JP4608025B1 - Copper alloy strip for electronic equipment with excellent heat dissipation and resin adhesion - Google Patents

Abstract

Provided is a Cu-Fe-P copper alloy thin plate suitable for use as a heat dissipation substrate in a chip-on-board that has good resin adhesion and can efficiently dissipate heat generated by LED chips and the like. .
The alloy contains Fe; 1.5 to 2.4% by mass, P; 0.008 to 0.08% by mass, and Zn; 0.01 to 0.5% by mass, with the balance being Cu and inevitable impurities. The orientation density of the Cube orientation measured by the EBSD method in the crystal structure in the depth range of 10 μm from the surface of the copper alloy strip is 10 to 20%, and the average crystal grain size measured by the EBSD method 12 to 20 μm, the maximum height Rz of the surface of the portion where the surface of the copper alloy strip has been roughened by the surface treatment agent is 1.0 to 2.0 μm, and the surface of the portion that has not been roughened The arithmetic average roughness Ra is 0.02 to 0.05 μm, the maximum height Rz is 0.20 to 0.40 μm, and the ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz is 0.00. 10-0.25.
[Selection] Figure 1

Description

  The present invention relates to a copper alloy strip for a Cu—Fe—P-based electronic device that is excellent in heat dissipation and resin adhesion, and is particularly suitable for use on a chip-on-board.

  LED lamps using light emitting diodes have been dramatically expanded in various fields such as backlights for liquid crystal displays, mobile phones, information terminals, and indoor / outdoor advertisements. In addition, LED lamps have features such as long life, high reliability, low power consumption, impact resistance, high purity display color, lightness, thinness, and other features. Application is also beginning to progress. When applying such LED lamps to various applications, it is important to obtain white light emission, and for the purpose of increasing brightness and heat dissipation, a plurality of LED chips are mounted on a board (board). A chip-on-board (COB) type coated with a resin layer has also been developed.

  Patent Document 1 has a light emitting element such as a blue LED chip, two or more kinds of phosphors having approximate specific gravity, and a specific gravity of 20% or more of the phosphor having the largest specific gravity among these phosphors. A phosphor-containing resin layer containing a transparent resin, and two or more kinds of phosphors have similar shapes to each other, and further have an approximate average particle diameter (D50 is 7 to 20 μm), between a plurality of LED lamps A light emitting device is disclosed in which variation in emission color is suppressed, and uniform, stable and highly efficient light emission can be obtained.

In Patent Document 2, a plurality of LEDs are arranged in a substantially linear shape on a heat-dissipating substrate, and a reflector that collectively surrounds two or more LEDs that are continuously arranged is disposed on the substrate. There has been disclosed a backlight device (light source) in which a light source plate is disposed to constitute a backlight light source, which can generate light with high luminance and low light emission unevenness, and is excellent in driving stability.
Aluminum has been mainly used as a substrate used for chip-on-board (COB), but in recent years, a copper alloy has been used from the balance of thermal conductivity, press workability, conductivity, and mechanical strength. In particular, the thermal conductivity that efficiently dissipates the heat generated by the LED chip is important, and since a resin layer (insulating layer) is formed on the surface by roughening, good resin adhesion is also required. It has been.

The copper alloy heat dissipation board used for such chip-on-board is a Cu-Fe-P copper alloy thin plate for lead frames that has a good balance of thermal conductivity, press workability, conductivity, and mechanical strength. In addition, a thin plate having silver or tin plating on its outermost surface is often used.
In Patent Document 3, the tensile modulus of the Cu-Fe-P-based copper alloy plate having a specific composition, which is obtained by a tensile test, exceeds 120 GPa, and the ratio between uniform elongation and total elongation, uniform elongation / Cu- having a total elongation of less than 0.50, a reduced shear surface ratio, high strength, and improved press punchability during stamping as measured as shown in FIG. An Fe-P copper alloy sheet is disclosed.

In Patent Document 4, the integrated intensity ratio I {200} / I {111} obtained by X-ray diffraction on the rolled surface is preferably 1.5 or less, and a foil having a thickness of 16 μm or less is desirable. As a mass%, Fe: 0.045-0.095%, P: 0.010-0.030%, and the total of elements other than Fe, P, and Cu is less than 1%, and the balance is Cu. In addition, Ni: 0.5 to 3.0%, Sn: 0.5 to 2.0%, P: 0.03 to 0.10%, and other than Ni, Sn, P, and Cu There is disclosed a copper alloy having a total of less than 1%, the balance being made of Cu, a conductivity of 85% IACS or more and excellent in bending resistance suitable for a conductive member of a flexible substrate.
Non-Patent Document 1 includes thermal conductivity, press, including Fe; 2.1 to 2.6% by weight, P; 0.015 to 0.15% by weight, and Zn; 0.05 to 0.20% by weight. A copper alloy strip having a balance between workability, conductivity, and mechanical strength is disclosed.

JP 2009-277998 A JP 2005-353507 A JP 2008-88499 A JP 2006-63431 A

“TAMAC194”, Mitsubishi Shindoh Co., Ltd., 2010

  Conventional Cu-Fe-P-based copper alloys used for chip-on-board have insufficient adhesion to the resin layer and lacked thermal conductivity to efficiently dissipate heat generated by LED chips and the like. .

  The present invention has been made in view of such circumstances, has good resin adhesion, and can be used as a heat dissipation substrate in a chip-on-board that can efficiently dissipate heat generated by LED chips and the like. A Cu—Fe—P-based copper alloy thin plate suitable for the above is provided.

The present inventors recrystallized very fine precipitate particles (Fe-P compounds) having a diameter of less than 15 nm with a small pinning effect for restraining the movement of particles in a high temperature region such as 500 ° C. Although the suppression effect cannot be expected so much, in transmission electron microscope observation, the peak value in the histogram of the diameter of the precipitate particles per 1 μm ² is in the range of 15 to 35 nm in diameter, and the precipitate particles have a diameter in the range. Is present at a frequency of 50% or more of the total frequency, and the precipitate particle (Fe-P compound) having a half width of 25 nm or less is very effective in suppressing recrystallization in a high temperature region around 500 ° C. It has been found that it greatly contributes to further improvement of heat resistance.

As a result of further intensive studies, the present inventors contain Fe; 1.5 to 2.4% by mass, P; 0.008 to 0.08% by mass, and Zn; 0.01 to 0.5% by mass. The copper alloy strip consisting of Cu and inevitable impurities as the balance has an orientation density of Cube orientation of 10% to 20% measured by the EBSD method in a depth range from the surface of the copper alloy strip to 10 μm. When the average crystal grain size measured by the EBSD method is 12 μm to 20 μm, the precipitate particles (Fe—P-based compound) on the surface of the copper alloy strip are very homogeneously dispersed, and a normal surface treatment agent It was found that a uniform roughening is achieved, and that the surface roughness Rz of the surface is 1.0 μm to 2.0 μm, the resin adhesion at high temperature and high humidity is particularly excellent. Therefore, the surface to which the resin is adhered is roughened with a surface treatment agent.
On the other hand, the surface on which the LED chip is directly mounted should not be roughened, the arithmetic average roughness Ra of the surface of the unroughened part is 0.02 to 0.05 μm, and the maximum height Rz is 0.20. When the ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz is 0.10 to 0.25, the heat generated from the LED or the like directly mounted on the surface of the strip It has also been found that the contact thermal resistance with the element is reduced and exhibits excellent characteristics as a heat dissipation substrate for chip-on-board.

  The copper alloy strip for electronic equipment having excellent heat dissipation and resin adhesion of the present invention is Fe; 1.5 to 2.4 mass%, P; 0.008 to 0.08 mass%, and Zn; 0.01 In copper alloy strips containing ~ 0.5% by mass, the balance being Cu and inevitable impurities, measured by EBSD method in a crystal structure in a depth range of up to 10 μm from the surface of the copper alloy strip. The orientation density of the Cube orientation is 10 to 20%, the average crystal grain size measured by the EBSD method is 12 to 20 μm, and the surface of the copper alloy strip is roughened by the surface treatment agent. The maximum height Rz is 1.0 to 2.0 μm, the arithmetic average roughness Ra of the surface of the unroughened portion is 0.02 to 0.05 μm, and the maximum height Rz is 0.20 to 0 .40 μm, the ratio Rq / R of the root mean square roughness Rq to the maximum height Rz z is 0.10 to 0.25.

When the orientation density of the Cube orientation measured by the EBSD method is less than 10%, the surface is not sufficiently roughened by the surface treatment agent, and when the orientation density exceeds 20%, the strain on the surface of the copper alloy strip is It becomes easy to occur and it becomes difficult to perform uniform roughening.
The Cube orientation is an orientation in which the <001> direction of the crystal is parallel to the rolling direction, the rolling surface normal, and the width direction, and the (100) plane is oriented on the rolling surface. As the Cube orientation develops, the abundance ratio of crystal grains having the Cube orientation increases, and when the Cube orientation develops excessively, the strength of the copper alloy decreases.
The orientation density of the Cube orientation in the EBSD method is such that an electron beam is incident on the sample surface and a Kikuchi pattern (Cube orientation mapping) is obtained from the reflected electrons generated at this time. By analyzing this Kikuchi pattern, the crystal orientation at the electron beam incident position can be known. Then, if the electron beam is scanned two-dimensionally on the sample surface and the crystal orientation is measured at every predetermined pitch, the orientation distribution on the sample surface can be measured.

When the average crystal grain size measured by the EBSD method is less than 12 μm, the effect of surface roughening is saturated and the cost is wasted. If the average crystal grain size exceeds 20 μm, it will hinder uniform surface roughening.
The average crystal grain size in the EBSD method was determined from a crystal grain size histogram and a histogram of each area ratio by analyzing the Kikuchi pattern (Cube orientation mapping).

The roughening of the surface to be in close contact with the resin is sufficient within the depth range of 10 μm or less from the surface of the copper alloy strip, and the orientation density of Cube orientation and the average crystal grain size within the depth range of up to 10 μm from the surface are If it is within the above numerical range, it is sufficient, and exceeding 10 μm is wasteful in terms of manufacturing cost.
Further, when the maximum roughness Rz of the surface roughened by the surface treatment agent is less than 1.0 μm, the resin adhesion is insufficient, and even if the maximum roughness Rz exceeds 2.0 μm, the coarse precipitate particles are not formed. Residual resin adhesion is insufficient, and adhesion at high humidity is deteriorated.
Further, when the arithmetic average roughness Ra of the surface where the surface is not roughened is 0.05 μm or the maximum height Rz exceeds 0.40 μm, the contact thermal resistance with the LED mounted directly on the surface is large. Therefore, in order to make Ra 0.02 μm or Rz less than 0.20 μm, a special surface treatment is required, which increases the manufacturing cost.
Further, when the ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz exceeds 0.25, the roughness uniformity is lost, and the contact thermal resistance with the LED chip directly mounted on the surface of the strip material. Becomes larger. If Rq / Rz is less than 0.10, the effect is saturated and the cost is wasted.

Furthermore, the copper alloy strip for electronic equipment excellent in heat dissipation and resin adhesion of the present invention contains Ni; 0.003 to 0.5 mass% and / or Sn; 0.003 to 0.5 mass%. You may do it.
These elements have an effect of improving the characteristics of the copper alloy for electronic devices, and the characteristics can be improved by selectively containing them in accordance with the application.

Furthermore, the copper alloy strip for electronic equipment excellent in heat dissipation and resin adhesion of the present invention contains at least one of Al, Be, Ca, Cr, Mg and Si, and the content is 0. 0007 to 0.5 mass% may be set.
These elements have an effect of improving the characteristics of the copper alloy for electronic devices, and the characteristics can be improved by selectively containing them in accordance with the application.

In the copper alloy strip for electronic equipment having excellent heat dissipation and resin adhesion according to the present invention, an insulating layer is formed on a portion where the surface is roughened, and an LED chip is provided on a portion where the surface is not roughened. The element is directly mounted.
Accordingly, it is possible to manufacture an LED package having excellent characteristics of a chip-on-board (COB) type in which a plurality of LED chips are mounted and coated with a resin layer for the purpose of increasing brightness and heat dissipation.

Furthermore, the copper alloy strip for electronic equipment excellent in heat dissipation and resin adhesion of the present invention may have a modified cross section in which a plurality of thick portions and thin portions are alternately arranged in the width direction, The roughened portion is a thin portion, and the portion where the surface is not roughened is a thick portion.
By using the copper alloy strip for electronic equipment having an irregular cross section according to the present invention, it is possible to manufacture an LED package having excellent characteristics of various variations.

  According to the present invention, a copper alloy strip for a Cu-Fe-P electronic device suitable for use in a chip-on-board that has good resin adhesion and can efficiently dissipate heat generated by an LED chip or the like. Can be provided.

It is sectional drawing which shows an example which mounted LED chip directly in the copper alloy strip for electronic devices which is embodiment of this invention. It is sectional drawing which shows an example which mounted LED chip directly in the copper alloy strip for electronic devices of the odd-shaped cross section which is embodiment of this invention. It is the schematic of the apparatus which measures the thermal resistance of the copper alloy strip for electronic devices which is embodiment of this invention.

Hereinafter, the copper alloy for electronic devices which is one Embodiment of this invention is demonstrated in detail.
[Component composition of the copper alloy strips]
The Cu—Fe—P-based copper alloy strip according to an embodiment of the present invention includes Fe; 1.5 to 2.4% by mass, P; 0.008 to 0.08% by mass, and Zn; It contains 5% by mass and the balance has a basic composition consisting of Cu and inevitable impurities. You may further selectively contain elements, such as Sn and Ni mentioned later, with respect to this basic composition.
(Fe)
Fe has the effect of improving the strength and heat resistance by forming precipitate particles dispersed in the copper matrix, but if its content is less than 1.5% by mass, the number of precipitates is insufficient, and the effect It can not be allowed to successful a. On the other hand, when the content exceeds 2.4% by mass, coarse precipitate particles that do not contribute to improvement in strength and heat resistance exist, and the precipitate particles effective in heat resistance are insufficient. . For this reason, it is preferable to make content of Fe into the range of 1.5-2.4 mass%.

(P)
P has the effect of improving the strength and heat resistance by forming precipitate particles dispersed in the copper matrix with Fe, but if the content is less than 0.008% by mass, the number of precipitate particles is insufficient. , You can not make the effect. On the other hand, if the content exceeds 0.08% by mass, coarse precipitates that do not contribute to improvement in strength and heat resistance exist, and precipitate particles having a size effective for heat resistance are insufficient. At the same time, the conductivity and workability are reduced. For this reason, it is preferable to make content of P into the range of 0.008-0.08 mass%.
(Zn)
Zn has the effect of improving the heat resistance peelability of the solder by solid solution in the copper matrix, and if it is less than 0.01% by mass, the effect cannot be achieved. On the other hand, even if the content exceeds 0.5% by mass, further effects cannot be obtained, and the amount of solid solution in the mother layer increases, resulting in a decrease in conductivity. For this reason, it is preferable to make content of Zn into the range of 0.01-0.5 mass%.

(Ni)
Ni has an effect of improving the strength by dissolving in the matrix, and if it is less than 0.003 mass%, the effect cannot be achieved. On the other hand, if the content exceeds 0.5% by mass, the conductivity is lowered. For this reason, when it contains Ni, it is preferable to set it as the range of 0.003-0.5 mass%.
(Sn)
Sn has an effect of improving the strength by dissolving in the matrix, and if it is less than 0.003 mass%, the effect cannot be achieved. On the other hand, if the content exceeds 0.5% by mass, the conductivity is lowered. For this reason, when it contains Sn, it is preferable to set it as the range of 0.003-0.5 mass%.
In addition, the copper alloy of this invention may contain 0.0007-0.5 mass% of at least 1 sort (s) among Al, Be, Ca, Cr, Mg, and Si. These elements have a role of improving various properties of the copper alloy, and are preferably added selectively depending on the application.

[Orientation density and average crystal grain size of Cube orientation in a depth range from the surface of the copper alloy strip to 10 μm]
The copper alloy strip for electronic equipment excellent in resin adhesion of the present invention has an orientation density of Cube orientation of 10% measured by the EBSD method in a crystal structure in a depth range of 10 μm from the surface of the copper alloy strip. The average crystal grain size measured by the EBSD method is 12 to 20 μm, and the surface of the copper alloy strip is uniformly roughened by the surface treatment agent and is not roughened. Part.
If the orientation density of the Cube orientation measured by the EBSD method is less than 10%, the surface is not sufficiently roughened by the surface treatment, and if the orientation density exceeds 20%, the surface strain becomes large and uniform roughening. It becomes difficult to do.
The Cube orientation is an orientation in which the <001> direction of the crystal is parallel to the rolling direction, the rolling surface normal, and the width direction, and the (100) plane is oriented on the rolling surface. As the Cube orientation develops, the abundance ratio of crystal grains having the Cube orientation increases, and when the Cube orientation develops excessively, the strength of the copper alloy decreases.
The orientation density of the Cube orientation in the EBSD method is such that an electron beam is incident on the sample surface and a Kikuchi pattern (Cube orientation mapping) is obtained from the reflected electrons generated at this time. By analyzing this Kikuchi pattern, the crystal orientation at the electron beam incident position can be known. Then, if the electron beam is scanned two-dimensionally on the sample surface and the crystal orientation is measured at every predetermined pitch, the orientation distribution on the sample surface can be measured.
If the average crystal grain size measured by the EBSD method is less than 12 μm, the effect of roughening the surface is saturated and the cost is wasted. If the average crystal grain size exceeds 20 μm, the coarse precipitate particles remain, which hinders uniform surface roughening.
The average crystal grain size in the EBSD method was determined from a crystal grain size histogram and a histogram of each area ratio by analyzing the Kikuchi pattern (Cube orientation mapping).
The roughening of the surface to be in close contact with the resin is sufficient if the depth is within 10 μm from the surface of the copper alloy strip. If it is in the said numerical range, it is enough, and exceeding 10 micrometers is useless in terms of manufacturing cost.

[Surface roughness and resin adhesion, contact resistance of copper alloy strip]
As described above, the surface of the copper alloy strip has a portion roughened by the surface treatment agent and a portion not roughened, and a resin is molded on the roughened surface to roughen the surface. The LED chip element is directly mounted on the surface of the part that is not made.
The surface roughened to the surface treatment agent has a surface roughness (maximum height) Rz of 1.0 μm to 2.0 μm. If the maximum height Rz is less than 1.0 μm, the resin adhesion is insufficient, and even if the maximum height Rz exceeds 2.0 μm, coarse precipitate particles remain and the resin adhesion becomes insufficient. Adhesion at humidity is poor.
On the other hand, the surface of the unroughened portion has an arithmetic average roughness Ra of 0.02 μm to 0.05 μm, a maximum height Rz of 0.20 μm to 0.40 μm, and a root mean square roughness Rq. The ratio Rq / Rz of the maximum height Rz is 0.10 to 0.25.
When the arithmetic average roughness Ra of the surface of the portion where the surface is not roughened is 0.05 μm or the maximum height Rz exceeds 0.40 μm, the contact thermal resistance with the LED directly mounted on the surface increases, In order to reduce Ra to 0.02 μm or Rz to less than 0.20 μm, a special surface treatment is required, which increases the manufacturing cost.
Further, when the ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz exceeds 0.25, the roughness uniformity is lost, and the contact thermal resistance with the LED chip directly mounted on the surface of the strip material. Becomes larger. If Rq / Rz is less than 0.10, the effect is saturated and the cost is wasted.

[Production method]
Next, manufacturing conditions for the Cu—Fe—P based copper alloy having the precipitate particles (Fe—P based compound) of the present invention will be described below. Except for cold rolling and low-temperature annealing conditions to uniformly disperse the precipitate particles in the crystal structure within a depth range of 10 μm from the surface of the copper alloy strip, the normal manufacturing process itself is greatly changed. Is unnecessary.
First, a copper alloy adjusted to the above-mentioned preferable component range is melt cast, and after chamfering the ingot, hot rolling is performed at a rolling rate of 60% or more, and then at 900 to 950 ° C. do of 300 seconds to a solution treatment.
(Aging treatment)
The copper alloy plate after solution treatment is subjected to aging treatment at 450 to 575 ° C. for 3 to 12 hours to precipitate precipitate particles having a wide particle size distribution, thereby obtaining precipitate particles having a final target configuration. create a foundation for. Precipitate particles do not sufficiently precipitate at 450 ° C. or less or 3 hours or less, and the copper alloy structure softens at 575 ° C. or more or 12 hours or more.

(First cold rolling)
The copper alloy sheet after the aging treatment is cold-rolled at a processing rate (rolling rate) of 60 to 70% to reduce the particle size of the precipitate and promote the precipitation of further precipitate particles. Since the preferential nucleation site of the precipitation phase becomes a dislocation cell boundary that is advantageous in terms of driving force for nucleation, the nucleation frequency is promoted. If the processing rate is less than 60%, it is insufficient to reduce the particle size of the precipitate particles, and if it exceeds 70%, the effect of promoting the nucleation frequency is hindered.
(First low temperature annealing)
The copper alloy sheet after the first cold rolling is subjected to low temperature annealing at 270 to 320 ° C. for 40 to 110 minutes, the diameter of the precipitate particles is shifted within a certain range value, and the depth is within 10 μm from the surface. The orientation density of the Cube orientation measured by the EBSD method in the crystal structure is 10% to 20%, the average crystal grain size measured by the EBSD method is 12 to 20 μm, and the surface treatment agent is used to form a copper alloy strip. The surface is uniformly roughened. If it is less than 270 ° C. or less than 40 minutes, there is no effect, and if it exceeds 320 ° C. or 110 minutes, it leads to coarsening of the precipitate particles, hindering the achievement of the pinning effect, and the homogeneity of the surface state is lost.
With this single low temperature annealing alone, it is impossible to shift the diameter of the precipitate particles within a certain range value and to bring the orientation density and average crystal grain size within a range of 10 μm depth from the surface within the predetermined range value. And further cold rolling and low temperature annealing are required.

(Second cold rolling)
The copper alloy sheet after the first low-temperature annealing is cold-rolled at a processing rate of 20 to 35% to produce a substrate that shifts the precipitate particles within a target diameter range. When the processing rate exceeds 35%, the rolling ratio as a whole increases, which leads to promoting recrystallization, and also adversely affects strength, conductivity, and Vickers hardness. If the processing rate is less than 20%, there is almost no effect.
(The second low-temperature annealing)
By subjecting the copper alloy sheet after the second cold rolling to low temperature annealing at 270 to 320 ° C. for 20 to 90 minutes, the diameter of the precipitate particles per 1 μm ² of the precipitate particles is shifted within a certain range value. The orientation density of the Cube orientation measured by the EBSD method in the crystal structure within a depth of 10 μm from the surface is 10% to 20%, and the average crystal grain size measured by the EBSD method is 12 μm to 20 μm. . If it is less than 270 ° C. or less than 30 minutes, there is no effect, and if it exceeds 350 ° C. or more than 100 minutes, it leads to coarsening of the precipitate particles, hindering the achievement of the pinning effect, and the homogeneity of the surface state is lost.
In this second low-temperature annealing, the diameter of the precipitate particles per 1 μm ² of the precipitate particles is shifted within a certain range value, and the Cube measured by the EBSD method in the crystal structure within the depth of 10 μm from the surface. If the orientation density of the orientation is 10% to 20% and the average crystal grain size measured by the EBSD method is not 12 μm to 20 μm, cold rolling and low-temperature annealing are further repeated at the above processing rate and heat treatment conditions. It will be necessary. In this case, there is no point in repeating cold rolling or low temperature annealing alone, and it is important to perform low temperature annealing after cold rolling.
The copper alloy for electronic devices according to the present embodiment having the above-described configuration is a Cu-Fe-P-based copper alloy that is easily subjected to uniform roughening treatment, has excellent resin adhesion, and has good heat dissipation. Become a strip.

[Surface roughening]
The Cu-Fe-P-based copper alloy strip obtained as described above is punched into a desired shape, masked at the site where the LED chip is mounted, and immersed in a surface treatment agent such as an etchant. Thus, a portion other than the portion subjected to masking is roughened.
The surface of the roughened portion has a surface roughness (maximum height) Rz of 1.0 μm to 2.0 μm, and the surface of the portion not roughened by masking has an arithmetic average roughness Ra of 0. 02 μm to 0.05 μm, the maximum height Rz is 0.20 μm to 0.40 μm, and the ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz is 0.10 to 0.25.

Use the form of a chip-on-board]
FIG. 1 shows an example of an LED package in which LED chips are directly mounted on a copper alloy strip for electronic equipment according to an embodiment of the present invention.
In this LED package, an insulating layer 2A and a conductive layer (circuit pattern) 2B are formed on a part of the surface of the substrate 1 made of the copper alloy strip of the embodiment, and the LED chip 3 is directly mounted on the substrate 1 for electrical On the other hand, the conductive layer 2 </ b> B is connected by a bonding wire 4. A reflector block 5 having a conical recess is provided on the substrate 1 so as to surround the LED chip 3, and the inner surface of the conical recess of the reflector block 5 functions as a reflection surface. The reflector block 5 is formed of a resin such as polybutylene terephthalate or polycarbonate, and is integrally formed on the substrate 1. In addition, a sealing resin 6 that fills the LED chip 3 is provided in the conical recess of the reflector block 5.
As described above, the surface of the substrate 1 is roughened by the surface treatment agent except for the portion where the LED chip 3 is mounted, and the reflector block 5 and the sealing resin are formed on the roughened surface. 6 is fixed, and the surface of the portion on which the LED chip 3 is mounted is a non-roughened surface, and the LED chip 3 is directly fixed to the non-roughened surface.

On the other hand, FIG. 2 shows an example in which an LED chip is directly mounted on a copper alloy strip for electronic equipment having an irregular cross section according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view corresponding to a vertical cross section of the LED chip portion in FIG. 1, in which the substrate 11 is formed from a deformed cross-section strip in which a thick portion 12 and thin portions 13 on both sides thereof are arranged in the width direction. The LED chip 3 is mounted on the thick portion 12 and electrically connected thereto. In the example shown in FIG. 2, the surface is roughened except for the portion where the LED chip 3 on the upper surface of the thick portion 12 of the substrate 11 is mounted, and the resin adheres to the roughened surface. Then, the upper surface of the thick portion 12 on which the LED chip 3 is mounted is a portion that is not roughened, and the LED chip 3 is directly fixed to the non-roughened surface.
In any example, the roughened surface has a surface roughness (maximum height) Rz of 1.0 μm to 2.0 μm, and the surface of the unroughened portion has an arithmetic average roughness Ra. 0.02 μm to 0.05 μm, the maximum height Rz is 0.20 μm to 0.40 μm, and the ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz is 0.10 to 0.25. is there.

Hereinafter, examples of the present invention will be described in detail including comparative examples.
An ingot having a thickness of 30 mm, a width of 100 mm, and a length of 250 mm, which is obtained by melting a copper alloy having the composition shown in Table 1 below (components other than additive elements are Cu and inevitable impurities) in a reducing atmosphere using an electric furnace Was made. The ingot was heated at 730 ° C. for 1 hour, then hot-rolled at a rolling rate of 67%, finished to a thickness of 10 mm, and the surface was chamfered to a plate thickness of 8 mm by milling, and then 920 ° C. After performing the solution treatment for 60 seconds, cold rolling was performed to a plate thickness of 1.5 mm. Next, after performing an aging treatment for 3 to 12 hours at 450 to 575 ° C., the first cold rolling, the first low temperature annealing, the second cold rolling, and the second low temperature annealing are performed under the conditions shown in Table 1. It carried out sequentially and obtained the 0.3 mm copper alloy thin plate shown in Examples 1-11 of Table 1, and Comparative Examples 1-9.

A specimen for observing the structure was collected from the obtained copper alloy thin plate, subjected to mechanical polishing and buff polishing, and then subjected to electrolytic polishing to adjust the surface. About each obtained test piece, the SEM model number "S-3400N" made by Hitachi High-Tech Co., Ltd. and the EBSD measurement / analysis system OIM (Orientation Imaging Macrograph) made by TSL are used to separate regions of 300 μm × 300 μm at intervals of 1 μm. Measured with Then, using the analysis software of the system (software name “OIM Analysis”), the orientation density of the Cube orientation (within 15 ° from the ideal orientation) and the average crystal grain size (the orientation difference between adjacent pixels is 15 °) The boundary was regarded as a grain boundary). Table 2 shows the orientation density of the Cube orientation and the average crystal grain size determined based on the EBSD measurement of these copper alloy thin plates.
Moreover, the surface roughness Ra, Rz, Rq of the test piece of these copper alloy thin plates was measured using the laser microscope (OLS300 by Olympus). The results of these measurements are shown in Table 2.
Further, a state in which a part masked were specimens of copper alloy _{sheet, H 2 SO 4: 70.5g /} L (0.72mol / L), H 2 O 2: 34g / L (1mol / L) The surface is roughened by immersion for 1 minute at 35 ° C. in a microetching agent having the following composition: the surface roughness Ra, Rz, Rq / Rz of the masked portion and the surface of the roughened portion for each sample piece The roughness Rz was measured using a laser microscope (OLS300 manufactured by Olympus). The results of these measurements are shown in Table 2.

  Next, evaluation of adhesiveness with resin was performed by bonding a test jig to the roughened surface of each test piece cut out from each sample using a film-type epoxy resin adhesive (TSA-66 manufactured by Toray Industries, Inc.). Thereafter, a shear test was performed at room temperature to inspect the fracture mode of the resin. At this time, when the fracture mode was in-resin fracture, ○, partial interface peeling was indicated by Δ, and complete interface peeling was indicated by ×. These measurement results are shown in Table 3.

Table 3 shows the measurement results of contact thermal resistance, tensile strength, Vickers hardness, and conductivity.
As shown in FIG. 3, the contact thermal resistance is obtained by measuring each sample 21 with a dimension of 50 mm × 50 mm × 0.1 mm, and a Si semiconductor device 22 in which a resistance element and a diode are incorporated in a non-roughened portion of the surface. It is crimped and supported on a stand 23 and fixed to the center of an acrylic case 24 of 300 mm × 300 mm × 300 mm. The Si semiconductor device 22 is heated in a windless state, and the temperature of the Si semiconductor device 22 and the copper alloy thin plate 21 is increased. It measured and computed from the following (1) formula.
Rth = (Tj−Tx) / P (1)
Tx: Temperature at the center of the back surface of the copper alloy thin plate to which the Si semiconductor device is bonded (K)
Tj: Temperature Tj (K) of the surface in contact with the copper alloy thin plate applied to the Si semiconductor device
P: Total heat loss amount P (W) given to the Si semiconductor device

The tensile strength was measured by preparing a JIS No. 5 piece with the test piece parallel to the rolling direction in the longitudinal direction.
Vickers hardness is 10 mm x 10 mm test piece, and 0.5 kg load is measured using a micro Vickers hardness meter (trade name "micro hardness meter") manufactured by Matsuzawa Seiki Co., Ltd. The hardness was taken as the average value.
The electrical conductivity was calculated by an average cross section method by processing a strip-shaped test piece of 10 mm × 30 mm by milling, measuring electric resistance with a double bridge type resistance measuring device.

From Table 3, the Cu-Fe-P-based copper alloy strip of the present invention is easily subjected to uniform roughening treatment with an ordinary surface treatment agent, has excellent resin adhesion, It can be seen that the heat generation can be efficiently dissipated and the tensile strength, Vickers hardness, and electrical conductivity are good, and it is suitable for use on a chip-on-board.
As mentioned above, although embodiment of this invention was described, this invention is not limited to this description, In the range which does not deviate from the technical idea of the invention, it can change suitably, for example, a viewpoint of glossiness and heat resistance. Therefore, tin or silver plating treatment may be applied to the surface of the portion where the surface of the copper strip is not roughened by an electrolytic plating method.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2A Insulating layer 2B Conductive layer 3 LED chip 4 Bonding wire 5 Reflector block 6 Sealing resin 11 Board | substrate 12 Thick part 13 Thin part

Claims (5)

  Copper alloy strip containing Fe; 1.5-2.4 mass%, P; 0.008-0.08 mass% and Zn; 0.01-0.5 mass%, with the balance being Cu and inevitable impurities In the material, the orientation density of the Cube orientation measured by the EBSD method in the crystal structure in the depth range of 10 μm from the surface of the copper alloy strip is 10 to 20%, and the average crystal measured by the EBSD method The particle size is 12 to 20 μm, the maximum height Rz of the surface where the surface of the copper alloy strip is roughened by the surface treatment agent is 1.0 to 2.0 μm, and the surface is not roughened The surface has an arithmetic average roughness Ra of 0.02 to 0.05 μm, a maximum height Rz of 0.20 to 0.40 μm, and a ratio Rq / Rz of the root mean square roughness Rq to the maximum height Rz. Is 0.10 to 0.25, heat dissipation and resin dense Copper alloy strip for electronic equipment with excellent wearability. The electronic device excellent in heat dissipation and resin adhesion according to claim 1, characterized by containing Ni; 0.003-0.5 mass% and / or Sn; 0.003-0.5 mass%. Copper alloy strips.   It contains at least one or more of Al, Be, Ca, Cr, Mg and Si, and its content is set to 0.0007 to 0.5 mass%. Item 3. A copper alloy strip for electronic equipment having excellent heat dissipation and resin adhesion. The insulating layer is formed in the part where the surface is roughened, and the LED chip element is directly mounted on the part where the surface is not roughened. heat radiation and resin adhesion excellent copper alloy strip material for electronic device according to. A plurality of thick portions and thin portions have an irregular cross section alternately arranged in the width direction, the roughened portion is a thin portion, and the surface is not roughened is a thick portion The copper alloy strip for an electronic device according to any one of claims 1 to 4, which is excellent in heat dissipation and resin adhesion.

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