JP2017160501A - Long-sized material of copper-molybdenum composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-sized material of a copper-molybdenum composite material that has a thin thickness as well as being long-sized.SOLUTION: The long-sized material of a copper-molybdenum composite material is a long-sized material of a copper-molybdenum composite material having a thickness of 0.1 mm or less and a length of 3 m or more.SELECTED DRAWING: None

Description

  The present invention relates to a long material of a copper-molybdenum composite material.

  Conventionally, copper-molybdenum composite materials are disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-121039 (Patent Document 1) and Japanese Patent No. 4615312 (Patent Document 2).

  Patent Document 1 discloses a hoop-like material of a copper-molybdenum composite material having a width of 20 mm, a thickness of 1.5 mm, and a length of about 300 mm by rolling, in paragraph 0051.

  In Patent Document 2, it is disclosed in paragraph 0079 that a rolling hoop of a copper-molybdenum composite material was obtained by hot rolling a rectangular material (temperature 150 to 300 ° C., processing rate 30 to 90%). Has been.

Japanese Patent Application Laid-Open No. 2002-121639 Japanese Patent No. 4615312

  However, in the prior art, the thickness of the copper-molybdenum composite material could not be made 0.1 mm or less and the length 3 m or more.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a long copper-molybdenum composite material having a small thickness.

  The long material of the copper-molybdenum composite material according to one embodiment of the present invention is a long material of a copper-molybdenum composite material having a thickness of 0.1 mm or less and a length of 3 m or more.

  According to the above, it is possible to provide a long material of a thin copper-molybdenum composite material having a small thickness.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.

1. Overall Configuration The long material of the copper-molybdenum composite material according to one embodiment of the present invention has a thickness of 0.1 mm or less and a length of 3 m or more.

  The long material of the copper-molybdenum composite material has a thickness of 0.1 mm or less. More preferably, it is 08 mm or less. By using this range, the above-mentioned copper-molybdenum composite lead frame, the extremely thin thermal stress buffer material interposed between the objects having different thermal expansion coefficients, or the extremely thin heat spreader, etc. are formed by continuous press punching. -Can be manufactured easily and inexpensively from a long material of molybdenum composite material. The thickness of the long material of the copper-molybdenum composite material is preferably 0.02 mm or more. If the thickness is less than 0.02 mm, the strength of the long material of the copper-molybdenum composite material may be insufficient.

  Note that “probable” indicates that there is a slight possibility that this will occur, and it does not mean that it will occur with a high probability.

  The measuring method of the thickness of the long material is as follows. At each of the both ends in the longitudinal direction of the long material and the substantially central portion, the thickness of the central portion in the width direction of the long material is measured at 10 locations at intervals of 5 cm in the longitudinal direction. Specifically, 10 points are measured in the region A at one end, 10 points are measured in the region B at the substantially central portion, 10 points are measured in the region C at the other end, and these are totaled. Let the average value of the measured value of a total of 30 places be the thickness of a long material. However, the range of less than 30 cm in the longitudinal direction from both extreme ends in the longitudinal direction of the long material was excluded from measurement. The measurement at both ends (region A and region C) in the longitudinal direction of the long material was started from a point of 30 cm in the longitudinal direction from both extreme ends.

  The variation in the thickness of the long material of the copper-molybdenum composite material is preferably within 20% of the thickness of the long material. More preferably, it is within 10%.

  The thickness variation in the present invention means that the measured values at the 30 locations are Tn (n = 1-30), and the average value of the measured values at the 30 locations is Tave ((T1 + T2 +... + T30) / 30). Of | Tn−Tave |.

  The length of the long material of the copper-molybdenum composite material is 3 m or more. Preferably, it is 10 m or more. Moreover, 5000 m or less is preferable. By setting the length to 3 m or more, it can be wound on a reel or the like and used as a hoop material. Continuous press punching can be performed. Although it may be as long as it is 3 m or more, it is preferably 5000 m or less from the viewpoint of actual use as a hoop material.

  The width of the long material of the copper-molybdenum composite material can be appropriately determined depending on the application. Usually, it is 4 mm or more and 100 mm or less.

2. Composition The copper composition of the long copper-molybdenum composite material is preferably 14% by volume (13% by mass) or more and 67% by volume (64% by mass) or less. When the range of copper exceeds this, the amount of copper having a large thermal expansion coefficient increases, so that the linear expansion coefficient also increases in the copper-molybdenum composite. In that case, there is a possibility that desired characteristics cannot be obtained in applications where the linear expansion coefficient needs to be reduced. If it is less than this, the amount of copper having a high thermal conductivity is reduced. As a result, the thermal conductivity of the copper-molybdenum alloy composite may be reduced. In applications that require high thermal conductivity, such as a heat sink, there is a possibility that desired characteristics cannot be obtained.

  In the long material of the copper-molybdenum composite material of the present invention, a part or all of the copper may be replaced with silver (Ag). However, from the viewpoint of cost, the content of Ag is preferably 0% by mass or more and 5% by mass or less.

  Moreover, 1 mass% or less of elements other than molybdenum, copper, and silver may be contained in the long material of the copper-molybdenum composite material of the present invention.

  Elements other than molybdenum, copper, and silver include oxygen (O), carbon (C), iron (Fe), nickel (Ni), chromium (Cr), magnesium (Mg), potassium (K), and calcium (Ca). , Tungsten (W), silicon (Si), aluminum (Al), lead (Pb), tin (Sn), manganese (Mn), and the like.

  Although the thermal expansion coefficient of the long material of the copper-molybdenum composite material is substantially determined by the above composition, the thermal expansion coefficient is preferably 7.0 ppm / ° C. or higher and 13.2 ppm / ° C. or lower.

  By setting this range, when a lead frame or the like formed from a long copper-molybdenum composite material is attached to a member for a semiconductor device having a low thermal expansion such as ceramics, or a semiconductor element is mounted on the lead frame or the like. In such a case, the thermal stress due to the difference in thermal expansion can be relaxed. As a result, the reliability of the semiconductor device can be improved.

  A surface coating layer such as plating may be formed on the surface of the long material of the copper-molybdenum composite material. As the surface coating layer, nickel (Ni), nickel-phosphorus (Ni-P), nickel-boron (Ni-B), copper (Cu), silver (Ag), gold (Au), ruthenium (Ru), rhodium (Rh) and a laminate thereof may be used.

3. Method for Producing Long Material of Copper-Molybdenum Composite Material An example of a method for producing a long material of a copper-molybdenum composite material is shown below. In addition, the manufacturing method of the elongate material of a copper-molybdenum composite material is not restricted to the following description.

(1) Production of copper-molybdenum composite material ingot (copper-molybdenum plate) First, a copper-molybdenum composite material is produced from raw materials.

(1-1) Molybdenum porous body manufacturing process Molybdenum powder is used as a raw material. This powder is formed using a press. This molded body is fired in a hydrogen atmosphere using a firing furnace to obtain a molybdenum porous body.

  The FSSS (Fisher Sub Sieve Sizer) particle size of the molybdenum powder is preferably 1 μm or more and 10 μm or less.

  When the particle diameter exceeds 10 μm, the molybdenum powder is further coarsened by grain growth during sintering, and there is a possibility that the positional variation of the thermal conductivity becomes large. The particle size may be less than 1 μm, but the molybdenum powder becomes expensive, resulting in high cost.

Molded density, 3 g / cm ³ or more, 9 g / cm ³ or less. If it is out of this range, the density of the fired porous molybdenum (skeleton) may not be within the following range.

  The firing atmosphere may be an inert gas atmosphere such as argon in addition to a hydrogen atmosphere. The firing temperature is preferably 1200 ° C. or higher and 1400 ° C. or lower, and the firing time is preferably 0.5 hour or longer and 20 hours or shorter. When either one of the firing temperature and firing time exceeds 1400 ° C. and 20 hours, the sintering proceeds excessively, and there is a possibility that independent vacancies (closed pores or voids) are generated in part. If the firing temperature and firing time are less than either 1200 ° C. or 0.5 hour, the bonding force between the molybdenum particles becomes weak, and the molybdenum porous body may not be able to form a strong skeleton. In that case, there is a possibility that the effect of reducing the thermal expansion coefficient of the strong molybdenum skeleton cannot be exhibited.

The density of the molybdenum porous body (skeleton) is preferably 1.0 g / cm ³ or more and 7.0 g / cm ³ or less. The porosity is preferably 14% by volume or more and 67% by volume or less. If the density is out of this range, the copper composition of the copper-molybdenum composite after copper infiltration (next step) cannot be made within the following range.

  By appropriately adjusting the molding density and the firing temperature, a molybdenum porous body having a porosity of 14% by volume to 67% by volume can be obtained. A complex can be obtained.

(1-2) Copper Infiltration Step A copper plate is placed on the obtained molybdenum porous body and heated in a hydrogen atmosphere using a firing furnace to infiltrate copper into the voids of the molybdenum porous body. Thereafter, excess copper is removed to prepare an ingot of a copper-molybdenum composite.

The atmosphere during infiltration may be an inert gas atmosphere such as argon in addition to a hydrogen atmosphere.
The infiltration temperature is preferably 1200 ° C. or higher and 1400 ° C. or lower. The infiltration time is preferably 0.5 hours or more and 20 hours or less. If at least one of 1400 ° C. and 20 hours is exceeded, the progress of the sintering of molybdenum becomes excessive even during the infiltration process, and the desired copper content may not be obtained. If it is less than at least one of 1200 ° C. and 0.5 hours, copper is not sufficiently filled in the voids of molybdenum, and voids are generated, which may reduce the thermal conductivity of the copper-molybdenum composite.

  The copper composition of the copper-molybdenum composite is the same as the preferred range of the composition of the long material / hoop material of the copper-molybdenum composite material.

  The method for producing an ingot of a copper-molybdenum composite according to (1-1) and (1-2) described above is a sintered body (porous body, made of low thermal expansion particles (molybdenum) formed in the shape of a base material in advance. This is a method (so-called infiltration method) of impregnating a high heat conductive metal (copper) melted into a skeleton). However, the method for manufacturing an ingot of a copper-molybdenum composite is not limited to this manufacturing method, and a high heat conductive metal (copper). ) Powder and low thermal expansion particles (molybdenum) are mixed, stamped and then sintered, filled with low thermal expansion particles in the mold corresponding to the shape of the substrate, and then melted in the mold Those prepared by various methods such as a method of impregnating a high heat conductive metal can be used.

(2) Production of long material of copper-molybdenum composite material The ingot of the copper-molybdenum composite material manufactured in the above-described process is formed into a long material by rolling.

(2-1) Warm rolling step This copper-molybdenum composite ingot is warm-rolled in the atmosphere using a two-stage rolling mill, cut to a predetermined size, and then hydrogenated using a belt furnace. Annealing is performed in the atmosphere. The atmosphere during the warm rolling may be an inert gas atmosphere such as argon in addition to the air atmosphere. The temperature of the ingot during warm rolling is preferably 100 ° C. or higher and 190 ° C. or lower. Exceeding this causes molybdenum in the copper-molybdenum to begin to oxidize, which may cause defects in the bonding of the copper-molybdenum on the surface layer, which may cause peeling of the surface layer, which may cause cracks and cracks.

  If it is less than this, the copper-molybdenum material cannot be sufficiently softened, and cracks and cracks may occur during rolling.

  The rolling reduction in the warm rolling process is preferably 70% or more and 90% or less. If it exceeds this, there is a risk of cracks and cracks due to work hardening by rolling. If it is less than this, the thickness may not be sufficiently reduced in the warm rolling process. As a result, when rolling further thinly in the subsequent steps, there is a possibility that rolling to a desired thickness cannot be performed, or that troubles such as generation of cracks and cracks may occur.

  The thickness of the copper-molybdenum composite after warm rolling is preferably 2 mm or more and 3 mm or less. If the thickness exceeds 3 mm, the thickness cannot be sufficiently reduced in the warm rolling process. Therefore, when rolling further thinly in the subsequent processes, it may not be possible to roll to a desired thickness, or problems such as cracks and cracks may occur. There is a risk of it coming. If it is less than 2 mm, cracks and cracks may occur in the warm rolling process. The annealing atmosphere may be an inert gas atmosphere such as argon in addition to the hydrogen atmosphere.

  The annealing temperature / time is preferably 700 ° C. or more and 900 ° C. or less, and preferably 0.3 hours or more and 20 hours or less. If the annealing temperature and time exceeds either 900 ° C. or 20 hours, it may be too soft and difficult to handle. If the annealing temperature and time are less than either 700 ° C. or 0.3 hours, distortion during rolling cannot be sufficiently removed, and cracking or cracking may occur when rolling further thinly in the subsequent steps. is there.

(2-2) Cold rolling process The copper-molybdenum composite after the warm rolling is cold rolled in the air using a four-high rolling mill. Then, it cut | disconnects so that it may become a predetermined dimension, and it anneals in a hydrogen atmosphere using a continuous furnace.

Note that cold rolling refers to rolling at room temperature (10 ° C. to 30 ° C.).
The same cold rolling process is repeated until the copper-molybdenum composite has a thickness of 0.12 mm.

  The rolling reduction of one cold rolling is preferably 3% or more and 7% or less. This cold rolling is repeated until a predetermined thickness is reached. When the rolling reduction exceeds 7%, a load more than necessary is applied to the material, and there is a possibility that cracking or cracking may occur. If the rolling reduction is less than 3%, uniform rolling cannot be performed in the thickness direction, and only the surface is rolled, so that distortion may occur and the rolled copper-molybdenum composite may be deformed.

The annealing atmosphere may be an inert gas atmosphere such as argon in addition to the hydrogen atmosphere.
The annealing temperature / time is preferably 700 ° C. or higher and 900 ° C. or lower, and more preferably 0.1 hour or longer and 20 hours or shorter. If it exceeds at least one of 900 ° C. and 20 hours, it may be too soft and difficult to handle. If it is less than at least one of 700 ° C. and 0.1 hour, the strain at the time of rolling cannot be sufficiently removed, and there is a possibility that cracking or cracking may occur at the next rolling.

(2-3) Final cold rolling step The copper-molybdenum composite after cold rolling having a thickness of 0.12 mm is melted in a mixed atmosphere of Ar and hydrogen using a continuous furnace. After annealing at a temperature close to, cold rolling is performed in the atmosphere using a four-high rolling mill until the thickness becomes 0.1 mm or less. Then, it cuts so that it may become a predetermined dimension.

Thereby, the elongate material of a copper-molybdenum composite can be obtained.
Moreover, a hoop material can be produced by winding this long material on a reel.

  Thus, by annealing at a temperature close to the melting temperature of copper and then cold rolling, the thickness of the copper-molybdenum composite is reduced to 0. 1 mm or less.

  The annealing atmosphere before final cold rolling may be a hydrogen atmosphere or an inert gas atmosphere such as argon in addition to the above atmosphere.

  The annealing temperature / time is preferably 1010 ° C. or higher and 1080 ° C. or lower, and more preferably 0.1 hour or longer and 2 hours or shorter. If the annealing temperature and time exceeds either 1080 ° C. or 2 hours, copper begins to elute, and copper and molybdenum may be separated. If the annealing temperature and time are less than either 1010 ° C. or 0.1 hour, distortion during rolling cannot be sufficiently removed and cracking or cracking may occur during rolling. Moreover, there exists a possibility that it may not become 0.1 mm or less which is desired thickness. Thus, by annealing at a temperature close to the melting temperature of copper and then cold rolling, the thickness of the copper-molybdenum composite is reduced to 0. 1 mm or less.

  The rolling reduction of the final cold rolling is preferably 3% or more and 7% or less per time. This is repeated until a predetermined thickness is reached. When the rolling reduction exceeds 7%, a load more than necessary is applied to the material, and there is a possibility that cracking or cracking may occur. If the rolling reduction is less than 3%, the desired thickness may not be 0.1 mm or less. In addition, the cost increases.

  After the final cold rolling step, annealing under appropriate conditions may be performed as necessary. It does not have to be done. For example, annealing in an inert gas atmosphere such as hydrogen gas or argon may be performed at 700 ° C. or higher and 900 ° C. or lower and 0.1 hour or longer and 2 hours or shorter.

4). EXAMPLES Hereinafter, the present invention will be described based on examples.

Example 1 (Sample No. 1)
(1) Manufacture of copper-molybdenum composite material ingot (copper-molybdenum plate) (1-1) Molybdenum porous body manufacturing process Molybdenum powder having a FSSS particle size of 4 μm by the Fischer method was used as a raw material. This powder was molded into a shape of 200 mm × 200 mm × 15 mm at a molding pressure of 100 MPa using a press machine. The molding density of the molded body after molding was 5 g / cm ³ . This molded body was fired at 1200 ° C. for 1 hour in a hydrogen atmosphere using a firing furnace to obtain a molybdenum porous body. The density of the porous molybdenum body after firing was 7 g / cm ³ and the porosity was 33% by volume.

(1-2) Copper infiltration step A copper plate having a purity of 99.9% (or oxygen-free copper) is arranged on the obtained molybdenum porous body, and is used in a hydrogen atmosphere in a hydrogen atmosphere at a temperature of 1200 ° C. for 1 hour. By heating, copper was infiltrated into the voids of the molybdenum porous body. Then, excess copper was removed to produce an ingot of a copper-molybdenum composite (33% by volume (30% by mass) copper) having a shape of 180 mm × 180 mm × 14 mm.

(2) Production of long material of copper-molybdenum composite material (2-1) Warm rolling step This copper-molybdenum composite ingot is in two steps until the thickness of the ingot is 160 ° C. and the thickness becomes 2.0 mm. After warm-rolling in the air using a rolling mill, it was cut into a length of 1000 mm × width of 160 mm, and annealed at 800 ° C. for 0.3 hours in a hydrogen atmosphere using a belt furnace.

(2-2) Cold rolling step The copper-molybdenum composite after the warm rolling is cold-rolled in the atmosphere using a four-high rolling mill, cut into a length of 16 m and a width of 150 mm, and a continuous furnace. Was annealed at 850 ° C. for 0.1 hour in a hydrogen atmosphere. This same cold rolling process was repeated until the thickness of the copper-molybdenum composite was 0.12 mm.

(2-3) Final cold rolling step The copper-molybdenum composite after cold rolling having a thickness of 0.12 mm was prepared using 10% Ar and 90% hydrogen by a continuous furnace. After annealing at 1050 ° C. for 0.25 hours in a mixed atmosphere, it is cold-rolled in air using a four-high rolling mill until the thickness becomes 0.05 mm, and the length is 26 m × width 140 mm Disconnected.

  Thereby, a long material of a copper-molybdenum composite having a length of 26 m, a width of 140 mm, and a thickness of 0.05 mm was obtained.

The thickness variation of the long material was 7% of the thickness of the long material.
Moreover, the hoop material was produced by winding this elongate material around a reel.

  Thus, by annealing at a temperature close to the melting temperature of copper and then cold rolling, the thickness of the copper-molybdenum composite is reduced to 0. 1 mm or less.

Next, the long material of sample number 2-22 was created.
Table 1 shows the physical properties such as the composition and thickness of the long material of Sample No. 2-22 and the manufacturing method thereof together with Sample No. 1.

The long materials of sample numbers 2 to 22 were manufactured based on the manufacturing method of sample number 1 in principle.
However, in Sample No. 2, the final cold rolling step (2-3) was not performed, and the cold rolling step (2-2) was repeated until there was no change in thickness. However, the thickness of the copper-molybdenum composite did not become 0.1 mm or less.

  In sample numbers 3 to 8, the copper composition of the copper-molybdenum composite was 33% by volume, and the annealing temperature in the final cold rolling step (2-3) was changed.

  In sample numbers 9 to 15, the copper composition of the copper-molybdenum composite was set to 15% by volume, and the annealing temperature in the final cold rolling step (2-3) was changed.

  In sample numbers 16 to 22, the copper composition of the copper-molybdenum composite was 65% by volume, and the annealing temperature in the final cold rolling step (2-3) was changed.

  In Sample No. 2, since the final cold rolling process was not performed, the thickness of the copper-molybdenum composite material did not become thinner than 0.12 mm even when the cold rolling process of (2-2) was repeated.

  In Sample Nos. 3, 9, and 16, the temperature was 1000 ° C. in the annealing of the final cold rolling process, so the temperature was low and the thickness was not thinner than 0.12 mm.

  In sample numbers 8, 15, and 22, the temperature was 1090 ° C. in the annealing in the final cold rolling process, so the temperature was high, and copper eluted and copper and molybdenum separated.

  In Sample Nos. 1, 4-7, 10-14, and 17-21, appropriate annealing was performed during the final cold rolling, and thus a long material having a thickness of 0.10 mm or less could be obtained.

  The embodiments and examples disclosed herein are illustrative in all respects and should not be construed as being restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include meanings equivalent to the scope of claims and all modifications within the scope.

  The present invention can be used, for example, in the field of a lead frame made of a long material of a copper-molybdenum composite material, a thermal stress buffer material, or a heat spreader.

Claims (7)

  A long material of a copper-molybdenum composite material having a thickness of 0.1 mm or less and a length of 3 m or more.   The long material of the copper-molybdenum composite material according to claim 1, wherein variation in thickness within one long material is 20% or less.   The long material of the copper-molybdenum composite material according to claim 1 or 2, which contains 14 vol% or more and 67 vol% of copper.   The long material of the copper-molybdenum composite material according to claim 3, wherein a part of the copper is replaced with silver, and the content of the silver is 5% by mass or less.   The long material of the copper-molybdenum composite material according to any one of claims 1 to 4, wherein a coefficient of thermal expansion is 7.0 ppm / ° C or more and 13.2 ppm / ° C or less.   A coating layer is formed on the surface, and the coating layer contains at least one selected from the group consisting of nickel, nickel-phosphorus, nickel-boron, copper, silver, gold, ruthenium, and rhodium. The elongate material of the copper-molybdenum composite material of any one of Claim 5.   The long material of the copper-molybdenum composite material according to any one of claims 1 to 6, wherein the thickness is 0.02 mm or more.