JPH04322889A - Clad stock and its production - Google Patents

Abstract

PURPOSE:To provide the clad stock and its manufacturing method by which thickness of an adherent foil wire can be set freely, for instance, within a wide range of 0.3mum-0.1mm by handling in the atmosphere and a press-contacting rolling method, and electronic stocks for various uses can be obtained easily ad efficiently. CONSTITUTION:By rewinding a pure Ag foil 1 coil, and radiating a YAG laser to the surface of the pure Ag foil 1 in an Ar atmospheric chamber 2, a non- contact type cleaning processing is executed, and also, by rewinding a Cu plate 3 coil, cleaning the surface with a wire brush 4, and thereafter, butting the Ag foil 1 and the cleaned surface and executing cold press-contacting, and thereafter, diffusion annealing is performed, and an Ag clad Cu plate on which an adherent stock foil adheres to a base plate stock in one wire inlay wire is obtained.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a cladding material used as an electronic material, in which metal or alloy strips such as Ag are pressure-bonded in stripes on the surface of a substrate. By applying the method, the thickness of the adhered foil strip after pressure rolling in the atmosphere can be reduced to, for example, 0.3 μm to 0.1 mm.
The present invention relates to a cladding material that can be set in a wide range of settings and that can easily provide electronic materials for various uses, and a method for manufacturing the same.

0002

2. Description of the Related Art Metal or alloy clad strips coated with precious metals in stripes are used as electronic materials for contacts, connectors, lead frames, etc. In addition, for contacts and connectors, materials with high springiness are usually used for the metal substrate, such as phosphor bronze, beryllium copper, brass, and stainless steel materials, and A
g or Ag alloy, etc. are deposited.

On the other hand, in lead frames as well, when Au is used as the wire for connecting the lead frames, Au or Ag is deposited on the wire bonding portions of the lead frames.

[0004] In addition, a structure in which a Fe--Cu alloy is clad with a Ni--Cu alloy is used as a contact material. Additionally, the applicant has proposed a structure in which a Cu alloy is clad with high-purity Cu as a lead frame material (Patent Application No. 2-8
No. 6380).

[0005] Metal or alloy clad strips coated with Ag in stripes have conventionally been produced by electroplating. On the other hand, the pressure welding method using rolls is advantageous in terms of production efficiency, cost, and accuracy, but it is necessary to polish the surface of the material to be bonded with a wire brush or the like before pressure welding. However, the surface of precious metal foil cannot be cleaned by polishing because it is damaged during polishing.In particular, Ag tends to form sulfides and oxides on its surface, and the surface of Ag foil stored in the atmosphere cannot be cleaned. Normally, sulfides and oxides are formed, and even if pressure welding is performed in that state, the sulfides and oxides will interfere with the bonding at the bonding interface, making it impossible to obtain sufficient bonding strength.
When joining Ag foils by cold pressure welding, for example, as shown in Example 1 of JP-A No. 62-263880 and Example 1 of JP-A No. 63-141734, which were previously proposed by the applicant, the Ag foil may become contaminated. It is essential that the Ag foil is not pressed against the surface immediately after it is made, or it must be pressed once after the Ag foil is made.
It was necessary to store it in an atmosphere and press it into the same atmosphere or immediately after taking it out from the atmosphere. For this reason, conventionally, cold pressure welding has been performed only for foil strips that do not require polishing, such as Al foil, and cold pressure welding has not been used for other types of foils.

[0006]

[Problems to be Solved by the Invention] Metal or alloy clad strips coated with Ag in stripes are manufactured by electroplating, but with the plating method it is necessary to cover unnecessary parts with masking tape. Further, since the tape is disposable, not only does it require extra auxiliary materials, but it is also difficult to accurately align the attachment position, resulting in a problem of poor positional accuracy of the adhered portion. moreover,
If the substrate material causes a chemical reaction with the plating solution, the intermediate layer must be plated separately, which increases processing costs.

[0007] Conventionally, the thickness of Ag foil strips that can be stably deposited using a pressure welding method using rolls has been limited to about 0.3 mm. If it was made thinner than this, it would tear during brushing for cleaning, making it virtually impossible to press it. When pressure-welding was performed using the conventional method, the thickness of Ag in the final product was approximately 0.1 mm. Further, although it is conceivable to repeat rolling many times, it is extremely inefficient and difficult to put into practical use industrially.

[0008] In the case of Ag material, the commercially available product is 0.185m.
There are m strips. Considerable care must be taken when polishing and pressing this material by brushing. In particular, it has been difficult to stably provide mass-produced products, such as twisting affecting the dimensional accuracy of the final product and disruption of Ag material supply due to breakage. In particular, if the thickness is less than 0.1 mm, cleaning by brushing becomes almost impossible. Therefore,
It is conceivable to press the Ag foil immediately after producing it as described above, but in industrial production it is difficult to produce and press the Ag foil continuously, and it is also difficult to press the Ag foil immediately after taking it out of the Ar storage atmosphere. Storage, handling, etc. are complicated, and it is difficult to say that this is a highly productive method. However, in order to obtain high-quality alloy foil cladding strips for electronic components, it is necessary to
Surface cleaning treatment of the adherend material such as foil is required.

[0009] In the electroplating method, the maximum thickness of Ag is 5 μm.
That's about it. Therefore, the maximum thickness by electroplating method is 5μ
It was not possible to obtain an Ag clad material having a thickness between m and the minimum thickness of 0.1 mm by the roll welding method.

On the other hand, in applications such as contacts and connectors, depending on the current capacity flowing through the Ag-adhered part, and in applications such as lead frames, depending on the thickness of the wire bonded to the Ag-adhered part. most efficient Ag
Although the thickness (amount) is selected, it has not always been possible to obtain an appropriate thickness due to limitations imposed by the above-mentioned manufacturing method.

Similar to Ag, materials that require cleaning treatment before pressure bonding, such as Cu and N, which tend to form oxides on the surface.
In applications using i and these alloys as adhering materials,
Both have the above-mentioned problems.

The present invention solves the above-mentioned problems of the clad material used as an electronic material, in which metal or alloy strips such as Ag are pressure-bonded in stripes on the substrate surface, and it can be handled in the atmosphere and by pressure-rolling. The object of the present invention is to provide a cladding material and a method for producing the same, in which the thickness of the adhered foil strip can be freely set within a wide range of, for example, 0.3 μm to 0.1 mm, and electronic materials for various uses can be easily and efficiently obtained. .

[0013]

[Means for Solving the Problems] This invention provides Ag, Cu,
The non-contact cleaning surface of at least one adherend material foil made of , Ni, or an alloy thereof and the cleaning surface of the substrate material are pressure-bonded and integrated, and the foil thickness is 0. This is a clad material characterized by having a thickness of 1 mm or less.

[0014] Furthermore, the present invention applies a non-contact cleaning method to the surface to be pressure-bonded of at least one adherend material foil made of Ag, Cu, Ni, or an alloy thereof having a thickness of 0.2 mm or less, and cleans the substrate material. A method for manufacturing a cladding material, characterized in that the surface of the cladding material which is to be pressed against the foil is subjected to a cleaning treatment, and then both are pressure-rolled so that the thickness of the pressed foil is 0.1 mm or less.

[0015]

[Operation] This invention uses pure Ag or A as the adherend material.
Thickness of g alloy (Ag-Cu, Ag-Cd, etc.) 0.2mm
Irradiate the surface of the following foil to be pressure welded with a YAG laser, etc.
After non-contact cleaning treatment, Fe-N was used as the substrate material.
i alloy, Fe-Ni-Co alloy, Fe-Ni-Cr alloy, pure Cu, Cr alloy, etc. are subjected to cleaning treatment with a wire brush etc. after softening annealing, and the cleaned side of the foil is placed on the pressure welding interface side.
It is characterized by pressure contact.

[0016] Ag foil exposed to the atmosphere tends to form sulfides on its surface, and since sulfides are porous, they grow quickly and adsorb moisture, so they can be used without surface treatment like Al foil. Pressure contact is not possible. Therefore, a non-contact cleaning process such as laser irradiation is applied to the Ag foil side, and a conventional cleaning process using a wire brush is applied to the substrate side, and then the clean surfaces are brought together and cold pressure welded. By applying a non-contact cleaning treatment to the adherend material foil, it is possible to use an adherend material foil with a thickness of 0.2 mm or less during handling and pressure rolling in the atmosphere, and the thickness of the Ag foil after pressure welding can be reduced. Cold pressure welding can now be freely set over a wide range of 0.3 μm to 0.1 mm. Further, the non-contact cleaning treatment of the adherend material has similar effects not only on Ag but also on Cu, Ni, and their alloys.

[0017] According to the present invention, the adherend material foil can be directly pressed onto the substrate by cold pressure welding, and the material is supplied by a mechanical guide ring, so that the positioning accuracy of the adherend material foil is good. Also,
Since a rolled material is used for the adherend material foil, there is little variation in the cladding thickness in the width direction and longitudinal direction. Furthermore, since it is manufactured using a pressure welding method, there is no need for plating solution treatment or indirect materials such as tape, which simplifies the process and improves manufacturing efficiency.

In the present invention, the cleaning treatment performed on the surface of the substrate to be pressed or the groove portion of the substrate provided as necessary includes polishing with a wire brush, buff polishing,
Laser irradiation, electron beam irradiation, ion sputtering, etc. can be employed. The preferred application conditions for the wire brush are when a rotating brush made of carbon steel wire with a diameter of 0.1 to 0.5 mm is used to polish the material surface to a so-called matte finish, and the finished surface roughness is 1.5 to 10 μm. It is.

In the present invention, in addition to the laser irradiation shown in the embodiment, electron beam irradiation, ion sputtering, etc. can be employed for the non-contact cleaning treatment of the adherend material foil. The atmosphere for laser irradiation may be air if it does not involve a temperature rise, such as in a laser scriber, but if it does involve a temperature rise, a non-oxidizing atmosphere such as an inert gas atmosphere or a reducing atmosphere is desirable. Preferred application conditions for the YAG laser are irradiation in an Ar atmosphere using an output of 100 W and a Q-SW oscillation frequency of 10 kHz. Note that the laser beam is scanned in the width direction of the plate using a galvanic mirror while moving the material in the longitudinal direction, and irradiates the entire surface of the adherend material so that no unscanned portion remains on the surface to be pressed. The scanning frequency of the galvanic mirror and the moving speed of the material may be appropriately selected depending on the material width, laser beam diameter, etc.

In this invention, the adherend material foil contains Ag,
Cu, Ni, or an alloy thereof is appropriately selected depending on the application, etc., but a plurality of foil strips made of the same type or different materials can be used depending on the pattern to be pressed against the substrate. The thickness of the adherend material foil before pressure bonding is preferably 0.2 mm or less,
Regarding the lower limit of the thickness, the groove depth on the substrate side that can be manufactured industrially is usually about 10 μm (0.01 mm), and if it is too thin, it will be difficult to handle, so the lower limit of the thickness is 0.01 mm.
That's about it. If a material thinner than this is available, it may be used.

[0021] The substrate material is appropriately selected depending on the use as an electronic material, but for lead frames, Fe-
Ni alloy, Fe-Ni-Co alloy, Fe-Cr alloy, and Fe, as well as copper-based lead frame materials, Cu-F
e alloy, Cu-Fe-Sn-P alloy, and for contacts and connectors, Cu, Cu alloy, Fe-Ni-Cr
Uses alloy, stainless steel, brass, and nickel silver. Furthermore, when used for decorative items, Cu, nickel silver, Ni, Ni-C
U alloy, brass, bronze, etc. can be used.

[0022] The softening annealing applied to the substrate material does not need to be performed on a substrate material that is already in a softened state, and since the annealing conditions differ depending on the substrate material, the temperature and time are selected depending on the material application.

[0023] In the cladding material obtained by the present invention, the thickness of the adherend material foil after pressure bonding can be freely set within a wide range of 0.3 μm to 0.1 mm. The thickness is 0.1 mm or less. For example, the thickness of the adherend material foil before pressure welding is 0.1 m.
Even if it is 0.1 mm, it will be less than 0.1 mm if it is pressed.

[0024]

[Example] Example 1 As shown in Fig. 1, one coil of pure Ag foil with a plate thickness of 0.01 mm and a plate width of 10 mm was unwound, and the surface of the pure Ag foil 1 was irradiated with a YAG laser in an Ar atmosphere chamber 2. After performing non-contact cleaning treatment, unwinding three coils of Cu plate with a thickness of 0.7 mm and a width of 30 mm, and cleaning the surface with a wire brush 4,
The Ag foils 1 were cold-pressed with their clean surfaces pressed against each other to make the clad plate thickness 0.3 mm, and then diffusion annealed at 500°C for 3 minutes to form an adherend material foil as shown in A in FIG. Ag coated on the substrate material in the form of a single inlay with a thickness of 3 μm
A clad Cu plate was obtained.

Example 2 As shown in FIG. 1, one coil of pure Ag foil with a plate thickness of 0.01 mm and a plate width of 10 mm was unwound in two strips, and pure A was heated in an Ar atmosphere chamber 2.
G foil 1 surface was irradiated with YAG laser for non-contact cleaning treatment, and Cu plate 3 with a plate thickness of 0.7 mm and a plate width of 60 mm was
After unwinding the coil and cleaning the surface with a wire brush 4, the two strips of Ag foil 1 were cold pressure welded with the cleaned surfaces brought together to make the clad plate thickness 0.3 mm.
Diffusion annealing was carried out at 0° C. for 3 minutes to obtain an Ag-clad Cu plate having a thickness of 3 μm in which a two-strip inlay of the adherend material foil as shown in FIG. 2B was adhered to the substrate material.

Example 3 YA was applied to the surface of a pure Ag foil with a thickness of 0.03 mm and a width of 10 mm.
G laser irradiation in Ar atmosphere, plate thickness 1.0 mm,
An Fe-42%Ni alloy plate with a width of 35 mm was annealed, then wire brushed, and cold pressure welded with the laser-treated surface of the Ag foil facing the substrate to a plate thickness of 0.25 mm, followed by diffusion annealing. Ag clad Fe-42 as shown in A of
%Ni alloy plate was obtained. Using the obtained Ag-clad Fe-42%Ni alloy plate with an Ag thickness of 7 μm, as shown in FIG.
The lead frame covered with foil 1 was punched and molded. For comparison, Ag was plated into 5 stripes.
When a lead frame was punched out from a μm-thick Fe-42%Ni alloy plate and the solder wettability of the Ag surface was examined, it was found that the Ag of the cladding material of this invention had a solder wettability equal to or higher than that of conventional plating. Indicated.

Example 4 YA was applied to the surface of a pure Ag foil with a thickness of 0.04 mm and a width of 10 mm.
G laser irradiation in Ar atmosphere, plate thickness 1.0 mm,
An Fe-42%Ni alloy plate with a plate width of 35 mm was annealed, then wire brushed, and cold pressure welded with the laser treated surface of the Ag foil facing the substrate to a plate thickness of 0.25 mm. After that, diffusion annealing was performed to adjust the Ag thickness. Ag-clad Fe-4 with a diameter of 10 μm
A 2% Ni alloy plate was obtained.

Example 5 A YAG laser was irradiated on the surface of a Ni-70% Cu alloy foil with a thickness of 0.03 mm and a width of 10 mm in an Ar atmosphere. After annealing the alloy plate, the foil was wire brushed, the laser-treated surface of the foil was placed on the substrate side, and cold pressure welded to a plate thickness of 0.3 mm. After that, diffusion annealing was performed to form a Ni-Cu alloy with a thickness of 7 μm.
An i-Cu alloy clad Fe-42%Ni alloy plate was obtained.

Example 6 YA was applied to the surface of a pure Cu foil with a thickness of 0.02 mm and a width of 10 mm.
G laser irradiation in Ar atmosphere, plate thickness 1.0 mm,
Wire brushing a Cu-2% Fe alloy plate with a plate width of 35 mm, cold pressure welding the foil with the laser treated side facing the substrate, and after making the plate thickness 0.25 mm, diffusion annealing was performed,
A pure Cu clad Cu-2% Fe alloy plate having a pure Cu thickness of 5 μm was obtained.

[0030]

Effects of the Invention This invention performs a non-contact cleaning treatment such as laser irradiation on the foil side of the adherend material such as Ag foil, and performs cleaning treatment with a wire brush etc. on the substrate side, and then The method involves cold pressure welding by butting together the adherend materials, which can be handled and pressure rolled in the atmosphere through a non-contact cleaning treatment of the adherend materials, and which uses adherend material foils with a thickness of 0.2 mm or less. As shown in the examples, cold pressure welding became possible in which the thickness of the Ag foil after pressure welding could be freely set within a wide range of 0.3 μm to 0.1 mm.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the manufacturing method of the present invention.

FIG. 2 is a perspective explanatory view of a clad plate according to the present invention.

FIG. 3 is a perspective explanatory view showing an example of a lead frame.

[Explanation of symbols]

1 Ag foil 2 Ar atmosphere chamber 3 Cu board 4 Wire brush

Claims (2)

[Claims] [Claim 1] A non-contact cleaning surface of at least one adherend material foil made of Ag, Cu, Ni, or an alloy thereof and a surface of the substrate material that has been cleaned are pressure-bonded and integrated. A cladding material characterized in that the foil thickness is 0.1 mm or less. [Claim 2] Ag, Cu, N with a thickness of 0.2 mm or less
A non-contact cleaning method is applied to the surface of the foil of at least one adherend material made of i or an alloy thereof, and the surface of the substrate material that is to be pressed to the foil is subjected to a cleaning treatment, and then the two are pressure-bonded. A method for producing a cladding material, characterized in that the thickness of the rolled and pressure-welded foil is 0.1 mm or less.