WO2019184768A1

WO2019184768A1 - Separable type conductive contact structure and preparation method therefor

Info

Publication number: WO2019184768A1
Application number: PCT/CN2019/078745
Authority: WO
Inventors: 王琎
Original assignee: 北京齐碳科技有限公司
Priority date: 2018-03-26
Filing date: 2019-03-19
Publication date: 2019-10-03
Also published as: CN110364539A; CN110364539B

Abstract

The present invention provides a separable type conductive contact structure and a preparation method therefor. Conductive interconnection which is repeatedly pluggable is realized by means of a contact surface of a suspended flexible conductive metal thin film and a conductive protrusion, and repeatable plugging of a vertical interconnection structure can be realized while high integration density is met, thereby realizing repeated use of expensive devices such as a VLSI signal processing circuit chip, and reducing consumable costs.

Description

Separable conductive contact structure and preparation method thereof

Technical field

The invention belongs to the field of electronic device preparation, and in particular relates to a separable conductive contact structure and a preparation method thereof.

Background technique

The vertical interconnection of large array electronic devices has been widely used in image sensor and multi-chip interconnection. In recent years, there are also potential requirements for large array biosensors, such as gene sequencing. In these applications, in addition to large arrays of electronic signal processing circuits, there is a need to build a one-to-one array of biological fluid chips, such as Ion Torron's ISFET chips. The usual method is to construct a fluid chip structure on the upper layer of a signal processing chip made of VLSI (Very Large Scale Integration), so that the process of the upper fluid structure is compatible with the VLSI process, and the array density is also matched. At present, the fluid chip of the biosensor needs to use special materials, such as biomaterials, carbon nanotubes and the like, so that the array density cannot be matched. In this case, the biosensor is usually manufactured in two parts: a signal amplification-processing chip obtained by a large-scale integrated circuit fabrication process (VLSI), and a sensing interface requiring a special fabrication method using a special material. The chip finally connects two or more chips through vertical interconnection to achieve the purpose of sensing. This has the advantage of avoiding excessive post-processing of non-VLSI technology on an expensive VLSI chip and making full use of the VLSI chip area to achieve a reduction in manufacturing cost. For example, the nanopore gene sequencer introduced by Oxford Nanopores in the United Kingdom separates the large array of nanopore fluid chips from the signal detection circuit chips and then combines them by vertical interconnection.

The vertical interconnection of prior art electronic components is generally: spring type probe (pogo pin), wire insertion, wire bonding, flip-chip bonding, solder ball bonding. Wait. However, in these methods, spring-type probes and patch cords can be separated and re-inserted, but the size is usually large, and high-density integration cannot be achieved; flip-chip bonding, solder ball bonding, etc. can increase the integration density, but For one-time interconnection, it is impossible to re-plug. In sensors or some other applications, the upper sensor chip has a short service life, or should be the principle of avoiding cross-contamination in medical treatment, and is a disposable consumable. If the one-time interconnection method is used, it means that the interconnected VLSI signal processing circuit chip will be discarded after being used once, which greatly increases the cost of consumables.

Summary of the invention

In view of the above, the present invention provides a detachable conductive contact structure and a preparation method thereof, which can realize re-pluggable conductive interconnection by suspending a flexible conductive metal film and a conductive protrusion contact surface, and can realize a high integration density while achieving The vertical interconnection structure can be repeatedly inserted and removed, thereby realizing the repeated use of some expensive devices such as a VLSI signal processing circuit chip, thereby effectively reducing the cost of consumables.

In order to achieve the above object, the technical solution of the present invention is as follows:

A separable conductive contact structure comprising a recessed structure and a convex contact body matched with the recessed structure, the upper layer component achieving a separable conductive connection through the recessed structure and the contact body and the lower layer component; the contact body It is a conductor or semiconductor contact.

Further, as one embodiment of the present invention, the upper layer member or the lower layer member is provided with a conductive layer, and the conductive layer is provided with a recessed structure, and the contact body is electrically connected to the upper layer device or the lower layer member through the conductive layer to realize electrical property. connection.

Further, as another embodiment of the present invention, a vertical wire layer and a conductive layer are further included, the conductive layer covers the recess structure, and the contact body can be pressed by the ductility of the conductive layer itself. Contacting; the conductive layer is electrically interconnected with the vertical wire layer, and the upper layer component is electrically connected to the lower layer component through the conductive layer and the vertical wire layer.

Further, a substrate layer and a spacer layer are sequentially formed on the upper layer member or the lower layer member, and the recess layer is formed in the spacer layer through the via hole.

Further, the spacer layer is further loaded with a flexible diaphragm layer, and the conductive layer is formed on the flexible diaphragm layer to be electrically interconnected with the vertical lead layer; the substrate layer, the spacer layer and the flexible diaphragm layer are vertically formed through the formation layer. The vertical wire layer is electrically connected to the upper layer member or the lower layer member.

Further, a method of directly adhering the ductile conductive film to cover the recessed structure of the spacer layer forms the conductive layer; the substrate layer and the spacer layer are sequentially vertically penetrated to form the vertical lead layer, and the upper layer member or the lower layer member Electrical connection. Further, a substrate layer is formed on the upper layer member or the lower layer member, and the recessed structure is formed by opening a hollow structure in the substrate layer, and a vertical wiring layer is formed through the substrate layer.

Further, a substrate layer is formed on the upper layer member or the lower layer member, the recessed structure is formed in the substrate layer opening hole, and metal is plated inside the recessed structure as a vertical wiring layer and the upper layer member or the lower layer member interconnected.

Further, the substrate layer is further loaded with a flexible diaphragm layer, and the conductive layer is formed on the flexible diaphragm layer to be electrically interconnected with the vertical wiring layer.

Further, a method of directly adhering the ductile conductive film covers the recessed structure of the substrate layer to form the conductive layer.

Further, as a preferred embodiment of the present invention, the flexible diaphragm layer or the conductive layer may be opened, and the opening shape is circular, circular, square, polygonal or polygonal.

The invention also provides a preparation method of a separable conductive contact structure, which comprises the following steps:

Step 1: Preparation of the contact surface of the upper part

(1) forming a vertical wire layer in a vertical through hole made of a substrate layer and a spacer layer as an interconnection substrate, and then performing a spacer layer hole in the vicinity of the vertical wire layer to form a recessed structure;

(2) punching a flexible diaphragm layer through a flexible circuit board technology, aligning and adhering to the vertical wiring layer, and covering the recessed structure;

(3) plating metal on the vertical wire layer to form a vertical interconnecting wire;

(4) forming a conductive layer on the flexible diaphragm layer, and forming a metal contact piece on the suspension flexible diaphragm layer corresponding to the recessed structure portion by etching, and further forming a link metal contact piece and the vertical wire a metal line between the layers.

Step 2: Preparation of contact surface of the lower part

The protruding contact body is formed by ball implantation or screen printing-melting.

Step 3: Contact

The lower contact body is aligned with the recess structure of the upper layer with the metal contact piece by a predetermined alignment structure, and is pressed together, and the contact body is pressed into the recess structure to form a conductive interconnection. The beneficial effects of the present invention are:

(1) Reproducible conductive contacts can be realized, and larger and smaller pitch interconnections can be achieved with respect to other pluggable contacts, providing parallelism of interconnection.

(2) The suspended flexible conductive film surface and the conductive convex surface can be realized by PCB process or micro-machining process, which is a mature and achievable structure. At the same time, the suspended flexible film has a bendable shape and can be guaranteed The convex surface of the contact has a certain pressing distance, so it is more uniform in the case of a large array and a large area, and it can ensure that the contact points at different positions have better conductive contact. Therefore, both of these structures can achieve higher density integration under the prior art level, and can meet the requirements of large array vertical integration.

(3) The present invention can be repeatedly inserted and removed, thereby realizing the detachable structure of the low-cost upper layer sensor chip and the lower layer expensive chip, thereby realizing repeated use of some expensive devices such as a VLSI signal processing circuit chip, thereby effectively reducing the cost of consumables.

DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from

1 is a schematic view of a separable conductive contact structure provided by the present invention;

Figure 2 is a first embodiment of a flexible membrane layer provided by the present invention;

Figure 3 is a second embodiment of a flexible membrane layer provided by the present invention;

Figure 4 is a third embodiment of a flexible membrane layer provided by the present invention;

5 is a separable conductive contact structure of a hollow substrate layer in the case of opening a conductive layer provided by the present invention;

6 is a separable conductive contact structure of a hollow substrate layer in which a conductive layer is not opened according to the present invention;

Figure 7 is a schematic view showing the comparison of the strip-shaped conductive layer in the open and non-opened flexible diaphragm layers;

Figure 8 is a large-scale interconnected array structure of the present invention;

9 is a method for preparing a separable conductive contact structure provided by the present invention;

detailed description

The invention is described below based on the examples, but the invention is not limited to only these examples.

Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, the example embodiments may be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and the exemplary embodiments will be fully conveyed by those skilled in the art. The same reference numerals will always be used to refer to the same elements.

It will also be understood that when an element is referred to as "between" or "in" An element, or an intermediate element. In contrast, when an element is referred to as “directly,” “directly. In addition, unless otherwise specified, the term "interconnect" as used in the present invention refers to an interconnected structure formed by electronic devices interconnected by interconnecting materials, components, interconnection processes, connection methods, and interconnection systems. The terms "upper", "lower", "bottom" and the like are used to describe the embodiments of the present invention, and are not intended to limit the scope of the present invention. It is easy to change the orientation by flipping and other operations on this basis.

The invention provides a separable conductive contact structure, comprising a recessed structure and a convex contact body matched with the recessed structure, and the upper layer component realizes a separable conductive connection through the recessed structure and the contact body and the lower layer component. The contact body referred to in the present invention is a conductor or a semiconductor conductive contact surface, such as a metal, graphene, carbon nanotube, etc., and other semi-metals and semiconductors having a certain conductivity.

In order to achieve the separable conductive contact effect of the present invention, the upper layer device or the interconnecting bottom is provided with a recessed structure, and the lower substrate/device or the upper side of the interconnect is provided with a convex contact body matched with the recessed structure, and the recessed structure and the contact body are inserted and removed. The connection and separation of the upper device or interconnect to the underlying substrate/device or interconnect is achieved. Or conversely, a protruding contact body is provided on the upper device or the interconnecting bottom, and a recessed structure is provided on the lower substrate/device or interconnect upper side. The present invention has been described for convenience of description, and only the former is described as an example.

Further, as a first embodiment of the present invention, as shown in FIG. 1, a conductive interconnecting vertical wiring layer and a conductive layer are provided, and the vertical wiring layer is passed through the via layer on the upper layer device or the interconnected bottom substrate layer or the upper layer device or Interconnected electrical connections. The upper device or interconnect is electrically connected through a vertical wire layer, a conductive layer to the underlying substrate/device or interconnect. The substrate layer can adopt various existing material substrate structures, such as a PCB substrate, and can be vertically perforated to form a vertical wire layer; or a silicon substrate can be used to form a vertical wire layer by using a through-silicon interconnection; or A glass substrate is formed by a glass interposer to form a vertical wiring layer.

The recessed structure is formed in the vicinity of the vertical conductive layer. Specifically, the recessed structure may be formed by adding a spacer layer under the substrate layer, and then forming a recessed structure in the spacer layer by etching or deposition. The spacer layer material may be combined with the substrate. The layers may be the same or different; or the recessed structure may be formed directly by etching on the substrate layer.

The lower side of the recessed structure of the embodiment is further covered with a flexible diaphragm layer having a thickness of 1 nm to 100 um. The diaphragm material may be a two-dimensional material such as graphene, or a polymer film such as polyimide, or a metal film such as Au. The membrane may be electrically conductive or non-conductive.

The flexible membrane layer can be formed by a flexible printed circuit board FPC technology to load a layer of polyimide film under the spacer layer; or a layer of curable dry film photoresist can be loaded by a dry film. Dry film photoresists such as ADEX, TMMF. A conductive layer may be formed on the flexible diaphragm layer by deposition etching or the like to form an electrical interconnection with the vertical wiring layer. The conductive layer may be formed by a method of meteorological deposition, liquid deposition or solid-state conductive film adhesion, and then forming an interconnection structure with the vertical wiring layer by etching, or forming the above interconnection by metal stripping.

Further, as a second embodiment of the present invention, a conductive layer is formed on the bottom of the recessed structure of the spacer layer by using a method of directly adhering the conductive film without using a flexible diaphragm layer, and the ductile conductive film may be Cu. Au, Ag, Pt, etc., may also be materials such as graphene, carbon nanotube film, and conductive polymer.

Further, as a third embodiment of the present invention, as shown in FIG. 5, the recessed structure is a hollow structure formed directly in the substrate layer, and is plated with metal inside the recessed structure and directly covered at the bottom thereof. The open-cell conductive layers are electrically interconnected. Alternatively, the conductive layer is a complete conductive layer as shown in FIG.

The conductive layer of the present invention may be linear, mesh or continuous film; it may cover the recessed structure completely, or may cover only a part, for example, a strip covering the edge or the middle. On the basis of the above structure, the press-fit contact is achieved by the ductility of the conductive layer itself.

The contact body of the present invention may be a spherical shape, a cube or the like, and is in contact with the conductive layer suspended at the bottom of the concave structure, and any shape capable of realizing the detachable insertion and extraction effect of the concave structure and the corresponding convex contact body is The scope of protection of the present invention. The contact body can deform the upper conductive film by applying a certain contact force, and the reliability of the contact is ensured.

The substrate layer referred to in the present invention is a PCB, a silicon wafer, a quartz, a glass or a III-V wafer.

Further, as a preferred embodiment of the present invention, the flexible diaphragm layer or the conductive layer is opened, and the shape of the opening may be circular, circular, and may be a square/polygon or a polygon such as a cross. In order to improve compressibility and elasticity, the plasticity in compression deformation is greater and more flexible. In addition, the flexible diaphragm layer opening manner may be the same as the bottom conductive layer opening aperture as shown in FIG. 2; or as shown in FIG. 3, larger than the bottom conductive layer opening aperture; or as shown in FIG. Opening aperture. Figure 7 is a schematic view showing the comparison of the strip-shaped conductive layer in the open and non-apert flexible diaphragm layers.

The above structure of the invention can realize the re-pluggable conductive contact, and can realize the interconnection of larger scale and smaller spacing than other pluggable contacts, provide parallelism of interconnection, and can realize large array size. Scale interconnection, as shown in Figure 8.

The upper structure and the lower structure shown in Figures 1-8 of the present invention are interchangeable and are not limited to the upper and lower relative positions of the illustration.

The invention also provides a method for preparing a separable conductive contact body, as shown in FIG. 9, wherein the substrate layer and the spacer layer are both PCB substrates, the flexible diaphragm layer is a PI film (ie, a polyimide film), a vertical wire layer and a conductive layer. The layers are all made of Cu. Proceed as follows:

Step 1: Preparation of the upper contact surface

1) forming a vertical wire layer in a vertical through hole formed in a PCB substrate layer and a spacer layer as an interconnection substrate, and then performing a spacer layer hole in the vicinity of the vertical wire layer to form a recessed structure;

2) by a flexible circuit board FPC technology, a PI film (thickness of 20um or less) is perforated, aligned and adhered to the vertical wire layer, and covers the recessed structure;

3) plating copper on the vertical wire layer to form a vertical interconnecting wire;

4) forming a conductive film layer, such as a Cu conductive layer, on the PI film by covering or depositing (meteorological or electroplating), and forming Cu contact on the suspended PI film corresponding to the recessed structure portion by etching The sheet, in turn, forms a metal Cu line between the linked Cu contact strip and the vertical wire layer.

Step 2: Preparation of the lower contact surface

Solder balls or molten gold balls are formed by processes such as ball placement, screen printing-melting or photolithography-plating.

Step 3: Contact

The lower metal ball is aligned with the concave structure with the Cu contact piece on the upper layer through a preset alignment structure, and is pressed together to press the metal ball into the concave structure to form a conductive interconnection.

The PCB substrate layer can be replaced by glass or silicon wafer. In step 2, step 2) uses Through silicon interposer or glass interposer technology to form a conductive connection through the substrate, and the corresponding recess structure can be patterned by dry film photoresist. Thick photoresist patterning, photolithography-dry etching or photolithography-wet etching to form a recessed structure on the corresponding surface of the substrate.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Further, various modifications and changes can be made thereto. Any modifications, equivalents, improvements, etc. made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

A separable conductive contact structure, comprising: a recessed structure and a convex contact body matched with the shape of the recessed structure, wherein the upper layer component or the lower layer component respectively passes through the recessed structure and the contact body and the corresponding lower layer The component or the upper component achieves a separable electrically conductive connection; the contact body is a conductor or a semiconductor contact.
A separable conductive contact structure according to claim 1, further comprising a vertical wiring layer and a conductive layer, said conductive layer covering said recessed structure, and being realized by ductility of the conductive layer itself The contact body may be pressed into contact; the conductive layer is electrically interconnected with the vertical wire layer, and the upper layer member is electrically connected to the lower layer member through the conductive layer and the vertical wire layer.
The separable conductive contact structure according to claim 2, wherein a substrate layer and a spacer layer are sequentially formed on the upper layer member or the lower layer member, and the substrate layer is not formed in the spacer layer through the via hole Concave structure.
A separable conductive contact structure according to claim 3, wherein said spacer layer is further loaded with a flexible diaphragm layer, said conductive layer being formed on said flexible diaphragm layer, electrically interconnected with the vertical conductor layer The substrate layer, the spacer layer, and the flexible separator layer are vertically formed to form the vertical wire layer, and are electrically connected to the upper layer member or the lower layer member.
The detachable conductive contact structure according to claim 3, wherein the method of directly adhering the ductile conductive film covers the recessed structure of the spacer layer to form the conductive layer; the substrate layer and the spacer layer are in turn The vertical wire layer is formed vertically to be electrically connected to the upper layer member or the lower layer member.
The separable conductive contact structure contact body according to any one of claims 2 to 5, characterized in that the conductive layer is opened, and the opening shape is circular, circular, square, polygonal or polygonal.
The separable conductive contact structure according to claim 2, wherein a substrate layer is formed on the upper layer member or the lower layer member, and the recessed structure is formed in the substrate layer by a hollow structure, and the substrate is penetrated The layers form a vertical wire layer.
A separable conductive contact structure according to claim 2, wherein a substrate layer is formed on said upper layer member or a lower layer member, said recessed structure is formed in said substrate layer opening hole, and said recess is formed The metallization inside the structure is electrically interconnected as a vertical wire layer with the upper or lower layer components.
A separable conductive contact structure according to claim 7 or 8, wherein the substrate layer is further loaded with a flexible diaphragm layer, and the conductive layer is formed on the flexible diaphragm layer, and the vertical wiring layer Electrical interconnection.
The separable conductive contact structure contact body according to claim 9, wherein the flexible diaphragm layer and the conductive layer are both opened, and the opening shape is circular, circular, square/polygonal or Polygon.
A separable conductive contact structure according to claim 7 or 8, wherein the conductive layer is formed by covering the recessed structure of the substrate layer by directly adhering the ductile conductive film.
The separable conductive contact structure contact body according to claim 11, wherein the conductive layer is uniformly opened, and the opening shape is circular, circular, square/polygonal or polygonal.
A method of fabricating a separable conductive contact structure according to claim 1, comprising the steps of:

Step 1: Preparation of the contact surface of the upper part

(1) forming a vertical wire layer in a vertical through hole made of a substrate layer and a spacer layer as an interconnection substrate, and then performing a spacer layer hole in the vicinity of the vertical wire layer to form a recessed structure;

(2) punching a flexible diaphragm layer through a flexible circuit board technology, aligning and adhering to the vertical wiring layer, and covering the recessed structure;

(3) plating metal on the vertical wire layer to form a vertical interconnecting wire;

(4) forming a conductive layer on the flexible diaphragm layer, and forming a metal contact piece on the suspension flexible diaphragm layer corresponding to the recessed structure portion by an etching or stripping process, and further forming a link metal contact piece and a metal line between the vertical wire layers.

Step 2: Preparation of contact surface of the lower part

The convex contact body is formed on the lower layer member.

Step 3: Contact

The contact layer of the lower layer is aligned with the recessed structure of the upper layer with the metal contact piece by a predetermined alignment structure, and is pressed together, and the contact body is pressed into the recessed structure to form a conductive interconnection.