Patent Publication Number: US-2021167035-A1

Title: Method and apparatus for creating a bond between objects based on formation of inter-diffusion layers

Description:
RELATED APPLICATIONS 
     This application is a Division of U.S. application Ser. No. 15/176,567 filed Jun. 8, 2016, which issues on Feb. 16, 2021 as U.S. Pat. No. 10,923,454, which claims priority to U.S. Provisional Application No. 62/173,057 filed Jun. 9, 2015, which are incorporated herein by reference. 
     It is intended that each of the referenced applications may be applicable to the concepts and embodiments disclosed herein, even if such concepts and embodiments are disclosed in the referenced applications with different limitations and configurations and described using different examples and terminology. 
    
    
     FIELD OF DISCLOSURE 
     The present disclosure generally relates to creating a bond between objects based on formation of inter-diffusion layers. More specifically, the present disclosure relates to creating a bond between metallic objects through formation of a contiguous inter-diffusion layer. 
     BACKGROUND 
     The required operating temperature for some electronic applications such as, for example, deep oil exploration, aerospace, and automotive, have increased beyond the current available die attach materials. The current aim now exceeds more than 250° C. for long periods of time, for example a few years. One important issue of the current high temperature die attach materials is the lead content, which has environmental hazards and its poisonous nature to species. On the other hand, the reliability of the current die attach materials deteriorates while being stored at high temperatures, and testing these materials can be very time consuming before being operational. Therefore, there is a need for die attach materials without any harmful elements or chemicals, which can withstand high temperatures of more than 250° C. for long periods of time without showing any loss of strength over conventional high temperature storage tests to fulfil the reliability requirement for the long operation times. 
     When two materials are in contact, inter-diffusion at the interface between them may improve their adhesion. However, this phenomenon may result in reduction of adhesion strength to a third material. The inter diffusion of the first and second material, such as, for example, the mating surface of substrate and die attach material, may weaken the attachment to the third material, such as, for example, the die. 
     BRIEF OVERVIEW 
     A thermally resistant connection for high temperature die attachments may be provided. This brief overview is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This brief overview is not intended to identify key features or essential features of the claimed subject matter. Nor is this brief overview intended to be used to limit the claimed subject matter&#39;s scope. 
     An object with a mating surface may attach to another object with another mating surface by creating an inter-diffusion layer. The inter-diffusion layer may be supplemented by an insert layer. Furthermore, the inter-diffusion layer may be supplemented by varying the surface geometry of either or both of the objects to be attached. 
     Accordingly, in some embodiments, the present disclosure provides a method of creating a bond between a first object and a second object. In some embodiments, the first object may be comprised in a substrate, such as for example, a semiconductor substrate. Accordingly, the second object may be comprised in a semiconductor die. Accordingly, the bond may facilitate attaching of the semiconductor die to the substrate. 
     The method may include a step of filling a space between the first object and the second object with a filler material. Further, in some embodiments, the filler material may be a bonding material. For instance, the filler material may include sintered silver nanoparticles. 
     Further, the method may include a step of heating the filler material to facilitate formation of a plurality of inter-diffusion layers. 
     Due to the heating, a first inter-diffusion layer may be formed between the filler material and the first object. Further, a second inter-diffusion layer may be formed between the filler material and the second object. The plurality of inter-diffusion layers may provide a physical bond between the first object and the second object. Further, in some embodiments, the plurality of inter-diffusion layers may provide at least one of a thermal conduction and electrical conduction between the first object and the second object. 
     Furthermore, in some embodiments, the first inter-diffusion layer may be contiguous with the second inter-diffusion layer. For example, when the spacing between the first object and the second object is reduced, the first inter-diffusion layer may overlap with the second inter-diffusion layer. Alternatively and/or additionally, the material characteristics of the first object, the filler material and the second object may be such that an extent of inter-diffusion may be large enough to result in an overlap of the inter-diffusion layer with the inter-diffusion layer. 
     In some embodiments, contiguity of the first inter-diffusion layer with the second inter-diffusion layer may further enhance mechanical, thermal and/or electrical characteristics of the bond between the first object and the second object. 
     Further, in some embodiments, a space between the first object and the second object may include at least one insert. Accordingly, in some embodiments, the method may further include placing the at least one insert in the space. 
     Further, in some embodiments, the at least one insert may be comprised in at least one of the first object and the second object. Accordingly, the method may further include a step of forming the at least one insert on at least one of the first object and the second object. The forming of the at least one insert may be performed using techniques such as etching, depositing, milling, patterning and so on. 
     Additionally, as result of the heating, a third inter-diffusion layer may be formed between the at least one insert and the filler material. Further, the third inter-diffusion layer may be contiguous with each of the first inter-diffusion layer and the second inter-diffusion layer. As a result, the use of the at least one insert may facilitate formation of a contiguous plurality of inter-diffusion layers. 
     Both the foregoing brief overview and the following detailed description provide examples and are explanatory only. Accordingly, the foregoing brief overview and the following detailed description should not be considered to be restrictive. Further, features or variations may be provided in addition to those set forth herein. For example, embodiments may be directed to various feature combinations and sub-combinations described in the detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate various embodiments of the present disclosure. The drawings contain representations of various trademarks and copyrights owned by the Applicants. In addition, the drawings may contain other marks owned by third parties and are being used for illustrative purposes only. All rights to various trademarks and copyrights represented herein, except those belonging to their respective owners, are vested in and the property of the Applicants. The Applicants retain and reserve all rights in their trademarks and copyrights included herein, and grant permission to reproduce the material only in connection with reproduction of the granted patent and for no other purpose. 
       Furthermore, the drawings may contain text or captions that may explain certain embodiments of the present disclosure. This text is included for illustrative, non-limiting, explanatory purposes of certain embodiments detailed in the present disclosure. In the drawings: 
         FIG. 1A  illustrates a method for formation of a connection or attachment of two surfaces by formation of a continuous inter-diffusion layer from one of the surfaces to another, in which placement of inserts in between the surfaces establishes the continuity; 
         FIGS. 1B, 1C and 1D  illustrate a cross section, showing formation of a connection or attachment of two surfaces by formation of a continuous inter-diffusion layer from one of the surfaces to another, in which placement of inserts in between the surfaces establishes the continuity; 
         FIGS. 2A, 2B and 2C  illustrate a cross section, showing formation of a connection or attachment of a surface to another surface by formation of a continuous inter-diffusion layer from one of the surfaces to an insert and another continuous inter-diffusion layer from that insert to the other surface; 
         FIG. 3A  illustrates a method for formation of a connection or attachment by diffusion of a material inside a gap between the two surfaces, which is formed by continuous inter-diffusion layer inside the gap from one of the surface to the other surface; 
         FIGS. 3B and 3C  illustrate a cross section, showing formation of a connection or attachment by diffusion of a material inside the gap between the two surfaces, which is formed by continuous inter-diffusion layer inside the gap from one of the surface to the other surface; 
         FIG. 4A  illustrates a cross-section showing formation of a plurality of inter-diffusion layers as a result of performing a method of creating a bond between a first object and second object according to some embodiments; 
         FIG. 4B  illustrates a cross-section showing formation of a contiguous plurality of inter-diffusion layers as a result of performing a method of creating a bond between a first object and second object according to some embodiments; 
         FIG. 5A  illustrates a cross-section of a placement of a first object, a second object, a filler material and an insert in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 5B  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object using the insert in accordance with some embodiments; 
         FIG. 5C  illustrates a cross-section of a placement of a first object, a second object, a filler material and an insert in physical contact with the first object and the second object in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 5D  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 6A  illustrates a cross-section of a placement of a first object, a second object, a filler material and a plurality of widely spaced inserts in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 6B  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object using the plurality of widely spaced inserts in accordance with some embodiments; 
         FIG. 6C  illustrates a cross-section of a placement of a first object, a second object, a filler material and a plurality of closely spaced inserts in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 6D  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object using the plurality of closely spaced inserts in accordance with some embodiments; 
         FIG. 7A  illustrates a cross-section of a placement of a first object and a second object made of one metal and an insert made of another metal in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 7B  illustrates a cross-section showing a contiguous, heterogeneous plurality of inter-diffusion layers that provides a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 7C  illustrates a cross-section of a placement of a first object made of one metal, a second object made of another metal and an insert made of yet another metal in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 7D  illustrates a cross-section showing a contiguous, heterogeneous plurality of inter-diffusion layers that provides a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 8A  illustrates a cross-section of a placement of a first object, a second object, a filler material and a plurality of inserts in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 8B  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object using the plurality of inserts in accordance with some embodiments; 
         FIG. 9A  illustrates a cross-section of a placement of a first object, a second object, a filler material and a plurality of inserts formed on the first object in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 9B  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object using the plurality of inserts formed in the first object in accordance with some embodiments; 
         FIG. 10A  illustrates a cross-section of a placement of a first object, a second object, a filler material and a plurality of inserts formed on each of the first object and the second object in order to create a bond between the first object and the second object in accordance with some embodiments; 
         FIG. 10B  illustrates a cross-section showing a contiguous plurality of inter-diffusion layers that provides a bond between the first object and the second object using the plurality of inserts formed in each of the first object and the second object in accordance with some embodiments; 
         FIG. 11  illustrates a method of creating a bond between a first object and a second object in accordance with some embodiments; 
         FIG. 12  illustrates a method of creating a bond between a first object and a second object involving placement of an insert in accordance with some embodiments; 
         FIG. 13  illustrates a method of creating a bond between a first object and a second object involving formation of an insert on at least one of the first object and the second object in accordance with some embodiments; 
         FIG. 14  illustrates a method of creating a bond between a first object and a second object involving placement of an insert and introduction of filler material in accordance with some embodiments; and 
         FIG. 15  illustrates a method of creating a bond between a first object and a second object in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art that the present disclosure has broad utility and application. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the disclosure and may further incorporate only one or a plurality of the above-disclosed features. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the embodiments of the present disclosure. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the display and may further incorporate only one or a plurality of the above-disclosed features. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present disclosure. 
     Accordingly, while embodiments are described herein in detail in relation to one or more embodiments, it is to be understood that this disclosure is illustrative and exemplary of the present disclosure, and are made merely for the purposes of providing a full and enabling disclosure. The detailed disclosure herein of one or more embodiments is not intended, nor is to be construed, to limit the scope of patent protection afforded in any claim of a patent issuing here from, which scope is to be defined by the claims and the equivalents thereof. It is not intended that the scope of patent protection be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself. 
     Thus, for example, any sequence(s) and/or temporal order of steps of various processes or methods that are described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal order, the steps of any such processes or methods are not limited to being carried out in any particular sequence or order, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and orders while still falling within the scope of the present invention. Accordingly, it is intended that the scope of patent protection is to be defined by the issued claim(s) rather than the description set forth herein. 
     Additionally, it is important to note that each term used herein refers to that which an ordinary artisan would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—as understood by the ordinary artisan based on the contextual use of such term—differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by the ordinary artisan should prevail. 
     Regarding applicability of 35 U.S.C. § 112, ¶6, no claim element is intended to be read in accordance with this statutory provision unless the explicit phrase “means for” or “step for” is actually used in such claim element, whereupon this statutory provision is intended to apply in the interpretation of such claim element. 
     Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one,” but does not exclude a plurality unless the contextual use dictates otherwise. When used herein to join a list of items, “or” denotes “at least one of the items,” but does not exclude a plurality of items of the list. Finally, when used herein to join a list of items, “and” denotes “all of the items of the list.” 
     The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar elements. While many embodiments of the disclosure may be described, modifications, adaptations, and other implementations are possible. For example, substitutions, additions, or modifications may be made to the elements illustrated in the drawings, and the methods described herein may be modified by substituting, reordering, or adding stages to the disclosed methods. Accordingly, the following detailed description does not limit the disclosure. Instead, the proper scope of the disclosure is defined by the appended claims. The present disclosure contains headers. It should be understood that these headers are used as references and are not to be construed as limiting upon the subjected matter disclosed under the header. 
     The present disclosure includes many aspects and features. Moreover, while many aspects and features relate to, and are described in, the context of die attachments, embodiments of the present disclosure are not limited to use only in this context. Furthermore, although various embodiments are disclosed with reference to a two-object operating environment, a plurality of objects may be attached using the methods and systems disclosed herein. Other applications consistent with embodiments disclosed herein may be used with, for example, wire bonding and welding. 
     I. Overview 
     Consistent with embodiments of the present disclosure, a thermally resistant connection for high temperature die attachments may be provided. This overview is provided to introduce a selection of concepts in a simplified form that are further described below. This overview is not intended to identify key features or essential features of the claimed subject matter. Nor is this overview intended to be used to limit the claimed subject matter&#39;s scope. The thermally resistant connection for high temperature die attachments may be used by individuals or companies to create a die attachment connection that can operate at and withstand high temperatures. 
     High temperature die attachment may be used for attaching, for example, electronic components to an electronic substrate in applications such as, for example, deep oil exploration, aerospace, and automotive applications. Embodiments of the present disclosure may create an attachment with the use of an inter-diffusion layer. 
     The inter-diffusion layer may be created, at least in part, with the use of an insert layer. The insert layer may sit between the objects to be attached. The insert layer may have space for inserting a filler material, such as, for example, a bonding material. Further, the insert layer material may have a custom profile. The custom profile may be selected or determined based on a desired properties of the attachment (e.g., thermal connectivity, porosity, and the like). Accordingly, the insert layer may be comprised of, for example, a mesh screen of a specified density. Alternatively, or in addition to the insert layer, the surface profiles of the objects to be attached may be contoured to further enable inter-diffusion between the objects. For example, in some embodiments, the objects may have contours deposited, patterned or milled out. 
     The space between the objects and the insert layer may further be filled with a filler material. The filler material may be, for example, but not limited to, a bonding material. The filler material may diffuse with at least one of the other materials during the inter-diffusion process. 
     Advantages over prior art may include:
         1) Lead-free high temperature die attach, which has environmental benefits;   2) No need to reach melting point of any element, which is an advantage over Solid-Liquid Inter-Diffusion (SLID) systems;   3) No need to reach high processing temperatures close to the melting point of the die attach materials, which can prevent formation of residual stresses inside the joint;   4) No need to use applied processing pressure on the die, which is advantageous over both SLID, micro and nano-particle sintering, and diffusion wielding (diffusion bonding) techniques;   5) The system strengthens over time at high temperatures;   6) Controlled porosity;   7) Easy prediction of the final structure after storage at high temperature and control over design of the final required structure;   8) Formation of a mostly void free layer as a section or all of the joint or interconnect as a result of the continuous inter-diffusion layer;   9) Can be used for large die sizes, which is an advantage over sintering techniques, which have problem with build-up of combusted organics inside the die attach, which can reduce the die attach strength, and also large die sizes can prevent oxygen penetration and stop perfect sintering to occur in the center; and   10) Controllable thermal and electrical conductivity as a result of selection of the material combinations and desired inter-diffusion layer.       

     Both the foregoing overview and the following detailed description provide examples and are explanatory only. Accordingly, the foregoing overview and the following detailed description should not be considered to be restrictive. Further, features or variations may be provided in addition to those set forth herein. For example, embodiments may be directed to various feature combinations and sub-combinations described in the detailed description. 
     II. Configuration 
     An operating environment associated with embodiments of the present disclosure may be comprised of two objects to be connected by die attachment. For example, one object may be an electrical component and the other object may be a substrate. The objects may have various surface conditions and profiles. 
     The objects may be connected by a continuous inter-diffusion layer. In some embodiments, the inter-diffusion layer may be supplemented with an insert layer. The insert layer may be placed between the two objects. The insert layer may take the form of a variety of shapes and sizes. The form of the insert layer may be designed to accommodate instruments, such as, for example, wires with cross sections within the operating environment. Moreover, the top and bottom surfaces of the insert layer may vary depending based on the characteristics of the operating environment, including, for example, properties of the objects being attached. For example, the surfaces may be conductive or nonconductive. 
     The one or more of the bonding surfaces (e.g., mating surface) of the objects may be contoured to enhance diffusion and contiguity of the inter-diffusion layers. For example, profiles may be deposited into or patterned or milled out of an object&#39;s surface. 
     Constituent with embodiments of the present disclosure, the surface profile of the objects, the insert layer in between the objects, or both, may create a space between the objects. The space between the objects, in turn, may further be filled with a filler material. The filler material is preferably a bonding material. 
     In some embodiments, the inter-diffusion layer may be formed chemically to form an intermetallic inter-diffusion layer. In other embodiments, the inter-diffusion layer may be formed without chemical reactions to form a miscible mixture. Still in other embodiments, the inter-diffusion layer may form a combination of intermetallic compounds and miscible mixtures. 
     III. Operation 
     Although the stages illustrated by the flow charts are disclosed in a particular order, it should be understood that the order is disclosed for illustrative purposes only. Stages may be combined, separated, reordered, and various intermediary stages may exist. Accordingly, it should be understood that the various stages illustrated within the flow charts may be, in various embodiments, performed in arrangements that differ from the ones illustrated. Moreover, various stages may be added or removed from the flow charts without altering or deterring from the fundamental scope of the depicted methods and systems disclosed herein. Ways to implement the stages of methods  100 ,  300 ,  1100 ,  1200 ,  1300 ,  1400  and  1500  will be described in greater detail below. 
       FIG. 1A  is a flow chart setting forth the general stages involved in a method  100  consistent with an embodiment of the disclosure for providing a thermally resistant connection for high temperature die attachments. Method  100  illustrates a method for forming a connection or attachment of two surfaces by formation of a continuous inter-diffusion layer from one of the surfaces to another, in which placement of inserts in between the surfaces establishes the continuity. 
       FIGS. 1B, 1C and 1D  illustrate a cross section, showing formation of a connection or attachment of two surfaces by formation of a continuous inter-diffusion layer from one of the surfaces to another, in which placement of inserts in between the surfaces establishes the continuity. 
     Method  100  may begin at starting block  109  and proceed to stage  110 , where an insert layer is selected. An object  101 , which may be, for example, an electronic component, with a mating surface  102  is subject to attachment or establishment of a connection to object  103 , which may be, for example, an electronic substrate, with mating surface  104 . Inserts  106  (e.g., may be one or more inserts, without altering the scope of the present disclosure), in this case represented as bars with rectangular cross sections, may have any shapes and sizes depending on the application and instruments, such as, for example, wires with circular cross sections. Inserts  106  may have surfaces  105 . 
     From stage  110 , where the insert layer is selected, method  100  may proceed to stage  120 , where the insert layer and filler material may be placed between objects to be attached. The inserts may be placed in between the mating surfaces  102  and  104 . The space formed by the separation between the mating surfaces  102  and  104 , while the inserts are there, may be filled with a material  107 , as shown in  FIG. 1C . In various embodiments, material  107  is preferentially a bonding material. 
     From stage  120 , where the insert layer and filler material is placed between the objects to be attached, method  100  may proceed to stage  130 , where the materials may be inter-diffused. Inter-diffusion of the material  107  with mating surfaces  102 ,  104 , and  105  may form a continuous inter-diffusion layer  108 . The continuous inter-diffusion layer  108  may form an interconnection, joint or attachment of object  101  to object  103 . 
     The inter-diffusion mechanism depends on the application, such as, for example, thermal diffusion for high temperature electronic applications, or diffusion as a result of high current density in power electronics applications. As an example, this inter-diffusion layer may be formed by a chemical reaction and, for example, form an intermetallic compound, or without chemical reaction and, for example, form a miscible mixture of materials  107  and materials on the mating surfaces  102 ,  104  and surfaces  105 . The continuous inter-inter-diffusion layer can also be a mixture of an intermetallic layer with a miscible mixture. 
     If the desired bond properties between the two objects are reached, method  100  may end at stage  150 . Alternatively, the materials may be modified to produce the desired bond properties. 
     For improvements on the mechanical abilities of the continuous inter-diffusion layers  108 , the shape and separation of the inserts  106  may be optimized, which can be dependent on the properties of the inter-diffusions and the initial characterizations of materials  107  and mating surfaces&#39;  102 ,  104  and  105  materials. 
     This inter-diffusion may result in movement of atoms of the filler material  107  towards the surfaces  102 ,  104  and  105 . Therefore, the initial porosity of the mating surfaces  102 ,  104  and  105  or the material  107  may be used to end up with final desired porosity shown in  FIG. 1D  inside the continuous inter-diffusion layer  108 . The initial design and shape of the inserts and mating surfaces may be varied to form the required final pores inside the continuous inter-diffusion layer. Also, this technique may enable control over the porosity after establishment of the diffusion mechanisms. For example, by increasing the initial porosity of material  107 , the flexibility of the final assembly may be improved. Alternatively, reduction in the porosity and reduction in the horizontal widths of inserts  106  may cause the continuous inter-diffusion layers  108  to thicken and therefore strengthen for better mechanical performance. While the above examples are used to show possible outcomes, results may vary depending on the application. 
     To enable the inter-diffusions, the mixing energy of the materials  107  with mating surfaces  102 ,  104 , and  105  may be lower than their unmixed energy to increase the attraction for diffusion. In addition, this inter-diffusion layer may also result in a chemical reaction to form an element or molecule as the continuous inter-diffusion layer, such as an intermetallic compound. 
     One example of this method may be utilized in attachment of an electronic chip to a substrate with gold mating surfaces. The method may begin by filling a gold mesh (with for example 20 μm thickness, square holes with 30 μm length and Sum bar width) with a silver bonding material. Next, the method may continue by placing the filled gold mesh in between the substrate and chip. The silver bonding materials can be made out of silver nanoparticle (NP) paste. The silver NP paste may then be sintered as a bonding material after placement between the chip and substrate. One benefit of silver nanoparticles may be formation of many grain and twin boundaries inside the sintered materials [S. A. Paknejad, G. Dumas, G. West, G. Lewis, S. H. Mannan, Microstructure evolution during 300° C. storage of sintered Ag nanoparticles on Ag and Au substrates, Journal of Alloys and Compounds, Volume 617, 25 Dec. 2014, Pages 994-1001, ISSN 0925-8388, http://dx.doi.org/10.1016/j.jallcom.2014.08.062.]. The high concentration of the grain and twin boundaries may increase the rate of the diffusion mechanisms and speed up the formation of the continuous inter-diffusion layer. Also, the sintered silver NPs can have initial porosity of for example 20%, which after the diffusions will end up in the middle of the continuous inter-diffusion layer, which may finally produce the assembly shown in  FIG. 1D . 
     This design enables densification of the continuous inter-diffusion layer at high temperatures. Such densification of the continuous inter-diffusion layer at high temperatures may emphasize on the fact that high temperatures can increase the mechanical strength of the joint till the diffusion stops and may leave a stable structure at high temperatures. (See “Thermally stable high temperature die attach solution.” Materials &amp; Design 89 (2016): 1310-1314. http://dx.doi.org/10.1016/j.matdes.2015.10.074 by Paknejad, Seyed Amir, Ali Mansourian, Yohan Noh, Khalid Khtatba, and Samjid H. Mannan.) The top and bottom surfaces of the inserts  106  may vary depending on the application. For example, they may be conductive or nonconductive. 
     The inserts may be in any form and sizes. Some examples of inserts may include electrodeposited mesh structures with parallel or crossing bars or wires, and woven mesh structures. The inserts may also be patterned, grown, and/or deposited on the object  101  and/or object  103 . 
     The density of the inserts  106  may vary in different locations between objects  101  and  103 . For example, at the center the density may be higher to increase the mechanical strength, while, closer to the edges, the density may be lower or with diagonal orientations to compensate for the coefficient of thermal expansion mismatch between the objects  101  and  103  and the inserts  106 . 
     Further, in some embodiments, the at least one insert  106  may be configured to enable a gap within the at least one insert  106  or a gap between at least a couple of inserts to reach an edge of at least one of the first object  101  and the second object  103 . Further, the gap allows vapors to travel into a space surrounding at least one of the first object  101  and the second object  103 . Method  100  may be implemented in formation of a connection or attachment of a surface to another surface by formation of a continuous inter-diffusion layer from one of the surfaces to an insert and another continuous inter-diffusion layer from that insert to the other surface as shown in  FIGS. 2A, 2B, and 2C . 
       FIGS. 2A, 2B, and 2C  illustrates a cross section, showing formation of a connection or attachment of a surface to another surface by formation of a continuous inter-diffusion layer from one of the surfaces to an insert and another continuous inter-diffusion layer from that insert to the other surface. 
     Method  100  may begin at starting block  109  and proceed to stage  110 , where an insert layer is selected. An object  201 , such as, for example, an electronic component with a mating surface  202 , is a subject of attachment or establishment of a connection to object  203 , which may be an electronic substrate, with mating surface  204 . In this case, inserts  206  are represented in bars with rectangular cross sections with mating surfaces  205 , which may have any shapes and sizes depending on the application and instruments. The inserts may be placed in between the mating surfaces  202  and  204 . 
     From stage  110 , where the insert layer is selected, method  100  may proceed to stage  120 , where the insert layer and filler material may be placed between objects to be attached. The space formed by the separation between the mating surfaces  202  and  204 , while the inserts are there, may be filled with a material  207 , as shown in  FIG. 2B , preferentially a bonding material. 
     From stage  120 , where the insert layer and filler material are placed between the objects to be attached, method  100  may proceed to stage  130 , where the materials may be inter-diffused. Inter-diffusion of the material  207  with mating surfaces  202 ,  204 , and  205  may form two continuous inter-diffusion layers  208  along the mating surfaces  205  to the mating surfaces  202  and  204  and also can be continuous inter-diffusion layer in between the gap formed from the mating surfaces  205  with the mating surfaces  202  and/or  204 . In addition, the inserts can be connected to each other before or after formation of the inter-diffusion layer for further stability. Such continuous layer may form an interconnection, joint or attachment of object  201  and object  203  to inserts  206 , which then would mean the objects  201  and  203  are attached together. This inter-diffusion may attract the filler materials  207  into the gap between the mating surfaces of  205  and  202  as well as gap between mating surfaces  205  and  204 . The inter-diffusion mechanism may depend on the application, such as, for example, thermal diffusion for high temperature applications. As an example this inter-diffusion layer may be formed by a chemical reaction and, for example, form an intermetallic compound or without chemical reaction and, for example, form a miscible mixture of materials  207  and materials on the mating surfaces  202 ,  204  and  205 . The continuous inter-diffusion layer may also be a mixture of intermetallic compounds with miscible mixtures. 
     If the desired bond properties between the two objects are reached, method  100  may end at stage  150 . Alternatively, the materials may be modified to produce the desired bond properties. Modifications to the materials and diffusion methods may be varied as discussed above to achieve desired bond properties. 
       FIG. 3A  is a flow chart setting forth the general stages involved in a method  300  consistent with an embodiment of the disclosure for providing a thermally resistant connection for high temperature die attachments. Method  300  illustrates a method for forming a connection or attachment by diffusion of a material inside a gap between the two surfaces, which may be formed by continuous inter-diffusion layer inside the gap from one of the surface to the other surface. 
       FIGS. 3B, and 3C  illustrate a cross section, showing formation of a connection or attachment by diffusion of a material inside a gap between the two surfaces, which is formed by continuous inter-diffusion layer inside the gap from one of the surface to the other surface. 
     Method  300  may begin at starting block  309  and proceed to stage  310 , where object surface profiles may be selected. An object  301 , which can be an electronic component, with a mating surface  302  is the subject of attachment or establishment of a connection to object  303 , which can be an electronic substrate, with mating surface  304 . Structures  305  on the objects  301  and  303  as shown in  FIG. 3B  with rectangular cross sections, may have any shapes and sizes depending on the application and instruments and may or may not be symmetric or similar. The structures  305  can also only be on one of the objects  301  or  303 . The various surface profiles may be deposited, patterned or milled out of objects  301  and/or  303 . 
     From stage  310 , where object surface profiles may be selected, method  300  may proceed to stage  320 , where filler material may be placed between the objects to be attached. The space formed by the separation between the structures  305  and the mating surfaces  302  and  304  may be filled with a material  306 , preferentially a bonding material. 
     From stage  320 , where filler material is placed between the objects to be attached, method  300  may proceed to stage  330 , where the materials may be inter diffused. Inter-diffusion of the material  306  with at least one of the mating surfaces  302  and/or  304  may form a continuous inter-diffusion layer  308  forming interconnection, joint or attachment of object  301  to object  303 . This inter-diffusion may attract the materials inside the gap  307  between the mating surfaces of  302  and  304  and improve the attachment. There also can be no gap  307  between the mating surfaces  302  and  304  and the inter-diffusion layer may be continuous from the edges of the structures  305  on both objects  301  and  303  for establishment of the joint, attachment or interconnection of the objects  301  and  303  by inter-diffusion among materials  306  and mating surfaces  302  and  304 . The inter-diffusion mechanism may depend on the application, such as, for example, thermal diffusion for high temperature electronic applications. As an example this inter-diffusion layer can be formed by a chemical reaction and, for example, form an intermetallic compound or without chemical reaction and, for example, form a miscible mixture of materials  306  and materials on the mating surfaces  302  and  304 . The continuous inter-diffusion layer may also be a mixture of intermetallic compounds with miscible mixtures. 
     If the desired bond properties are achieved, method  300  may end at stage  350 . Alternatively, the materials may be modified to produce the desired result. Modifications to the materials and diffusion methods may be varied as discussed above to achieve desired bond properties. 
     Various elements may be used in conjunction with embodiments of the present disclosure. The elements include, but are not limited to, for example, Cu, Ag, Au, Al, Pt, Ti, Tw, Ni, Ta, Pd, Sn, Zn, Pb (only for special applications), Sb, Bi, Cd, Si, Ge, and In. 
     Any of the  102 ,  104 ,  105 ,  107 ,  202 ,  204 ,  205 ,  207 ,  302 ,  304 , and  306  may be made from them, any combinations or alloys of them, or be made out of their oxides. 
     The whole inserts  106  and  206 , and structures  305  can also be involved into the diffusion and be part of the inter-diffusion layers  108 ,  208 , and  308 . In addition, inserts  106  and  206  may be connected or attached together inside or outside the separation between objects  101  and  103  in case of inserts  106  or separation between objects  201  and  203  in case of inserts  206 . These connections of inserts may achieve improved mechanical properties and stability and support for other inserts and consequently improved mechanical stability of the inter-diffusion layers  108  and  208  in order. 
     Any of the materials  107 ,  207 , and  306  could have been pre-deposited, milled or patterned on any of the objects subject of being attached or connected. 
     Further, the present disclosure also provides a method  1100 , as illustrated in  FIG. 11 , of creating a bond between a first object  402  and a second object  404  as illustrated in  FIG. 4A  and  FIG. 4B . Further, in some embodiments, the first object  402  may be comprised in a substrate, such as for example, a semiconductor substrate. Accordingly, the second object  404  may be comprised in a semiconductor die. Further, the bond may facilitate attaching of the semiconductor die to the substrate. 
     In some embodiments, the first object  402  and/or the second object  404  may include one or more metals, such as, but not limited to, Cu, Ag, Au, Al, Pt, Ti, Tw, Ni, Ta, Pd, Sn, Zn, Pb (only for special applications), Sb, Bi, Cd, Si, Ge, and In. For instance, in some embodiments, each of the first object  402  and the second object  404  may include at least one metal, such as Gold (Au). 
     The method  1100  may include a step  1110  of filling a space between the first object  402  and the second object  404  with a filler material  406 . Further, in some embodiments, the filler material  406  may be a bonding material. For instance, the filler material  406  may include sintered silver nanoparticles. 
     Further, the method  1100  may include a step  1120  of heating the filler material  406  to facilitate formation of a plurality of inter-diffusion layers. Heating of the filler material  406  may be performed by directly heating the filler material  406 . Alternatively and/or additionally, one or more of the first object  402  and the second object  404  may be heated while the filler material  406  may receive heat through thermal conduction. 
     Further, in some embodiments, the heating may be performed to a temperature below a melting point of each of the first object  402 , the second object  404 , the filler material  406  and the at least one insert  502 . 
     Due to the heating, a first inter-diffusion layer  408  may be formed between the filler material  406  and the first object  402 . Further, a second inter-diffusion layer  410  may be formed between the filler material  406  and the second object  404 . The plurality of inter-diffusion layers may provide a physical bond between the first object  402  and the second object  404 . Further, in some embodiments, the plurality of inter-diffusion layers may provide at least one of a thermal conduction and electrical conduction between the first object  402  and the second object  404 . 
     In some embodiments, the method  1100  may further include applying external pressure to at least one of the first object  402  and the second object  404  to further facilitate formation of the plurality of inter-diffusion layers. Accordingly, in some embodiments, the plurality of inter-diffusion layers may be formed under atmospheric pressure. 
     As a result of formation of the plurality of inter-diffusion layers, as illustrated in  FIG. 4A , a path  412  for thermal and/or electrical conduction may be formed between the first object  402  and the second object  404 . The path may begin from the first object  402 , and pass through each of the first inter-diffusion layer  408 , the filler material  406  and the second inter-diffusion layer  410  and finally end in the second object  404 . Further, due to the material characteristics of the first inter-diffusion layer  408  and the second inter-diffusion layer  410 , the path  412  may be characterized by enhanced thermal and/or electrical conduction. For instance, thermal, mechanical and/or electrical characteristics associated with the bond between the first object  402  and the second object  404  may remain within an effective range even in the presence of extreme environments, such as high temperature, high pressure etc. 
     Furthermore, in some embodiments, the first inter-diffusion layer  408  may be contiguous with the second inter-diffusion layer  410  as illustrated in  FIG. 4B . For example, when the spacing between the first object  402  and the second object  404  is reduced, the first inter-diffusion layer  408  may overlap with the second inter-diffusion layer  410 . Alternatively and/or additionally, the material characteristics or quantity of the first object  402 , the filler material  406  and the second object  404  may be such that an extent of inter-diffusion may be large enough to result in an overlap of the inter-diffusion layer  408  with the inter-diffusion layer  410 . 
     Accordingly, a path  414  for thermal and/or electrical conduction may be formed. The path may begin from the first object  402 , and pass through each of the first inter-diffusion layer  408  and the second inter-diffusion layer  410  and finally end in the second object  404 . In some embodiments, contiguity of the first inter-diffusion layer  408  with the second inter-diffusion layer  410  may further enhance mechanical, thermal and/or electrical characteristics of the bond between the first object  402  and the second object  404 . 
     Further, in some embodiments, a space between the first object  402  and the second object  404  may include at least one insert  502  as illustrated in  FIG. 5A . Accordingly, in some embodiments, the method  1100  may further include placing the at least one insert  502  in the space. 
     Further, in some embodiments, the at least one insert  502  may be comprised in at least one of the first object  402  and the second object  404  as exemplarily illustrated in  FIG. 9A , where the at least insert  502  may include inserts  902   a - 902   c . Accordingly, the method  1100  may further include a step of forming the at least one insert  502  on at least one of the first object  402  and the second object  404 . The forming of the at least one insert  502  may be performed using techniques such as etching, depositing, milling, patterning and so on. 
     Further, the at least one insert  502  may be in physical contact with the filler material  406 . In some embodiments, the at least one insert  502  may include an insert layer. Further, in some embodiments, the insert layer may include a mesh screen. 
     Additionally, as result of heating, a third inter-diffusion layer  504  may be formed between the at least one insert  502  and the filler material  406 . Further, the third inter-diffusion layer  504  may be contiguous with each of the first inter-diffusion layer  408  and the second inter-diffusion layer  410 . 
     For example, due to placement of the at least one insert  502  as shown in  FIG. 5A , the third inter-diffusion layer  504  may include inter-diffusion layers  504   a  to  504   d  surrounding the at least one insert  502  as shown in  FIG. 5B . Further, as shown, inter-diffusion layer  504   c  may be contiguous with the first inter-diffusion layer  408 . Similarly, inter-diffusion layer  504   d  may be contiguous with the second inter-diffusion layer  410 . Further, inter-diffusion layer  504   c  may be contiguous with inter-diffusion layer  504   d  through each of inter-diffusion layer  504   a  and  504   b . Accordingly, paths of thermal and/or electrical conduction such as path  506   a  and  506   b  may be formed. 
     Alternatively, in some embodiments, the at least one insert  502  may be placed as illustrated in  FIG. 5C , where the at least one insert  502  may be in physical contact with each of the first object  402  and the second object  404 . Accordingly, as a result of the heating, the plurality of inter-diffusion layers  504   a  and  504   b  as illustrated in  FIG. 5D  may be formed. 
     Further, in some embodiments, at least one of the first object  402 , the second object  404 , the at least one insert  502  and the filler material  406  may include at least one of grain boundaries and twin boundaries which may facilitate formation of the plurality of inter-diffusion layers. For instance, the filler material  406  such as sintered silver may include many grain boundaries and twin boundaries which may enhance the diffusion of gold atoms into sintered silver and allow for fast formation of the plurality of inter-diffusion layers. Additionally, in some instances, the presence of grain boundaries and twin boundaries may facilitate formation of the plurality of inter-diffusion layers without necessarily applying external pressure. Accordingly, the first object  402  and the second object  404  may be bonded under atmospheric pressure. 
     Further, in some embodiments, as illustrated in  FIG. 6A , the at least one insert  502  may include a plurality of inserts  602   a  to  602   c . The plurality of inserts, in some instances may be individual members. Alternatively, in some instances, the plurality of inserts  602   a  to  602   c  may be physically connected to each other, for example, in the form of a mesh screen. Accordingly, due to the heating, the plurality of inter-diffusion layers as illustrated in  FIG. 6B  may be formed. 
     Further, a spacing of the plurality of inserts  602   a  to  602   c  may be such that, the inter-diffusion layers formed around the inserts  602   a  to  602   c  may not be physically contiguous. For instance, the inter-diffusion layer formed around the insert  602   a  may not be physically contiguous with the inter-diffusion layer formed either around  602   b  or  602   c . As a result, paths  604  for thermal and/or electrical conduction may be formed between the first object  402  and the second object  404 . 
     However, in some embodiments, as illustrated in  FIG. 6C , a spacing of the plurality of inserts  602   a  to  602   g  may be such that, the inter-diffusion layers formed around the inserts  602   a  to  602   g  may be physically contiguous. For instance, the inter-diffusion layer formed around the insert  602   a  may be physically contiguous with the inter-diffusion layer formed either around  602   b . As a result, paths  604  for thermal and/or electrical conduction may be formed between the first object  402  and the second object  404 . Further, the paths  604  may pass through the contiguous, plurality of inter-diffusion layers formed around the plurality of inserts  602   a - g.    
     Further, in some embodiments, each of the first object  402 , the second object  404  and the at least one insert  502  may include of a metal, such as Gold. Additionally, the plurality of inter-diffusion layers, such as for example, inter-diffusion layers  504   a - d  in  FIG. 5 , may be homogeneous. 
     Further, in some embodiments, as illustrated in  FIG. 7A , each of the first object  402  and the second object  404  comprise a first metal, such as, for example, Copper. Whereas, the at least one insert  502  may include a second metal, such as, for example, Gold. Accordingly, the plurality of inter-diffusion layers, such as inter-diffusion layers  408 ,  504  and  410  as illustrated in  FIG. 7B  may be heterogeneous. 
     Further, in some embodiments, as illustrated in  FIG. 7C , the first object  402  may include a first metal such as Copper, the second object  404  may include a second metal such as Aluminum and the at least one insert  502  may include a third metal such as Gold. Further, the plurality of inter-diffusion layers, such as inter-diffusion layers  408 ,  504  and  410  as illustrated in  FIG. 7D  may be heterogeneous. 
     Further, in some embodiments, an inter-diffusion layer between the filler material  406  and an object may be formed based on diffusion of particles from the filler material  406  into the object and diffusion of particles from the object into the filler material  406 . Further, the object may be one of the first object  402 , the second object  404  and the at least one insert  502 . 
     Further, in some embodiments, an inter-diffusion layer between the filler material  406  and an object may be formed based on a chemical reaction between the filler material  406  and the object. Further, the object may be one of the first object  402 , the second object  404  and the at least one inserts  502 . 
     Further, in some embodiments, an inter-diffusion layer between the filler material  406  and an object may be formed based on electro-migration between the filler material  406  and the object. Further, the object may be one of the first object  402 , the second object  404  and the at least one inserts  502 . 
     Further, in some embodiments, the at least one insert  502  may be configured to enable a gap within the at least one insert  502  or a gap in between the at least two inserts  502  to reach an edge of at least one of the first object  402  and the second object  404 . Further, the gap allows vapors to travel into a space surrounding at least one of the first object  402  and the second object  404 . 
     Further, in some embodiments, the at least one insert  502  may include a plurality of inserts, such as inserts  802   a  to  802   c  as illustrated in  FIG. 8A . Further, the plurality of inserts  802   a - c  span the space. Further, a first insert, such as insert  802   a , may be proximal to a surface of the first object  402  and the second insert, such as insert  802   c , may be proximal to a surface of the second object  404 . Accordingly, due to the heating, a plurality of inter-diffusion layers  804 ,  806  and  808  may be formed as illustrated in  FIG. 8B . Further, the plurality of inter-diffusion layers  804 ,  806  and  808  may facilitate thermal and/or electrical conduction between the first object  402  and the second object  404 . 
     Further, in some embodiments, the at least one insert  502  may include a plurality of inserts, such as inserts  902   a  to  902   c  as illustrated in  FIG. 9A . Further, the inserts  902   a - c  may be included in the first object  402 . Accordingly, in some instances, the inserts  902   a - c  may be formed on the first object  402  by one or more techniques such as etching, depositing, patterning, contouring and so on. Further, due to the heating, the plurality of inter-diffusion layers  904  and  906  may be formed as illustrated in  FIG. 9B . 
     Further, in some embodiments, the at least one insert  502  may include a plurality of inserts, such as inserts  1002   a  to  1002   c  and  1004   a - 1004   c  as illustrated in  FIG. 10A . Further, the inserts  1002   a  to  1002   c  may be included in the first object  402 . Similarly, the inserts  1004   a  to  1004   c  may be included in the second object  404 . Accordingly, in some instances, the inserts  1002   a  to  1002   c  and  1004   a - 1004   c  may be formed on the first object  402  and the second object  404  respectively by one or more techniques such as etching, depositing, patterning, contouring and so on. Further, due to the heating, the plurality of contiguous inter-diffusion layers  1006  and  1008  may be formed as illustrated in  FIG. 10B . 
     Further, as illustrated in  FIG. 12 , a method  1200  of creating a bond between a first object  402  and a second object  404  according to some embodiments may be provided. The method  1200  may include a step  1210  of filling a space between the first object  402  and the second object  404  with the filler material  406 . Further, the method  1200  may include a step  1220  of placing the at least one insert  502  in the space. Additionally, the method may include a step  1230  of heating the filler material  406  to facilitate formation of a contiguous plurality of inter-diffusion layers. 
     Further, as illustrated in  FIG. 13 , a method  1300  of creating a bond between the first object  402  and the second object  404  according to some embodiments may be provided. The method  1300  may include a step  1310  of forming the at least one insert  502  on at least one of a first object  402  and a second object  404 . Further, the method  1300  may include a step  1320  of filling the space between the first object  402  and the second object  404  with the filler material  406 . Additionally, the method  1300  may include a step  1330  of heating the filler material  406  to facilitate formation of a contiguous, plurality of inter-diffusion layers. 
     Further, as illustrated in  FIG. 14 , a method  1400  of creating a bond between the first object  402  and the second object  404  according to some embodiments may be provided. The method  1400  may include a step  1410  of placing the at least one insert  502  at a location in a space formed between the first object  402  and the second object  404 . Further, the method may include a step  1420  of introducing the filler material  406  proximal to the location. Additionally, the method may include a step  1430  of heating at least one of the at least one insert  502  and the filler material  406 . Further, the heating may facilitate formation of an inter-diffusion layer. Furthermore, a first portion of the inter-diffusion layer may be formed by diffusion between the filler material  406  and the at least one insert  502 . Likewise, a second portion of the inter-diffusion layer may be formed between the filler material  406  and the first object  402 . Additionally, a third portion of the inter-diffusion layer may be formed between the filler material  406  and the second object  404 . Further, the first portion may be contiguous with each of the second portion and third portion. As a result, the first object  402  and the second object  404  may be connected through a contiguous plurality of inter-diffusion layers. 
     Further, as illustrated in  FIG. 15 , a method  1500  of creating a bond between a first object  402  and a second object  404  according to some embodiments may be provided. The method  1500  may include a step of filling a space between the first object  402  and the second object  404  with the filler material  406 . Additionally, the method may include a step of heating the filler material  406  to facilitate formation of an inter-diffusion layer from the first object  402  to the second object  404  by diffusion of the filler material  406  inside a gap between the first object  402  and second object  404 . 
     Further, a method of creating a bond between a first object  402  and a second object  404  according to some embodiments is provided. The method may include a step of filling a space between the first object  402  and the second object  404  with a filler material  406 . Additionally, the method may include a step of heating the filler material  406  to facilitate formation a plurality of inter-diffusion layers. Further, a first inter-diffusion layer  408  may be formed between the filler material  406  and the first object  402 . Further, a second inter-diffusion layer  410  may be formed between the filler material  406  and the second object  404 . 
     Further, in some embodiments, a semiconductor device formed based on one or more methods of the present disclosure is also provided. The semiconductor device may include a semiconductor die and a substrate. Further, the semiconductor die may be attached to the substrate based on a bond formed between a first object  402  comprised in the semiconductor die and second object  404  comprised in the substrate. Further, the bond may be created by a step of filling a space between the first object  402  and the second object  404  with a filler material  406 . Additionally, a step of heating the filler material  406  to facilitate formation a plurality of inter-diffusion layers may be performed. Further, a first inter-diffusion layer  408  may be formed between the filler material  406  and the first object  402 . Further, a second inter-diffusion layer  410  may be formed between the filler material  406  and the second object  404 . Further, the first inter-diffusion layer  408  may be contiguous with the second inter-diffusion layer  410 . 
     Further, in some embodiments, an electronic module formed based on methods of the present disclosure is also provided. The electronic module may include a substrate and at least one chip. Further, a first set of inserts may be placed inside a space between the substrate and the at least one chip. Further, a second set of inserts may be placed inside a space formed by the substrate, the at least one chip and the first set of inserts. Further, diffusion of the second set of inserts occurs into at least one of a space between the substrate&#39;s mating surface and the at least one chip&#39;s mating surface, a gap between the first set of the inserts and the substrate and a gap between the first set of inserts and the at least one chip. Further, the diffusion may result in formation of at least one of a continuous diffusion layer from the substrate to the at least one chip and a continuous diffusion layer from the first set of the inserts to the substrate and a continuous diffusion layer from the first set of the inserts to the at least one chip. 
     The depicted embodiments in the figures are used as examples only. For example, in some embodiments, the vertical inter-diffusion layers may be connected directly to the first object and the second object. In other embodiments, the vertical inter-diffusion layers may only be connected to the first object and the second via the horizontal inter-diffusion layers. It should be understood that, while all variations are possible, the direct connection of the vertical inter-diffusion layers and the first and second objects are preferred. 
     The thermal and/or electrical conduction paths are not limited to the paths shown in figures and also they may also work in the opposite way, for example, by insulating or reducing electrical and/or thermal conduction. 
     Any combination of any of the eight methods above or all of them together can also be used to produce an inter-connection, joint or attachment. Moreover, modifications to the methods above may be possible to product the inter-connection without deviating from the spirit and scope of the present disclosure. 
     While the specification includes examples, the disclosure&#39;s scope is indicated by the following claims. Furthermore, while the specification has been described in language specific to structural features and/or methodological acts, the claims are not limited to the features or acts described above. Rather, the specific features and acts described above are disclosed as example for embodiments of the disclosure. 
     Insofar as the description above and the accompanying drawing disclose any additional subject matter that is not within the scope of the claims below, the disclosures are not dedicated to the public and the right to file one or more applications to claims such additional disclosures is reserved.