Additional formic acid steam catalytic body device convenient to disassemble and assemble

Abstract

The invention discloses an additional formic acid steam catalytic body device convenient to disassemble and assemble, which comprises a catalytic converter, the catalytic converter comprises a honeycomb-shaped gas channel, and the inner surface of the honeycomb-shaped gas channel is coated with a catalyst layer; and the catalyst carrier is used for bearing and sealing the catalyst, and a connector connected with a formic acid atmosphere furnace gas circuit is arranged on the catalyst carrier. Compared with a formic acid atmosphere furnace with a catalytic device, the formic acid atmosphere furnace has the advantages that an atmosphere in-situ activation function can be added on the formic acid atmosphere furnace through an additional assembly mode on the premise of not additionally installing and modifying a gas circuit, so that the purchase and modification cost of a machine can be greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of microelectronic packaging, and in particular to a formic acid vapor catalyst device which is convenient to disassemble and assemble. Background Art

[0002] Due to environmental concerns, several countries and regions, including the European Union, have enacted legislation to restrict the use of lead-containing solder in electronic products. Lead-free solder faces the problem of poor wettability and requires the use of complex flux, but as the density of interconnect bump arrays increases, its residual problem may affect device performance, so the flux-free soldering process has a high market potential.

[0003] At present, formic acid vapor atmosphere has been widely reported to be suitable for the reflow soldering process of electronic packaging. It can not only remove the oxides of the substrate metal pole, but also achieve the wettability of tin-based lead-free solder, and has the characteristic of no residue after the process. In addition, formic acid atmosphere also has a good auxiliary effect as a reducing atmosphere in the new solid-state sintering of metal nanoparticles, and it is reported to have broad prospects in the chip mounting process of power devices. Therefore, a large number of commercial models of sintering furnaces or reflow furnaces compatible with formic acid vapor atmosphere have begun to appear on the market, which are used in the field of electronic packaging.

[0004] According to the latest research reports, the use of precious metals such as Rh, Pt, and Pd to catalyze formic acid can not only reduce the process temperature and shorten the process time, but also greatly enhance the effectiveness of formic acid. The principle is to convert the functional groups in formic acid into highly active H radicals in advance through chemical adsorption on the surface of the above-mentioned metals, greatly improving its low-temperature reduction efficiency. However, the commercial atmosphere sintering furnaces available on the market are not equipped with catalytic units for formic acid. At the same time, the prototypes of the existing formic acid catalytic units are only equipped with fixed catalysts. After the catalyst efficiency decreases, the entire module can only be replaced, and it is difficult to update with the progress of catalysis-related research. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a universal formic acid vapor catalyst device that can be easily attached to a commercial atmosphere furnace to solve the efficiency problem of the existing formic acid atmosphere furnace and realize in-situ activation of the formic acid atmosphere.

[0006] The technical solution adopted by the present invention is: a formic acid vapor catalyst device that is easy to disassemble and assemble, comprising:

[0007] A catalyst, the catalyst comprising a honeycomb-shaped gas channel, the inner surface of the honeycomb-shaped gas channel being coated with a catalyst layer;

[0008] The catalyst carrier is used for carrying and sealing the catalyst, and the catalyst carrier is provided with an interface connected to the gas path of the formic acid atmosphere furnace.

[0009] Furthermore, the catalyst further comprises a catalyst housing, wherein the catalyst housing is located at the periphery of the honeycomb-shaped gas channel, and the honeycomb-shaped gas channel is composed of a through-hole honeycomb catalyst carrier.

[0010] Furthermore, the through holes of the through-hole honeycomb catalyst carrier are 300-500 meshes, the shape of the holes is circular or non-circular, the material is ceramic or metal alloy, the thickness of the catalyst layer is 0.3-0.5 mm, and the catalyst is Pt, PtPd or / and PtRh.

[0011] Furthermore, the catalyst carrier is longer than the catalyst, the inner diameter of the catalyst carrier is loosely matched with the outer diameter of the catalyst, and both ends of the catalyst carrier are provided with integral flange structures.

[0012] Furthermore, the two ends of the catalyst carrier are respectively provided with a first plane sealing groove, a sealing ring is provided in the groove, and a flange suitable for normal pressure-negative pressure operation or a flange suitable for normal pressure-positive pressure operation is matched;

[0013] The flange for normal pressure-negative pressure operation is made of resin, and includes a flange pipe integrally formed with the flange for normal pressure-negative pressure operation, and a female FPA bead connector and a male FPA bead connector are respectively provided at the ends of the two flange pipes;

[0014] The flange working under normal pressure and positive pressure is made of resin or corrosion-resistant metal, a screw hole is provided in the middle of the flange, a second plane sealing groove and a sealing ring are provided outside the screw hole, the thread is a sealed threaded through hole, and is equipped with a stainless steel or copper joint.

[0015] Furthermore, the material of the flange working under normal pressure-negative pressure includes polyimide, silicone resin or PFA plastic; the material of the flange working under normal pressure-positive pressure includes polyimide, silicone resin, PFA plastic, stainless steel or copper alloy.

[0016] Furthermore, it also includes a catalyst body shell, which is used to cover the catalyst carrier, including: a shell, a heating unit and a shell cover; the heating unit is provided on the inner side of the shell, the heating unit is covered on the outer periphery of the catalyst carrier, the heating unit is provided with a wiring point and a thermocouple jack, and the shell cover is located at both ends of the shell.

[0017] Furthermore, a supporting ring for holding up the heating unit and the catalyst carrier is provided on the inner surface of the shell, and fixing feet are provided on the outer surface of the shell.

[0018] Furthermore, a gap is left between the heating unit and the shell for filling with high temperature resistant, flame retardant and heat-insulating material.

[0019] The formic acid vapor catalyst device is used in a lead-free solder reflow and chip mounting atmosphere furnace.

[0020] The present invention provides a formic acid steam catalyst device that is easy to disassemble and assemble. Compared with a formic acid atmosphere furnace with an attached catalytic device, the present invention can add an atmosphere in-situ activation function to the formic acid atmosphere furnace by adding components without additional installation or modification of the gas path, thereby shortening the time required for processes related to the use of formic acid atmosphere, reducing process temperature, improving product quality and process efficiency, and significantly reducing the cost of purchasing and modifying the machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the overall structure of a formic acid steam catalyst device that is convenient for disassembly and assembly and attachment provided in an embodiment of the present invention.

[0022] Figure 2 A schematic diagram of the catalyst structure of a formic acid steam catalyst device that is convenient to disassemble and assemble according to an embodiment of the present invention.

[0023] Figure 3 A schematic diagram of a catalyst carrier structure for a formic acid vapor catalyst device that is convenient for disassembly and assembly and attachment provided in an embodiment of the present invention.

[0024] Figure 4 A schematic diagram of the structure of a catalyst housing of a formic acid steam catalyst device that is convenient for disassembly and assembly and attachment is provided in an embodiment of the present invention.

[0025] Figure 5 This is a chip mounting strength diagram of the same nano copper paste provided in an embodiment of the present invention under nitrogen, formic acid, and catalytic formic acid atmospheres.

[0026] Figure 6 The shear section microstructure of the nano-copper paste sintered layer in a catalytic formic acid atmosphere and the corresponding EDS element analysis provided by the embodiment of the present invention.

[0027] The figures are marked as follows: catalyst 1, catalyst carrier 2, catalyst body shell 3, first plane sealing groove 201, flange 202 for working at normal pressure-negative pressure, flange 203 for working at normal pressure-positive pressure, second plane sealing groove 204, shell 301, heating unit 302, shell cover 303, supporting ring 3011, fixing foot 3012, wiring point 3021, thermocouple jack 3022. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The specific implementation methods do not limit the scope of protection claimed in the present invention.

[0029] A formic acid vapor catalyst device that is easy to disassemble and attach, comprising:

[0030] The catalyst 1 comprises a honeycomb-shaped gas channel, the inner surface of which is coated with a catalyst layer;

[0031] The catalyst carrier 2 is used to carry and seal the catalyst 1, and the catalyst carrier 2 is provided with an interface connected to the gas path of the formic acid atmosphere furnace.

[0032] The present embodiment provides a formic acid steam catalyst device that is easy to disassemble and assemble. Compared with a formic acid atmosphere furnace with an attached catalytic device, an in-situ activation function of the atmosphere can be added to the formic acid atmosphere furnace by means of additional components without additional installation or modification of the gas path. This can shorten the time required for processes related to the use of formic acid atmosphere, reduce process temperatures, improve product quality and process efficiency, and significantly reduce the cost of purchasing and modifying the machine.

[0033] Preferably, the catalyst 1 further comprises a catalyst housing, which is located at the periphery of the honeycomb-shaped gas channel, and the honeycomb-shaped gas channel is composed of a through-hole honeycomb catalyst carrier. The through-hole honeycomb catalyst carrier has a through hole of 300 to 500 meshes, a circular or non-circular hole shape, a ceramic or metal alloy material, a catalyst layer thickness of 0.3 to 0.5 mm, and a catalyst of Pt, PtPd or / and PtRh.

[0034] In this embodiment, Figure 2 As shown, the interior of the catalyst 1 is a honeycomb-shaped gas channel, which provides a tubular channel shape for gas flow. The exterior is a stainless steel shell, and the cross-sectional shape of the shell can be circular, elliptical, rectangular, etc. Different cross-sectional shapes can be selected according to different applicable occasions. The internal honeycomb-shaped gas channel is composed of a through-hole honeycomb catalytic carrier. The through holes of the honeycomb catalytic carrier are 300 to 500 meshes, and the shape of the holes can be circular or non-circular. The carrier material can be selected from ceramics or metal alloys. The gas flow path area can be adjusted by changing the number of through holes of the honeycomb catalytic carrier in the catalytic body. In addition, a catalyst coating with a thickness of 0.3 to 0.5 mm is coated on the honeycomb catalytic carrier. The catalyst coating can be made according to demand, and the catalyst can be replaced according to the situation. Pt coating, Pt+Pd coating (preferably in a ratio of 2:1), and Pt+Rh coating (preferably in a ratio of 2:1) are preferred.

[0035] Preferably, the catalyst carrier 2 is longer than the catalyst 1, the inner diameter of the catalyst carrier 2 is loosely matched with the outer diameter of the catalyst 1, and integral flange structures are provided at both ends of the catalyst carrier 2.

[0036] In this embodiment, the catalyst carrier 2 is similar in shape to the catalyst 1, such as Figure 3As shown. The inner diameter of the catalyst carrier 2 is in clearance with the outer diameter of the catalyst 1, and the length is slightly longer than that of the catalyst 1, for example, the total length of the catalyst 1 is 100mm, and the total length of the catalyst carrier 2 is 110mm; both ends have integral flange structures, and according to the national standard GB / T 33509-2017 General Specification for Mechanical Seals, a flat sealing groove 201 is made, and the corresponding standard fluororubber O-ring should be assembled.

[0037] Preferably, both ends of the catalyst carrier 2 are respectively provided with a first planar sealing groove 201, a sealing ring is provided in the groove, and is matched with a flange 202 suitable for normal pressure-negative pressure operation or a flange 203 suitable for normal pressure-positive pressure operation; the flange 202 for normal pressure-negative pressure operation is made of resin, and includes a flange pipe integrally formed with the flange for normal pressure-negative pressure operation, and at the ends of the two flange pipes, a female FPA bead connector and a male FPA bead connector are respectively provided; the flange 203 for normal pressure-positive pressure operation is made of resin or corrosion-resistant metal, a screw hole is provided in the middle of the flange, a second planar sealing groove 204 and a sealing ring are provided outside the screw hole, and the thread is a sealed threaded through hole, and is equipped with a stainless steel or copper joint.

[0038] In this embodiment, the flange cover of the catalyst carrier 2 has two options according to the positive pressure and negative pressure conditions:

[0039] Resin flanges suitable for normal pressure to negative pressure working environments, whose materials include but are not limited to polyimide, silicone resin, PFA plastic, etc. It includes a high-diameter flange pipe, which is integrally formed with the flange, and at the end of the flange pipe, one end is equipped with an FPA bead connector (female) and the other end is equipped with an FPA bead connector (male).

[0040] The flange is suitable for working in normal pressure and positive pressure environment. In addition to resin, it can also be made of corrosion-resistant metals such as stainless steel and copper alloy. A screw hole is dug in the middle of the flange, and the thread is a sealed threaded through hole, which can be equipped with stainless steel or copper pneumatic quick-connect fittings of corresponding thread models. The second plane sealing groove 204 is equipped outside the screw hole according to the size of the screw hole and the national standard GB / T 33509-2017 General Specification for Mechanical Seals, and the corresponding standard fluororubber O-ring is equipped.

[0041] Furthermore, the material of the flange 202 working under normal pressure and negative pressure includes polyimide, silicone resin or PFA plastic; the material of the flange 203 working under normal pressure and positive pressure includes polyimide, silicone resin, PFA plastic, stainless steel or copper alloy.

[0042] Preferably, the catalyst housing 3 is also included, which is used to cover the catalyst carrier 2, and includes: a shell 301, a heating unit 302 and a shell cover 303; a heating unit 302 is provided inside the shell 301, and the heating unit 302 is covered on the outer periphery of the catalyst carrier 2, and a wiring point 3021 and a thermocouple jack 3022 are provided on the heating unit 302, and the shell cover 303 is located at both ends of the shell 301. A supporting ring 3011 for supporting the heating unit 302 and the catalyst carrier 2 is provided on the inner surface of the shell 301, and a fixing foot 3012 is provided on the outer surface of the shell 301. A gap is left between the heating unit 302 and the shell 301 for filling with high temperature resistant, flame retardant and heat-insulating materials.

[0043] In this embodiment, Figure 4 As shown, the catalyst housing 3 can be in the shape of a cylindrical tube, with a supporting ring 3011 on the inner surface of the tube to facilitate the lifting of the heating unit 302 and the catalyst carrier 2; there are four fixing feet 3012 on the outer surface of the tube to facilitate the stable placement of the device; the total length of the catalyst housing 3 is slightly shorter than the catalyst carrier 2 to reserve a flange disassembly position. The reserved space between the heating unit 302 of the catalyst housing 3 and the shell 301 should be filled with high temperature resistant and flameproof insulation materials to improve the insulation efficiency and prevent the catalyst housing 3 from overheating.

[0044] In summary, the present invention discloses a formic acid steam catalyst device that is convenient to disassemble and attach to a formic acid atmosphere reactor, and a formic acid steam catalyst device that is convenient to attach to a commercial formic acid atmosphere furnace to solve the efficiency problem of the existing formic acid atmosphere furnace. Under the premise of ensuring the air tightness of the original machine, the in-situ activation of the formic acid atmosphere is realized. It has the advantages of convenient installation and disassembly, reversible modification of the gas path, easy maintenance of the catalytic module, and replaceable catalytic body. It includes a catalyst 1, a catalyst carrier 2 and a catalyst shell 3. The catalyst 1 is a honeycomb gas channel with a catalytic material coated on the inner surface, which has a roughly tubular shape forming a gas flow channel. The catalyst carrier 2 has a detachable design that is convenient for catalyst replacement and maintenance, and has an airtight design for positive or negative pressure conditions. At the same time, according to the positive or negative pressure conditions during service, two flange structures are designed, equipped with a quickly detachable FPA bead joint or a pneumatic quick-connect joint. The catalyst shell 3 includes a fan-shaped temperature control heater and a thermal insulation material covering the catalyst carrier 2. The present invention can realize in-situ activation of atmosphere in a formic acid atmosphere furnace by means of additional components without modifying the gas circuit, and can replace the catalyst according to the situation, thereby shortening the process time and lowering the process temperature, improving product quality and process efficiency, and reducing the cost of machine purchase and modification.

[0045] The formic acid vapor catalyst device is used in a lead-free solder reflow and chip mounting atmosphere furnace.

[0046] The present invention is applied in a lead-free solder reflow and chip mounting atmosphere furnace. Compared with a formic acid atmosphere furnace without a catalytic device, the present invention can significantly improve the formic acid reduction efficiency, reduce the process temperature required for sintering by more than 30%, and significantly improve the mechanical properties of the sintered layer, shorten the process time, and improve product quality and process efficiency.

[0047] Example 1 A formic acid vapor catalyst device that is easy to disassemble and assemble and its application

[0048] like Figures 1 to 4 As shown, the formic acid steam catalyst device of this embodiment 1, which is convenient for disassembly and assembly, includes a catalyst 1, a catalyst carrier 2, and a catalyst housing 3. The catalyst carrier 2 is equipped with two flanges for negative pressure and positive pressure: a flange 202 for normal pressure-negative pressure and a flange 203 for normal pressure-positive pressure. The flange used for negative pressure is a resin flange with a high-diameter flange pipe, and the ends of the flange pipes at both ends have FPA bead joints, one male and one female respectively; the flange used for positive pressure is a flange with a flat sealing groove and a pneumatic quick joint connected by a thread. Two fan-shaped heating units 302 are arranged in the catalyst housing 3 to wrap the catalyst carrier 2 for overall heating. Among them, the surface of the fan-shaped heating unit has a wiring place 3021 and a thermocouple jack 3022, which are connected to the AC temperature controller. The flanges at both ends are sealed, inserted into the fan-shaped heating unit 302, and then inserted into the catalyst housing 3 filled with flame-retardant and heat-insulating materials, and the housing cover 303 is covered for use.

[0049] When using:

[0050] Negative pressure working condition: Cut the middle of the machine formic acid pipe and install one male and one female FPA bead connector. The machine end bead connector (male) is connected to the catalyst carrier 2 bead connector (female), and the other end is connected to the gas path in the same way.

[0051] Positive pressure working condition: cut the middle of the machine formic acid pipe, connect the original gas path to the pneumatic joints at both ends of the catalyst carrier 2, and the connection can be completed.

[0052] Afterwards, the original gas path and the catalyst 1 can maintain a positive pressure or negative pressure state for a long time, and the formic acid vapor will be introduced into the atmosphere furnace cavity through the air inlet, the preheated catalyst 1, and the air outlet.

[0053] When replacing the catalyst:

[0054] Open the outer shell cover 303, remove the flange, and replace the internal catalyst 1.

[0055] Restore the original gas path:

[0056] Negative pressure working condition: unscrew and remove the two ends of the FPA bead-in connector that connects the machine to the catalyst, and then connect the FPA male and female bead-in connectors on the original air line of the machine to restore.

[0057] Positive pressure working condition: remove both ends of the pneumatic quick connectors connecting the machine to the catalyst, and equip it with a double-head pneumatic connector to restore it.

[0058] like Figure 5 As shown in the figure, the chip mounting strength of the same nano copper paste in nitrogen, formic acid, and catalytic formic acid atmospheres. It can be seen that under the low temperature process of 210℃, catalytic formic acid can obtain the chip mounting structure with the best mechanical properties, and its mechanical properties are better than those obtained under the 300℃ process in the uncatalyzed formic acid atmosphere, indicating that this process can greatly reduce the sintering temperature of the nano copper paste while improving its performance.

[0059] like Figure 6 As shown in the figure, the shear section microstructure of the nano copper paste sintered layer and the corresponding EDS element analysis. It can be seen that the sintered layer is completely composed of pure copper with high thermal conductivity, electrical conductivity and stability, with less organic residue. The shell formed by the nano copper particles in the process constitutes a dense and continuous organization, indicating that the modified structure is sufficient to provide excellent thermal, electrical and mechanical support.

[0060] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application. The above are only preferred implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A formic acid vapor catalyst device that is easy to disassemble and attach, characterized in that: include: A catalyst (1), the catalyst (1) comprising a honeycomb-shaped gas channel, the inner surface of the honeycomb-shaped gas channel being coated with a catalyst layer; The catalyst carrier (2) is used to carry and seal the catalyst (1), and the catalyst carrier (2) is provided with an interface connected to the gas path of the formic acid atmosphere furnace.

2. The formic acid vapor catalyst device according to claim 1, characterized in that: The catalyst (1) further comprises a catalyst shell, wherein the catalyst shell is located at the periphery of the honeycomb-shaped gas channel, and the honeycomb-shaped gas channel is composed of a through-hole honeycomb catalyst carrier.

3. The formic acid vapor catalyst device according to claim 2, characterized in that: The through holes of the through-hole honeycomb catalytic carrier are 300-500 meshes, the shape of the holes is circular or non-circular, the material is ceramic or metal alloy, the thickness of the catalyst layer is 0.3-0.5 mm, and the catalyst is Pt, PtPd or / and PtRh.

4. The formic acid vapor catalyst device according to claim 1, characterized in that: The catalyst carrier (2) is longer than the catalyst (1), the inner diameter of the catalyst carrier (2) is loosely matched with the outer diameter of the catalyst (1), and both ends of the catalyst carrier (2) are provided with integral flange structures.

5. The formic acid vapor catalyst device according to claim 4, characterized in that: The two ends of the catalyst carrier (2) are respectively provided with a first plane sealing groove (201), a sealing ring is provided in the groove, and a flange (202) suitable for normal pressure-negative pressure operation or a flange (203) suitable for normal pressure-positive pressure operation is matched; The normal pressure-negative pressure working flange (202) is made of resin and comprises a flange pipe integrally formed with the normal pressure-negative pressure working flange, and a female FPA bead connector and a male FPA bead connector are respectively provided at the two ends of the flange pipe; The flange (203) working under normal pressure and positive pressure is made of resin or corrosion-resistant metal. A screw hole is provided in the middle of the flange. A second plane sealing groove (204) and a sealing ring are provided outside the screw hole. The thread is a sealed threaded through hole and is equipped with a stainless steel or copper joint.

6. The formic acid vapor catalyst device according to claim 5, characterized in that: The material of the flange (202) working at normal pressure and negative pressure includes polyimide, silicone resin or PFA plastic; the material of the flange (203) working at normal pressure and positive pressure includes polyimide, silicone resin, PFA plastic, stainless steel or copper alloy.

7. The formic acid vapor catalyst device according to claim 1, characterized in that: The invention also comprises a catalytic body shell (3), the catalytic body shell (3) is used to cover the catalyst carrier (2), and comprises: a shell (301), a heating unit (302) and a shell cover (303); the heating unit (302) is provided on the inner side of the shell (301), the heating unit (302) covers the outer periphery of the catalyst carrier (2), the heating unit (302) is provided with a wiring point (3021) and a thermocouple jack (3022), and the shell cover (303) is located at both ends of the shell (301).

8. The formic acid vapor catalyst device according to claim 7, characterized in that: A supporting ring (3011) for supporting the heating unit (302) and the catalyst carrier (2) is provided on the inner surface of the shell (301), and a fixing foot (3012) is provided on the outer surface of the shell (301).

9. The formic acid vapor catalyst device according to claim 1, characterized in that: A gap is left between the heating unit (302) and the shell (301) for filling with high temperature resistant, flame retardant and heat-insulating material.

10. Use of the formic acid vapor catalyst device according to any one of claims 1 to 9 in a lead-free solder reflow and chip mounting atmosphere furnace.

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