JP2008118071A - Mounting component, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting component that can have high reliability regardless of the size of a semiconductor element chip to be mounted, and to provide a semiconductor device using the mounting component. <P>SOLUTION: The mounting component is provided with a die pad that allows the polygonal bottom of a semiconductor element chip to be secured to a portion of the top surface of an insulating member with a hot-melt metal joining member. The die pad has, at its periphery, multiple elongated portions that correspond to respective bottom end portions of semiconductor chips having similar and different bottom sizes, and the width of each elongated portion is decreased toward the end. A semiconductor device has the mounting component provided with the die pad that allows the polygonal bottom of the semiconductor element chip to be secured to a portion of the top surface of the insulating member with the hot-melt metal joining member. The die pad has, at its periphery, the multiple elongated portions that correspond to the respective bottom end portions of the semiconductor element chip, and the width of each elongated portion is decreased toward to the end. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a mounting component for mounting a semiconductor chip such as a light emitting diode (hereinafter also referred to as “LED”), and a semiconductor device using the same.

As a conventional semiconductor element chip mounting component, the shape of the die pad made of a metal film formed on the top surface of the insulating substrate is similar to the shape of the semiconductor element chip to be mounted. 2. Description of the Related Art A mounting component that can make each side of a semiconductor chip and a die pad portion substantially parallel is known.

However, in the mounting component described above, when the die pad has a similar shape that is moderately larger than the semiconductor chip, the semiconductor element chip moves away from the center along the upper surface of the die pad portion and is fixed as it is. There was a problem that.

Therefore, in order to prevent the semiconductor element chip from being fixed while being displaced from the center of the die pad, the length dimension and width dimension of the die pad rectangle are set to 0.50 to 1.50 of the length dimension and width dimension of the semiconductor element chip. A method of doubling is disclosed. Furthermore, for the purpose of reducing the raised height of the joining member, it has also been disclosed that a substantially rectangular extension part extending integrally outward from the die pad is partially provided around the die pad.

JP 2003-264267 A

However, in the mounting component having the above configuration, when the bottom surface of the semiconductor element chip has a size that covers at least a part of the extension, the extension has a substantially rectangular shape with a uniform width. The self-alignment effect in the diagonal direction of the semiconductor element chip hardly occurs, and it is difficult to fix the semiconductor element chip to the center of the die pad.

Therefore, the present invention provides a mounting component that can be mounted with high reliability regardless of the size of a semiconductor element chip to be mounted, and a semiconductor device using the same.

The mounting component of the present invention includes a die pad capable of fixing the bottom surface of a semiconductor element chip having a polygonal bottom surface to a part of the top surface of the insulating member with a heat-meltable metal bonding member. The die pad has a plurality of elongated portions on the periphery corresponding to respective bottom surface angles of a plurality of semiconductor element chips having different sizes of the bottom surfaces, and the width of the elongated portions is , Narrowing toward the tip side.

A semiconductor device according to the present invention has a mounting component including a die pad in which a bottom surface of a semiconductor element chip having a polygonal bottom surface is fixed to a part of a top surface of an insulating member by a heat-meltable metal bonding member. In the semiconductor device, the die pad has a plurality of elongated portions on the periphery corresponding to the respective bottom corners of the semiconductor element chip, and the width of the elongated portion is narrowed toward the tip side. Features.

In the mounting component and the semiconductor device of the present invention, it is preferable that a tip of the elongated portion has an acute angle.

  In the semiconductor device of the present invention, the contact angle between the upper surface of the insulating member and the metal bonding member is 100 degrees or more, and the contact angle between the upper surface of the die pad and the metal bonding member is 80 degrees or less. It is preferable.

In particular, in the semiconductor device of the present invention, when the semiconductor element chip is a light emitting element chip, color unevenness between the light emitting devices can be reduced.

The mounting component according to the present invention includes a die pad having a good self-alignment effect with respect to a semiconductor element chip of an arbitrary size, so that the semiconductor element chip is accurate regardless of the size of the mounted semiconductor element chip. Can be implemented well. The semiconductor device of the present invention has high reliability since the semiconductor element chip is mounted with high accuracy.

The best mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below exemplifies a mounting component and a semiconductor device for embodying the technical idea of the present invention, and does not limit the mounting component and the semiconductor device of the present invention to the following. Absent. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name and reference sign indicate the same or the same members, and detailed description will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

The semiconductor device of the present invention uses a mounting component having an insulating member 101 and a metal die pad 102 formed on the upper surface of the insulating member 101, and uses the upper surface side of the die pad 102 and the bottom surface of the semiconductor element chip 103. The side is fixed with a heat-meltable metal joining member. 1 to 7 are schematic plan views showing the first to seventh embodiments. The semiconductor element chips 103, 203, 303, and 404 mounted on the mounting components shown in FIGS. 1 to 4 are substantially rectangular parallelepipeds each having a substantially square bottom surface with different sizes. The semiconductor element chips 503, 603, and 703 mounted on the mounting component according to 7 are substantially rectangular parallelepipeds each having a substantially rectangular bottom surface having different sizes.

(Insulating member 101)
In the mounting component of the present invention, a metal die pad 102 is formed on the upper surface side of the insulating member 101. The size and shape of the insulating member 101 are not particularly limited, and may be any shape such as a cylinder, an elliptical column, a sphere, an oval, a triangular column, a quadrangular column, a polygonal column, or a shape similar to these. . Further, the insulating member 101 may be formed of any material as long as the insulating property can be ensured. Examples thereof include resins such as polyphthalamide (PPA), polycarbonate resin, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), ABS resin, epoxy resin, phenol resin, acrylic resin, PBT resin, ceramic, glass, and the like. Among them, it is suitable that the contact angle with a joining member described later is more than 90 °, and it is preferable to use a material having a contact angle of 100 ° or more. By selecting such a material, a semiconductor element chip is used. The self-alignment effect at the time of fixing can be expressed more significantly. Moreover, you may mix and use various dyes or pigments for the insulating member 101 as a coloring agent. For _{example, Cr 2 O 3, MnO 2} , Fe 2 O 3, carbon black and the like. Here, the contact angle in this specification represents the property of the material, and is an angle formed between the liquid surface and the solid surface where the free upper surface of the stationary liquid joining member contacts the upper surface of the solid. That means. Specifically, it can be measured by a static method at a melting point of the joining member +40 to 50 ° C.

(Die pad 102)
The material constituting the die pad 102 formed on the upper surface of the insulating member 101 is not particularly limited as long as the contact angle between at least the upper surface of the die pad 102 and a heat-meltable metal bonding member described later is 90 degrees or less. It is preferable to use a material of 80 degrees or less, more preferably 60 degrees or less, and further preferably 45 degrees or less. From another viewpoint, the difference between the contact angle between the upper surface of the die pad 102 and the bonding member and the contact angle between the insulating member 101 and the bonding member is preferably 10 degrees or more, more preferably It is preferably 20 degrees or more, more preferably 30 degrees or more. As a result, the bonding member infiltrates into the region of the die pad 102 that is more easily wetted than the insulating member 101, and the semiconductor element chip 101 can be easily aligned with the desired region of the die pad. Thus, by selecting the material of at least the upper surface of the die pad, the self-alignment effect at the time of fixing the semiconductor element chip 101 can be exhibited more significantly. Further, when using a semiconductor light emitting device chip, it is preferable that at least the upper surface of the die pad has a light reflectance of 70% or more, more preferably 80% or more, even more preferably with respect to light from the semiconductor device chip. Is preferably 85% or more, more preferably 90% or more. Here, the light reflectance in this specification refers to a value measured by an SCI method using a CMS-35SP spectrophotometer manufactured by Murakami Color Research Laboratory. The die pad 102 can be composed of a single layer film or a laminated film of Al, Ag, Au, Pd, or the like, for example. As the film forming method, various known methods such as vapor deposition, sputtering, plating, etc. can be used.

The top surface shape of the die pad 102 of the present invention has a plurality of elongated portions whose widths are narrowed toward the tip, and the elongated portions have a similar bottom surface size during the reflow process. It corresponds to each bottom corner of a plurality of different semiconductor element chips. As a result, the semiconductor element chip can be fixed in a state in which the semiconductor element chip is not displaced or floated and can maintain high reliability even when used in a severe environment. Here, the elongated portion of the die pad 102 is not particularly limited as long as the width is gradually narrowed toward the tip, and may have two corners at the tip as shown in FIGS. As shown in FIG. 2, each corner provided at the tip may be rounded. 3 and 6, when the bottom surfaces of the semiconductor element chips 303 and 603 to be mounted are sized to circumscribe the die pads 302 and 602, it is preferable that the tip of the elongated portion has an acute angle. Thereby, the precision which mounts the bottom face of semiconductor element chip 303,603 on die pad 302,602 can be raised more. Further, as shown in FIGS. 5 to 7, it is preferable to have a side parallel to the side of the semiconductor element chip to be mounted between the adjacent elongated portions, whereby the mounting accuracy can be further improved.

(Conductive member 105)
A pair of conductive members 105 are formed on the upper surface of the insulating member 101 so as to be separated from the die pad 102, and the conductive members 105 are electrically connected to the electrodes of the semiconductor element chip 103, respectively. The conductive member 105 is not particularly limited as long as it has conductivity, but is preferably formed of a material having a relatively high thermal conductivity. For example, a material having a thermal conductivity of about 200 W / (m · K) or more, a material having a relatively large mechanical strength, or a material that can be easily punched or etched is preferable. For example, metal such as copper, aluminum, gold, silver, tungsten, iron, nickel or iron-nickel alloy, phosphor bronze, iron-containing copper, etc. or a metal plating film such as silver, aluminum, copper, gold, etc. is applied on the upper surface. Scraps etc. are listed.

  As shown in FIG. 4, one of the conductive members 105 and the die pad 102 may be integrally connected by a connecting portion 406. In this case, the connecting portion 104 is preferably provided at the distal end portion of the elongated portion of the die pad 102, which can prevent the connecting portion 104 from hindering the self-alignment effect.

(Semiconductor element chips 103, 303, 403, 503, 603, 703)
The semiconductor element chip 103 used in the present invention is not particularly limited as long as the bottom surface fixed to the die pad 102 is a polygon among the conventionally known semiconductor element chips 103, and the bottom surface and the top surface facing the bottom surface. And do not have to have the same shape. Further, specific material configurations include various semiconductors such as nitride semiconductors such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN, III-V group compound semiconductors, and II-VI group compound semiconductors on a substrate. Can be obtained by forming a laminated structure including an active layer. As a substrate, an insulating substrate such as sapphire or spinel (MgA1 ₂ O ₄ ) whose main surface is any one of C-plane, A-plane, and R-plane, silicon carbide, silicon, ZnS, ZnO, GaAs, diamond; Examples thereof include oxide substrates such as lithium niobate and neodymium gallate, and nitride semiconductor substrates (GaN, AlN, etc.). Examples of the semiconductor structure include homostructures such as MIS junctions, PIN junctions, and PN junctions, heterojunctions, and double heterojunctions. Alternatively, the semiconductor active layer may have a single quantum well structure or a multiple quantum well structure in which a thin film in which a quantum effect is generated is formed. The active layer may be doped with donor impurities such as Si and Ge and / or acceptor impurities such as Zn and Mg. The emission wavelength of the resulting light-emitting element can be changed from the ultraviolet region to red by changing the semiconductor material, the mixed crystal ratio, the In content of InGaN in the active layer, the type of impurities doped in the active layer, etc. . The semiconductor element chip 103 used in the present invention may be a single-sided electrode in which an n-electrode and a p-electrode are formed on the upper surface facing the bottom surface, or each electrode is formed on the top surface and the bottom surface. Alternatively, it may be a double-sided electrode.

  The bottom surface of the semiconductor element chip 103 has a metal film on the entire surface or a part thereof. At least the outermost surface of the metal film is preferably made of a material having a contact angle larger than 90 degrees with a heat-meltable metal joining member described later, and a material having a higher melting point than the joining member. It is possible to prevent the bonding material from diffusing and penetrating to the semiconductor element side during reflow. Specific materials include Au, Ag, Cu, Pt and the like. As the film forming method, various known methods such as vapor deposition, sputtering, plating, etc. can be used. The metal film can be formed by vapor deposition, sputtering, plating, or the like.

Further, when using a semiconductor light emitting element chip, it is preferable not to form a metal film on the entire bottom surface of the semiconductor element chip, but to provide a plurality of metal parts spaced apart from each other on the bottom surface. Thereby, the light extraction efficiency from the bottom surface side of the light emitting element chip can be increased. In addition, it is preferable that such a metal part has a light reflecting function in which at least a surface facing the bottom surface of the semiconductor light emitting element chip has a reflectance of 70% or more with respect to light from the semiconductor light emitting element chip. Thereby, the light absorption by a metal part can be suppressed. Further, when an electrode is formed on the bottom surface side of the semiconductor light emitting element chip, the electrode itself can be made of a material having both conductivity and the above-described light reflecting function. , Au, Pd and the like.

In addition, the member having the light reflecting function described above significantly impairs the light reflecting function when other members are mixed. Therefore, the semiconductor light emitting chip has a first layer having a light reflecting function from the bottom surface side of the semiconductor element chip, and an ultra-high layer such as Mo, W, Nb, Rh, Ta, and Ti covering the first layer. A third layer made of a material of a high melting point material having good wettability with a second layer made of a melting point material and a joining member such as Au, Ag, Cu, and Pt covering the second layer; It is preferable to have. Thereby, it can suppress that a joining member mixes in the 1st layer which has a light reflectivity function. Each of these layers can be laminated using various methods such as known methods such as vapor deposition, sputtering, and plating.

(Heat-meltable metal joining member (not shown))
The heat-meltable metal bonding member is used for mounting and fixing the semiconductor element chip 103 on the die pads 102a and 102b. For example, SnPb-based, SnAgCu-based, AuSn-based, SnZn-based, SuCu-based, etc. A solder material can be preferably used. Among these, AuSn solder materials are preferable in terms of heat resistance and bonding reliability when a semiconductor device is reflow-fixed. Optionally, Bi, In or the like may be added to these for the purpose of improving wettability or solder cracking property.

(Wire 104)
The electrode on the upper surface side of the semiconductor element chip 101 is electrically connected to the conductive member 105 with a wire 104. The wire 104 preferably has good ohmic properties with the electrodes of the semiconductor element chip 101, good mechanical connectivity, or good electrical and thermal conductivity. The thermal conductivity, preferably ^{0.01cal / S · cm 2 · ℃} / than about cm further ^{0.5cal / S · cm 2 · ℃} / cm or higher order is more preferable. Considering workability and the like, the diameter of the wire 104 is preferably about 10 μm to 45 μm. Examples of such a wire 104 include metals such as gold, copper, platinum, and aluminum, and alloys thereof.

  In the semiconductor device of the present invention, the semiconductor element chip 103 fixed on the upper surface of the die pad 102 is usually electrically connected to the conductive member 105 and then covered with a sealing member. As a result, the semiconductor element chip can be protected from external force, moisture, and the like, and the wire used as the conduction means can be protected. Examples of the material for the sealing member include resins having excellent weather resistance such as epoxy resins, silicone resins, acrylic resins, urea resins, or combinations thereof, glass, and the like. The sealing member preferably has a small difference in thermal expansion coefficient from the material of the insulating member 101, and can thereby prevent the destruction of integrity due to thermal stress on each member. The sealing member may contain a pigment, a diffusing agent, and a fluorescent material.

In the case where a semiconductor light emitting element is used as the semiconductor element chip 101, it is essential that the sealing member has a light transmitting property capable of transmitting light from the semiconductor light emitting element. The translucent sealing member contains a diffusing agent or a fluorescent material, or the diffusing agent is applied to the outermost surface of the translucent sealing member, thereby reducing the directivity from the semiconductor light emitting element and increasing the viewing angle. Or the wavelength of light emitted from the semiconductor light emitting element to the part can be converted. When the light from the light-emitting element is high-energy short-wavelength visible light, nitrogen-containing CaO—Al ₂ O activated with a perylene derivative, ZnCdS: Cu, YAG: Ce, Eu and / or Cr, which is an organic fluorescent material Various fluorescent materials such as an inorganic fluorescent material such as _3- SiO ₂ are preferably used.

In a semiconductor light emitting device, when white light is obtained, particularly when a YAG: Ce fluorescent material is used, a yellow color which is a complementary color emitted from the blue light emitting element and the fluorescent material partially absorbing the light depending on its content. Thus, white light can be obtained relatively easily and reliably. Similarly, when a nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ phosphor activated with Eu and / or Cr is used, the light from the blue light emitting element and part of the light are absorbed depending on the content thereof. Red light, which is a complementary color emitted from the fluorescent material, is mixed, and white light can be obtained relatively easily and with high reliability. In addition to these fluorescent materials, any of the known fluorescent materials described in, for example, Japanese Patent Application Laid-Open Nos. 2005-19646 and 2005-8844 can be used. In the case of a light-emitting device that obtains light of a predetermined color by mixing light emitted from a light-emitting element and light that has been wavelength-converted into a fluorescent material, a light-reflective material is formed at the interface between the insulating substrate and the light-emitting element. By forming the die pad, it is possible to reduce the wraparound of light to the side surface of the light emitting device, which is caused by the light from the bottom surface of the light emitting element being transmitted through the insulating member. As a result, it is possible to mix light appropriately and to obtain light emission with less color unevenness.

The shape of the sealing member is not particularly limited, and a lens may be provided as part of the sealing member or attached to the upper surface side of the sealing member. For example, a plastic or glass lens or the like may be provided as a sealing member above the semiconductor element chip, or a separate lens may be provided above the sealing member that directly covers the semiconductor element chip. May be. Further, when a semiconductor light emitting element chip is used, various components such as a reflection member, an antireflection member, a light diffusion member, etc. are provided on the upper surface side of the insulating member 101 in order to efficiently extract light from the semiconductor light emitting element chip. May be provided.

Industrial application fields

  Various transistors, switching diodes, Zener diodes, variable capacitance diodes, illumination light sources, various indicator light sources, in-vehicle light sources, display light sources, liquid crystal backlight light sources, traffic lights, in-vehicle components, signboard channel letters, etc. Can be used for light source.

1 is a schematic plan view of a semiconductor device according to an embodiment of the present invention. It is a schematic plan view of the semiconductor device of the 2nd Embodiment of this invention. It is a schematic plan view of the semiconductor device of the 3rd Embodiment of this invention. It is a schematic plan view of the semiconductor device of the 4th Embodiment of this invention. It is a schematic plan view of the semiconductor device of the 5th Embodiment of this invention. It is a schematic plan view of the semiconductor device of the 6th Embodiment of this invention. It is a schematic plan view of the semiconductor device of the 7th Embodiment of this invention.

Explanation of symbols

101 Insulating member 102, 202, 302, 402, 502, 602, 702 Die pad 103, 303, 403, 503, 603, 703 Semiconductor element chip 104 Wire 105 Conductive member 406 Connecting portion

Claims (6)

A mounting component including a die pad capable of fixing the bottom surface of a semiconductor element chip having a polygonal bottom surface to a part of the top surface of the insulating member with a heat-meltable metal bonding member,
The die pad has a plurality of elongated portions on the periphery corresponding respectively to the bottom surface corners of a plurality of semiconductor element chips having different sizes of the bottom surface.
The mounting part according to claim 1, wherein a width of the elongated portion is narrowed toward a distal end side. The mounting component according to claim 1, wherein a tip of the elongated portion has an acute angle. A semiconductor device having a mounting component including a die pad in which a bottom surface of a semiconductor element chip having a polygonal bottom surface on a part of an upper surface of an insulating member is fixed by a heat-meltable metal bonding member,
The die pad has a plurality of elongated portions on the periphery corresponding to the bottom corners of the semiconductor element chip,
2. A semiconductor device according to claim 1, wherein a width of the elongated portion is narrowed toward a distal end side. The semiconductor device according to claim 3, wherein a tip of the elongated portion has an acute angle. The contact angle between the upper surface of the insulating member and the metal bonding member is 100 degrees or more, and the contact angle between the upper surface of the die pad and the metal bonding member is 80 degrees or less. 5. The semiconductor device according to 4.   The semiconductor device according to claim 3, wherein the semiconductor element chip is a light emitting element chip.

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