CN113395837B - Wet laser forming method for nano metal circuit and structure - Google Patents

Abstract

The invention relates to the technical field of integrated circuits, in particular to a wet laser forming method of a nano metal circuit and a nano metal structure, which comprises the following steps: s1, presetting a circuit on a carrier plate to form a carrier plate to be formed with the circuit, and then coating a nano metal paste in a wet state on the surface of the carrier plate to be formed with the circuit; s2, modifying the surface of the nano metal paste on the circuit to-be-formed carrier plate to form a pre-sintering neck; irradiating the surface of the nano metal paste on the circuit to-be-formed carrier plate for at least one time by adopting laser to complete circuit sintering to obtain a circuit forming carrier plate; s3, cleaning the line forming carrier plate; and S4, carrying out surface treatment on the cleaned circuit forming carrier plate to obtain the circuit carrier plate. The invention can control the appearance of the circuit, optimize the quality of the circuit and improve the forming efficiency of the circuit.

Description

A Wet Laser Forming Method for Nano Metal Circuits and Structures

technical field

The invention relates to the technical field of integrated circuits, and more specifically, to a wet laser forming method for nanometer metal circuits and structures.

Background technique

With the development of electronic and electrical products in the direction of ultra-large-scale integration, digitization, and mass production, traditional printed circuit manufacturing methods include chemical methods and template (or screen) printing methods. , it is easy to bring large errors to high-density and high-precision printed circuit boards; the minimum line width and line spacing are greatly limited, and during the corrosion process, disconnections often occur, especially in large-scale motor computers. High-density multilayer printed boards, due to the high wiring density and thin printed lines, are more prone to corrosion and disconnection at individual positions, resulting in a large amount of waste of precious metals and man-hours.

With the rapid development of laser printing technology, its application fields are becoming wider and wider. Applying laser printing technology to coat metal particles on the broken line to be formed and then perform laser forming can achieve the purpose of rapid prototyping of circuits. This method is simple to operate. , low cost, short time-consuming, is considered to be the most effective method at present.

However, in the current process of laser forming metal lines, it is difficult to effectively control the line width and surface quality of the lines. The large temperature fluctuations in the sintering process lead to the problem that the surface of the formed circuit is difficult to keep flat. In addition, laser forming lines still lack effective line cleaning methods: after laser forming lines, the residual unsintered nano-metal particles will cause faults such as short circuits in existing lines. However, conventional ultrasonic cleaning methods will disperse nano metal particles throughout the circuit, further increasing the risk of short circuit and other failures.

The Chinese patent document with the publication number CN110753454B discloses a method for forming and repairing fine circuits, which includes the following steps: Step 1. Deposit a thin copper layer on the first surface of the light-transmitting plate by physical vapor deposition, Then increase the thin copper layer to the required thickness by electroplating; step 2, turn the light-transmitting plate over, and then cover the first surface of the light-transmitting plate on the circuit carrier; step 3, adjust the focal length of the laser transmitter so that the laser The laser emitted by the transmitter is focused on the thin copper layer on the first surface of the light-transmitting plate, and the laser beam passes through the light-transmitting plate to irradiate the thin copper layer according to the preset track, and the laser melts the thin copper metal on the track. Covered on the circuit board. Step 4. Remove the light-transmitting plate from the circuit carrier, and then clean the surface of the circuit carrier to remove the residual copper in the unsintered part, and complete the formation of the fine circuit.

However, the above scheme first needs to apply the copper layer by physical vapor deposition, and also needs to increase the thickness by electroplating, which is cumbersome to operate.

Contents of the invention

The object of the present invention is to overcome the deficiencies of the prior art, and provide a wet laser forming method for nanometer metal circuits and structures, which can control the morphology of the circuits, optimize the quality of the circuits, and improve the efficiency of circuit forming.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A wet laser forming method for nanometer metal circuits and structures is provided, comprising the following steps:

S1. Pre-set the circuit on the carrier to form the circuit to be formed carrier, and then coat the surface of the circuit to be formed carrier with nano-metal paste in a wet state;

S2. Modifying the surface of the nano-metal paste on the circuit to be formed on the carrier to form a pre-sintered neck; using a laser to irradiate the surface of the nano-metal paste on the circuit to be formed on the carrier at least once to complete the circuit sintering , forming a circuit forming carrier;

S3. Cleaning the circuit forming carrier plate;

S4. Surface treatment is performed on the cleaned circuit-forming carrier to obtain a circuit carrier.

The invention is a wet laser forming method of nanometer metal circuit and structure, directly coating the nanometer metal paste in a wet state on the circuit carrier to be formed, which can reduce the coating time and improve the forming efficiency of the carrier; and By modifying the surface of the nano-metal paste on the circuit board to be formed to form a pre-sintered neck, the fluidity of the nano-metal paste can be reduced; and performing high-power sintering on the surface of the nano-metal paste to obtain the final circuit carrier. The invention can control the shape of the circuit, optimize the quality of the circuit, and improve the forming efficiency of the circuit.

Further, in step S2, the modification process includes any of the following steps:

a. Using an area flash light source to irradiate the circuit to be formed on the carrier board, so that the solvent in the nano-metal paste is volatilized, and the nanoparticles are initially sintered to form a pre-sintered neck;

b. Using laser light to irradiate the carrier plate to be formed on the circuit, so that the solvent in the nano-metal paste is volatilized, and the nano-particles are initially sintered to form a pre-sintered neck;

c. Using a pre-drying device to heat the carrier plate to be formed on the whole or part of the circuit, so that the solvent in the nano-metal paste is volatilized, and the nano-particles are initially sintered to form a pre-sintered neck.

Further, before performing the modification treatment, macromolecular long-chain organic substances are added to the nano-metal paste to form a nano-metal-organic mixture.

Further, the macromolecular long-chain organic compound includes any one or more of epoxy resin, hydroxyl resin, and ethyl acrylate.

Further, the nano-metal-organic mixture has a content of 0.01-10% of the macromolecular long-chain organic compound, and a content of the nano-metal paste of 90-99.99% by mass percentage.

Further, said step b includes any of the following steps:

b1. Using a single laser to irradiate the circuit to be formed on the carrier board;

b2. Using multiple lasers to irradiate the circuit to be formed carrier; wherein, a main laser is set to irradiate the circuit on the circuit to be formed carrier; and at least two secondary lasers are arranged on both sides of the main laser, The secondary laser irradiates the areas on both sides of the circuit on the carrier plate to be formed, so that the solvent in the nano-metal paste is volatilized, and the nano-particles are preliminarily sintered to form a pre-sintered neck.

Further, in step b1, the single laser is any one of the following:

A laser with a spot size of 1 to 10 times the line width and a pulse of more than 20 ns; or a continuous laser.

Further, when performing modification treatment in step S2, the temperature of the nano-metal paste does not exceed 300°C.

Further, in step S1, after the coating of the nano-metal paste is completed, a glass plate is added to the circuit-to-be-formed carrier, and the glass plate is provided with a groove structure having the same shape as the circuit.

Further, in step S4, the surface treatment specifically includes: spraying an organic solution on the surface of the cleaned circuit-forming carrier to form an anti-oxidation layer on the surface, and then obtain the circuit carrier.

Compared with prior art, the beneficial effect of the present invention is:

The invention is a wet laser forming method of nanometer metal circuit and structure, directly coating the nanometer metal paste in a wet state on the circuit carrier to be formed, which can reduce the coating time and improve the forming efficiency of the carrier; and By modifying the surface of the nano-metal paste on the circuit board to be formed to form a pre-sintered neck, the fluidity of the nano-metal paste can be reduced; and performing high-power sintering on the surface of the nano-metal paste to obtain the final circuit carrier. The invention can control the shape of the circuit, optimize the quality of the circuit, and improve the forming efficiency of the circuit.

Description of drawings

FIG. 1 is a flowchart of a wet laser forming method for nanometer metal circuits and structures according to the present invention.

Fig. 2 is a schematic structural diagram of the present invention when step S2 is executed.

Fig. 3 is a schematic structural diagram of the present invention after step S2 is completed.

Fig. 4 is a schematic structural diagram of the present invention after step S3 is completed.

Fig. 5 is a schematic structural diagram of using multiple lasers in Embodiment 2 of the present invention.

Fig. 6 is a schematic structural diagram of using multiple lasers in Embodiment 3 of the present invention.

Fig. 7 is a schematic diagram of the structure of the laser in Embodiment 4 of the present invention when the laser has a coarse spot and a long pulse.

FIG. 8 is a schematic diagram of the laser scanning direction in Embodiment 4 of the present invention.

Fig. 9 is a schematic structural diagram of Embodiment 5 of the present invention.

Fig. 10 is a schematic structural diagram of Embodiment 8 of the present invention.

Icon marks are explained as follows:

1-nano-metal paste, 2-line substrate to be formed, 3-laser, 4-sintered line, 5-glass plate.

detailed description

The present invention will be further described below in combination with specific embodiments. Wherein, the accompanying drawings are only for illustrative purposes, showing only schematic diagrams, rather than physical drawings, and should not be construed as limitations on this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings will be omitted, Enlargement or reduction does not represent the size of the actual product; for those skilled in the art, it is understandable that certain known structures and their descriptions in the drawings may be omitted.

In the drawings of the embodiments of the present invention, the same or similar symbols correspond to the same or similar components; The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific Orientation structure and operation, therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes, and should not be construed as limitations on this patent. Those of ordinary skill in the art can understand the specific meanings of the above terms according to specific situations.

Example 1

As shown in Figures 1 to 4, a first embodiment of a wet laser forming method for nanometer metal circuits and structures of the present invention includes the following steps:

S1. Pre-set the circuit on the carrier to form the carrier 2 to be formed, and then coat the nano-metal paste 1 in a wet state on the surface of the carrier 2 to be formed. Specifically, the coating thickness of the nano metal paste 1 is 1-200 μm, and the nano metal paste 1 is a nano copper paste.

S2. After step S1, modify the surface of the nano-metal paste 1 on the carrier plate 2 to be formed to form a pre-sintered neck;

Wherein, the modification treatment is specifically as step a: using an area flash light source to irradiate the vicinity of the circuit on the carrier board 2 to be formed, so that the solvent in the nano metal paste 1 is volatilized, and the nanoparticles are initially sintered to form a pre-sintered neck. It should be noted that the range of the vicinity of the circuit refers to the range of 1 to 10 times the width of the preset circuit on the carrier board. Also, when performing the modification treatment, keep the temperature of the nano metal paste 1 not exceeding 300°C.

After forming the pre-sintered neck, use the laser 3 to irradiate the surface of the nano-metal paste 1 on the circuit to be formed carrier 2 at least once, complete the circuit sintering to obtain the sintered circuit 4, and obtain the circuit forming carrier; wherein, the laser 3 is adjusted to emit The laser in question is a fine-spot and short-pulse laser; specifically, the fine-spot and short-pulse laser refers to a laser whose spot size is 0.5 to 1 times the width of the preset line on the carrier and whose single pulse time is 1-100 ns.

S3. Cleaning the circuit forming carrier to remove residual metal particles.

S4. Perform surface treatment on the cleaned circuit-forming carrier to obtain a circuit carrier; wherein, the surface treatment specifically includes: spraying an organic solution on the surface of the cleaned circuit-forming carrier to form an anti-oxidation layer on the surface, and then obtain a circuit carrier board. Specifically, the organic solution is any one of imidazole, PVP, PEG, and CTAB.

Example 2

This embodiment is similar to Embodiment 1, the difference is that this embodiment includes the following steps:

S1. Pre-set the circuit on the carrier to form the carrier 2 to be formed, and then coat the nano-metal paste 1 in a wet state on the surface of the carrier 2 to be formed.

S2. Modify the surface of the nano-metal paste 1 on the circuit to be formed carrier to form a pre-sintered neck; at the same time, use a laser to irradiate the surface of the nano-metal paste 1 on the circuit to be formed carrier 2 at least once to complete The circuit is sintered, and then the circuit-shaped carrier board is obtained.

Specifically, the same laser 3 can be used to irradiate the laser used for modification treatment and circuit sintering, and a laser beam splitter or laser diffractometer is installed on the laser 3, so that the laser 3 can emit the main laser for circuit sintering. . The sub-laser used for modification treatment; wherein, the sub-laser is located in front of the main laser, and it should be noted that the front refers to the front direction along the laser scanning direction, as shown in FIG. 5 .

S3. Cleaning the circuit forming carrier to remove residual metal particles.

S4. Surface treatment is performed on the cleaned circuit-forming carrier to obtain a circuit carrier.

Example 3

This embodiment is similar to Embodiment 2, the difference is that when performing modification treatment and circuit sintering in step S2, set coarse spot, long pulse laser to carry out modification treatment in front, and set fine spot, short pulse laser Line sintering is performed at the rear, as shown in Figure 6. It should be noted that the coarse spot and long pulse laser refer to the laser whose spot size is 1 to 10 times the width of the preset circuit on the carrier, and the pulse is more than 20ns; the thin spot and short pulse laser refer to the spot size of A laser that is 0.5 to 1 times the width of the preset line on the carrier and has a single pulse time of 1-100 ns.

Example 4

This embodiment is similar to Embodiment 1, the difference is that in step S2, the modification treatment is specifically as in step b: use laser to irradiate the circuit to be formed on the carrier plate, so that the solvent in the nano metal paste is volatilized, and the nanoparticles are initially sintered. A pre-sintered neck is formed. Wherein, in this embodiment, step b1 is performed: a single laser beam is used to irradiate the circuit to be formed on the carrier plate, so as to form a pre-sintered neck, as shown in FIG. 7 and FIG. 8 .

Specifically, the single-channel laser can be: coarse spot and long pulse laser; wherein, the coarse spot and long pulse laser refer to the laser whose spot size is 1 to 10 times the width of the preset line on the carrier and whose pulse is more than 20ns .

Specifically, the single laser beam can also be a continuous laser beam.

Wherein, the spot of the single-channel laser is any one of circular, elliptical, or rectangular. The long axis of the laser spot is perpendicular to the direction of the line, and the length of the long axis of the laser spot is 1 to 10 times the width of the preset line on the carrier board. . When scanning with laser irradiation, the scanning method is to perform multiple overlapping scans in parallel or perpendicular to the line direction.

Example 5

This embodiment is similar to embodiment 4. In step S2, the modification treatment is specifically as in step b: use laser to irradiate the circuit to be formed on the carrier plate, so that the solvent in the nano metal paste is volatilized, and the nano particles are preliminarily sintered to form a pre-sintered neck. The difference is that this embodiment executes step b2:

Multiple lasers are used to irradiate the circuit to be formed carrier 2; among them, a main laser is set to irradiate the circuit on the circuit to be formed carrier; at least two secondary lasers are arranged on both sides in front of the main laser, and the secondary laser irradiates the circuit The area near the circuit on the substrate to be formed is irradiated to volatilize the solvent in the nano-metal paste 1, and the nano-particles are initially sintered to form a pre-sintered neck; as shown in FIG. 9 .

Among them, the range of the nearby area means that the maximum distance between the laser center of the secondary laser is 1 to 10 times the width of the preset circuit on the carrier, and the laser spot size is set to be 1 to 10 times the width of the preset circuit on the carrier.

Example 6

This embodiment is similar to Embodiment 1, the difference is that in step S2, the modification process is specifically as in step c: use a pre-drying device to heat the carrier plate 2 to be formed on the whole or in part, so that the nano-metal paste The medium solvent volatilizes, and the nanoparticles are initially sintered to form a pre-sintered neck. Specifically, the pre-drying device is any one of an infrared heating device, a directional radiation heating device, a directional high-temperature inert heating device, and a reducing gas blowing heating device.

Example 7

This embodiment is similar to Embodiments 1-6, except that, before the modification treatment, macromolecular long-chain organic substances are added to the nano metal paste 1 to form a nano metal organic mixture. Wherein, the macromolecular long-chain organic compound includes any one or more of epoxy resin, hydroxyl resin, and ethyl acrylate. Specifically, the nano-metal-organic mixture has a content of 0.01-10 percent of macromolecular long-chain organic matter, and a content of nano-metal paste of 90-99.99 percent by mass percentage. Therefore, during the modification process, the solvent in the nano-metal paste is volatilized by light source irradiation, the nano-metal-organic mixture is heated and shrunk, and the nano-particles are preliminarily sintered to form a pre-sintered neck.

Example 8

This embodiment is similar to Embodiments 1 to 7, except that in step S1, after the coating of the nano-metal paste 1 is completed, a glass plate 5 is added to the circuit carrier to be formed; wherein, the glass plate 5 There is a groove structure similar to the shape of the circuit; as shown in Figure 10. Specifically, the shape of the groove structure is similar to that of the circuit means that the width of the groove structure is 1-10 times the width of the predetermined circuit on the carrier, and the thickness of the groove structure is the same as that of the circuit. After the glass plate 5 is covered, the groove structure can distinguish the nano-metal paste 1 at the line position from the nano-metal paste 1 at other positions, preventing the directional flow of the nano-metal paste 1 during the sintering process of the line.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (8)

1. A wet laser forming method for nano metal lines and structures is characterized by comprising the following steps:

s1, presetting a circuit on a carrier plate to form a carrier plate to be formed with the circuit, and then coating a nano metal paste in a wet state on the surface of the carrier plate to be formed with the circuit; after the coating of the nano metal paste is finished, covering a glass plate on the circuit to-be-formed support plate, wherein the glass plate is provided with a groove structure similar to the circuit in shape; after the glass plate is covered, the groove structure can distinguish the nano metal paste at the position of the circuit from the nano metal paste at other positions, so that the nano metal paste is prevented from flowing directionally in the process of sintering the circuit;

s2, modifying the surface of the nano metal paste on the circuit to-be-formed carrier plate to form a pre-sintering neck; irradiating the surface of the nano metal paste on the circuit to-be-formed carrier plate for at least one time by adopting laser to complete circuit sintering to obtain a circuit forming carrier plate; wherein the modification treatment comprises any one of the following steps:

a. irradiating the circuit to-be-formed support plate by adopting an area flashing light source to volatilize the solvent in the nano metal paste, and preliminarily sintering the nano particles to form a presintering neck;

b. irradiating the circuit to-be-formed support plate by adopting laser to volatilize a solvent in the nano metal paste, and preliminarily sintering nano particles to form a presintering neck;

c. a pre-drying device is adopted to heat the carrier plate to be formed of the circuit wholly or locally, so that the solvent in the nano metal paste is volatilized, and nano particles are primarily sintered to form a pre-sintering neck;

s3, cleaning the circuit forming support plate;

and S4, carrying out surface treatment on the cleaned circuit forming carrier plate to obtain the circuit carrier plate.

2. The wet laser forming method of nano-metal lines and structures as claimed in claim 1, wherein before modification, macromolecular long-chain organics are added to the nano-metal paste to form a nano-metal-organic mixture.

3. The wet laser forming method of nano metal lines and structures as claimed in claim 2, wherein the macromolecular long-chain organic substance comprises any one or more of epoxy resin, hydroxyl resin and ethyl acrylate.

4. The wet laser forming method for the nano metal circuit and the nano metal structure as claimed in claim 2, wherein the nano metal organic mixture comprises, by mass, 0.01 to 10% of the macromolecular long-chain organic substance, and 90 to 99.99% of the nano metal paste.

5. The method of claim 1, wherein step b comprises any of the following steps:

b1. irradiating the circuit to-be-formed support plate by adopting single laser;

b2. irradiating the circuit to-be-formed support plate by adopting a plurality of laser beams; setting a main laser to irradiate the circuit on the circuit support plate to be formed; and then at least two auxiliary lasers are arranged on two sides of the main laser, and the auxiliary lasers irradiate areas on two sides of the circuit on the carrier plate to be formed on the circuit, so that the solvent in the nano metal paste is volatilized, and the nano particles are primarily sintered to form a pre-sintering neck.

6. The wet laser forming method for nano metal lines and structures as claimed in claim 5, wherein in step b1, the single laser is any one of the following:

laser with the spot size of 1 to 10 times of the line width and the pulse of more than 20 ns;

and (4) continuous laser.

7. The wet laser forming method of nanometal lines and structures according to claim 1, characterized in that the temperature of the nanometal paste does not exceed 300 ℃ when the modification treatment is performed in step S2.

8. The wet laser forming method of nano-metal lines and structures as claimed in claim 1, wherein in step S4, the surface treatment specifically comprises: and spraying organic solution on the surface of the cleaned circuit forming carrier plate to form an anti-oxidation layer on the surface, and then obtaining the circuit carrier plate.

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