JP2008159844A - Electronic component package structure and its method for manufacturing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new package structure and its method for manufacturing which simultaneously satisfies both thinning and high reliability of package in an electronic component package composed by forming and sealing a hollow portion on a function element. <P>SOLUTION: A resin layer in which a space is prepared on a function region and a metal layer are laminated, wherein the metal layer is composed by separating an identical material into a portion forming a lid to cover the space and a portion forming an external terminal, the identical structure can be easily obtained by cutting a whole surface plating to a predetermined thickness after the whole surface plating on the patterned resin layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a package structure for an electronic component represented by a surface acoustic wave filter or the like used for a high-frequency electronic circuit and having a functional element sealed in a hollow state, and a method for manufacturing the same.

  The package of an element that exhibits a specific electrical function by forming an electrode pattern or a fine structure on the surface of a single crystal wafer, represented by a surface acoustic wave filter, changes its characteristics when the functional part surface is covered with a resin or the like. A hollow structure is employed so that other objects do not come into contact with a particularly functionally important part of the element surface.

  FIG. 4 shows a package structure of a general surface acoustic wave filter (hereinafter abbreviated as SAW filter).

  For the purpose of reducing package dimensions, so-called flip chip mounting is performed in which a surface acoustic wave element (hereinafter abbreviated as SAW element) 104 is mounted on a substrate 101 with a functional surface facing the substrate side. A structure sealed with is generally used. It has a hollow structure 108 in which the surface of the functional part is not covered with the sealing material.

  The above structure is a structure in which a SAW element is cut out from a wafer into individual pieces, and then the individual elements are mounted on a substrate. For the purpose of further miniaturization, after forming a hollow sealing structure with a wafer, dicing is performed. A structure in which a package is completed by dividing it into pieces is proposed, and an example thereof is shown in FIG.

  FIG. 5 is a cross-sectional view of the element after being singulated. On the single crystal material 110 on which the functional portion 111 and the electrode 112 are formed, the resin layer 113 for forming the space 116 and the resin layer 113 are formed thereon. The circuit board 114 is bonded, and reference numeral 115 denotes an external connection terminal.

  Compared to the package shown in FIG. 5, the package having such a structure does not have a sealing structure that surrounds the SAW element, and therefore can be further downsized.

For example, Patent Document 1 is known as prior art document information relating to the invention of this application.
Special Table 2002-532934

  The package structure disclosed in the prior art shown in FIG. 5 has a problem in reliability in actual use.

  SAW filters are often used in small communication devices typified by mobile phones. Recently, functional modules are created by mounting electronic components including SAW filters in advance and mounted on the motherboard of the device. Assembling method is used.

  A functional module is an assembly of components formed so as to exhibit specific functions by mounting electronic components at high density on a small circuit board, and is sealed with resin except for external electrode portions. It is common. As the resin sealing method, the transfer mold method is most often used. In the resin molding process, a high temperature of 150 ° C. or higher and a high pressure of several MPa or higher are applied to the electronic component.

  The mounting structure disclosed in Patent Document 1 is a circuit board in which the lid of the space portion is called a printed board. In the circuit board, the surface of the fiber reinforced resin sheet is coated with a copper foil, and the circuit board does not have sufficient rigidity and strength against an external force at a high temperature.

  In the above transfer molding process, when high temperature and high pressure are applied, the circuit board forming the cover of the space part is easily deformed, the space is crushed, and the characteristics of the SAW filter are changed.

  In addition, in order to obtain a circuit board that can withstand high temperature and high pressure, it is necessary to increase the thickness, resulting in an increase in the thickness of the entire package.

  In order to solve the above problems, an electronic component package structure according to the present invention includes a substrate having a functional region and an electrode formed on a surface, a resin layer having a space on the functional region, and a metal layer. The metal layer is formed by separating the metal material into a part that forms a lid that covers the functional region and a part that forms an external electrode.

  The electronic component package structure of the present invention is a structure in which a resin layer having a space and a metal layer are laminated, and a lid that covers the functional area is formed by the metal layer, so that it has high rigidity and a high temperature such as a transfer mold. Even when exposed to high pressure, there is little deformation of the space part, and there is an effect that high reliability can be obtained. Further, even a sufficiently thin structure can withstand high temperature and high pressure, so that the thickness of the entire package can be reduced. Has the effect.

  Furthermore, since the lid that covers the external electrode and the functional region is formed of the same material, both can be formed in one step, and the process can be simplified.

  In addition, the method for manufacturing an electronic component package according to the present invention includes forming a hollow layer using a photosensitive resin layer on a wafer having a large number of elements having functional regions and electrodes on the surface, and then forming a copper foil on the entire surface of the resin layer. Etc., and a through hole for connection with the electrode is made in the film material, and a metal layer is deposited on the through hole, and at the same time, a metal layer is deposited on the film material on the hollow portion, Through-hole electrode part, comprising a step of simultaneously forming a cover and a hollow part cover, a step of dividing a plated metal layer into a plurality of parts, and a step of dicing and including each of the laminated layers. And the hollow part lid can be formed at the same time, and the process is simplified.

  Further, in the step of dividing the plated metal layer into a plurality of parts, after forming a patterned resin layer on the film material, a metal thin film is formed on the entire surface, and this metal thin film is used as a plating electrode. A metal layer is plated on the surface. Further, after the plating is formed, the surface is cut or ground to remove a predetermined thickness from the outermost layer of the metal layer, and the patterned resin layer is exposed to form a metal layer divided into a plurality by the resin layer. Compared to the photoresist etching method generally used as a method for dividing a metal layer into a predetermined pattern, the method of obtaining has an effect that a fine pattern can be obtained, and the thickness variation is very small in the wafer. That is, there is an effect that a package having a uniform thickness can be obtained.

(Embodiment)
Hereinafter, an electronic component package according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a SAW filter package in the embodiment.

  A resin layer 4 having a space 5 is formed on the surface of the single crystal substrate 1 on which the IDT portion 2 and the electrode 3 are formed, and a copper layer 6 is laminated on the surface of the resin layer 4.

  Connection from the electrode 3 to the external electrode 7 is performed by filling the connection hole 8 provided in the resin layer 4 with copper.

  The external electrode 7 is made of copper which is the same material as 6 forming the lid of the space 5, and is separated from other electrodes and the lid 6 portion by the insulating resin layer 9.

  Copper was used for the metal layer that forms the electrode and the hollow cover because the plating film was easy to form, and the filling of the bottomed hole and the plating of the cover part could be performed simultaneously, and the electrical resistance was low. This is because the characteristics are good. However, if a similar metal layer can be formed, it is not limited to copper.

  Next, a manufacturing method for realizing such a package structure will be described.

  FIG. 2 is a cross-sectional view of the SAW filter package for explaining the process.

  As shown in FIG. 2A, a photosensitive resin layer 4 is formed with a uniform thickness on the surface of a single crystal substrate 1 on which a plurality of IDTs 2 and electrodes 3 are formed. Since the thickness of the resin layer corresponds to the height of the space, it is determined in consideration of the package height after completion and the required pressure resistance.

  This figure shows a single crystal substrate in which two sets of IDT portions and electrodes are formed.

  Next, as shown in FIG. 2B, using the photosensitivity of the resin layer 4, the space 5 and the connection hole 8 are formed on the electrode 3 on the IDT portion 2.

  Next, as illustrated in FIG. 2C, the film material 10 is bonded to the entire surface of the resin layer 4.

  In this embodiment, a copper foil having a thickness of 5 μm is used as the film material. It can adhere | attach easily by apply | coating an adhesive thinly to the adhesion surface of copper foil. Moreover, when an uncured epoxy resin is used for the resin layer 4, the copper foil can be bonded without using another adhesive by curing the resin layer 4 in a state where the copper foil 10 is pressed against the resin layer 4. .

  Next, as shown in FIG. 2D, the copper foil 10 is etched by a photolithography method to form an opening 11 on the connection hole 8 and a pattern 12 for electrical isolation from other electrodes.

  At this time, since the copper foil 10 is sufficiently thin with a thickness of 5 μm, the pattern 12 can be very fine.

  Next, as shown in FIG. 3A, a patterned resin layer 13 is provided.

  The resin layer 13 is provided so that at least the opening 11 on the connection hole and the copper foil 10 on the space 5 are exposed.

  The thickness of the resin layer 13 is greater than the copper thickness required on the space 5.

  The copper thickness required on the space 5 is a value determined from the pressure resistance required for the completed electronic component package.

  Next, as shown in FIG. 3B, a metal thin film 14 to be a plating electrode in the next step is formed. In this embodiment, a total of 300 nm of a titanium film and a copper film is formed by sputtering.

  The metal thin film 14 needs to be formed inside the connection hole 8 and also on the surface of the electrode 3.

  Next, as shown in FIG. 3C, a copper layer 15 is formed by plating on the entire surface using the metal thin film 14 formed in the previous step as a plating electrode. As the copper layer thickness at this time, it is necessary that at least the inside of the connection hole 8 is filled, and a copper layer having a final thickness or more is formed on the space 5.

  Next, as shown in FIG. 3D, the surface of the plated copper layer 15 is cut, the copper deposited on the resin layer 13 is removed, and cutting is performed until the resin layer 13 is exposed.

  As a result, the plated copper layer formed on the entire surface is divided into a plurality of portions by the resin layer 13. The resin layer 13 is pattern-designed so that the divided portions correspond to the plurality of external connection electrodes 16 and the lid 17 on the space 5.

  Further, the copper layer 17 corresponding to the lid on the space 5 can also serve as an external connection electrode.

  Thus, the plated copper layer 15 can be divided into fine patterns while having a sufficient thickness for protecting the space 5 from external pressure.

  Next, as shown in FIG. 3E, the package is completed by dicing and dividing into individual pieces.

  In this embodiment, a surface acoustic wave filter (SAW) element is used. However, the present invention is not limited to this, and other objects such as an acceleration sensor element and an angular velocity sensor element have a functional structure on the surface. Therefore, the device can be applied to a package in which the element surface is kept in a hollow state.

  As described above, the electronic component package structure of the present invention can be applied to a package in which the element surface is maintained in a hollow state, and is small and highly reliable.

  In addition, the manufacturing method of the electronic component package of the present invention can form a metal layer having a sufficient thickness that can withstand external pressure, and can divide the metal layer into fine portions to form electrodes. A reliable and small electronic component package is provided with a small number of processes.

Sectional drawing of the electronic component package in embodiment of this invention The figure which shows the manufacturing method of the electronic component package in the embodiment The figure which shows the manufacturing method of the electronic component package in the embodiment Cross section of conventional package Cross section of conventional package

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Single crystal substrate 2 IDT part 3 Electrode 4 Resin layer 5 Space on IDT 6 Metal layer (lid part)
7 Metal layer (external electrode part)
8 Connection hole 9 Insulating resin layer

Claims (4)

It is a structure in which a resin layer having a space on the functional region and a metal layer are laminated on a substrate having an element having a functional region and an electrode on the surface, and the metal layer is a lid that covers the functional region An electronic component package structure, wherein the same material is separated into a portion for forming an external electrode and a portion for forming an external electrode. Forming a photosensitive resin layer on a wafer having a plurality of elements each having a functional region and an electrode on the surface; removing the resin layer on the functional region and the electrode using photosensitivity; and the resin. A step of laminating a film material on the entire surface of the layer, a step of forming a through hole in the film material on the electrode, a metal layer being deposited by plating on the through hole on the electrode, and a film material other than the through hole An electron comprising: a step of depositing a metal layer thereon; a step of dividing the deposited metal layer into a plurality of parts; and a step of dicing the wafer including the laminated layers into individual pieces. Manufacturing method of component package. Forming a photosensitive resin layer on a wafer having a plurality of elements each having a functional region and an electrode on the surface; removing the resin layer on the functional region and the electrode using photosensitivity; and the resin. A step of laminating a film material on the entire surface of the layer, a step of forming a through hole in the film material on the electrode, a step of forming a metal thin film on the entire surface after forming a patterned resin layer on the film material, Forming a metal layer on the surface of the metal thin film as a plating electrode, cutting or grinding the surface after the plating to remove a predetermined thickness from the outermost layer, and forming the patterned resin layer An electronic component package comprising: a step of dividing the metal layer formed by plating into a plurality of parts; and a step of dicing the wafer including the laminated layers into individual pieces. Production method. 4. The method of manufacturing an electronic component package according to claim 2, wherein the film material is a copper foil, and the metal layer to be plated is copper.

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