JP2005243967A - Package for housing electronic part and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package that efficiently radiates heat generated by electronic parts in air and adheres the parts firmly to a heat radiation material and an electronic device using this package. <P>SOLUTION: A package 8 for housing the electronic parts comprises a plane heat radiation material 1 with an area 10 for mounting the electronic parts 11 at the center of the top, and a frame 5 mounted in a way that it surrounds the above mint area 10 formed at the top of the heat radiation material 1 and has multiple lead wiring conductors 6 from the inside to the outside. The heat radiation material 1 is provided with a penetrating metal 3 made of copper or an alloy mainly made of copper from the top to the bottom in the center of a frame base substance 2 manufactured by impregnating copper into a sintered body made of tungsten or molybdenum, and copper layers 4a and 4b covering upper and lower sides of the base substance 2 and the penetrating metal frame 3 in a way that a difference between thermal expansion coefficients in heat radiation material 1 and the frame 5 is less than or equal to 3×10<SP>-6</SP>/°C. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic component storage package for storing an electronic component such as a semiconductor element, which has a heat dissipation structure with good heat dissipation characteristics, and an electronic device using the same.

  Conventionally, electronic component storage packages for storing electronic components such as semiconductor elements, piezoelectric vibrators, and light emitting elements are generally made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, and a glass ceramic. Copper-tungsten alloy or copper powder and molybdenum obtained by melting copper powder and tungsten powder to dissipate the heat generated during the operation of the frame body and electronic components well into the outside or the atmosphere It is composed of a heat radiating member made of a copper-molybdenum alloy obtained by melting powder and a lid, and a frame is disposed so as to surround the mounting part of the electronic component on the upper surface of the heat radiating member, A plurality of layers made of tungsten, molybdenum, manganese, copper, silver, etc. from the inside to the outside of the recesses formed by the frame and the heat dissipation member Line conductors are derived are applied to the frame.

  The electronic component is bonded and fixed to the mounting portion on the upper surface of the heat radiating member via a bonding material such as glass, resin, or brazing material, and each electrode of the electronic component is electrically connected to the wiring conductor via a bonding wire. After that, the lid body is joined to the frame body through a sealing material made of glass, resin, brazing material, etc., and the electronic component is accommodated in the container composed of the heat radiation member, the frame body, and the lid body. Thus, an electronic device as a product is obtained (for example, see Patent Document 1 below). This electronic device may be mounted on an external heat sink by screwing or the like in order to further improve the heat dissipation efficiency.

An electronic component storage package including a heat radiating member made of such copper-tungsten alloy or copper-molybdenum alloy has a high heat conductivity of the heat radiating member, and a thermal expansion coefficient of the heat radiating member is a semiconductor as an electronic component. Electronic component storage package that mounts high heat-generating semiconductor elements such as power ICs and high-frequency transistors because the thermal expansion coefficient is close to that of silicon, gallium arsenide, which is the component material of the element, and ceramic materials used as the component material of the package It is attracting attention as.
Japanese Patent Laid-Open No. 9-312361

  In recent years, a heat dissipation member having a thermal conductivity of 300 W / m · K or more has been demanded due to an increase in the amount of heat generated with the high integration of power ICs and high-frequency transistors. However, the heat conductivity of the heat radiating member made of the above-mentioned alloy material of tungsten and copper or the alloy material of molybdenum and copper is about 200 W / m · K, which is low for that requirement, so the heat dissipation characteristics are insufficient. There was a problem.

  On the other hand, it has been proposed to use a heat dissipation member formed by impregnating copper into a composite material in which tungsten or molybdenum and copper are formed in a matrix, that is, a sintered body made of tungsten or molybdenum.

  However, in an electronic component storage package using a heat dissipation member made of a composite material in which tungsten or molybdenum and copper are formed in a matrix, tungsten or molybdenum has a low thermal conductivity and a low thermal expansion coefficient, and copper Since both the conductivity and the thermal expansion coefficient are high, the thermal conductivity and the thermal expansion coefficient of the heat radiating member are both increased as the copper content is increased. Therefore, if the copper content is increased in order to improve the thermal conductivity of the heat dissipation member, the difference in coefficient of thermal expansion between the electronic component and the heat dissipation member increases, and the electronic component can be firmly bonded to the heat dissipation member. There was a problem that it was impossible.

  The present invention has been devised in view of the above problems in the prior art, and the purpose thereof is to dissipate the heat generated by the electronic component well to the outside or the atmosphere, and the electronic component is used as a heat dissipation member. An object of the present invention is to provide an electronic component storage package that can be firmly bonded and an electronic device using the same.

The electronic component storage package of the present invention includes a flat plate-like heat radiating member having an electronic component mounting portion at the center of the upper surface, and an inner surface to an outer surface attached to the upper surface of the heat radiating member so as to surround the mounting portion. A frame body having a plurality of wiring conductors to be led out, and the heat radiating member is made of copper from the upper surface to the lower surface of the central portion of the frame-shaped substrate formed by impregnating a sintered body made of tungsten or molybdenum with copper. Alternatively, a through metal body made of an alloy containing copper as a main component is embedded, and a copper layer is formed to cover the upper and lower surfaces of the base body and the through metal body, respectively, and the heat dissipation member and the frame body The difference in thermal expansion coefficient is 3 × 10 ⁻⁶ / ° C. or less.

  The electronic device according to the present invention includes the electronic component storage package according to the present invention, the electronic component mounted on the mounting portion and having an electrode electrically connected to the wiring conductor, and the upper surface of the frame. A lid attached to cover the electronic component or a sealing resin filled to cover the electronic component is provided inside the frame.

According to the electronic component storage package of the present invention, the heat radiating member has copper or copper as a main component from the upper surface to the lower surface of the central portion of the frame-shaped substrate formed by impregnating the sintered body made of tungsten or molybdenum with copper. And a copper layer is formed to cover the upper and lower surfaces of the base body and the penetrating metal body, and the difference in thermal expansion coefficient between the heat radiating member and the frame body is 3 × 10 6. ^Since it is ^-6 / ° C or less, it has a higher heat conduction part made of copper with a larger volume under the mounting part of the electronic component than a heat dissipation member made by impregnating copper in a sintered body made of tungsten or molybdenum. The heat generated in the electronic component can be transferred more in the direction perpendicular to the mounting surface of the electronic component, and as a result, the heat generated in the electronic component is largely transmitted through the heat radiating member. It can dissipate very well in the air or on an external heat sink.

  Further, even if a through metal body made of copper or an alloy containing copper as a main component is thermally expanded, a frame-like base body formed by impregnating copper into a sintered body made of tungsten or molybdenum restrains the through metal body. The thermal expansion of the whole heat radiating member can be suppressed. Therefore, although the proportion of copper in the heat radiating member is large, the thermal expansion of the entire heat radiating member can be reduced, and the strong bonding between the electronic component and the heat radiating member can be maintained.

  In addition, the copper layers formed on the top and bottom of the heat dissipation member can transfer more heat generated by the electronic components in the direction parallel to the heat dissipation member, and can be transmitted both in the direction perpendicular to the heat dissipation member and in the direction parallel to it. This can greatly improve the heat dissipation of the electronic component. As a result, the electronic component can be operated normally and stably over a long period of time.

In addition, since the difference in thermal expansion coefficient between the heat dissipation member and the frame is 3 × 10 ⁻⁶ / ° C. or less, the difference in coefficient of thermal expansion between the heat dissipation member and the frame due to the heat generated when the electronic component is activated. Therefore, it is possible to reduce the warpage caused by the heat dissipation member, to prevent the joint between the heat radiating member and the frame, and to prevent the electronic component from being destroyed. As a result, the electronic component can be operated normally and stably over a long period of time.

  According to the electronic device of the present invention, the electronic component storage package of the present invention, the electronic component mounted on the mounting portion and having the electrode electrically connected to the wiring conductor, and the electronic component on the upper surface of the frame body are provided. Since it has a sealing resin filled so as to cover the electronic component on the inside of the lid or frame attached so as to cover, it has the characteristics of the electronic component storage package of the present invention, It is possible to provide an electronic device that can operate the electronic component stably over a long period of time, with extremely good heat dissipation characteristics of the electronic component.

  Next, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an example of an embodiment of an electronic component storage package and an electronic apparatus using the same according to the present invention, wherein 1 is a heat dissipation member, 2 is a base of the heat dissipation member 1, 3 is a through metal body, 4 is a copper layer (4a is a copper layer on the upper surface side of the heat radiating member 1, 4b is a copper layer on the lower surface side of the heat radiating member 1), 5 is a frame body, and 6 is a wiring conductor. The heat radiation member 1 and the frame 5 mainly constitute an electronic component storage package 8 for storing the electronic component 11. In addition, after mounting the electronic component 11 on the mounting portion 10 of the heat radiating member 1, a sealing resin 13 is filled in the recess 5 a composed of the heat radiating member 1 and the frame 5 so as to cover the electronic component 11. The electronic device 14 of the present invention is configured by sealing the electronic component 11 by attaching the lid to the upper surface of the frame 5 so as to cover the recess 5a.

  The frame body 5 is made of an aluminum oxide sintered body, a mullite sintered body, glass ceramics, or the like, and is attached by surrounding and fixing the mounting portion 10 to the upper surface of the heat radiating member 1 via a brazing material. . Note that a brazing metal layer (not shown) may be formed at the joint portion of the frame body 5 with the heat radiating member 1 when this brazing material is bonded and fixed. The frame 5 may be made of metal. In that case, in order to insulate the wiring conductor 6 from the metal constituting the frame 5, the periphery of the wiring conductor 6 is made of an insulator such as ceramics, resin, or glass. Cover it.

  In addition, the heat dissipating member 1 has an electronic component 11 fixed to the mounting portion 10 at the center of the upper surface of the heat dissipating member 1 through an adhesive such as resin, glass, or brazing material. When a brazing material is used as the adhesive, a brazing metal layer (not shown) may be formed at the joint 10 of the heat dissipation member 1 with the electronic component 11. However, when sufficient brazing can be performed by the copper layer 4a bonded to the mounting portion 10 on the upper surface of the heat radiating member 1, a brazing metal layer is not particularly necessary.

  If the frame 5 is made of, for example, an aluminum oxide sintered body, an appropriate organic binder, solvent, plasticizer, dispersant, etc. are added to the raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide. A ceramic green sheet (ceramic green sheet) is formed by mixing and adding to a mud-like shape, and then adopting a doctor blade method and a calender roll method. After that, the ceramic green sheet is appropriately punched. Conductive paste made by mixing an appropriate organic binder and solvent with powders of metal materials such as tungsten, molybdenum, manganese, copper, silver, nickel, palladium, gold, etc. After printing and applying to the pattern of 6, this green sheet Laminating several sheets, it is produced by firing at a temperature of about 1600 ° C..

  In addition, a wiring conductor 6 is formed on the frame body 5 so as to be led out from the inner surface of the recess 5a formed by the heat radiating member 1 and the frame body 5 (around the mounting portion 10) to the outer surface of the frame body 5. Each electrode of the electronic component 11 is electrically connected via a bonding wire 12 to one end inside the recess 5a. A lead terminal 7 for connection to an external electric circuit board is connected to the other outer end of the frame 5 of the wiring conductor 6.

  The wiring conductor 6 is made of a refractory metal such as tungsten or molybdenum, and a metal paste obtained by adding and mixing an appropriate organic binder, solvent or the like to a metal powder such as tungsten or molybdenum is preliminarily applied to the ceramic green sheet serving as the frame 5. By printing and applying in a predetermined pattern by a screen printing method or the like, the heat radiating member 1 and the frame body 5 are deposited from the inner surface of the recess 5 a to the outer surface of the frame body 5.

  Further, when the wiring conductor 6 is coated with a metal having excellent corrosion resistance such as nickel and gold on the exposed surface and excellent bonding property of the bonding wire 12 to a thickness of 1 to 20 μm by a plating method, the wiring conductor 6 is obtained. As a result, it is possible to effectively prevent the oxidative corrosion of the bonding wire 12 and to strengthen the connection of the bonding wire 12 to the wiring conductor 6. Therefore, it is desirable that the wiring conductor 6 is coated with a metal having excellent corrosion resistance, such as nickel and gold, and excellent bonding properties on the exposed surface to a thickness of 1 to 20 μm.

  The heat dissipating member 1 of the present invention is a penetrating metal body made of copper or an alloy containing copper as a main component from the upper surface to the lower surface of the center portion of a frame-like substrate 2 formed by impregnating a sintered body made of tungsten or molybdenum with copper. 3 is embedded, and copper layers 4a and 4b are joined to cover the base 2 and the upper and lower surfaces of the through metal body 3, respectively.

  The heat radiating member 1 has a function of absorbing heat generated by the operation of the electronic component 11 and dissipating it into the atmosphere or conducting it to an external heat radiating plate. Such a heat radiating member 1 is, for example, first pressure-molded with tungsten powder or molybdenum powder having an average particle size of 5 to 40 μm so that a through hole is formed in a portion to be the mounting portion 10 of the electronic component 11, By sintering this in an atmosphere of 1300 to 1600 ° C., a porous body having through holes formed in the mounting portion 10 of the electronic component 11 from the upper surface to the lower surface is prepared in advance. Then, the porous body is impregnated with 10 to 50% by mass of copper at about 1200 ° C. in a hydrogen atmosphere to impregnate the sintered body of tungsten or molybdenum with copper (tungsten or molybdenum and copper). A flat substrate 2 (made of a matrix) is produced. A through metal body 3 made of copper is embedded in the through hole formed in the center of the base body 2 from the upper surface to the lower surface of the base body 2, and the copper layer 4a and the upper surface of the base body 2 and the through metal body 3 are covered. It is formed by covering the lower surface of the substrate 2 and the penetrating metal body 3 with a copper layer 4b.

  Examples of the method for embedding the through metal body 3 in the through hole of the base 2 and the method for depositing the upper and lower copper layers 4 include a method of firing after inserting a metal body containing copper powder. Alternatively, the through metal body 3 may be embedded in the through hole of the base 2 and then the upper and lower surfaces of the base 2 may be formed by joining upper and lower copper layers 4 with an Ag-based brazing material.

  The material of the penetrating metal body 3 is not limited to pure copper, but may be an alloy containing copper as a main component. Such an alloy containing copper as a main component is an alloy containing 50% by mass or more of copper. For example, a copper-tag stainless alloy, a copper-molybdenum alloy, or the like is used. Similarly, the copper impregnated in the substrate 2 is not limited to pure copper, but may be an alloy mainly composed of copper similar to the through metal body 3.

In the present invention, the difference in thermal expansion coefficient between the heat radiating member 1 and the frame 5 is 3 × 10 ⁻⁶ / ° C. or less. Thereby, the curvature resulting from the difference of the thermal expansion coefficient of the heat radiating member 1 and the frame 5 by the heat | fever which generate | occur | produces when the electronic component 11 act | operates can be reduced, and the joining part of the heat radiating member 1 and the frame 5 can be reduced. It is possible to prevent destruction and destruction of the electronic component 11. As a result, the electronic component 11 can be operated normally and stably over a long period of time.

When the difference in thermal expansion coefficient between the heat radiating member 1 and the frame 5 is greater than 3 × 10 ⁻⁶ / ° C., the thermal expansion coefficient between the heat radiating member 1 and the frame 5 is increased when the electronic component 11 operates and generates heat. Due to the bending caused by the difference and the bending stress generated at the joint between the heat radiating member 1 and the frame 5, cracks are likely to occur at the joint between the heat radiating member 1 and the frame 5 and the electronic component 11 is hermetically sealed. It becomes difficult to stop, or cracks are likely to occur in the bonding material for bonding the electronic component 11 and the copper layer 4a due to the generated bending stress. In the case where a crack occurs in the bonding material that joins the electronic component 11 and the copper layer 4a due to the bending stress generated at the joint between the heat dissipation member 1 and the frame 5, the electronic component 11 and the copper layer 4a Sufficient connections cannot be ensured between them, and it becomes difficult to transfer heat generated in the electronic component 11 well into the heat radiating member 1.

  Preferably, the outer periphery of the penetrating metal body 3 is larger than the outer periphery of the electronic component 11, and is particularly preferably larger by the thickness of the base 2. As a result, more heat generated in the electronic component 11 can be transmitted in a direction perpendicular to the mounting portion 10 of the electronic component 11 on the upper surface of the heat radiating member 1 from the lower surface. It becomes possible to give heat spread in the direction parallel to the heat radiating member 1 from the outer periphery to the outside, and the heat dissipation can be further improved.

  Note that if the outer periphery of the through metal body 3 is larger than the thickness of the base 2 with respect to the outer periphery of the electronic component 11, the thermal expansion of the through metal body 3 increases and the mounting portion 10 is easily distorted. As a result, the electronic component 11 is easily peeled off.

  The arithmetic mean roughness Ra of the surface of the copper layer 4a on the upper surface side of the heat radiating member 1, that is, the mounting portion 10 side on which the electronic component 11 is mounted is preferably a smooth surface of Ra ≦ 30 (μm). . In the case of Ra> 30 (μm), when the electronic component 11 is bonded and fixed to the mounting portion 10 via a bonding material such as glass, resin, or brazing material, voids tend to be generated in the bonding material. is there. The void generated in the bonding material not only lowers the bonding strength between the electronic component 11 and the heat radiating member 1, but also impedes heat transfer between the electronic component 11 and the heat radiating member 1, and the electronic component storage package 8. And tends to reduce the heat dissipation of the electronic device 14.

  The arithmetic average roughness Ra of the surface of the copper layer 4b on the lower surface side of the heat radiating member 1, that is, the side opposite to the mounting portion 10 on which the electronic component 11 is mounted, is preferably Ra ≦ 30 (μm). . Usually, the electronic component storage package 8 is connected to a support substrate made of a metal body such as aluminum or copper or a ceramic body having high thermal conductivity by screwing or using a molten metal such as solder or a brazing material. At this time, when the arithmetic average roughness Ra of the lower surface of the copper layer 4b on the lower surface of the base 2 is Ra> 30 (μm), it is difficult to sufficiently bring the electronic component storage package 8 and the support substrate into close contact with each other. As a result, a gap is likely to be generated between them, and as a result, the heat generated in the electronic component 11 may not be efficiently transferred from the electronic component storage package 8 to the support substrate. Therefore, the lower surface, which is the outer surface of the lower copper layer 4b, is preferably a smooth surface with Ra ≦ 30 (μm) so as to obtain good adhesion to the support substrate.

  If the thickness of each of the copper layers 4a and 4b is greater than 800 μm, the stress generated due to the difference in thermal expansion between the base 2 and the copper layers 4a and 4b tends to increase, so that sufficient bonding strength cannot be obtained. It is desirable to keep Further, if the thickness of the copper layers 4a and 4b is 50 μm or more, the heat generated by the operation of the electronic component 11 is sufficiently spread in the plane direction of the copper layers 4a and 4b. Therefore, it is desirable to set it to 50 μm or more.

  Further, the copper layers 4 (4a, 4b) bonded to the upper and lower surfaces of the base 2 of the heat radiating member 1 are, for example, the mounting portion 10 for the electronic component 11 among the upper and lower surfaces where the penetrating metal body 3 is embedded. In addition, it is sufficient if it is formed at the joint portion with the external heat radiating plate, and it is not always necessary to cover the entire upper and lower surfaces of the heat radiating member 1 as shown in FIG.

  Thus, the electronic component 11 is bonded and fixed onto the mounting portion 10 of the heat dissipation member 1 of the electronic component storage package 8 described above via an adhesive made of glass, resin, brazing material, etc., and each electrode of the electronic component 11 is attached. Electrically connected to a predetermined wiring conductor 6 via the bonding wire 12, and then a sealing resin such as an epoxy resin so as to cover the electronic component 11 inside the recess 5a composed of the heat radiating member 1 and the frame 5 The electronic component 11 is sealed by filling 13 and sealing the electronic component 11 by attaching a lid made of resin, metal, ceramics or the like to the upper surface of the frame 5 so as to cover the recess 5a. By doing so, the electronic device 14 as a product is obtained.

  In addition, this invention is not limited to the example of the above embodiment, A various change is possible if it is the range which does not deviate from the summary of this invention. For example, in order to efficiently dissipate the heat generated in the electronic component 11 from the heat radiating member 1 to the atmosphere, heat radiating fins are connected to the copper layer 4 b joined to the base 2 of the heat radiating member 1 and the lower surface of the through metal body 3. Alternatively, the heat radiation fins may be joined to the copper layer 4b by brazing or the like, and the heat radiation fins may be integrated with the heat radiation member 1, whereby the heat generated by the operation of the electronic component 11 is dissipated. The action of absorbing by 1 and dissipating into the atmosphere can be further improved.

  Next, samples were prepared as follows, and the electronic component storage package of the present invention was evaluated.

  First, as the heat radiating member 1 shown in FIG. 1, a member having a size of 34 mm × 17.4 mm and a thickness of 1.9 mm was prepared.

  The base 2 of the heat radiating member 1 was formed of a material obtained by impregnating a sintered body made of tungsten with copper, and the thickness thereof was 1.00 mm. Moreover, the copper plate as the copper layer 4 (4a * 4b) of the heat radiating member 1 was 0.45 mm in thickness, respectively.

The penetrating metal body 3 is formed on the base 2 with a size of 20 mm × 5 mm, and the copper plate 4 (4a, 4b), the base 2 and the penetrating metal body 3 are bonded to a B silver alloy (72.0% by mass of silver). The brazing material 15 was made of 28.0% by mass of copper. Thereby, the heat radiating member 1 with a thermal expansion coefficient of 20 × 10 ⁻⁶ / ° C. was obtained.

  A frame 5 made of Fe—Ni—Co alloy, Ni steel and alumina ceramics is joined to these heat radiating members 1 with a brazing material made of a B silver alloy (72.0% by mass of silver and 28.0% by mass of copper). A storage package 8 was obtained. Then, the junction part of the thermal radiation member 1 and the frame 5 was observed, and the presence or absence of a crack etc. was confirmed.

Table 1 shows the test results for the above evaluation tests. Table 1 shows the results of external observation of the joint between the heat radiating member 1 and the frame 5 in the electronic component storage package 8.

  As is clear from the results shown in Table 1, it was found that there is a clear relationship between the difference in thermal expansion coefficient between the materials of the heat radiating member 1 and the frame 5 and the occurrence of cracks at the joint between the heat radiating member 1 and the frame 5. .

That is, as shown in Table 1, when the difference between the thermal expansion coefficient of the heat radiating member 1 and the thermal expansion coefficient of the frame 5 is smaller than 3 × 10 ⁻⁶ / ° C., between the heat radiating member 1 and the frame 5 It was found that the bonding state was good. On the other hand, when the difference between the thermal expansion coefficient of the heat radiating member 1 and the thermal expansion coefficient of the frame body 5 is larger than 3 × 10 ⁻⁶ / ° C., the frame body 5 is cracked or warped. Was found to occur.

It is sectional drawing which shows an example of embodiment of the electronic component storage package of this invention, and the electronic device of this invention using the same.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ..... Heat-dissipating member 2 ...... Base | substrate 3 ..... Penetration metal body 4, 4a, 4b ... Copper layer 5 ... ······· Frame 5a ······················· 6
10 ・ ・ ・ ・ ・ ・ ・ ・ ・ Mounting part
11 ・ ・ ・ ・ ・ ・ ・ ・ ・ Electronic parts
14 .... Electronic devices

Claims (2)

A frame having a flat plate-like heat radiating member having an electronic component mounting portion at the center of the upper surface, and a plurality of wiring conductors that are attached to the upper surface of the heat radiating member so as to surround the mounting portion and lead out from the inner surface to the outer surface The heat radiating member is made of copper or an alloy containing copper as a main component from the upper surface to the lower surface of the central portion of a frame-like base body formed by impregnating a sintered body made of tungsten or molybdenum with copper. A through metal body is embedded, and copper layers are respectively formed covering the base and the top and bottom surfaces of the through metal body, and a difference in thermal expansion coefficient between the heat dissipation member and the frame is 3 × 10. Electronic component storage package characterized by being ⁻⁶ / ° C. or lower. The electronic component storage package according to claim 1, the electronic component mounted on the mounting portion and having an electrode electrically connected to the wiring conductor, and an upper surface of the frame so as to cover the electronic component An electronic device comprising: an attached lid or a sealing resin filled inside the frame so as to cover the electronic component.

Images