Method for forming a bonded joint

Abstract

The invention relates to a method for forming a bonded joint between a structure that is applied to a glass substrate, in particular a printed conductive structure and an electrical connecting component, in particular a solder base by using solder coated or non-solder coated reactive nanometer multilayer foils which are made from at least two exothermally reacting materials. Initially preconfiguring the reactive nanometer multilayer foils according to the opposing joining surfaces of the conductive structure and the electrical closure element is performed. Thereafter arranging a solder preform respectively between the respective joining surface and the nanometer multilayer foil for non-solder coated foils or arranging an additional solder preform for already solder coated nanometer multilayer foils is performed, wherein the solder preform or the additional solder preform includes a larger, in particular double thickness layer compared to another solder preform between the nanometer multilayer foil and the a conductive structure applied to the glass substrate so that a reduction of the temperature introduction into the conductive structure and a leveling of uneven portions is caused. After temporarily applying a pressure force which is applied between the joining surfaces triggering the exothermal reaction of the nanometer multilayer foil is performed by an electrical impulse or a laser impulse.

Claims

1. A method for forming a bonded joint between a structure that is applied to a glass substrate and an electrical connecting component by using solder coated or non-solder coated reactive nanometer multilayer foil which is made from at least two exothermally reacting materials, the structure having a first joining surface and the electrical connecting component having a second joining surface, the first joining surface being situated opposite the second joining surface, the first joining surface and the second joining surface together defining opposing joining surfaces, characterized by the steps: preconfiguring the solder coated or non-solder coated reactive nanometer multilayer foil to fit the opposing joining surfaces of the structure and the electrical connecting component; arranging a solder preform respectively between the non-solder coated reactive nanometer multilayer foil and at least one of the first joining surface and the second joining surface for non-solder coated foil or arranging an additional solder preform for already solder coated reactive nanometer multilayer foil between the solder coated reactive nanometer multilayer foil and the structure, wherein the solder preform or the additional solder preform includes a larger layer with a greater thickness compared to another solder preform between the solder coated or non-solder coated reactive nanometer multilayer foil and the structure applied to the glass substrate so that a reduction of a temperature introduction into the structure and a leveling of uneven portions is caused; temporarily applying a pressure force P which is applied between the opposing joining surfaces; and triggering of an exothermal reaction of the solder coated or non-solder coated reactive nanometer multilayer foil, wherein a recess is provided in a surface of the electrical connection component for introducing an ignition impulse into the solder coated or non-solder coated reactive nanometer multilayer foil.

2. The method according to claim 1, characterized in that the solder coated or non-solder coated reactive nanometer multilayer foil protrudes at least beyond one side of at least one of the first joining surface and the second joining surface for introducing the ignition impulse into the solder coated or non-solder coated reactive nanometer multilayer foil.

3. The method according to claim 1, characterized in that a total thickness of the solder coated or non-solder coated reactive nanometer multilayer foil is sized as a function of properties of the structure and a base of the structure with respect to a thermal energy that is to be released.

4. The method according to claim 1, characterized in that at least a portion or components of the solder coated or non-solder coated reactive nanometer multilayer foil are directly applied to at least one of the first joining surface and the second joining surface.

5. The method of claim 1, characterized in that the electrical connecting component is a solder base.

6. The method of claim 1, characterized in that the structure is a printed conductive structure.

7. The method of claim 1, characterized in that the larger layer with the greater thickness is a layer with a double thickness.

8. The method of claim 4, characterized in that the at least one portion or components of the solder coated or non-solder coated reactive nanometer multilayer foil are deposited on at least one of the first joining surface and the second joining surface.

Description

(1) The invention is subsequently described in more detail with reference to an embodiment and drawing figures.

(2) FIG. 1 illustrates a sectional view of a schematic configuration of a joint using nanometer multilayer foils.

(3) FIG. 2 is a front perspective view of an electrical connection element, showing a recess provided in the surface thereof.

(4) FIG. 3 is a cross-sectional view of an exemplary joint using nanometer multilayer foil, showing solder layers having different thicknesses.

(5) FIG. 4 is a cross-sectional view of an exemplary joint using nanometer multilayer foil, showing an additional solder layer.

(6) FIG. 5 is a cross-sectional view of an exemplary joint using nanometer multilayer foil, showing the uneven portions thereof.

(7) FIG. 6 is an exploded cross-sectional view of the exemplary joint using nanometer multilayer foil shown in FIG. 4.

(8) According to the drawing figures a component, in particular a soldering base made from a metal material, in particular a special alloy is arranged on a printed conductive structure, in particular configured a silver layer 2.

(9) The conductive structure this means the silver layer 2 is arranged on a glass substrate 3.

(10) Between the silver layer 2 and the glass substrate 3 there is a color layer 4.

(11) The surface of the silver layer 2 and the respective bottom side of the soldering base 1 form joining surfaces 2.

(12) A solder coated or non-solder coated reactive nanometer multilayer foil 5 is now arranged as a nano scale multilayer system between the joining surfaces.

(13) When using a solder coated multilayer system 5, amounts of the solder 6 are applied on both surface sides.

(14) When using non solder coated multilayer systems 5 a corresponding solder preform 6 is formed between the joining surfaces with the multilayer system 5 connected there between.

(15) The corresponding multilayer systems 5 are preconfigured with respect to their joining surfaces.

(16) According to an advantageous embodiment the solder preform or an additional solder preform 6a between the nanometer multilayer foil 5 and the conductive structure 2 applied to the glass substrate 3 are configured so that the conductive structure 2 has a greater, in particular at least a double layer thickness compared to another solder preform, thus the preform that is arranged between the solder base 1 and the nanometer multilayer foil 5. Thus, it is assured that no excessively high temperature is introduced into the conductive structure 2. Furthermore the provided solder gap is filled sufficiently so that uneven portions 8 are filled.

(17) After a pressing force P is applied which acts between the joining surfaces an exothermal reaction of the foil is triggered. This is represented in the FIGURE representation by a lightening symbol.

(18) Triggering the exothermal reaction can be done by a laser impulse or an electrical discharge.

(19) According to an advantageous embodiment a recess 7 is provided in the surface of the electrical connection component for introducing the ignition impulse into the nanometer multilayer 5.

(20) In order to introduce the ignition impulse into the nanometer multilayer foil 5 it can protrude beyond at least one side of the joining surfaces according to the figure representations.

(21) By selecting reactive materials systems for producing reactive foils the adiabatic reaction temperature can be selected. Maximum adiabatic temperatures can be in a range of 1600 C. for in Ni/AL reaction systems.

(22) By using reactive nanometer multilayer foils a respective local heat source is created with respect to the respective joining surfaces. As a consequence the introduction of heat energy and stress into adjacent components is minimized since the thermal energy is released directly in the joint gap, this means in the instant embodiment in the solder gap. External heating by an oven through induction or similar is not necessary.

(23) Process efficiency can be increased further in that solder that is necessary for bonding is applied directly to the foil so that an interconnection is created that is easy to use and which forms the solder material and the heat source at the same time.