JP2011205423A - Mounting structure of electronic component, and method of manufacturing electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting structure of an electronic component, prevented from degradation of its characteristics by preventing an influence by outgassing, and also to provide a method of manufacturing an electronic component.SOLUTION: This mounting structure 2 of an electronic component 1 is used for mounting the electronic component 1 on a substrate 3 including connection electrodes 33, 34. The electronic component 1 has: a functional piece 11 having a predetermined function; first resin projection parts 24 where surfaces thereof are covered with coating films 25, 26 each including a conductive part electrically connected to the functional piece 11; and second resin projection parts 15 formed inside regions surrounded by the first resin projection parts 24 and each having adhesiveness at least on a surface thereof. The second resin projection parts 15 are used for mounting the electronic component 1 on the substrate 3 in the state where the conductive parts of the coating films 25, 26 are subjected to metallic junction to the connection electrodes 33, 34.

Description

  The present invention relates to an electronic component mounting structure and an electronic component manufacturing method.

  For example, in an electronic component including a functional piece such as a crystal resonator, an excitation electrode provided on the crystal resonator and a connection electrode for connecting to a drive circuit that drives the crystal resonator are in conductive contact with a conductive paste such as solder. It is fixed in a state (see, for example, Patent Document 1). When such a conductive paste is used, for example, when an impact such as a drop impact is applied, the connection portion between the crystal resonator and the connection electrode may be damaged, which is a factor of reducing connection reliability.

JP-A-11-261360

  Therefore, the bump electrode composed of the elastic core portion and the conductive film provided on the surface of the core portion is provided on the excitation electrode, and the bump electrode and the connection electrode are electrically conductively contacted through the adhesive. A component mounting structure is also conceivable. However, when such a bump electrode is employed, there is a possibility that the vibration characteristics of the crystal resonator are changed by the outgas generated from the adhesive, and the reliability is lowered.

  The present invention has been made in view of such circumstances, and provides an electronic component mounting structure and an electronic component manufacturing method capable of preventing deterioration of electronic component characteristics by preventing the influence of outgassing. The purpose is to do.

  In order to solve the above problems, an electronic component mounting structure according to the present invention is an electronic component mounting structure in which an electronic component is mounted on a substrate having a connection electrode, and the electronic component has a predetermined function. A first resin protrusion having a surface covered with a covering film including a conductive portion electrically connected to the functional piece, and a region surrounded by the first resin protrusion. A second resin projection having at least a surface adhesiveness, and the second resin projection is formed on the coating film by elastic deformation of the first resin projection. The electronic component is mounted on the base material in a state where the conductive portion is metal-bonded to the connection electrode.

  According to the electronic component mounting structure of the present invention, the first resin protrusion covered with the coating film is used as an electrical contact, the second resin protrusion functions as an adhesive, and further covers The film and the connection electrode are metal-bonded to obtain a structure in which a good conduction state is maintained and the electronic component is mounted on the substrate. Here, since the first resin protrusion is covered with the coating film, the influence of outgas generated from the resin can be prevented. Further, the second resin protrusion is surrounded by the first resin protrusion and is further sealed by metal bonding. Thereby, the influence of the outgas generated from the second resin protrusion can be prevented. Therefore, it is possible to prevent deterioration of the characteristics of the electronic component due to outgassing. In addition, since both the first and second resin protrusions have elasticity, it is possible to reduce the addition to the conduction part even when an external impact is applied, and to obtain excellent conduction reliability. be able to.

  In the electronic component mounting structure, the functional piece is preferably a crystal piece. In the present invention, the electronic component constitutes a crystal resonator including a crystal piece. Therefore, as described above, the vibration characteristics of the crystal resonator due to outgas are prevented from being deteriorated, and the crystal resonator has high conduction reliability.

  In the electronic component mounting structure, it is preferable that the first resin protrusion and the second resin protrusion are made of the same photosensitive resin material. According to this configuration, the first and second resin protrusions can be formed simultaneously by, for example, photolithography. Therefore, the manufacturing process of an electronic component is simplified and manufacturing cost can be reduced.

  In the electronic component mounting structure, it is preferable that the height of the second resin protrusion is lower than the height of the first resin protrusion. According to this configuration, the first resin protrusion is elastically deformed so that the conductive portion and the connection electrode are in close contact with each other, and the second resin protrusion can be reliably sealed.

  In the electronic component mounting structure, it is preferable that a width in a cross-sectional shape of the second resin protrusion is smaller than a width in a cross-sectional shape of the first resin protrusion. For example, when the first and second resin protrusions are formed by applying a liquid resin material by spin coating or the like, patterning, and then melting the resin, the width in the cross-sectional shape of the protrusions is relatively By increasing the height, the height of the protrusion can be formed relatively high. Therefore, the height of the second resin protrusion as described above can be formed lower than the height of the first resin protrusion.

  In the electronic component mounting structure, it is preferable that the coating film is constituted by an electrode layer provided on the functional piece. If it does in this way, a coating film can be formed with an electrode layer at the time of manufacture of electronic parts, and a manufacturing process can be simplified.

  The electronic component manufacturing method of the present invention is provided inside a functional piece having a predetermined function, a first resin protrusion formed on the functional piece, and a region surrounded by the first resin protrusion. And a surface of the first resin protrusion including a second resin protrusion made of the same material as the first resin protrusion and having an adhesive function, and a conductive portion electrically connected to the functional piece. A method of manufacturing an electronic component mounted on a substrate having a connection electrode, and a step of applying a resin material having a function as an adhesive on the functional piece; A width of the first resin pattern for forming the first resin projection by patterning the resin material and a region surrounded by the first resin pattern is wider than the first resin pattern. Narrowly configured the second resin protrusion Forming a second resin pattern, and by melting each of the first resin pattern and the second resin pattern, the height of the second resin protrusion is set to the first resin. The method includes a step of forming the protrusions lower than a height of the protrusions, and a step of forming a coating film covering the first resin protrusions.

  When the product obtained by the method for manufacturing an electronic component of the present invention is mounted on a base material, the first resin projection portion whose surface is covered with a coating film and the periphery are surrounded by the first resin projection portion. This prevents the influence of outgas. In this electronic component, since the second resin protrusion is surrounded by the first resin protrusion, the second resin protrusion is securely sealed by elastically deforming the first resin protrusion. In addition, since metal bonding is performed, the influence of outgas generated from the second resin protrusion can be reliably prevented. As described above, an electronic component in which deterioration of characteristics due to outgassing is prevented can be manufactured.

  The method for manufacturing an electronic component may further include a step of forming an electrode layer electrically connected to the functional piece on the functional piece, and forming the coating film by a part of the electrode layer. Is preferred. According to this structure, a coating film can be formed with an electrode layer, and the manufacturing process of an electronic component can be simplified.

It is a figure which shows the cross-sectional structure of a crystal oscillator package. It is a top view of FIG. It is the figure which looked at the quartz oscillator from the lower part. It is a figure which shows the AA 'line arrow cross-section structure in FIG. It is a figure which shows the formation process of a bump electrode and an adhesion part. It is a figure for demonstrating the mounting method of a crystal oscillator.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

  FIG. 1 is a view showing a crystal resonator package to which an electronic component mounting structure according to the present invention is applied. FIG. 1 is a diagram illustrating a cross-sectional configuration of a crystal resonator package, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a diagram of the crystal resonator viewed from below. 4A and 4B are cross-sectional structural views corresponding to the line AA ′ in FIG. 3, and are diagrams for explaining the shape of the resin protrusion.

  As shown in FIGS. 1 and 2, a crystal resonator package (electronic component mounting structure) 2 includes a crystal resonator (electronic component) 1, a container (base material) 3 for sealing the crystal resonator 1, It has. As shown in FIGS. 1 to 3, the crystal resonator 1 includes a crystal piece (functional piece) 11, a pair of excitation electrodes 12 and 13 that excite the crystal piece 11, a bump electrode 14, and an adhesive portion 15. I have.

  As will be described in detail later, the container 3 is formed with connection electrodes 33 and 34 used for electrical connection with the crystal unit 1 and terminal electrodes 35 and 36 when mounted on a circuit board (not shown). ing.

  The crystal piece 11 is a plate-like member having a substantially U shape in a plan view and having a tuning fork type planar shape in which two arm portions 22 and 23 extend in parallel in the same direction from the base portion 21. Each of the pair of excitation electrodes 12 and 13 is formed of a conductive material such as Al (aluminum) or Au (gold), and is formed on one surface of the crystal piece 11. The excitation electrode 12 is formed from the base portion 21 to the arm portion 22 on one surface of the crystal piece 11. The excitation electrode 13 is formed from the base 21 to the arm 23 on one surface of the crystal piece 11.

  The bump electrode 14 is formed on one surface of the base 21 and is provided in a state of being electrically connected to the excitation electrodes 12 and 13. As shown in FIG. 1 and FIG. 3, the bump electrode 14 includes a protruding resin core part (first resin protruding part) 24 and a pair of conductive films (covering films) formed on the surface of the resin core part 24. ) 25 and 26.

  The conductive films 25 and 26 are formed by patterning after film formation by sputtering, for example. In the present embodiment, the Au / Cr layer formed by sputtering is patterned so as to be continuous with the excitation electrodes 12 and 13 and is electrically connected to the excitation electrodes 12 and 13. That is, the crystal resonator package 2 uses the bump electrode 14 as an electrical contact between the crystal resonator 1 and the container 3.

  The conductive films 25 and 26 are made of, for example, Au (gold), TiW (titanium / tungsten), Cu (copper), Cr (chromium), Ni (nickel), Ti, W, NiV (nickel / vanadium), Al, You may form with metals and alloys, such as Pd (palladium) and lead-free solder, these single layers, or what laminated | stacked multiple types.

  As shown in FIG. 2, the resin core portion 24 has a substantially circular shape in plan view, and the conductive films 25 and 26 that cover the resin core portion 24 also have an annular shape. Further, the resin core portion 24 has a substantially semicircular cross-sectional shape by melting a resin pattern after patterning a resin material by a photolithography technique or an etching technique as will be described later.

  Since the resin core portion 24 is covered with the conductive films 25 and 26 as described above, various resin materials can be used. For example, polyimide resin, acrylic resin, phenol resin, silicone resin, silicone-modified polyimide resin, epoxy resin, etc. The photosensitive insulating resin or the thermosetting insulating resin is used (in this embodiment, an epoxy resin is used).

  Further, a projection-like adhesive portion (second resin projection portion) 15 is provided on the inner side of the region surrounded by the resin core portion 24 (bump electrode 14) on one surface of the base portion 21. As shown in FIG. 1, the adhesive core 15 is elastically deformed by the resin core portion 24 constituting the bump electrode 14 following the surface shapes of connection electrodes 33 and 34 described later, and the conductive films 25 and 26 are connected to each other. The crystal resonator 1 can be mounted on the container body 31 in a state where the electrodes 33 and 34 are metal-bonded. As shown in FIG. 1, the crystal unit 1 has a cantilever support structure in which a base 21 is supported by a container 3.

  Various materials can be used as the adhesive portion 15 as long as the material has adhesiveness at least on the surface. Specifically, in the present embodiment, the adhesive portion 15 is made of the same material as the resin core portion 24 (epoxy resin). Consists of. Thus, by comprising the resin core part 24 and the adhesion part 15 from the same material, a photolithography process and an etching process can be performed on the same conditions, and a manufacturing process can be simplified. In addition, you may comprise the adhesion part 15 by forming separately the adhesive layer which has adhesiveness on the surface of resin which does not function as an adhesive material.

  As shown in FIG. 4A, the height h <b> 1 of the bonding portion 15 is set to be lower than the height h <b> 2 of the resin core portion 24. As a result, the resin core portion 24 is elastically deformed as described above so that the conductive films 25 and 26 and the connection electrodes 33 and 34 are in close contact with each other, and the bonding portion 15 is reliably sealed by metal bonding. it can.

  Also, as shown in FIG. 4B, the width B in the cross-sectional shape of the bonding portion 15 is set smaller than the width A in the cross-sectional shape of the resin core portion 24. Thus, by designing the width B of the bonding portion 15 to be small, it is possible to easily obtain a shape in which the height h1 of the bonding portion described above is lower than the height h2 of the resin core portion 24 in the manufacturing process described later. .

  The container 3 includes a container body 31 and a lid body 32 that covers the container body 31. The container body 31 is formed in a substantially box shape, and is formed of an insulating material such as ceramics. Connection electrodes 33 and 34 are formed on the upper surface of the bottom of the container body 31. Terminal electrodes 35 and 36 for mounting on a circuit board (not shown) or the like are formed on the bottom surface of the bottom of the container body 31. Each of the connection electrodes 33 and 34 is configured, for example, by laminating an Au film on a Ni plating layer formed on a W film, and is connected to a terminal electrode via a wiring (not shown) formed on the container body 31. 35 and 36 are connected to each other. The lid 32 is formed of an insulating material such as ceramics, for example, similarly to the container body 31. The lid 32 is joined to the opening of the container main body 31 by brazing or the like, and seals the crystal unit 1 in a space formed between the lid 32 and the container main body 31.

  As described above, in the crystal resonator package 2 according to the present embodiment, the bump electrode 14 is used as an electrical contact to be metal-bonded, and a good conduction state is maintained by the bonding portion 15 and the crystal resonator 1 is placed on the container 3. Can be implemented. Since the resin core part 24 is covered with the conductive films 25 and 26, it is possible to prevent a problem that the outgas generated from the resin core part 24 deteriorates the vibration characteristics of the crystal resonator 1 (crystal piece 11). Further, as shown in FIG. 1, the adhesive core 15 is elastically deformed in accordance with the surface shape of the connection electrodes 33 and 34 so that the conductive films 25 and 26 are brought into close contact with each other and metal-bonded. That is, the adhesive portion 15 is sealed by being surrounded by the bump electrode 14. Thereby, the malfunction that the outgas generated from the adhesion part 15 reduces the vibration characteristic of the crystal oscillator 1 (crystal piece 11) can be prevented. In addition, since the conductive films 25 and 26 and the connection electrodes 33 and 34 are metal-bonded, the electrical resistance between the conductive films 25 and 26 and the connection electrodes 33 and 34 can be reduced. Performance can be increased.

  As described above, according to the crystal resonator package 2 according to the present embodiment, it is possible to prevent deterioration in the characteristics of the crystal resonator 1 (electronic component) due to outgas generated from the resin material, and it is highly reliable. Can provide. Moreover, since both the resin core part 24 and the adhesion part 15 have elasticity, even when an external impact is applied, the addition of the bump electrode 14 and the connection electrodes 33 and 34 to the conduction part can be reduced. And excellent conduction reliability can be obtained. In addition, since the bump electrode can be manufactured by a photolithography technique, the electrode can be made smaller than the conventional conductive paste.

  As an embodiment of the electronic component manufacturing method of the present invention, a process of manufacturing the crystal unit package 2 (crystal unit 1) will be described. The present embodiment is characterized in the step of forming the bump electrode 14 and the bonding portion 15. Therefore, below, it demonstrates centering around the method of manufacturing the bump electrode 14 and the adhesion part 15. FIG.

  First, as shown in FIG. 5A, a photosensitive resin material 50 is applied to one surface of the crystal piece 11 by spin coating. Specifically, in the present embodiment, an epoxy resin having a function as an adhesive is applied in an adhesion process described later. Subsequently, exposure and development processes are performed. Specifically, as shown in FIG. 5B, openings corresponding to the first resin pattern P1 constituting the resin core portion 24 and the second resin pattern P2 constituting the adhesive portion 15 are provided. A photomask M on which is formed is used. In the photomask M, the width of the first opening H1 corresponding to the first resin pattern P1 is larger than the width of the second opening H2 corresponding to the second resin pattern P2. Note that the second opening H2 is disposed inside the region surrounded by the first opening H1.

  By performing exposure processing and development processing using such a photomask M, a first resin pattern P1 and a second resin pattern P2 are formed on the crystal piece 11, as shown in FIG. 5C. Is done. The width H11 in the cross-sectional shape of the first resin pattern P1 is larger than the width H12 in the cross-sectional shape of the second resin pattern P2.

  As described above, in the present embodiment, the first and second resin patterns P1 and P2 can be formed by the same photolithography process by being composed of the same photosensitive resin material. Thereby, the manufacturing process can be simplified. Further, since the first and second resin patterns P1 and P2 are formed by photolithography, a fine pattern can be formed.

  Subsequently, as shown in FIG. 5D, the first resin pattern P1 and the second resin pattern P2 are heated and melted to form the semicircular resin core portion 24 and the adhesive portion 15. Various methods can be exemplified as the heating method. In this embodiment, for example, the crystal unit 1 is placed in a heating furnace to perform the heat treatment.

  At this time, as the first resin pattern P1 and the second resin pattern P2 are melted, the second resin pattern P2 having a small width H12 becomes lower in height than the first resin pattern P1 having a large width H11. . Thereby, the resin core portion 24 and the adhesive portion 15 having a height lower than that of the resin core portion 24 are formed on the crystal piece 11.

  After forming the resin core portion 24 and the adhesive portion 15 in this way, the excitation electrodes 12 and 13 are formed on the crystal piece 11. The excitation electrodes 12 and 13 are patterned into a desired shape after forming an Au / Cr layer by sputtering, for example. Specifically, the Au / Cr layer is patterned so that the resin core portion 24 is covered and the adhesive portion 15 is exposed. Thereby, the conductive films 25 and 26 covering the excitation electrodes 12 and 13 and the resin core portion 24 can be formed. As described above, in the present embodiment, the manufacturing process can be simplified by forming the conductive films 25 and 26 by a part of the excitation electrodes 12 and 13. Through the above steps, the crystal resonator 1 including the resin core portion 24 and the adhesive portion 15 at the connection portion of the excitation electrodes 12 and 13 can be manufactured.

  Next, a method for mounting the crystal unit 1 will be described with reference to FIG. Here, FIG. 6 is a cross-sectional view showing the bump electrode 14 when the crystal unit 1 is mounted on the container 3. First, the bump electrode 14 and the bonding portion 15 provided on the crystal unit 1 are brought into contact with and pressed against the connection electrodes 33 and 34 formed on the container body 31 (see FIGS. 6A and 6B). ). The crystal unit 1 is mounted while heating.

  At this time, the resin core portion 24 is elastically deformed to follow the shape of each of the connection electrodes 33 and 34. The conductive film 25 is metal bonded following the surface shape of the connection electrode 33 along with the elastic deformation of the resin core portion 24, and the conductive film 26 is metal bonded following the surface shape of the connection electrode 34. Thereby, the conductive film 25 and the connection electrode 33, and the conductive film 26 and the connection electrode 34 are metal-bonded with a sufficient contact area. Further, the adhesive portion 15 having a height lower than that of the resin core portion 24 contacts the connection electrodes 33 and 34. And the adhesion part 15 is hardened. Therefore, the bonding portion 15 bonds the bump electrode 14 and the connection electrodes 33 and 34 by elastic deformation of the resin core portion 24, and each metal bonding of the conductive film 25 and the connection electrode 33 to the conductive film 26 and the connection electrode 34. The state can be maintained.

  As described above, the crystal unit 1 is mounted in the container body 31. Thereafter, the container body 31 and the lid body 32 are joined to seal the crystal unit 1. In this way, the crystal resonator package 2 is formed. At this time, since the resin core portion 24 is covered with the conductive films 25 and 26, the outgas generated from the resin core portion 24 is prevented from deteriorating the vibration characteristics of the crystal resonator 1 (crystal piece 11). Further, the bonding portion 15 is surrounded by the bump electrode 14 and is metal-bonded, thereby being sealed as shown in FIG. 6B, and the outgas generated from the bonding portion 15 is generated by the crystal resonator 1 (crystal It is possible to prevent the vibration characteristics of the piece 11) from being lowered. According to the crystal resonator package 2 formed as described above, the reliability of the crystal resonator 1 is improved by preventing the deterioration of the characteristics of the crystal resonator 1 caused by the outgas generated from the resin material. Further, when an impact such as a drop impact is applied to the connection portion between the crystal resonator 1 and the container body 31, the resin core portion 24 is elastically deformed to absorb the impact.

  In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention. For example, in the above-described embodiment, only one bonding portion 15 is provided in the bump electrode 14 having an annular shape in plan view. You may make it improve. In the above embodiment, the bonding portion 15 has a circular shape in plan view, but may be formed in a bowl shape. The bowl shape refers to a columnar shape in which the inner surface (bottom surface) in contact with the crystal piece 11 is a flat surface and the non-contact outer surface side is a curved surface. Specifically, the substantially bowl-like shape includes those having a substantially semicircular, almost semi-elliptical, and substantially trapezoidal cross section.

  DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator (electronic component), 2 ... Crystal oscillator package (electronic component mounting structure), 3 ... Container (base material), 11 ... Crystal piece (functional piece), 12, 13 ... Excitation electrode, 15 ... Adhesion (second resin protrusion), 24 ... resin core (first resin protrusion), 25,26 ... conductive film (coating film, conductive part), 33,34 ... connection electrode, 50 ... photosensitive Resin material, P1... First resin pattern, P2... Second resin pattern.

Claims (8)

An electronic component mounting structure for mounting an electronic component on a substrate having a connection electrode,
The electronic component is
A functional piece having a predetermined function;
A first resin protrusion having a surface covered with a coating film including a conductive portion electrically connected to the functional piece;
A second resin projection provided inside the region surrounded by the first resin projection and having adhesiveness at least on the surface;
Have
The electronic component mounting structure, wherein the second resin protrusion is mounted on the base member in a state where the conductive portion of the coating film is metal-bonded to the connection electrode.   2. The electronic component mounting structure according to claim 1, wherein a height of the second resin protrusion is lower than a height of the first resin protrusion.   3. The electronic component mounting structure according to claim 2, wherein a width in a cross-sectional shape of the second resin protrusion is smaller than a width in a cross-sectional shape of the first resin protrusion.   The electronic component mounting according to any one of claims 1 to 3, wherein the first resin protrusion and the second resin protrusion are made of the same photosensitive resin material. Structure.   The electronic component mounting structure according to any one of claims 1 to 4, wherein the functional piece is a crystal piece.   The electronic component mounting structure according to any one of claims 1 to 5, wherein the coating film is configured by an electrode layer provided on the functional piece. A functional piece having a predetermined function, a first resin protrusion formed on the functional piece, and a region surrounded by the first resin protrusion and the same as the first resin protrusion A second resin protrusion made of a material and having an adhesive function; and a coating film that includes a conductive portion electrically connected to the functional piece and covers the surface of the first resin protrusion. A method for producing an electronic component mounted on a substrate having a connection electrode,
Applying a resin material having a function as an adhesive on the functional piece;
A width of the first resin pattern for forming the first resin projection by patterning the resin material and a region surrounded by the first resin pattern is wider than the first resin pattern. Forming a second resin pattern for narrowly forming the second resin protrusion, and
Forming the height of the second resin protrusions lower than the height of the first resin protrusions by melting the first resin pattern and the second resin pattern, respectively;
Forming a coating film covering the first resin protrusion,
An electronic component manufacturing method comprising: Further comprising a step of forming an electrode layer electrically connected to the functional piece on the functional piece;
The method of manufacturing an electronic component according to claim 7, wherein the coating film is formed by a part of the electrode layer.

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