JP5453713B2 - Semiconductor device and method for forming the same - Google Patents

Description

  The present invention relates to a semiconductor device on which a semiconductor element is mounted and a method for forming the same, and more particularly, to a light emitting device used for a backlight of a liquid crystal display, a panel meter, a display lamp, a portable electronic device, and the like.

  In recent years, a semiconductor device equipped with a light emitting element has a plurality of light emitting elements mounted in one package, a light emitting element of a different light emission color, or a different semiconductor element having a different function from the light emitting element. As a result, products that can be used for various purposes have been developed. For example, in order to ensure the reliability of a light emitting element, a semiconductor device is provided in which a protective element for protecting the light emitting element from destruction due to overvoltage is mounted together with the light emitting element.

  An example of such a semiconductor device will be described more specifically below. A semiconductor device includes a support provided with a recess for housing a semiconductor element, a lead electrode exposed on the bottom surface of the recess, a light emitting element disposed on the lead electrode, and a lead electrode in the recess. And a conductive wire that connects the electrodes of the semiconductor elements and the lead electrodes of the support, and a sealing member that covers the elements and the conductive wires in the recesses. Here, as the support, a molded body formed by injecting molding resin into a frame insert type package, that is, a mold holding the lead electrode, and curing the molding resin is preferably used. In addition, the light emitting element and the protective element that do not require electrical connection on the back surface side that is bonded to the mounting portion are bonded to the mounting portion of the lead electrode with an insulating adhesive such as epoxy resin. On the other hand, a light-emitting element or a protective element having an electrode on the back surface side that is bonded to the mounting part is bonded to the mounting part of the lead electrode with a conductive adhesive such as silver paste. Here, the protective element is electrically connected to the lead electrode by a conductive adhesive or a conductive wire, and constitutes a circuit that is antiparallel to the light emitting element.

  In such a semiconductor device, when a part of the adhesive applied on the lead electrode flows on the lead electrode to the connection part of the conductive wire, the connection part of the conductive wire is covered with the adhesive, There is a concern that the connection strength of the conductive wire to the connection portion may decrease. In addition, the insulating adhesive that adheres the light emitting element to the lead electrode and the conductive adhesive that adheres the protective element may interfere with each other, thereby impairing the respective functions.

  Therefore, for example, a notch for preventing the flow of adhesive is provided in a part of the lead electrode, or a lead electrode for arranging the light emitting element and a lead electrode for arranging the protective element are separately provided on the support. There are things to do. Further, as a simpler means for preventing the flow of the adhesive on the lead electrode, as disclosed in the following Patent Document 1, the cross section between the mounting portion of the light emitting element and the connecting portion of the conductive wire is used. May provide a V-shaped groove. If the groove is provided in the lead electrode in this way, it becomes unnecessary to complicate the shape of the lead electrode due to the notch as described above and to dispose separate lead electrodes. For this reason, even if a plurality of types of semiconductor elements are arranged on the same lead electrode, the configuration of the semiconductor device can be relatively simplified.

  Furthermore, when measures are taken to prevent the flow of the adhesive in the groove on the lead electrode, in order to reliably block the flow of the adhesive, the light emitting element is surrounded so as to surround the four sides of the light emitting element mounting portion. It is necessary to provide the groove in a shape that conforms to the external shape. As a method of providing such a groove, for example, as disclosed in Patent Document 2, a die is pressed against the surface of the lead frame, and pressure is applied to deform the surface of the lead frame to form a groove. A so-called press process is mentioned. In the press working disclosed in Patent Document 2, a die having a grid-like convex portion corresponding to the shape of the groove on the processing surface is used so that the shape of the groove becomes a grid shape.

JP 2002-261187 A JP 2006-156437 A

  In the semiconductor device as described above, it is required to bond a plurality of types of semiconductor elements with different types of adhesives on the same lead electrode without complicating the arrangement and shape of the lead electrode. Furthermore, with the miniaturization of the semiconductor element, the possibility of mutual interference of the adhesive and the flow to the connecting portion of the conductive wire is increased, and in such a semiconductor device, in order to reliably suppress the flow of the adhesive, The groove formed on the lead electrode is preferably formed so as to reliably surround the mounting portion of the semiconductor element.

  However, if the pattern shape of the groove is complicated in order to reliably surround the mounting portion of the semiconductor element, it is difficult to form the groove in the lead electrode formation process. That is, in the press work as shown in the above-mentioned prior art, if the shape to be formed becomes complicated, the cost of the mold design associated therewith increases. Further, in consideration of the consumption of the processing surface of the mold for molding such a complicated shape, it is necessary to replace the mold at an early stage in order to maintain high accuracy in forming the groove.

  Accordingly, an object of the present invention is to provide a highly reliable semiconductor device with reduced manufacturing cost and a method for forming the same.

  In order to achieve the above object, a semiconductor device according to the present invention includes a semiconductor element, a pair of positive and negative lead electrodes having a mounting portion on which the semiconductor element is disposed, and the lead electrodes are disposed, and the semiconductor element is accommodated therein. A semiconductor device comprising: a support portion having a concave portion; an adhesive that adheres the semiconductor element to the lead electrode; and a conductive wire that connects the electrode of the semiconductor element to the lead electrode. The electrode includes at least a first groove provided between the side wall of the recess and the mounting portion, and a second groove provided between the connection portion of the conductive wire and the mounting portion. And the first groove portion and the second groove portion intersect at least at one place.

  The lead electrode has a plurality of mounting portions, and a third groove portion that intersects at least one of the first groove portion and the second groove portion is provided between the mounting portions. It is preferable.

  The support portion has an insulating separation portion provided between a pair of positive and negative lead electrodes, and at least one of the lead electrodes has a fourth groove portion extending along the insulating separation portion. Is preferred.

  In order to achieve the above object, a semiconductor device according to the present invention includes a semiconductor element, a lead electrode having a mounting portion on which the semiconductor element is disposed, a support portion on which the lead electrode is disposed, and the semiconductor element. A semiconductor device comprising: an adhesive that adheres to the lead electrode; and a conductive wire that connects the electrode of the semiconductor element to the lead electrode, wherein the lead electrode has a plurality of groove portions partially intersected And at least one of the groove portions is provided between the connecting portion of the conductive wire and the mounting portion of the semiconductor element.

  In order to achieve the above object, a method for forming a semiconductor device according to the present invention includes a semiconductor element, a lead electrode having a mounting portion on which the semiconductor element is disposed, a support portion on which the lead electrode is disposed, A method of forming a semiconductor device, comprising: an adhesive that bonds a semiconductor element to the lead electrode; and a conductive wire that connects the electrode of the semiconductor element to the lead electrode. A first step of forming one groove portion; a second step of forming a second groove portion that intersects a part of the first groove portion after forming the first groove portion; and the semiconductor element. A third step of bonding the lead wire to the mounting portion of the lead electrode with the adhesive, and extending the conductive wire across at least one of the first groove portion or the second groove portion. , Electrodes of the semiconductor element And having a fourth step of connecting the lead electrode.

  After the second step, the first groove portion is disposed between the mounting portion and the side wall of the support portion, and the second groove portion is disposed between the mounting portion and the connection portion of the conductive wire. It is preferable to have the process of forming the side wall of the said support part so that may be arrange | positioned.

  The fourth step preferably includes a step of connecting the electrode of the semiconductor element and the lead electrode by extending the conductive wire across the second groove.

  It is preferable to have a step of forming a third groove portion between a plurality of mounting portions.

  The first to third groove portions are preferably formed by pressing the mold against the main surface of the lead electrode and applying pressure.

  The first to third groove portions are preferably formed by cutting a part of the main surface of the lead electrode.

  According to the present invention, the flow of the adhesive is suppressed by the groove even when a plurality of semiconductor elements are bonded to the same lead electrode with a plurality of types of adhesives without complicating the arrangement and shape of the lead electrodes. Therefore, a highly reliable semiconductor device that does not cause poor adhesion of semiconductor elements or poor connection of conductive wires can be obtained. Further, the present invention can be formed with low manufacturing cost of such a highly reliable semiconductor device.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a semiconductor device and a method for forming the semiconductor device for embodying the technical idea of the present invention, and the present invention does not limit the semiconductor device and the method for forming the semiconductor device 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.

  FIG. 1 is a top view of a semiconductor device 100 according to this embodiment. 2 is a cross-sectional view of the semiconductor device 100 in the XX direction of FIG. FIG. 5 is a cross-sectional view schematically showing a part of a cross section of the lead electrodes 106 and 111 in the semiconductor device 100 according to this embodiment.

  As shown in FIG. 1, the semiconductor device 100 in this embodiment includes a semiconductor element 108, a second lead electrode 111 having a mounting portion on which the semiconductor element 108 is disposed, the second lead electrode 111, and the first lead electrode 111. A support portion 110 having a recess for holding the lead electrode 106 and housing the semiconductor element 108, an adhesive for bonding the semiconductor element 108 to the second lead electrode 111, and one electrode of the semiconductor element 108 being connected to the first electrode The semiconductor device includes a first conductive wire 107 connected to the lead electrode 106 and a second conductive wire 112 connecting the other electrode of the semiconductor element 108 to the second lead electrode 111. Note that the end portions of the first lead electrode 106 and the second lead electrode 111 are spaced apart from each other on the bottom surface of the concave portion of the support portion, and an insulating separation portion 105 is provided between these end portions. Yes. Further, the mounting portion of the semiconductor element and the connecting portion of the conductive wire are provided on the main surface of the lead electrode exposed at the bottom surface of the concave portion of the support portion 110.

  With respect to such a semiconductor device, the present inventor has made various studies in order to provide a highly reliable semiconductor device with reduced manufacturing costs. As a result, the lead electrode has at least a first groove portion between the side wall of the recess and the mounting portion of the semiconductor element, and a second groove portion between the connecting portion of the conductive wire and the mounting portion. In addition, the first groove portion and the second groove portion include grooves having different stretching directions, and the grooves are crossed at least at one place in the stretching direction. It came to solve.

  That is, the present invention has a groove on the main surface of the lead electrode on which the semiconductor element is arranged, and this groove is provided at least between the side wall of the concave portion of the support and the mounting portion of the semiconductor element. It is comprised from the groove part and the groove part provided between the mounting part of a semiconductor element, and the connection part on the lead electrode of an electroconductive wire. In addition, although the groove | channel which comprises the groove part in this form is one for each groove part as shown in figure, the groove | channel with the substantially same extending | stretching direction may be included in each groove part. By including a plurality of grooves in each groove part, the effect of suppressing the flow of the adhesive can be enhanced.

  Further, the grooves included in the groove portions are respectively extended on the lead electrodes, and a part of the grooves overlap each other to form a cross-shaped crossing portion. Such intersections ensure connection between grooves formed in different steps and having different extension directions, and an adhesive for adhering semiconductor elements can be used for the wall surface of the concave portion of the support or the conductive wire. It will not flow out to the connection. For this reason, the semiconductor device of the present invention can make the connection of the semiconductor element or the conductive wire to the lead electrode strong and can be a highly reliable semiconductor device. Note that the shape of the intersection is not limited to the cross shape as in the present embodiment. That is, the intersecting portion of the present invention is not limited to those in which a plurality of grooves having different stretching directions intersect at a right angle, as long as they intersect at least one place by varying the stretching direction of each groove by a predetermined angle. Good.

  The lead electrode includes a plurality of semiconductor element mounting portions, and a third portion having an end portion intersecting at least one of the first groove portion and the second groove portion between the mounting portions. It is preferable that a groove is provided. This is because the mutual interference of the adhesive that adheres the semiconductor element to the lead electrode can be suppressed.

  Further, the lead electrode is provided in a pair of positive and negative on the support portion, and one lead electrode or conductive wire on which the semiconductor element is mounted along the insulating separation portion provided between the ends of the opposing lead electrodes. It is preferable that a fourth groove portion different from the first to third groove portions is provided in at least one of the other lead electrodes connected to the first and third groove portions. This is because it is possible to suppress the adhesive from flowing through the insulating separation part to the connection part of the conductive wire. Further, when a configuration is adopted in which the tip portions of the first to third groove portions are not connected to the insulating separation portion, the lead portion between the tip portion on the insulating separation portion side of the groove portion and the insulating separation portion is passed through. This is because the adhesive can be prevented from flowing.

  A method of forming a semiconductor device according to the present invention includes a semiconductor element, a lead electrode having a mounting portion for disposing the semiconductor element, a support portion having a recess for holding the lead electrode and accommodating the semiconductor element, and a semiconductor element. A method of forming a semiconductor device comprising: an adhesive that adheres to the lead electrode; and a conductive wire that connects an electrode of a semiconductor element to the lead electrode. With respect to such a method for forming a semiconductor device, the present inventor has made various studies in order to provide a highly reliable method for forming a semiconductor device while reducing manufacturing costs. As a result, the method for forming a semiconductor device according to the present invention has solved the problem by including at least the following steps.

  (1) a step of forming a first groove on the main surface of a lead electrode to which a semiconductor element or a conductive wire is connected; (2) an end of the first groove formed in the previous step; and an end of the groove Forming a second groove part by crossing the parts; (3) attaching the semiconductor element to the mounting part on the lead electrode with an adhesive; and (4) the first groove part or the second groove part. A step of extending the conductive wire so as to straddle at least one of the grooves, and connecting the electrode of the semiconductor element and the lead electrode with the conductive wire. Hereinafter, a method for forming a semiconductor device according to this embodiment will be described in detail.

  The groove formed in the lead frame can be formed relatively easily by press working using a mold or cutting. In order to sufficiently divide the mounting area of the semiconductor element and the conductive wire connection area on the lead electrode, if the shape of the groove surrounding the mounting area of the semiconductor element becomes geometrically complicated, it can be used for pressing. The design of the mold to be performed becomes complicated and the design cost increases.

  Therefore, the method for forming a semiconductor device in this embodiment does not form grooves at a time on the lead main surface, but forms a plurality of grooves with different extension directions separately by subdividing the process of forming the grooves. To do. That is, after a step of forming one groove on the main surface of the lead electrode, another groove having a different extension direction from the groove is surrounded with the previously formed groove so that the semiconductor element mounting portion is surrounded. It is formed in a separate process. Furthermore, when the groove forming step is divided in this way, even if an end of one groove is connected to an end of another groove, the connection may not be successful and the groove may be partially discontinuous. . In such a discontinuous portion of the groove, the function of suppressing the flow of the adhesive cannot be sufficiently achieved. Therefore, in the method for forming a semiconductor device of the present invention, for the purpose of surely preventing the discontinuity of the groove part, the part of the groove part is formed so as to overlap with a part of the other groove part. Thereby, a groove part in which a plurality of grooves having different extending directions are crossed at least at one place is formed.

  Thereby, the manufacturing cost of the semiconductor device that can sufficiently prevent the flow of the adhesive for adhering the semiconductor elements without causing discontinuity of the groove portion around the mounting portion can be suppressed.

  In this embodiment, a semiconductor device including a support portion having a recess is mainly described. However, a semiconductor device and a method for forming the semiconductor device according to the present invention are provided in a semiconductor device including a support portion having a sidewall that forms a recess. There is no limit. That is, the present invention can also be applied to a lead electrode disposed on a flat plate-like support portion that does not have a recess for housing a semiconductor element. When the support part has a side wall that forms a recess, and the groove part of the lead electrode and the side wall of the recess are connected at the bottom part of the side wall, the adhesive that flows from the mounting part to the side wall of the recess through the groove part However, there is a concern that the flow range may be further expanded along the inner wall of the recess. Therefore, it is preferable that the groove on the lead electrode is provided with a gap between the groove and the bottom of the side wall of the recess.

  Further, the support portion having the concave portion is formed such that the first groove portion and the second groove portion formed in separate steps support the semiconductor element mounting portion and the conductive wire connection portion on the lead electrode main surface, respectively. It is preferable to form so that it may be located between the side wall which forms the recessed part of a part. For example, after the first and second groove portions are formed in different orientations outside the region to be the semiconductor element mounting portion, the first groove portion is disposed between the semiconductor element mounting portion and the recess side wall of the support portion. In addition, the support portion is preferably formed so that the second groove portion is disposed between the mounting portion of the semiconductor element and the connection portion of the conductive wire.

  The package having the recesses in this embodiment can form the recesses integrally with the formation of the support part, and the inner surface of the through hole is placed in the recess by arranging a plate material having a through hole in the flat support part. It can also be a wall. In the case of a package having such a recess, the groove can be formed in the lead electrode after the recess is formed, but it is preferable to form the recess after the groove is formed in the lead electrode. This is because the latter method does not obstruct the side wall of the recess compared to the step of forming the groove in the lead electrode after forming the recess, so that the groove can be easily formed. Note that when forming a semiconductor device that does not include a recess for housing a semiconductor element, the side wall of the recess does not become an obstacle, so the groove can be used before or after the step of placing the lead electrode on the support. It can be formed easily.

  When a semiconductor device including a plurality of semiconductor elements is provided, it is preferable to include a step of forming a support by providing a plurality of mounting portions and a step of forming a groove between the mounting portions. The groove formed between the mounting portion of the semiconductor element and the mounting portion of another semiconductor element can also reduce the manufacturing cost of the semiconductor device by dividing the groove forming process.

  The groove is preferably formed by a so-called press process in which a die is pressed against the main surface of the lead electrode and pressure is applied to deform the lead electrode main surface. According to this method, it is easy to adjust the depth of the groove by changing the pressing pressure, and the groove can be easily formed as compared with other forming methods. Can be suppressed. Alternatively, the groove is formed by cutting a part of the main surface of the lead electrode. According to this, compared with the thing by press work, the depth of a groove | channel can be deepened easily and a groove part can be reliably formed in the circumference | surroundings of a mounting part.

  In the wire bonding step of connecting the conductive wire to the electrode of the semiconductor element and the lead electrode, the groove spanned by the extended conductive wire is a groove formed in a later step in a plurality of steps of forming the groove portion. Is preferred. That is, the groove formed between the mounting portion of the semiconductor element and the connection portion of the conductive wire may be a groove formed in a later step by intersecting the end portion with the previously formed groove. preferable. This is because the groove formed later than the groove formed earlier has a higher effect of suppressing the flow of the adhesive to the connecting portion of the conductive wire because the shape of the groove is not collapsed. Hereinafter, the semiconductor device of this embodiment, a method for forming the semiconductor device, and each component will be described in detail.

[Step of forming lead electrode]
First, a metal plate is punched to form a lead frame having a plurality of pairs of protrusions that form a pair of positive and negative lead electrodes. The groove in the main surface of the lead electrode can be formed by pressing or cutting the main surface of the lead electrode during or after the punching process to the metal flat plate performed in a plurality of times. Or you may form a groove part by combining those formation methods with respect to one lead electrode.

  The material of the lead electrode is not particularly limited as long as it is conductive. However, the lead electrode is required to have good adhesion and electrical conductivity to a conductive wire, a bump, or the like that is a member electrically connected to the semiconductor element. The specific electric resistance is preferably 300 μΩ-cm or less, more preferably 3 μΩ-cm or less. Preferred examples of materials that satisfy these conditions include iron, copper, iron-containing copper, tin-containing copper, and aluminum.

  The surface of the lead electrode is preferably covered with a metal made of silver, gold or palladium after the punching process into the metal flat plate and the formation of the groove. Thereby, when a light emitting element is mounted, the light reflectance on the surface of the lead electrode can be improved. These metal materials can be preferably disposed on the surface of the lead electrode by a method such as plating or sputtering.

  FIG. 5 is a cross-sectional view partially enlarged showing a cross section in a direction perpendicular to the main surface of the lead electrode in the groove formed on the main surface of the lead electrode by press working. When forming the groove by press working, considering the strength of the lead electrode, workability, and the flow blocking effect of the adhesive, the groove depth D (distance from the main surface of the lead electrode to the deepest part of the groove) is: It is preferable that they are 5 micrometers or more and 200 micrometers or less. Further, the width W of the groove is preferably 5 μm or more and 250 μm or less in consideration of the flow preventing effect of the adhesive. Furthermore, the inclination angle φ of the inner surface forming the groove having a V-shaped cross section is 15 ° with respect to the lead electrode main surface in consideration of workability when the groove is formed by press working and the effect of preventing the flow of the adhesive. The angle is preferably 75 ° or less.

[Process of forming package]
The package in this embodiment is a support body on which a semiconductor element and a sealing member can be arranged, and includes a pair of positive and negative lead electrodes and a support portion that is an insulating material that insulates and holds the lead electrodes. It is a member provided. In the package of this embodiment, a molded body in which a molding material is molded on the lead frame by injection molding is preferably used.

  The lead electrode is a conductor that supplies power to the semiconductor element from the outside of the semiconductor device. In particular, the lead electrode according to this embodiment is integrally formed at the time of molding the package so that one end is inserted into the package from the side of the package and the other end protrudes from the side of the package.

  A lead frame having a groove on the main surface is sandwiched between a convex shape and a concave shape. At this time, the end portion of the lead electrode is arranged in an internal space formed by a convex shape and a concave shape. Next, a molding material is injected into the internal space from the gate provided on the back surface of the mold to cover at least the end portion of the lead electrode.

  The molding material for the package is not particularly limited, and may be a liquid crystal polymer, a polyphthalamide resin, polybutylene terephthalate (PBT), or the like. In particular, a semi-crystalline polymer resin containing a high melting point crystal such as a polyphthalamide resin is suitable as a packaging material because of its good adhesion to a sealing member (eg, epoxy resin or silicone resin). Used for Moreover, in order to improve the reflectance of the light from a light emitting element, white pigments, such as a titanium oxide, can be contained in a molding material. Finally, after the filled molding material is cured, the molded body is removed from the convex mold and the concave mold.

[Process of arranging semiconductor elements]
An adhesive is disposed on a mounting portion of the semiconductor element provided on the main surface of the lead electrode, and a semiconductor element such as a light emitting element or a protective element is bonded with the adhesive. Here, the “mounting portion” in the present embodiment refers to a region having approximately the same size as the outer shape of the bonding surface of the semiconductor element to be arranged among the regions provided on the lead electrode. In this embodiment mode, a semiconductor device in which a light emitting element is arranged on a support together with a protective element will be described. Zener diodes, capacitors, etc.), or a semiconductor device on which a combination of at least two of them is mounted. Hereinafter, in particular, the light emitting element will be described in detail.

(Light emitting element)
Examples of the light emitting element in this embodiment include semiconductor light emitting elements made of various semiconductors such as ZnSe and GaN. Moreover, short-wavelength emission can nitride semiconductor capable of efficiently exciting the fluorescent substance _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferably exemplified. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal.

  When a nitride semiconductor is used as the material of the light emitting element, a material such as sapphire, spinel, SiC, Si, ZnO, or GaN is preferably used for the semiconductor substrate. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by MOCVD or the like. Further, the semiconductor substrate can be removed after the semiconductor layer is laminated.

  In the case of a light emitting device that emits white mixed color light, the emission wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less in consideration of the complementary color relationship with the emission wavelength from the fluorescent material and the deterioration of the sealing resin, and 420 nm. More preferably, it is 490 nm or less. In order to further improve the excitation and emission efficiency of the light emitting element and the fluorescent material, 450 nm or more and 475 nm or less are more preferable.

(adhesive)
The adhesive for fixing the semiconductor element to the lead electrode is selected from a conductive adhesive and an insulating adhesive, and the type and material thereof are not particularly limited.

  The conductive adhesive is, for example, a metal paste, eutectic material (for example, Au-Sn), carbon paste, or brazing material containing at least one selected from Au, Ag, Bi, Cu, In, Pb, Sn, and Zn. It can be. By setting it as such an adhesive agent, the electrode arrange | positioned at the back surface of a semiconductor element and the conductor wiring of a support body can be electrically connected, or the heat dissipation from a semiconductor element can be improved. The metal material contained in the metal paste is preferably Ag, and when an Ag paste having an Ag content of 80% to 90% is used, a semiconductor device having excellent heat dissipation can be obtained.

  Examples of the insulating adhesive include an adhesive mainly composed of glass, epoxy resin, or silicone resin.

(Conductive wire)
After fixing the light emitting element and the protective element to the support with an adhesive, each electrode of each semiconductor element and the lead electrode are connected by a conductive wire.

The conductive wire is required to have good ohmic properties, mechanical connectivity, electrical conductivity, and thermal conductivity with the electrode of the light emitting element. Preferably ^{0.01cal / (s) (cm 2} ) (℃ / cm) or higher as heat conductivity, and more preferably ^{0.5cal / (s) (cm 2} ) (℃ / cm) or more. In consideration of workability and the like, the diameter of the conductive wire is preferably Φ10 μm or more and Φ45 μm or less. When the sealing member contains a fluorescent material, the conductive wire is easily disconnected at the interface between the portion containing the fluorescent material and the portion not containing the fluorescent material. Therefore, the diameter of the conductive wire is more preferably 25 μm or more, and more preferably 35 μm or less from the viewpoint of securing the light emitting surface of the light emitting element and ease of handling. Specific examples of such conductive wires include conductive wires using metals such as gold, copper, platinum, and aluminum, and alloys thereof.

  In order to prevent poor electrical connection between the conductive wire and the lead electrode, it is preferable that a plurality of bonding portions between the conductive wire and the lead electrode are provided on the lead electrode for one conductive wire.

[Step of forming sealing member]
In order to protect the semiconductor element from the external environment, a translucent sealing member is provided. The material of the sealing member filled in the recess of the package is cured so as to cover the semiconductor element or the conductive wire, thereby covering the semiconductor element or the conductive wire with the sealing member.

(Sealing member)
The material of the sealing member is not particularly limited. For example, a translucent resin having excellent weather resistance such as a silicone resin, an epoxy resin, a urea resin, a fluororesin, and a hybrid resin including at least one of those resins is used. Can be used. The sealing member is not limited to an organic material, and an inorganic material having excellent light resistance such as glass and silica gel can also be used. Moreover, the sealing member of this form can add all members, such as a viscosity extender, a light-diffusion agent, a pigment, and a fluorescent substance, according to a use. Examples of the light diffusing agent include barium titanate, titanium oxide, aluminum oxide, silicon dioxide, calcium carbonate, and a mixture containing at least one of them. Furthermore, a lens effect can be given by making the light emission surface side of the sealing member a desired shape. Specifically, a convex lens shape, a concave lens shape, an elliptical shape as viewed from the light emission observation surface, or a shape obtained by combining a plurality of them can be used.

(Fluorescent substance)
The semiconductor device of this embodiment includes a light emitting element and can contain a fluorescent material in the sealing member. As an example of such a fluorescent material, there is a fluorescent material containing a rare earth element described below.

Specifically, a garnet having at least one element selected from the group of Y, Lu, Sc, La, Gd, Tb, and Sm, and at least one element selected from the group of Al, Ga, and In (Steorite) type fluorescent material. In particular, the aluminum garnet phosphor includes Al and at least one element selected from Y, Lu, Sc, La, Gd, Tb, Eu, Ga, In, and Sm, and is selected from rare earth elements. It is a phosphor activated by at least one element, and is a phosphor that emits light when excited by visible light or ultraviolet light emitted from a light emitting element. For example, in addition to yttrium-aluminum oxide phosphor (YAG phosphor), Tb _2.95 Ce _0.05 Al ₅ O ₁₂ , Y _2.90 Ce _0.05 Tb _0.05 Al ₅ O ₁₂ , Y _2.94 Ce _0.05 Pr _0.01 Al ₅ O ₁₂ , Y _2.90 Ce _0.05 Pr _0.05 Al ₅ O _{12 and the} like. Among these, particularly in the present embodiment, two or more kinds of yttrium / aluminum oxide phosphors containing Y and activated by Ce or Pr and having different compositions are used.

In addition, the nitride-based phosphor contains N and at least one element selected from Be, Mg, Ca, Sr, Ba, and Zn, and C, Si, Ge, Sn, Ti, Zr, and Hf And a phosphor activated by at least one element selected from rare earth elements. Examples of the nitride phosphor include (Sr _0.97 Eu _0.03 ) ₂ Si ₅ N ₈ , (Ca _0.985 Eu _0.015 ) ₂ Si ₅ N ₈ , (Sr _0.679 Ca _0.291). Eu _0.03 ) ₂ Si ₅ N ₈ , and the like.

[Process for forming lead electrode]
As shown in FIG. 1, the lead electrode protruding from the outer wall surface of the package is bent along the outer wall surface of the package to form a connection terminal for connecting to a conductor wiring or the like provided on the mounting substrate.

  As shown in FIG. 1, the semiconductor device of this embodiment has a light emitting surface for emitting light on the upper surface of the package. As shown in the figure, a pair of positive and negative lead electrodes for supplying power to the semiconductor element protrude from the side surface of the package. These side surfaces are a pair of side surfaces facing each other. It is preferable that the protruding portion of the lead electrode is bent from the side surface of the package from which the lead electrode is protruded along the back surface side adjacent to the side surface, and the end portion of the lead electrode is disposed on the back surface of the package. As a result, the semiconductor device can be mounted on the wiring substrate without the solder connecting the mounting substrate and the semiconductor device having an adverse effect on the light emitting surface side.

[Step of separating into semiconductor devices]
By cutting the connection portion between the lead frame and each lead electrode, the semiconductor devices of this embodiment are individually separated from the assembly of semiconductor devices formed on the lead frame. When the hanger lead for supporting the package is provided on the lead frame, the package is released from the support by the hanger lead after the forming process. In this manner, by using the hanger lead, the forming process can be performed on the lead electrodes of the respective semiconductor devices, so that the mass productivity of the semiconductor device can be improved.

  Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

  FIG. 1 is a top view of a semiconductor device 100 in the present embodiment. 2 is a cross-sectional view of the semiconductor device 100 in the XX direction of FIG. FIG. 5 is a cross-sectional view schematically showing a part of the cross section of the lead electrode in the semiconductor device 100 according to the present embodiment.

  The semiconductor device 100 according to the present embodiment includes a plurality of semiconductor elements 108, a lead electrode 111 having a mounting portion on which the semiconductor elements 108 are disposed, and a recess that holds the lead electrode 111 and accommodates the semiconductor element 108. The semiconductor device includes a support portion 110, an adhesive that bonds the semiconductor element 108 to the lead electrode 111, and a conductive wire 112 that connects the electrode on the upper surface side of the semiconductor element 108 to the lead electrode 111. Hereinafter, the semiconductor device in this example will be described in detail.

  In the lead electrode in this embodiment, a groove is formed in advance at the stage of the lead frame. The lead frame in this embodiment is formed by punching a metal flat plate mainly made of iron-containing copper, and a groove is formed by press working on the lead electrode main surface of the lead frame. In this embodiment, the groove depth D (distance from the main surface of the lead electrode to the deepest portion of the groove) is 20 μm, and the groove width W is 23 μm. Further, the inclination angle φ of the inner surface forming the groove having a V-shaped cross section is 60 ° with respect to the lead electrode main surface.

  The support in this embodiment is such that the lead electrode is arranged and the insulating support portion is integrally formed by holding the lead frame with a mold and injection molding using a polyphthalamide resin as a material. It is a package formed by. The support portion has a recess having a substantially circular opening at the center of the upper surface side. One pair of positive and negative lead electrodes 106 and 111 formed from a part of the lead frame has one end exposed at the bottom surface of the recess, and the other end protrudes from a part of the outer wall surface of the package. In the package of this embodiment, a pair of positive and negative lead electrodes protrude from a pair of side surfaces facing each other. The pair of positive and negative lead electrodes (the first lead electrode 106 and the second lead electrode 111) are opposed to each other with a gap at the bottom surface of the recess of the package. The insulating separation part 105 is formed by exposing a part of the support part 110 from between the end portions of the first lead electrode 106 and the second lead electrode 111. The insulating separation portion 105 preferably has a convex portion protruding from the main surface of the lead electrode. In the present embodiment, a part of the support part 110 extends from the back side of the package, and the convex part extends in the longitudinal direction along the insulation separation part 105 when viewed from the opening side of the concave part. Have As a result, it is possible to prevent the adhesive from flowing beyond the insulating separation portion 105 to the connection portion of the first conductive wire 107. In the following description, the direction in which the first lead electrode 106 and the second lead electrode 111 protrude is defined as the Y-axis direction, and the direction perpendicular thereto is defined as the X-axis direction.

  The semiconductor element in the present embodiment includes three LED chips 108 having a rectangular shape with an outer shape of 240 μm × 420 μm square, and a Zener diode 104 that protects the LED chips 108 from destruction due to overvoltage. These semiconductor elements are arranged in a straight line in the X-axis direction at the bottom surface of the recess, as shown in the figure. The LED chip 108 is bonded to the mounting portion on the lead electrode 111 with an insulating adhesive mainly composed of an epoxy resin with the longitudinal direction oriented in the Y-axis direction. Further, the Zener diode 104 is bonded to the same lead electrode 111 as the lead electrode to which the LED chip 108 is bonded with Ag paste in order to electrically connect the electrode provided on the back surface thereof to the lead electrode 111. . The side wall 115 forming the recess of the package has a substantially circular appearance when the semiconductor device 100 is viewed from the upper surface direction. However, a part of the side wall 115 is notched and the notched portion is formed. A part of the main surface of the lead electrode is exposed on the bottom surface (hereinafter referred to as “notch”). The Zener diode 104 of the present embodiment is disposed in the notch. Accordingly, the LED chip 108 can be arranged in the center of the recess without considering the region where the Zener diode 104 is disposed in the center of the recess, and the light distribution can be improved.

  In the present embodiment, the groove provided on the lead electrode exposed from the bottom surface of the recess includes a first groove 101 extending in the Y-axis direction, a second groove 102 extending in the X-axis direction, and the LED chip. And a third groove 103 extending in the Y-axis direction between the mounting portion and the mounting portion of the Zener diode. In addition, after forming the 1st groove | channel 101 and the 3rd groove | channel 103, the 2nd groove | channel 102 is a 2nd groove | channel on each one end part in the 1st groove | channel 101 and the 3rd groove | channel 103. It is formed so that both ends of 102 overlap. In addition, on the lead electrode, the second groove 102 is provided so as to cross a virtual line connecting the center of the mounting portion of the semiconductor element and the connection portion of the conductive wire.

  The first groove 101 and the third groove 103 are linearly extended from the recess side wall 115 starting from the insulating separation part 105 side, and are longer than the longitudinal size of the LED chip 108 mounting part. The Y-axis direction extends to the front of the recess side wall 115. The end portions of the first groove 101 and the third groove 103 on the insulating separation portion 105 side are provided at a predetermined interval from the insulating separation portion 105. That is, the first groove 101 and the third groove 103 are not connected to the insulating separation part 105. Thereby, it is possible to prevent the material forming the support portion from entering the groove portion via the insulating separation portion 105 and form the groove portion on the main surface of the lead electrode.

  Further, the second groove 102 has one end portion intersecting with the end portion of the first groove 101, and the other end portion intersecting with the third end portion 103. The crossing portions (the crossing portion 109 of the first groove and the second groove and the crossing portion of the second groove and the third groove) in which the end portions of these grooves cross each have a cross shape, and the package Are provided at a predetermined interval from the recess side wall 115. Note that the shape of the intersection is not limited to a cross shape as in the present embodiment. That is, the present invention is not limited to the case where a plurality of grooves having different extending directions intersect at right angles, and it is sufficient that the grooves extend at least at one place by changing the extending direction of each groove by a predetermined angle. By providing the intersecting portion, the material forming the support portion can be prevented from entering the groove portion at the time of molding the package, and the groove portion can be reliably formed on the main surface of the lead electrode.

  The area of the region surrounded by the grooves formed by the first to third grooves is about 4 times larger than the total area of the three LED chip 108 mounting portions in consideration of the amount of adhesive and the like. Has been.

  The first conductive wire 107, which is one of the conductive wires that connect the positive and negative electrodes provided on the upper surface of the LED chip 108 and the positive and negative lead electrodes, is extended beyond the insulating separation part 105, and the first The lead electrode 106 is connected. The other second conductive wire 112 is connected to the second lead electrode 111 across the second groove 102 among the grooves constituting the groove. The conductive wire 112 extended beyond the second groove 102 is joined to the second lead electrode 111 at two locations. In order to provide a plurality of connecting portions between the conductive wire and the second lead electrode 111 in the recess, the distance between the second groove 102 and the side wall 115 of the recess is set between the first groove 101 and the side wall 115 of the recess. The support part is formed so as to be larger than the interval.

  FIG. 3 is a top view of the semiconductor device 200 in this embodiment. In the semiconductor device 200 according to the present embodiment, the groove portion of the lead electrode main surface has the fourth groove 204 along the insulating separation portion 105 separately from the first to third grooves according to the first embodiment. In addition, the configuration is the same as that of the first embodiment except that the insulating separation portion 105 is not provided with a protruding portion protruding from the main surface of the lead electrode.

  That is, the grooves constituting the groove portions in the present embodiment are the first to third grooves in the first embodiment, and the short sides of the plurality of LED chips 108 starting from the notches for arranging the Zener diodes. And a fourth groove 204 extending to a position intersecting with the end of the first groove 101 on the side of the insulating separation part 105.

  Even in the case where the insulating separation portion 105 is not provided with a convex portion protruding from the lead electrode main surface as in this embodiment, the fourth groove 204 of this embodiment allows the adhesive of the semiconductor element to be transferred to the semiconductor element. It is possible to prevent outflow from the mounting portion to the connecting portion of the first conductive wire 107 beyond the insulating separation portion 105.

  In the groove portion of the first embodiment, the end portion on the insulating separation portion 105 side in the first groove and the third groove is not connected to the insulation separation portion 105 between the first lead electrode and the second lead electrode. . That is, the first groove and the third groove are not penetrated to the insulating separation portion 105. Therefore, there exists a possibility that the flow of an adhesive may arise from the location in which the groove | channel is not formed.

  On the other hand, the groove portion of the present embodiment intersects the end portion of the first groove 101 and the third groove 103 on the insulating separation portion 105 side and a part of the fourth groove 204 extended along the insulating separation portion 105. By doing so, the four sides of the plurality of LED chips 108 are surrounded by a groove portion constituted by a plurality of continuous grooves. Such a groove portion can reliably prevent the adhesive from flowing.

  FIG. 4 is a top view of the semiconductor device 300 in this embodiment. The semiconductor device 300 according to the present embodiment is different from the semiconductor device 300 according to the second embodiment except that a groove other than the first to fourth grooves is provided between the LED chip 108 and the LED chip 108 disposed adjacent thereto. The configuration is the same as that of the second embodiment.

  That is, in this embodiment, the grooves constituting the groove portion of the lead electrode are the insulating separation between the LED chip 108 and the LED chip arranged adjacent thereto, in addition to the first to fourth grooves in the second embodiment. A fifth groove 305 is provided extending from the side of the part 105 in the Y-axis direction until the end part intersects the second groove 102 in the Y-axis direction. In addition, the end of the fifth groove 305 on the insulating separation portion 105 side is connected to intersect with the fourth groove 204. The fifth groove 305 can prevent the adhesive that adheres the LED chip 108 to the second lead electrode 111 from being disposed across the mounting portions of the plurality of LED chips 108.

  The light emitting device according to the present invention can be used as a light source used in a backlight of a liquid crystal display, a panel meter, an indicator lamp, a portable electronic device, and the like.

FIG. 1 is a top view schematically showing a semiconductor device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a semiconductor device in one embodiment of the present invention. FIG. 3 is a top view schematically showing a semiconductor device in one embodiment of the present invention. FIG. 4 is a top view schematically showing a semiconductor device in one embodiment of the present invention. FIG. 5 is an enlarged view schematically showing a part of a cross section of a semiconductor device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 200, 300 ... Semiconductor device 101 ... 1st groove | channel 102 ... 2nd groove | channel 103 ... 3rd groove | channel 104 ... Protection element 105 ... Insulation isolation | separation part 106 ... First lead electrode 107 ... first conductive wire 108 ... light emitting element 109 ... intersection 110 between first groove and second groove 110 ... support 111 ... second Lead electrode 112 ... second conductive wire 113 ... intersection 114 of second groove and third groove ... sealing member 115 ... concave side wall 204 ... fourth groove 305 ... Fifth groove

Claims (5)

A pair of positive and negative lead electrodes having a mounting portion for disposing a plurality of LED chips and a Zener diode ;
An insulating adhesive that bonds the plurality of LED chips to the mounting portion; and a conductive adhesive that bonds the Zener diode;
The lead electrode is disposed, and a support portion having a recess for accommodating the plurality of LED chips and the Zener diode ;
A conductive wire connecting the electrodes of the plurality of LED chips and the Zener diode to the lead electrode, and a semiconductor device comprising:
The plurality of LED chips are arranged adjacent to each other,
The lead electrode includes a first groove provided between a side wall of the recess and the mounting portion, a second groove provided between the connection portion of the conductive wire and the mounting portion, A third groove provided between the plurality of LED chips and the Zener diode, the first groove and the third groove having substantially the same extending direction ;
The semiconductor device characterized in that the second groove portion intersects the first groove portion and the third groove portion . The support portion has an insulating separation portion provided between a pair of positive and negative lead electrodes, and at least one of the lead electrodes has a fourth groove portion extending along the insulating separation portion. Item 14. The semiconductor device according to Item 1. A lead electrode having a mounting portion for disposing a plurality of LED chips and a Zener diode ;
An insulating adhesive for bonding the plurality of LED chips to the mounting portion; and a conductive adhesive for bonding the Zener diode to the mounting portion;
A supporting portion for positioning the lead electrodes,
A conductive wire connecting the plurality of LED chips and the electrodes of the Zener diode to the lead electrode, and a method of forming a semiconductor device,
A first step of forming a first groove between the side wall of the recess and the mounting portion on the main surface of the lead electrode;
After forming the first groove, the second groove is formed so that the extending direction is substantially the same as that of the first groove and is positioned between the plurality of LED chips and the Zener diode . And the process of
A third step of adhering the plurality of LED chips adjacent to the mounting portion;
A fourth step of forming a second groove portion between the connecting portion of the conductive wire and the mounting portion, intersecting the first groove portion and the third groove portion,
A method for forming a semiconductor device, comprising: a fifth step of extending the conductive wire across at least the second groove and connecting the electrode of the LED chip and the lead electrode. . The method of forming a semiconductor device according to claim 3 , wherein the groove is formed by pressing a mold against a main surface of the lead electrode and applying pressure. The method for forming a semiconductor device according to claim 3 , wherein the groove is formed by cutting a part of a main surface of the lead electrode.

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