JPH0257475B2 - - Google Patents

Description

[Detailed description of the invention]

Field of Application This invention relates to a method for manufacturing a cladding plate for electronic components, in which an adherend material is crimped on the entire surface or locally at required points on a metal or alloy substrate by cold welding. There is no need for subsequent diffusion annealing or strain relief annealing, the internal strain in the width direction of the cladding material is uniform, deformation after etching and punching is prevented, and quality and adhesion are good. This invention relates to a manufacturing method that enables highly efficient cladding of adherend materials. Background technology Fe-Ni sealing material (40~55% Ni-Fe)-Al plate, (substrate-adherent material, hereinafter the same arrangement) Fe-Ni sealing material (40~55% Ni-Fe) as a cladding material for electronic components. 55%Ni-Fe)-Ag brazing plate, Fe-Ni sealing material (40-55%Ni-Fe)-Ag
Plate, Kovar alloy plate (25~50%Ni−10~20%Co−
Fe)-Ag brazed plate, two-layer striped clad plate, etc.
Fe-Ni sealing material (40-55% Ni-Fe)-Al plate,
Kovar alloy plate (25~50%Ni−10~20%Co−)
Fully clad plates made of Fe)-Ag solder plates, etc. are used. For example, in the production of Al striped electronic component cladding materials, a metal substrate strip of 42% Ni-Fe alloy is annealed in a reducing atmosphere, the substrate surface is cleaned, and then the surface to be cold-welded is The part is cleaned by wire brushing, and one or multiple Al strips in a desired pattern are superimposed on this substrate and cold welded using rolling rolls, and after welding, or at least one cold rolling process. After this, diffusion annealing is performed at 600°C or less to completely bond the Al strip to the metal substrate, and cold rolling is performed at least once to adjust the dimensions and shape of the cladding material. Furthermore, in order to remove the internal stress strain that remains unevenly in the width direction of the substrate due to the striped cladding or the residual strain at the edge after punching, heat treatment is performed at a temperature of 550°C or lower, or heat treatment is performed at a temperature of 550°C or lower. Generally, a manufacturing method is adopted in which tension is applied to the cladding strip to add elongation and correction. However, in the case of a so-called striped clad board in which one or more stripes of adherend material are provided on the surface of the substrate,
In mechanical polishing such as wire brushing, the surface of the substrate other than the surface scheduled for pressure welding, for example, the entire surface, is polished, and as a result of polishing, cracks occur, scale-like metal powder is generated, adhesion, and foreign matter remain on the polished surface. There is a risk that metal powder, foreign matter, or gas may be drawn into the pressure contact surface during pressure welding of adherends, resulting in a problem that the surface of the adherend may swell. Furthermore, in addition to problems such as deterioration of the quality of the surface of the clad plate, conventional manufacturing methods require a large number of steps and heat treatments, increasing manufacturing costs, and causing defects in the adhered materials during diffusion annealing. and deterioration of surface quality had become a problem. Furthermore, in the production of cladding plates, a method has been proposed in which a laser beam is irradiated onto the pressure-welding surface before cold pressure welding (Japanese Patent Application Laid-open No. 52-60256 and Japanese Patent Application Laid-open No. 114590-1983). In the method disclosed in the former publication, at least one of the moving metal plates is directed toward the other to form a V-shaped section, and a laser beam is focused on the contact part (the part to be welded) of the V-shaped part. Since welding is performed by irradiating the laser beam, it is extremely troublesome to adjust the laser beam to focus it on the V-shaped contact area.Also, the moving metal plate is transported while vibrating, so the focus of the laser beam is always adjusted to the welding position. It is not easy to be stabilized. In addition, the latter method does not focus on the welding part of the two metal plates to be welded (not in a focused state).
Since an energy beam is used, it is effectively used to directly heat the opposing surfaces of two metal plates, and there is no dissipation due to reflection, making it an extremely efficient welding method. However, since both of the above methods use an energy beam (laser beam) as a heat source for heating and welding the welding object, the formation of an alloy layer due to melting cannot be avoided, and the formation of an alloy layer becomes a problem. It is difficult to manufacture clad plates for electronic components using heat welding, and the thickness of the molten alloy layer is approximately 100 μm, so the thickness of the plate is approximately 100 μm.
It cannot be applied to the production of clad plates for electronic components using the following adherend materials and substrates. Purpose of the Invention The present invention solves the problems caused by cleaning the surface of a metal plate in the conventional cladding method, prevents blistering on the surface of the adherend and provides excellent cladding plate surface quality, which is indispensable in the past. The diffusion annealing process after cold pressure welding, which was previously required, can be omitted, and complete bonding can be achieved with only the cold pressure welding process.Furthermore, softening annealing may be performed if necessary to adjust the mechanical properties. The object of the present invention is to provide a method for manufacturing a clad plate for electronic components that can uniformize internal stress in the width direction of a metal substrate without strain relief annealing, and can prevent deformation after punching. Structure and Effects of the Invention The present invention has been made with the aim of creating a manufacturing method that can omit the diffusion annealing process after cold pressure welding in a manufacturing method for cladding materials for electronic components, and has also been developed to improve cleaning of substrate surfaces and cladding materials. As a result of various studies aimed at improving the quality of the adherend surface of the board and increasing the adhesion strength, we found that after preheating the surface of the substrate to be adhered to during running using a heating device in a non-oxidizing atmosphere,
By irradiating the surface of the substrate to be adhered with a laser beam uniformly over the entire surface, and by irradiating the laser beam with a wavelength that is easily absorbed by foreign matter, oil, fat, and moisture that cause bonding defects, foreign matter adhering to the surface can be removed.
Oils, fats, and water absorb laser light, gasify, and remove, resulting in a clean surface. When an adherend material is pressed onto the surface, interatomic bonds easily occur because the surface is clean, making it difficult to use in practical applications. It has been found that sufficient adhesion strength can be obtained without causing any problems. Furthermore, by using a laser beam with a wavelength that is easily absorbed not only by foreign objects but also by the substrate, that is, a wavelength of 5 μm or less, the extreme surface layer of 2 μm or less, preferably on the submicron order, can be melted and solidified to form a hardened layer. During cold pressure welding of adherends, fine microcracks are formed on the surface of the hardened layer on the substrate surface due to sliding deformation, etc., and the exposure of the new surface significantly improves the adhesion strength between the substrate and the adherend. It is possible to prevent cracks on the surface, generation and adhesion of metal powder and residual foreign matter caused by conventional mechanical polishing, and there is no gas entrainment, eliminating swelling on the surface of the clad material, and eliminating the need for conventional diffusion annealing. I realized that it was no longer necessary. Furthermore, as a result of various studies on the application of this pressure welding method to cladding materials for lead frames with strict product shape and dimensional accuracy, we found that we formed concave grooves on one main surface of the metal substrate, A laser beam is irradiated onto the surface of the metal substrate including the concave groove positions on the other main surface opposite to the main surface to be formed, and when an adherend material is cold-pressed onto the surface of the irradiated layer of the substrate formed by the irradiation, the substrate width is The internal stress in the direction is equalized,
In particular, when the adherend material is Al, the above-mentioned diffusion annealing process and residual strain relief annealing process are unnecessary, and deformation after punching can be achieved by simply cold welding or cold rolling after cold welding. This invention was completed based on the discovery that a cladding plate for electronic parts without any cladding can be obtained. That is, the present invention forms at least one concave groove on one main surface of a metal or alloy substrate surface, and includes the concave groove as it is or after annealing the substrate in a non-oxidizing or reducing atmosphere. Alternatively, the substrate surface including the concave groove position on the other main surface opposite to the concave groove forming main surface is preheated as necessary and then irradiated with a laser beam, and the surface of the irradiated layer of the substrate formed by the irradiation is , a method for manufacturing a clad plate for electronic components, characterized by cold pressure welding of adherend materials. More specifically, the present invention provides a metal substrate having two smooth main surfaces, e.g.
Concave grooves equal to the cross-sectional area of the Al or Al alloy strips clad in the desired pattern are formed on one main surface of the Ni-Fe alloy or Kovar alloy by cold rolling in the same arrangement pattern. In order to remove residual strain, annealing is performed at 850°C to 1050°C in a non-oxidizing or reducing atmosphere, and then the recessed groove position on the opposite main surface including the recessed groove or on the side where no recessed groove is formed is A laser beam is irradiated onto the surface of the substrate containing the aluminum to form a molten solidified hardened layer on the irradiated surface, and Al and Al alloy strips are cold-pressed onto the surface hardened layer at a reduction rate of 25% to 70%. A crack is generated in the hardened layer, and within this crack, Al and Al alloy strips are formed.
During cold pressure welding, the material is pushed in and the pressure welding is complete, eliminating the need for diffusion annealing to stabilize the bond, which was previously considered indispensable.The internal strain of the clad material is evened out, making subsequent welding easier. No deformation or distortion occurs in the product during punching or etching, eliminating the need for distortion-relief annealing. Further, in the present invention, a substrate including grooves formed in a metal or alloy substrate formed with grooves and annealed in a non-oxidizing or reducing atmosphere, or including positions corresponding to the grooves on multiple sides on the opposite side from the main surface on which the grooves are formed. The surface is irradiated with a laser beam, but by preheating the surface before irradiation, a clad plate can be manufactured with high efficiency. Alternatively, it is also possible to manufacture the recessed groove by forming multiple grooves, performing the irradiation treatment described above, press-contacting multiple layers of the adherend material, and then slitting it to a desired width. Preferred Embodiment of the Invention In this invention, preheating is performed in a non-oxidizing atmosphere such as Ar or N ₂ gas or in a reducing atmosphere such as H ₂ gas, for example, using a light beam, YAG laser, CO ₂ laser, high frequency With a heating device such as
Preferably, it is preheated to 200°C to 1000°C. If the heating temperature is less than 200°C, it is unfavorable in terms of cleaning the surface, and if it exceeds 1000°C, it is unfavorable in terms of extreme surface oxidation or deformation of the substrate, so the preheating temperature is preferably 200°C to 1000°C. . In this invention, the laser beam irradiation method is to use a mirror to run a spot-shaped beam two-dimensionally on the surface to be adhered to the material to be adhered, or to spread the beam in the width direction of the plate using a mirror or lens. Either the beam is irradiated all at once and the entire surface to be coated is irradiated uniformly, or the beam is irradiated in a zigzag pattern, meandering, or partially in a striped manner over the surface to be coated. In addition, in this invention, the surface state of the adherend material partially irradiated with the laser beam is such that a hardened layer is formed by cleaning the irradiated surface and melting and solidifying the extreme surface layer, and the non-irradiated portion also forms a hardened layer as described above. The surface is cleaned by the thermal influence of the irradiated area. Therefore, when the adherend material is cold-welded to the laser beam irradiation area, as mentioned above, in the irradiation area,
Since the adherend material and the substrate material are firmly bonded and the surface of non-irradiated areas is also cleaned, the adhesion between the adherend material and the substrate material is improved and sufficient adhesive strength can be obtained. In this invention, the type and combination of the substrate and the adherend material may be any combination that can be used for cladding, and the laser beam irradiation may be applied as long as it can remove deposits, oils, and moisture from the surface, preferably 2 μm. Any method may be used as long as it is possible to melt and solidify the extreme surface layer described below.For example, the beam is focused in a spot shape and irradiated in a direction perpendicular to the substrate surface, and the substrate and the laser beam are aligned in the longitudinal direction of the substrate. It is possible to adopt methods such as moving the laser beam in the same direction or in the opposite direction, or moving the laser beam in the longitudinal direction of the substrate while vibrating the laser beam in the width direction of the substrate. Alternatively, a method may be adopted in which the laser beam is oscillated by a laser oscillator, focused by a collimator and a lens, and guided to a desired position by an optical fiber for irradiation. In this invention, the laser beam irradiation conditions are such that the beam power density is 100kW/mm ² ~
The range is preferably 1500kW/mm ² , more preferably 300kW/mm ² to 900kW/mm ² . If the power density of the laser beam is less than 100kW/mm ² , there is no surface cleaning effect for pressure welding, and if it exceeds 1500kW/mm ² , the surface becomes more uneven and holes are formed in the substrate as the power density increases. It generates and is undesirable. Further, it is effective if the laser wavelength is 5 μm or less, but if it exceeds 2 μm, the absorption effect on the substrate decreases, so it is desirable to use a wavelength of 2 μm or less. The metal or alloy substrate in this invention is Fe
-Ni-based sealing material (40-55% Ni-Fe), Kovar alloy plate (25-50% Ni-10-20% Co-Fe), Cu alloy plate (Be less than 1.1%, Ti less than 1.0%) , Cr1.6% or less,
Fe6.0% or less, Ni15.0% or less, Zn43% or less, B0.5
% or less, Si6.0% or less, Pb0.08% or less, P0.5 or less,
Te 0.6% or less, Mg 0.6% or less, Zr 0.7% or less, Mn7
% or less, Co2% or less, Ag1.5% or less, Cd1.3% or less, Al12% or less, Sn12% or less.However, if two or more types of additive elements are contained, the total amount is 45% or less. % or less, the balance consisting of Cu) is preferred. In addition, Al, Al alloy plate, Ag
Preferred are plates, Ag brazed plates, brass brazed plates, and soldered plates. Furthermore, in the case of a fully clad plate for electronic components according to the present invention, the thickness of the plate is 0.05 mm.
The thickness is preferably 1.0 mm to 1.0 mm, and in the case of a striped clad plate, the thickness is preferably 0.05 to 1.0 mm, and the thickness may be appropriately selected depending on the intended use. Disclosure of the Invention Based on Drawings FIG. 1 is a perspective explanatory view of a substrate showing the cladding method according to the invention. Here, an example will be described in which a single strip of Ag solder plate is cold-welded in the widthwise center of a 42% Ni-Fe alloy plate in the form of a stripe. The 42% NiFe alloy plate 1 coil is uncoiled, and then a concave groove forming roll 9 is used to form concave grooves on the lower surface.
After being annealed in the cold welding roll 2, the material is annealed. An irradiation box 3 is arranged behind the pressure roll 2 to irradiate the upper surface of the alloy plate 1 passing with a laser beam.The irradiation box 3 surrounds the entire alloy plate 1 and has Ar gas vented inside. , the configuration allows laser beam irradiation in an Ar gas atmosphere. A laser beam is emitted from a laser oscillator 4 such as a YAG laser, passes through a collimator 5 and a galvanic mirror 6, and then passes through an fθ lens 7.
After the light is condensed and focused, the position of the fθ lens 7 is adjusted so that a required width of the alloy plate 1 at the center in the width direction can be irradiated at a position separated by a required distance from the focal point. Note that the laser beam generator used in the present invention can increase the laser scanning speed by using a polyhedral mirror or a segment mirror instead of the galvanic mirror 6, and can increase the laser scanning speed by using a cylindrical lens. By irradiating the sheet width direction all at once, it is possible to improve the processing speed. The alloy plate 1 is irradiated with a laser beam in a zigzag or striped manner to melt and solidify the extreme surface layer at a required width at the center in the width direction, here, at a position corresponding to the recess grooves on the upper surface opposite to the recess grooves. This creates a new surface from which deposits, oil, and moisture have been removed. On the other hand, after being uncoiled, the Ag brazing plate 8 is fed from above the alloy plate 1 to the pressure welding roll 2.
It is pressed onto the surface irradiated by the laser beam irradiation. At this time, microcracks occur on the surface of the molten solidified layer on the irradiated surface due to sliding deformation due to pressure welding.
Since the internal newly formed surface is exposed and the Ag solder plate 8 is pressed against the surface, the cleanliness is superior compared to conventional mechanically polished surfaces, and the adhesion strength between the alloy plate 1 and the Ag solder plate 8 is improved. The rolling ratio can be lower than that of the conventional method, and soft products can be obtained with high efficiency. For example, in the case of lead frame materials, punching and bending are facilitated in the post-cladding process, which is extremely advantageous in improving the lead strength and quality of the material. In Fig. 1, we explained an example in which a single strip of adherend material was cold-welded on an alloy plate, but it can be manufactured in the same way whether it is the entire surface of the alloy plate or multiple strips, and excellent adhesion can be achieved. Strength and product properties can be obtained. Moreover, not only one main surface but also a double-sided clad plate in pressure contact with the other main surface can be manufactured in the same manner. Therefore, the oscillation method of the laser beam, the irradiation output, the distance between the focal point of the fθ lens and the irradiation surface, the moving speed of the irradiated side, etc., depend on the material and dimensions of the substrate material, as well as the material dimensions of the adhered material. It is necessary to select it appropriately. Examples Example 1 The metal substrate was made of 42Ni with a thickness of 1 mm and a width of 25 mm.
Fe alloy plate, adherend material: plate thickness 0.03mm, plate width 3.0mm
mm, 85Ag-Cu brazing plate was used. A single groove having a depth of 0.3 mm and a width of 3.0 mm was formed in the center of one main surface of the metal substrate by cold rolling. Then, the metal substrate strip was heated in hydrogen at 1000°C.
Annealed for 30 seconds. Thereafter, a laser beam was irradiated onto the concave grooves on the main surface where the concave grooves were formed. The irradiation conditions at that time were as follows. The atmospheric gas in the irradiation box was Ar gas, and the substrate movement speed was 10 m/min. The laser irradiation device has a wavelength of 1μm and an output of 100W.
Using a 10 kHz Q-switch YAG laser with a lens focal length of 100 mm, the method according to the invention shown in FIG.
A zigzag-shaped irradiation surface is formed by the laser beam continuously in the longitudinal direction of the substrate with a beam irradiation width of 3 mm and a pitch width of 0.5 mm, as shown in Fig. 2.
An irradiated part a and a non-irradiated part b are formed, and the Ag brazing plate is placed on the same irradiated surface using a pressure roll at a rolling rate of 60.
% cold pressure welding. After that, it is cold rolled once and has a thickness of 0.25.
A striped clad plate according to the present invention having dimensions of 25 mm and a plate width of 25 mm was obtained. The total rolling ratio is 75%.
It was hot. For comparison, using the same type of metal substrate and adhering material, the substrate surface was subjected to conventional mechanical polishing using a 0.1 mmφ wire rotating brush at a moving speed of 22 m/s. Ag brazing plates were cold-welded to obtain striped clad plates of the same size. The dimensions, appearance, and mechanical properties of the two types of clad plates obtained were examined, and the results are shown in Table 1. As is clear from Table 1, it can be seen that according to the method of the present invention, a soft product can be obtained, and a clad board with excellent appearance properties and extremely high quality can be obtained.

【table】

[Table] Example 2 42% Ni− with a thickness of 0.5 mm and a width of 23 mm on a metal substrate.
Using an Fe alloy plate, form a groove with a width of 5.5 mm and a depth of 0.1 mm in the center of one main surface of the metal substrate,
After annealing at 1000° C. for 30 seconds, the groove-corresponding position on the main surface opposite to the main surface forming the concave grooves was preheated to 400° C. with a light beam in an N ₂ gas atmosphere. Furthermore, using a Q-switch pulse laser with a wavelength of 1 μm and an output of 100 W, the laser beam was irradiated onto the metal substrate in a zigzag pattern as shown in Figure 2 under the same laser beam irradiation conditions as in Example 1, and the irradiated area was A and a non-irradiated part b are formed, and after cold welding of Al as the adherend material, one cold rolling is performed to obtain a sheet according to the present invention having dimensions of 0.25 mm in thickness and 23 mm in width. A striped clad plate was obtained.
Note that the total rolling reduction was 50%. Furthermore, we measured the hardness from the surface layer to the inside of the substrate after laser beam irradiation in the present invention before pressure contact, and the hardness condition from the surface layer to the inside after wire brushing in the comparative example.
The results are shown in the figure. As is clear from Figure 3, the surface layer after wire brushing has a thickness of about 10 μm and is hardened, and the hardened layer has a lower deformability than the inside.
Cracks occur due to deformation during pressure welding, and the adherend adheres well to the new surface that appears in the cracks. This can be understood from the fact that when heat treatment is performed as an adhesion test after pressure bonding, this crack becomes a starting point for diffusion. The above aspects that occur during wire brushing are:
It is effective as a surface treatment before pressure welding, but on the other hand, if such treatment is performed until the clean surface necessary for pressure welding is obtained by reducing deposits, oil, and moisture, the polished surface will become extremely rough and flaky metal will be removed. There is a risk of dust generation and adhesion and gas entrainment on the pressure contact surface, and it is difficult to apply such polishing to a narrow striped area on the substrate where the polishing is to be applied. On the other hand, with the laser beam irradiation according to the present invention, it is possible to apply the laser beam to the desired striped area as in the embodiment, and by selecting the irradiation conditions, the laser beam irradiation does not cause a rough surface and removes deposits, oil, fat, moisture, etc. is removed, and the thickness of the melt-solidified layer can be controlled. In addition, due to the generation of microcracks during pressure welding, the new surface of this melted solidified layer is distributed more uniformly and densely than in the comparative example, so the fact that the adherend adheres well is due to heat treatment, which prevents diffusion. This was also confirmed by the fact that the process progressed uniformly.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a substrate and an apparatus showing the cladding method according to the present invention. FIG. 2 is a top view of the substrate showing the laser beam irradiation method in the embodiment. FIG. 3 is a graph showing the relationship between substrate depth and Vickers hardness of a clad plate according to the present invention. DESCRIPTION OF SYMBOLS 1... Alloy plate, 2... Pressure roll, 3... Irradiation box, 4... Laser oscillator, 5... Collimator, 6...
Galvanic mirror, 7...fθ lens, 8...Ag brazing plate, 9...concave groove forming roll, 10...annealing furnace, a
...irradiated part, b... non-irradiated part.

Claims (1)

[Claims] 1. At least one concave groove is formed on one main surface of a metal or alloy substrate surface, and the substrate is annealed as it is or after annealing in a non-oxidizing or reducing atmosphere.
A laser beam is irradiated onto the substrate surface including the recessed grooves or the position of the recessed grooves on the other main surface opposite to the main surface where the recessed grooves are formed, and an adherend material is applied to the surface of the irradiated layer of the substrate formed by the irradiation. A method for manufacturing a cladding plate for electronic components, characterized by cold pressure welding. 2. Forming at least one concave groove on one main surface of a metal or alloy substrate surface, and then annealing the substrate as it is or in a non-oxidizing or reducing atmosphere,
After preheating the substrate surface including the recessed grooves or the position of the recessed grooves on the other main surface opposite to the main surface on which the recessed grooves are formed, the substrate surface is irradiated with a laser beam, and the substrate formed by the irradiation is heated. On the surface of the irradiated layer,
A method for manufacturing a clad plate for electronic components, which comprises cold pressure welding of adherend materials.