Planar electrode and wire leading method thereof

Abstract

The invention belongs to the technical field of MEMS, and relates to a planar electrode and a wire leading method thereof.The planar electrode comprises a base body, an electrode layer, a wire and a wiring groove, the wiring groove comprises a first fixing section, a conductive section and a second fixing section, the first fixing section and the second fixing section are arranged on the side, away from the electrode, of the base body, and the conductive section is arranged on the side, used for arranging the electrode, of the base body; a first through hole and a second through hole which are communicated with the first fixed section and the second fixed section are respectively formed in two ends of the conductive section, and one end, far away from the first through hole, of the first fixed section penetrates out of the base body; the wire penetrates into the first fixing section, the conductive section through the first through hole and the second fixing section through the second through hole, the other end of the wire penetrates out of the base body in the direction, away from the first through hole, of the first fixing section to serve as a lead connector, and filler is arranged in the conductive section. The electrode layer covers the position of the conductive section part to conduct the electrode layer, or a conductive layer used for conducting the electrode layer covers the electrode layer, and the conductive layer covers the position of the conductive section part to conduct the electrode layer.

Description

Technical Field

[0001] The invention belongs to the technical field of MEMS and relates to a planar electrode and a lead method thereof. Background Art

[0002] In the field of MEMS (micro-electromechanical systems) packaging technology, lead packaging is a key step in connecting MEMS sensors or actuators to external circuits. Traditional lead solutions include wire bonding, welding, and dispensing. Although these methods have been widely recognized in practical applications, they have significant limitations in certain application scenarios.

[0003] Wire bonding is achieved by connecting metal wires (wires) to pre-prepared bonding points on the chip. This method requires additional processing steps to prepare the bonding points, and the metal wires themselves have a certain thickness, so it will significantly increase the surface thickness of the entire MEMS chip.

[0004] Welding technology is usually used to connect the leads to the contact points on the chip surface. Although this connection method is reliable, it requires the use of solder paste or heating to achieve the bonding between materials during the welding process, which also increases the thickness of the chip. Especially when there are many leads or they are densely distributed, the additional thickness will have an adverse effect on the overall design of the MEMS device.

[0005] Glue dispensing technology is a process of applying a layer of glue to a pre-prepared position on the chip surface and then inserting the lead wire. Although glue dispensing can provide better mechanical and electrical connections, it will also increase the surface thickness of the chip due to the presence of glue. In addition, the glue dispensing process requires precise control of the amount of glue and the use of tools for positioning and inserting wires, which not only increases manufacturing costs but also affects production efficiency.

[0006] The above limitations are a challenge for applications with strict chip size restrictions, such as thin smartphone sensors, space-constrained instruments and equipment, and restrict the chip surface heat transfer design. Therefore, for MEMS application scenarios that require the realization of leads while maintaining chip miniaturization and thinness, a new planar electrode and lead method is urgently needed to overcome the limitations of the above traditional methods. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a planar electrode and a lead method thereof, which embeds the leads by laser drilling and grooving, which can not only achieve lead connection without basically increasing the thickness of the chip, but also ensure good electrical performance and mechanical stability while keeping the chip thin, so as to overcome the limitations of the above-mentioned traditional methods.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A planar electrode, comprising a substrate, an electrode layer arranged on the substrate, a wire as a lead and a wiring groove, wherein the wiring groove comprises a first fixed segment, a conductive segment and a second fixed segment, wherein the first fixed segment and the second fixed segment are arranged on a side of the substrate away from the electrode layer, the conductive segment is arranged on a side of the substrate for arranging the electrode layer, a first through hole and a second through hole are respectively provided at both ends of the conductive segment, and an end of the first fixed segment away from the first through hole passes through the substrate;

[0010] One end of the wire passes through the first fixed section, passes through the first through hole into the conductive section, passes through the second through hole into the second fixed section, and the other end passes through the substrate along the direction of the first fixed section away from the first through hole to serve as a lead connector. A filler is provided in the conductive section to fix the wire and conduct electricity;

[0011] The electrode layer at least covers part of the conductive segment so that the wire is connected to the electrode layer, or a conductive layer for connecting the electrode layer is covered on the electrode layer, and the conductive layer at least covers part of the conductive segment so that the wire is connected to the electrode layer.

[0012] Furthermore, fillers are provided in the first fixing section and the second fixing section to further fix the wire.

[0013] The present invention also provides a lead method for a planar electrode, using the planar electrode, specifically comprising the following steps:

[0014] S1. Use laser processing equipment to groove and punch the planar electrode to be treated as a lead and the electrode layer has been arranged to form a wiring groove;

[0015] S2. Adding a conductive layer on one side of the substrate where the electrode layer is arranged to connect the electrode layer and the conductive segment;

[0016] S3. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove;

[0017] S4. Add filler in the wiring groove to fix the wire and conduct electricity, and complete the lead.

[0018] Furthermore, the thickness of the conductive layer is 20 nm to 5 um.

[0019] Furthermore, the diameter or thickness of the wire is less than or equal to 2.5 mm.

[0020] Furthermore, the filler is a conductive medium, and the components of the conductive medium contain one or more of tin, gold, silver, copper, platinum, aluminum, zinc, iron, nickel or graphite.

[0021] The present invention also provides a lead method for a planar electrode, using the planar electrode, specifically comprising the following steps:

[0022] S1. Use laser processing equipment to groove and punch the planar electrode to be treated as a lead and the electrode layer has been arranged to form a wiring groove;

[0023] S2. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove;

[0024] S3. Add filler in the wiring trough to fix the wire and make it conductive;

[0025] S4. Add a conductive layer connected to the electrode layer on one side of the substrate where the electrode layer is arranged, so as to connect the electrode layer with the wire, thereby completing the lead.

[0026] The present invention also provides a lead method for a planar electrode, using the planar electrode, specifically comprising the following steps:

[0027] S1. Using laser processing equipment to groove and punch the substrate in the planar electrode where the lead wires are not arranged and the electrode layer is not arranged to form a wiring groove;

[0028] S2. Arranging an electrode layer, or an electrode layer and a conductive layer connected to the electrode layer, on one side of the substrate where the conductive segment is arranged, and correspondingly arranging an electrode layer in the conductive segment as a conductive layer, or a conductive layer;

[0029] S3. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove;

[0030] S4. Add fillers in the wiring groove to fix the wires, and make the wires conduct with the electrode layer through the conductive layer, or directly conduct with the electrode layer, thereby completing the lead.

[0031] The present invention also provides a lead method for a planar electrode, characterized in that the planar electrode is used and specifically comprises the following steps:

[0032] S1. Using laser processing equipment to groove and punch the substrate in the planar electrode where the lead wires are not arranged and the electrode layer is not arranged to form a wiring groove;

[0033] S2. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove;

[0034] S3. Add filler in the wiring groove to fix the wire and conduct electricity;

[0035] S4. Arranging an electrode layer on one side of the substrate where the conductive segment is arranged, and the electrode layer extends into the conductive segment to serve as a conductive layer, so that the wire is connected to the electrode layer, thereby completing the lead;

[0036] Alternatively, an electrode layer and a conductive layer connected to the electrode layer are arranged on one side of the substrate where the conductive segment is arranged, and the conductive layer covers the conductive segment so that the conductive segment and the electrode layer are connected, so that the wire is connected to the electrode layer through the conductive layer, thereby completing the lead.

[0037] The beneficial effects of the present invention are:

[0038] The present invention provides a planar electrode and a lead method thereof, which embeds a wire as a lead by laser drilling and grooving, and can not only realize the lead connection without substantially increasing the thickness of the planar electrode, but also can ensure good electrical performance and mechanical stability while maintaining the thinness of the planar electrode, and has extremely low cost, overcoming the limitations of traditional lead solutions in size control and heat transfer design, and providing a new solution for innovative lead and packaging technology of MEMS sensors, especially for applications in thin sensors and space-constrained instruments and equipment, and has significant market potential and technical value.

[0039] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0041] Figure 1 A front view (upper left), a top view (lower left) and a partial enlarged view of the front view (upper right) of a planar electrode in a state where a wiring groove is not processed in an embodiment;

[0042] Figure 2 1. A front view (middle left), a top view (lower left), a bottom view (upper left), a top axonometric view (lower right), and a bottom axonometric view (upper right) of a planar electrode in an embodiment;

[0043] Figure 3 It is a schematic diagram of the process of a lead-in method for a planar electrode in an embodiment.

[0044] Reference numerals: 1 - electrode layer, 2 - substrate, 3 - first fixing section, 4 - conductive section, 5 - second fixing section, 6 - wire, 7 - filler, 8 - conductive layer. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0046] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0047] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0048] See also Figure 1-2 , is a planar electrode, comprising a substrate 2, an electrode layer 1 arranged on the upper surface of the substrate 2, a wire 6 as a lead and a wiring groove, wherein the wiring groove comprises a first fixed segment 3, a conductive segment 4 and a second fixed segment 5, wherein the first fixed segment 3 and the second fixed segment 5 are arranged on a side of the substrate 2 away from the electrode layer 1 (the lower surface of the substrate 2), the conductive segment 4 is arranged on a side of the substrate 2 for arranging the electrode layer 1 (the lower surface of the substrate 2), and has an overlapping portion with the electrode layer 1, and a first through hole and a second through hole connecting the first fixed segment 3 and the second fixed segment 5 are respectively provided at both ends of the conductive segment 4, and an end of the first fixed segment 3 away from the first through hole passes through the substrate 2;

[0049] One end of the wire 6 passes through the first fixed section 3, passes through the first through hole into the conductive section 4, passes through the second through hole into the second fixed section 5, and is bent and fixed in the second fixed section 5. The other end passes through the substrate 2 along the direction of the first fixed section 3 away from the first through hole as a lead connector.

[0050] The conductive segment 4 is provided with a filler 7 to fix the conductive wire 6 and conduct electricity, and is covered with a conductive layer 8 that is conductive to the electrode layer 1 to ensure the conductive wire 6 is conductive to the electrode layer.

[0051] Specifically, in this embodiment, the planar electrode has an overall thickness of 0.5 mm, the electrode layer 1 has a thickness of 0.5 um, and a width of 1 mm.

[0052] Preferably, in this embodiment, the conductive layer 8 is arranged above the filler 7 .

[0053] In another embodiment, the conductive layer 8 is arranged below the filler 7 .

[0054] Furthermore, ceramic fillers are provided in the first fixing section 3 and the second fixing section 5 to further fix the wire.

[0055] Specifically, the filler 7 in the conductive segment 4 is a conductive medium, specifically one or more conductive components including tin, gold, silver, copper, platinum, aluminum, zinc, iron, nickel, graphite, etc.;

[0056] The diameter of the wire 6 is 0.127 mm, the width and depth of the wiring groove are approximately 0.15 mm, and the angle between the first fixing section 3 and the second fixing section 5 is 90°.

[0057] In another embodiment, the included angle between the first fixing section 3 and the second fixing section 5 is 45°.

[0058] See also Figure 3 , a lead method for a planar electrode, specifically comprising the following steps:

[0059] S1. Use laser processing equipment to groove and punch the planar electrode of the lead to form a wiring groove;

[0060] The wiring groove includes a first fixing section 3, a conductive section 4 and a second fixing section 5, wherein the first fixing section 3 and the second fixing section 5 are arranged on a side of the substrate 2 away from the electrode layer 1 (the lower surface of the substrate 2), and the conductive section 4 is arranged on a side of the substrate 2 for arranging the electrode layer 1 (the lower surface of the substrate 2), and has an overlapping portion with the electrode layer 1, and a first through hole and a second through hole connecting the first fixing section 3 and the second fixing section 5 are respectively provided at both ends of the conductive section 4, and an end of the first fixing section 3 away from the first through hole passes through the substrate 2;

[0061] S2. Mask the planar electrode using photolithography, the hollowed-out area is the conductive segment 4 of the wiring groove and the position on the electrode layer 1 that needs to be conductive, and a copper conductive layer 8 is sputtered on the upper surface of the planar electrode using magnetron sputtering. The thickness of the conductive layer 8 is 0.3 um. After sputtering, a lift-off process is used to make the sputtered conductive layer 8 exist only in the photolithography hollowed-out area;

[0062] Because there are usually multiple electrode layers on the surface of the substrate, if there is no other design between the electrode layers, direct coating may cause abnormal conduction between the electrodes. Adding a mask can only coat the conductive layer at the specified position.

[0063] S3. Insert the wire 6 into the first fixed section 3, the conductive section 4, and the second fixed section 5 in sequence to arrange the wire into the wiring groove.

[0064] S4. Add solder paste into the wiring groove and fix the wire 6 through reflow soldering to further fix and conduct electricity.

[0065] Preferably, when preparing the conductive layer in step S2, the planar electrode can also be masked by means of tape or mask plate, and a conductive layer can be added to the surface of the chip to be wired by physical sputtering, chemical plating, evaporation, electrodeposition or chemical deposition, and the conductive layer in the mask area can be cleaned when necessary to avoid abnormal conduction of multiple electrode layers. The purpose of the conductive layer coating is to extend the electrode layer so that it is conductive with the wire. After the conductive layer is coated, if the mask is performed in step S2, it may be necessary to perform a lift-off process, or tear off the tape, remove the mask and other necessary process steps.

[0066] In another embodiment, in step S4, solder paste may be added into the conductive segment 4 of the wiring slot, and non-conductive fillers may be added into the first fixing segment 3 and the second fixing segment 5 to save costs.

[0067] In another embodiment, the order of steps S2, S3, and S4 can be exchanged to complete the lead wiring, such as first arranging the wires in S3, then filling and fixing in S4, and finally covering with a conductive layer in S2.

[0068] In another embodiment, the steps of masking and covering the conductive layer in step S2 can be combined with the step of making the electrode layer, that is, the conductive layer is completed when the electrode layer is made, or the electrode layer is directly used as the conductive layer and covers the conductive segment, and the lead step can be adjusted accordingly. First, after the wiring groove is formed in the slotted through hole of the substrate 2, the electrode layer and the conductive layer are prepared, and the electrode layer or the conductive layer covers the conductive segment accordingly. Finally, the wire is connected to the conductive layer or the electrode layer through the filler in the conductive segment.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A planar electrode, characterized in that: The invention comprises a substrate, an electrode layer arranged on the substrate, a wire as a lead and a wiring groove, wherein the wiring groove comprises a first fixing section, a conductive section and a second fixing section, wherein the first fixing section and the second fixing section are arranged on a side of the substrate away from the electrode layer, the conductive section is arranged on a side of the substrate for arranging the electrode layer, a first through hole and a second through hole connecting the first fixing section and the second fixing section are respectively arranged at two ends of the conductive section, and an end of the first fixing section away from the first through hole passes through the substrate; One end of the wire passes through the first fixed section, passes through the first through hole into the conductive section, passes through the second through hole into the second fixed section, and the other end passes through the substrate along the direction of the first fixed section away from the first through hole to serve as a lead connector. A filler is provided in the conductive section to fix the wire and conduct electricity; The electrode layer at least covers part of the conductive segment so that the wire is connected to the electrode layer, or a conductive layer for connecting the electrode layer is covered on the electrode layer, and the conductive layer at least covers part of the conductive segment so that the wire is connected to the electrode layer.

2. The planar electrode according to claim 1, characterized in that: Fillers are provided in the first fixing section and the second fixing section to further fix the wire.

3. A method for wiring a planar electrode, characterized in that: The planar electrode according to any one of claims 1 to 2 is used, and specifically comprises the following steps: S1. Use laser processing equipment to groove and punch the planar electrode to be treated as a lead and the electrode layer has been arranged to form a wiring groove; S2. Adding a conductive layer on one side of the substrate where the electrode layer is arranged to connect the electrode layer and the conductive segment; S3. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove; S4. Add filler in the wiring groove to fix the wire and conduct electricity, and complete the lead.

4. The lead-in method of planar electrodes according to claim 3, characterized in that: The thickness of the conductive layer is 20nm-5um.

5. The lead-in method of planar electrodes according to claim 3, characterized in that: The diameter or thickness of the wire is less than or equal to 2.5 mm.

6. The lead-in method of planar electrodes according to claim 3, characterized in that: The filler is a conductive medium, and the conductive medium contains one or more of tin, gold, silver, copper, platinum, aluminum, zinc, iron, nickel or graphite.

7. A method for wiring a planar electrode, characterized in that: The planar electrode according to any one of claims 1 to 2 is used, and specifically comprises the following steps: S1. Use laser processing equipment to groove and punch the planar electrode to be treated as a lead and the electrode layer has been arranged to form a wiring groove; S2. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove; S3. Add filler in the wiring trough to fix the wire and make it conductive; S4. Add a conductive layer connected to the electrode layer on one side of the substrate where the electrode layer is arranged, so as to connect the electrode layer with the wire, thereby completing the lead.

8. A method for wiring a planar electrode, characterized in that: The planar electrode according to any one of claims 1 to 2 is used, and specifically comprises the following steps: S1. Using laser processing equipment to groove and punch holes on the substrate in the planar electrode where the lead wires are not arranged, to form wiring grooves; S2. Arranging an electrode layer on one side of the substrate where the conductive segment is arranged, and the electrode layer extends into the conductive segment to serve as a conductive layer; or an electrode layer and a conductive layer conductively connected to the electrode layer are arranged on one side of the substrate where the conductive segment is arranged, and the conductive layer covers the conductive segment so that the conductive segment is conductively connected to the electrode layer; S3. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove; S4. Add fillers in the wiring groove to fix the wires, and make the wires conduct with the electrode layer through the conductive layer, or directly conduct with the electrode layer, thereby completing the lead.

9. A method for wiring a planar electrode, characterized in that: The planar electrode according to any one of claims 1 to 2 is used, and specifically comprises the following steps: S1. Using laser processing equipment to groove and punch holes on the substrate in the planar electrode where the lead wires are not arranged, to form wiring grooves; S2. Insert one end of the wire successively into the first fixed section, the first through hole, the conductive section, the second through hole and the second fixed section to arrange the wire into the wiring groove; S3. Add filler in the wiring groove to fix the wire and conduct electricity; S4. Arranging an electrode layer on one side of the substrate where the conductive segment is arranged, and the electrode layer extends into the conductive segment to serve as a conductive layer, so that the wire is connected to the electrode layer, thereby completing the lead; Alternatively, an electrode layer and a conductive layer connected to the electrode layer are arranged on one side of the substrate where the conductive segment is arranged, and the conductive layer covers the conductive segment so that the conductive segment and the electrode layer are connected, so that the wire is connected to the electrode layer through the conductive layer, thereby completing the lead.

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