CN221304677U

CN221304677U - Electrical connector for electronic components

Info

Publication number: CN221304677U
Application number: CN202322401235.9U
Authority: CN
Inventors: 王缮柏
Original assignee: Advanced Semiconductor Engineering Inc
Current assignee: Advanced Semiconductor Engineering Inc
Priority date: 2023-09-05
Filing date: 2023-09-05
Publication date: 2024-07-09
Anticipated expiration: 2033-09-05

Abstract

The application provides an electric connector of an electronic component, comprising: a connection pad, a bonding pad, and a barrier material; the solder is arranged on the connecting pad, and the solder comprises liquid metal; the barrier material is disposed between the solder and the connection pad and is configured to block diffusion of the liquid metal to the connection pad. According to the application, the blocking material is arranged between the connecting pad and the solder, and the blocking material is used for blocking the diffusion of the liquid metal in the solder, so that the diffusion time of the liquid metal is prolonged, and the metallurgical reaction between the liquid metal and the connecting pad can be slowed down, thereby reducing the consumption of the liquid metal before the connection, and further avoiding the situation that the two electric connecting pieces cannot be connected due to too little liquid metal.

Description

Electrical connector for electronic components

Technical Field

The application relates to the technical field of electric connectors, in particular to an electric connector of an electronic element.

Background

In the process of multiple reflow soldering, if the melting point of the solder in the last reflow soldering is higher than that in the previous reflow soldering, the previous solder point will be melted when the last reflow soldering is performed. Therefore, there is a proposal to form a eutectic layer with a high temperature melting point after the solder of the previous reflow soldering is subjected to the reflow soldering process, and the melting point of the eutectic layer is higher than that of the solder of the next reflow soldering to solve the foregoing problems.

Gallium (Ga) has a melting point (about 29 ℃) near room temperature and is in a liquid state at 29 ℃ or higher. Ga is easy to react metallurgically with other metals at low temperature, and is nontoxic, and can be used as a low-temperature welding material. Ga can react with Sn and Cu at room temperature to generate eutectic layers such as Sn-3Ga with a melting point of 230 ℃ and CuGa ₂ with a melting point of 550 ℃ and the like, and the eutectic layers are used as connecting pieces between welding pads.

Therefore, ga can be used as a bonding material to be disposed on the Cu pad, so that Ga reacts with Sn or Cu to form a eutectic layer (CuGa ₂ or Sn-3 Ga) with a high temperature melting point, so as to solve the problem that a solder joint formed by the previous reflow in the multiple reflow processes may be melted during the subsequent reflow.

However, ga diffuses very rapidly and reacts easily with other metals, and even at room temperature, it reacts with metals such as Cu and Sn.

Referring to fig. 1, fig. 1 is a schematic diagram showing a conventional structure of an electrical connector 20 with liquid metal. As shown in fig. 1, the electrical connector 20 includes Cu pads 21, sn solders 22, and Ga metal 23. The Sn solder 22 is interposed between the Ga metal 23 and the Cu pad 21. The contact surface between Ga and Sn spontaneously reacts at room temperature to form tin-gallium alloy 25. Most of the Ga, however, reacts with Cu by diffusion through Sn to produce eutectic layer 24 (i.e., cuGa ₂),CuGa₂ is not available for subsequent bonding).

It can be seen that the Ga metal 23 disposed on the Cu pad 21 is largely consumed by reacting with the Cu pad 21 to form CuGa ₂. This results in too little Ga metal 23 remaining on the Cu pads 21, which in turn results in two Cu pads 21 being too small to be bonded due to too little Ga metal 23 in the subsequent bonding process.

Referring to fig. 2, fig. 2 is a schematic diagram showing the actual process of the conventional electrical connector 20 with liquid metal. In fig. 2, schematic diagrams of 0 minutes, 10 minutes, 40 minutes and 120 minutes after the Ga metal 23 is disposed on the Sn solder 22 on the Cu pad 21 are shown from left to right, respectively, and it can be seen that Ga is mostly consumed at 10 th minute.

Therefore, how to slow down the metallurgical reaction of the Ga metal 23 and the Cu pad 21 is a technical problem to be solved.

Disclosure of utility model

The application provides an electric connector of an electronic element.

In a first aspect, the present application provides an electrical connector for an electronic component, comprising: a connection pad; solder disposed on the connection pads, the solder comprising a liquid metal; a barrier layer disposed between the solder and the connection pad, configured to block diffusion of the liquid metal to the connection pad.

In some alternative embodiments, the barrier layer is alloyed with the solder or intermetallic compound.

In some alternative embodiments, the solder comprises tin.

In some alternative embodiments, the solder is an alloy of tin and the liquid metal.

In some alternative embodiments, the solder is an intermetallic compound of tin and the liquid metal.

In some alternative embodiments, the barrier layer has a melting point that is higher than the melting point of the solder.

In some alternative embodiments, the barrier layer has a melting point greater than 900 ℃.

In some alternative embodiments, the barrier layer is an intermetallic compound.

In some alternative embodiments, the barrier layer is a metal.

In some alternative embodiments, the barrier layer is an alloy containing the solder and the connection pad material.

In some alternative embodiments, the liquid metal is gallium or indium.

In some alternative embodiments, the barrier material is nickel or Cu ₆Sn₅.

In order to solve the technical problem that Ga metal is easy to diffuse at room temperature and reacts with a Cu welding pad, so that the bonding is influenced by a large amount of consumption, the application provides an electric connecting piece of an electronic element.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the accompanying drawings in which:

FIG. 1 is a schematic illustration of a prior art electrical connection with liquid metal in a construction change;

FIG. 2 is a schematic illustration of a practical process for making an electrical connection with liquid metal in the prior art;

FIG. 3 is a schematic view of the structure of one embodiment of an electrical connector of an electronic component according to the present application;

FIG. 4 is a schematic illustration of a structural variation of an electrical connector of an electronic component according to the present application;

Fig. 5 is a schematic diagram of a practical process of an electrical connection of an electronic component according to the application.

Reference numerals/symbol description:

11-connection pads; 12-solder; 13-base solder; 14-liquid metal; 15-a barrier layer; 21-Cu bonding pads; 22-Sn solder; 23-Ga metal; 24-eutectic layer; 25 tin gallium alloy.

Detailed Description

The following description of the embodiments of the present application will be given with reference to the accompanying drawings and examples, and it is easy for those skilled in the art to understand the technical problems and effects of the present application. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant application and are not limiting of the application. In addition, for convenience of description, only parts related to the relevant application are shown in the drawings.

It should be readily understood that the meanings of "on", "above" and "above" in the present application should be interpreted in the broadest sense so that "on" means not only "directly on" but also "on" including intermediate components or layers that exist therebetween.

Further, spatially relative terms, such as "below," "under," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or component's relationship to another element or component as illustrated in the figures. In addition to the orientations depicted in the drawings, the spatially relative terms are intended to encompass different orientations of the device in use or operation. The device may be otherwise oriented (rotated 90 ° or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The term "layer" as used herein refers to a portion of material that includes regions having a certain thickness. The layers may extend over the entire underlying or overlying structure, or may have a degree less than the extent of the underlying or overlying structure. Furthermore, the layer may be a region of homogeneous or heterogeneous continuous structure having a thickness less than the thickness of the continuous structure. For example, the layer may be located between the top and bottom surfaces of the continuous structure or between any pair of horizontal planes therebetween. The layers may extend horizontally, vertically and/or along a tapered surface. The substrate (substrate) may be a layer, may include one or more layers therein, and/or may have one or more layers thereon, and/or thereon. One layer may comprise multiple layers. For example, the semiconductor layer may include one or more doped or undoped semiconductor layers, and may have the same or different materials.

The term "substrate" as used herein refers to a material to which subsequent layers of material are added. The substrate itself may be patterned. The material added to the top of the substrate may be patterned or may remain unpatterned. In addition, the substrate may include a variety of semiconductor materials such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide, and the like. Alternatively, the substrate may be made of a non-conductive material, such as glass, plastic, or sapphire wafer, or the like. Further alternatively, the substrate may have a semiconductor device or a circuit formed therein.

It should be noted that, the structures, proportions, sizes, etc. shown in the drawings are only used for being matched with those described in the specification for understanding and reading, and are not intended to limit the applicable limitation of the present application, so that the present application has no technical significance, and any modification of structures, changes in proportions or adjustment of sizes, without affecting the efficacy and achievement of the present application, should still fall within the scope covered by the technical content disclosed in the present application. Also, the terms "upper", "first", "second", and "a" and the like are used herein for descriptive purposes only and are not intended to limit the scope of the application for which the application may be practiced, but rather for relative changes or modifications without materially altering the technical context.

It should be further noted that, in the embodiment of the present application, the corresponding longitudinal section may be a section corresponding to a front view direction, the corresponding transverse section may be a section corresponding to a right view direction, and the corresponding horizontal section may be a section corresponding to an upper view direction.

In addition, the embodiments of the present application and the features in the embodiments may be combined with each other without collision. The application will be described in detail below with reference to the drawings in connection with embodiments.

Referring to fig. 3, fig. 3 is a schematic structural view of one embodiment of an electrical connector of an electronic component according to the present application. As shown in fig. 3, the electrical connector of the electronic component of the present application includes:

A connection pad 11;

Solder 12 disposed on the connection pads 11, the solder 12 including a liquid metal 14, and further, the solder 12 may further include a base solder 13;

A barrier layer 15, disposed between the solder 12 and the connection pad 11, is configured to block diffusion of the liquid metal 14 to the connection pad 11.

Here, the connection pad 11 includes, but is not limited to, a Cu pad made of copper (Cu). The connection pad 11 may be a connection pad located on a surface of an electronic component such as a substrate or a chip. The connection pad 11 is Cu as an example.

Here, the base solder 13 includes, but is not limited to, tin (Sn), tin-silver alloy (SnAg), or the like. Hereinafter, the base solder 13 is described by taking Sn as an example.

Here, the liquid metal 14 includes, but is not limited to, gallium (Ga) or Indium (In) or an alloy thereof. The liquid metal 14 is hereinafter described by taking Ga as an example.

Here, the barrier layer 15 may be composed of a barrier material to block diffusion of the liquid metal 14.

In some alternative embodiments, the barrier material may be selected from a higher melting point material, such as a higher melting point metallic material. When selecting the metal material, metals that will react with the liquid metal 14, such as aluminum and copper, are excluded, and metals that will not react with the liquid metal 14, such as W (tungsten), rh (rhodium), mo (molybdenum), nb (niobium), V (vanadium), cr (chromium), ti (antimony), pd (palladium), co (cobalt), ni (nickel), au (gold), ag (silver), fe (iron), zr (zirconium), pt (platinum), etc., are selected.

In some alternative embodiments, the barrier material has a melting point that is higher than the melting point of the solder 12.

In some alternative embodiments, the blocking material has a melting point greater than 900 ℃.

In some alternative embodiments, the barrier material may be a metal alloy material in addition to a pure metal material, for example, an alloy containing the solder 12 and the material of the connection pad 11, such as Cu ₆Sn₅.

In some alternative embodiments, the barrier material may be selected from a metallic material that can be formed on the connection pad 11 by electroplating for ease of fabrication.

In some alternative embodiments, the process of manufacturing the electrical connector of the electronic component of the present application may include: forming Cu pad (copper pad) as the connection pad 11; next, a barrier material is disposed on the exposed surface of the connection pad 11 to form a barrier layer 15, which may be formed by electroplating, electroless plating, heat treatment, or the like; next, sn is disposed on the barrier material to form a base solder 13, such as, but not limited to, electroplating; next, ga is disposed on the Sn surface to form the liquid metal 14, which includes but is not limited to electroplating.

Here, by providing a barrier material between the connection pad 11 and the solder 12 as the barrier layer 15, diffusion of the liquid metal 14 in the solder 12 is blocked by the barrier material, so that the time of diffusion of the liquid metal 14 is prolonged, so that the metallurgical reaction time of the liquid metal 14 and the connection pad 11 is lengthened, and thus, the waiting time (Q-time) allowed between the process arrangements can be lengthened, which is not as urgent as the prior art shown in fig. 1, thereby making it possible to perform bonding between the connection pads 11 with the liquid metal 14. Compared with the prior art, the consumption of the liquid metal 14 before the bonding is effectively reduced, and enough liquid metal 14 can be remained for bonding, so that the situation that the two electric connectors cannot be bonded due to too little liquid metal 14 can be avoided.

Referring to fig. 4, fig. 4 is a schematic diagram showing a structure of an electrical connector of an electronic component according to the present application. As shown in fig. 4, after the barrier material is disposed on the solder 12 on the connection pad 11 as the barrier layer 15, the barrier material diffuses to react with other parts of the electrical connector, and depending on the materials selected for the barrier layer 15, the liquid metal 14, the base solder 13, the connection pad 11, etc., the final structure of the electrical connector of the electronic component of the present application may be three after waiting for the reaction for a certain period of time to stabilize the structure, as shown in A, B and C in fig. 4. The following description will be given separately.

Structure A

Here, the barrier material remains in place as a barrier layer 15.

Here, the base solder 13 and the liquid metal 14 in the solder 12 may form an alloy such as a tin-gallium alloy, or may form an intermetallic compound (INTERMETALLIC COMPOUND, IMC).

(II) Structure B

Here, the barrier material forms an intermetallic compound with a part of the connection pads 11 and/or a part of the solder 12 as a barrier layer 15 between the remaining connection pads 11 and the remaining solder 12. That is, the barrier layer 15 may be an intermetallic compound of a barrier material with a portion of the connection pad 11 and/or a portion of the solder 12.

(III) Structure C

Here, the barrier material is alloyed into the solder 12 in the form of an alloying element, and is combined with the solder 12 as an alloy or intermetallic compound. In other words, the final solder 12 may be an alloy or intermetallic compound of the combination of the liquid metal 14 and the base solder 13 and the barrier material. The final solder 12 is provided on the connection pads 11 without a separate barrier layer 15 in between. It will be appreciated that although eventually there is no separate barrier layer 15, diffusion of the liquid metal 14 to the connection pad 11 is still prevented due to the combination of the barrier material with the liquid metal 14 and the base solder 13 as an alloy or intermetallic compound.

Referring to fig. 5, fig. 5 is a schematic diagram showing a practical process of an electrical connector of an electronic component according to the present application. In fig. 5, schematic diagrams of 0 minutes, 10 minutes, 40 minutes, and 120 minutes after the liquid metal 14 is disposed on the base solder 13 are shown from left to right, respectively. It can be seen that the liquid metal 14 remains substantially undisturbed at 10 minutes, without diffusion; at 40 minutes, there is little diffusion of the liquid metal 14; the liquid metal 14 is not consumed in large amounts by diffusion and reaction until 120 minutes. Therefore, the reaction time between the liquid metal 14 and the connection pad 11 can be prolonged by more than 1000% by the barrier layer 15, so that the liquid metal 14 is not consumed in a large amount in the normal process.

While the application has been described and illustrated with reference to specific embodiments thereof, the description and illustration is not intended to limit the application. It will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof within the embodiments thereof without departing from the true spirit and scope of the application as defined by the appended claims. The illustrations may not be drawn to scale. There may be a distinction between technical reproduction and actual implementation in the present application due to variables in the manufacturing process, etc. Other embodiments of the application not specifically illustrated may exist. The specification and drawings are to be regarded in an illustrative rather than a restrictive sense. Modifications may be made to adapt a particular situation, material, composition of matter, method or process to the objective, spirit and scope of the present application. All such modifications are intended to fall within the scope of the claims appended hereto. Although the methods disclosed herein have been described with reference to particular operations being performed in a particular order, it should be understood that these operations may be combined, sub-divided, or reordered to form an equivalent method without departing from the teachings of the present disclosure. Thus, the order and grouping of the operations is not a limitation of the present application unless specifically indicated herein.

Claims

1. An electrical connector for an electronic component, comprising:

A connection pad;

The solder comprises a base solder and a liquid metal, wherein the base solder is arranged on the connecting pad, and the liquid metal is arranged on the base solder;

A barrier layer disposed between the solder and the connection pad, configured to block diffusion of the liquid metal to the connection pad;

the barrier layer is alloyed with the solder or intermetallic compound;

the melting point of the barrier layer is higher than the melting point of the solder and higher than 900 ℃;

The barrier layer is an intermetallic compound.

2. The electrical connector of electronic components of claim 1, wherein the base solder is tin or a tin silver alloy.

3. The electrical connector of electronic components of claim 2, wherein the liquid metal is gallium or indium.

4. The electrical connector of claim 2, wherein the connection pad is copper.

5. An electrical connector for an electronic component, comprising:

A connection pad;

A solder arranged on the connection pad, wherein the solder is a tin-gallium alloy, or the solder is an intermetallic compound of tin and gallium, or the solder is an intermetallic compound of tin and indium;

A barrier layer disposed between the solder and the connection pad configured to block diffusion of gallium or indium to the connection pad, the barrier layer having a melting point greater than 900 ℃.

6. The electrical connector of electronic components of claim 5, wherein the barrier layer has a melting point that is higher than a melting point of the solder.

7. The electrical connector of claim 5, wherein the barrier layer is an intermetallic compound.

8. The electrical connector of claim 5, wherein the barrier layer is metal.

9. The electrical connector of electronic components of claim 5, wherein the barrier layer is a metal alloy.

10. The electrical connector of electronic components of claim 5, wherein the barrier layer is nickel or Cu6Sn5.