows a third embodiment of a contact welding assembly 1' in a top view. As can be seen, the welding contact is essentially similar to that of the embodiment of Figure 9. However, for simplicity, the schematic diagram of the welding machine has been omitted in Figure 13.

[0092] As can be seen in the case of this embodiment in figure 13, two contact pads, a first contact pad 3 and a second contact pad 9, are realised on the substrate 2 as provided. The method described in relation to figures 7 to 10 allows contact to two separate terminal electrodes on the electronic component 5 facing the substrate.

[0093] For each of the contact pads 3 and 9, a weld contact 101 and 102 is applied, one on the first subpad 31 or 91 and the other on the second subpad 32 or 92.

[0094] The welds made to the first and second contact pads can be made simultaneously or one after the other.

[0095] FIG. 14 illustrates a second embodiment of a chip assembly 11, here in a flip-chip configuration, that can be manufactured by a method incorporating the steps illustrated in FIG.

[0096] The electronic component 4 of FIG. 14 has a flip-chip configuration since both terminal electrodes 5 and 6 are located on the same side of the electronic component 4.

[0097] The electronic component 4 is assembled on the substrate 2. The carrier substrate 2 comprises a first contact pad 3, which itself consists of two spatially separated subpads, namely a first subpad 31 and a second subpad 32. Similarly, a second contact pad 9 is provided on the carrier substrate 2, which consists of a first subpad 91 and a second subpad 92. The first subpad 31 and the second subpad 32 are electrically connected only by a bridging first terminal electrode 5 of the electronic component 4. Between both the first terminal electrode 5 and each of the subpads 31 and 32, a welding spot is formed, which is not explicitly labeled here for the sake of simplicity. Similarly, the subpads 91 and 92 are bridged by a second terminal electrode 6, which also faces the substrate. A welding spot is likewise provided.

[0098] Moreover, the first subpad 31 and another first subpad 91 are each contacted by a bonding wire 10 in this assembly in order to incorporate the chip assembly 11 including the electronic component 5 into an electronic circuit.

[0099] Finally, a portion of the process of providing a contact pad, specifically a first contact pad comprising two sub-pads, is shown in Figures 15-18.

[0100] As shown in FIG. 15, firstly a carrier substrate 2 is provided, which is preferably an insulating substrate, for example made of or containing alumina.

[0101] A metal layer 301 is then deposited or applied to the substrate 2 as shown in Figure 16. Any suitable method can be used to apply the metal layer. Methods can include physical vapor deposition, using baked electrodes, deposition of metal foil, sputtering, galvanic deposition, or chemical electroplating.

[0102] 17, the metal layer 301 is then structured by a structuring method or preferably by an etching method, such as wet or dry etching, to form a structured metal layer 302. As shown, in such a step the contact pads, which may each be provided with a subpad, are already pre-provided.

[0103] Moreover, in a next step, which may also be a sub-step of the previous etching step, the weld bumps 7 are etched from the structured metal layer 302. The step shown in Fig. 18 is preferably a sub-step of the previous etching step, since this allows to minimize the number of process steps and may be more efficient. [Explanation of symbols]

[0104] 1 Welding Assembly 1' Contact Welding Assembly 2 Carrier Board 3 First Contact Pad 4. Electronic Components 5 First terminal electrode 6 Second terminal electrode 7 Welding Bump 8 Welding Spot 9 Second Contact Pad 10 Bonding vias 11 Chip Assembly 31 First subpad of the first contact pad 32 Second subpad of the first contact pad 91 first subpad of second contact pad 92 Second subpad of second contact pad 100 Welding Machine 101 First Welded Contact 102 Second Welded Contact 301 Metal layer 302 Structured metal layer

Claims

1. 1. A method for establishing an electrical connection, comprising: Providing an electronic component (4) having a first weld; Providing a first contact pad (3) disposed on a carrier substrate (2) and including two separate sub-pads (31, 32); bringing the first weld into mechanical contact with the two subpads (31, 32); applying a welding current between one and the other of the two subpads (31, 32) while maintaining said mechanical contact, and forming a welding spot (8) on each of the two subpads (31, 32) by the same welding current to weld both of the first weld and the two subpads (31, 32); A method comprising:

2. The method according to claim 1 , wherein the first weld is a part of a first terminal electrode (5) of the electronic component (4).

3. The method of claim 1 , wherein maintaining the mechanical contact during the welding is supported by pressing the weld and the electrical contact together.

4. 2. The method according to claim 1, wherein the first contact pad (3) and / or the first weld comprises a weld bump (7) through which a welding current can be passed to form a localized weld spot (8).

5. 2. The method according to claim 1, wherein the method is subsequently or simultaneously applied in that two terminal electrodes (5, 6) are welded to two separate contact pads (3, 9) on the same carrier substrate.

6. The method of claim 1 , wherein the outermost metal of the weld and the electrical contact portion is the same.

7. The method of claim 6 , wherein the electrical contact or weld comprises silver, gold, copper, nickel, molybdenum, or tungsten.

8. A chip assembly (11) comprising an electronic component (4) assembled on a carrier substrate (2), A chip assembly (11), wherein a first contact pad (3) of the carrier substrate includes two separate sub-pads (31, 32) arranged on the carrier substrate, and a first terminal electrode (5) of the electronic component (4) is connected to both of the two sub-pads (31, 32).

9. 9. The chip assembly (11) according to claim 8, wherein the electronic component (4) comprises a second terminal electrode (6) welded to a second contact pad (9) on the carrier substrate.

10. 9. The chip assembly (11) according to claim 8, wherein the first contact pads (3) are connected to connection means for incorporating the chip assembly (11) into an electronic circuit.

11. The chip assembly (11) of claim 8, wherein a welding spot (8) connects the first terminal electrode (5) and the first contact pad (3).

12. 9. The chip assembly (11) of claim 8, wherein the outermost metal of the first terminal electrode (5) and the first contact pad (3) is the same.

13. The chip assembly (11) of claim 12, wherein the first terminal electrode (5) and the first contact pad (3) comprise silver, gold, copper, nickel, molybdenum or tungsten.

14. 9. The chip assembly (11) of claim 8, wherein the first contact pad (3) comprises two subpads (31, 32) electrically bridged by one terminal electrode of the electronic component (5), the two subpads (31, 32) being electrically and spatially separated except for the electrical bridge by the terminal electrode (5).

15. Use of the chip assembly (11) according to claim 8 or 14, wherein the connection for incorporating the chip assembly (11) into an electronic circuit is made by only one sub-pad of the first contact pad (3).

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