JP2005294390A - Metal package and manufacturing method of electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise assembling accuracy such as positioning of each component and improve productivity and quality by simplifying the assembling process of electronic device and metal package thereof, and also reducing the number of processes. <P>SOLUTION: In the lead frame 14 of a terminal component, a metal lead frame 2 with many metal base components 3 integrally formed thereon via a coupling portion 8 is allocated on a jig 1 with the lower surface side thereof turned upward. Further, a glass tablet 12 for sealing glass is also allocated to the internal side of the circumferential wall 6 at the lower surface of the metal base component, and many sets of terminal components 15 are integrally formed thereon via a coupling portion 19. This lead frame 14 of the terminal component is allocated with each mount electrode 17 thereof inserted into a through-hole 13 of the corresponding glass tablet and into a terminal hole 5 of the metal base component. Moreover, the lead frame 14 is heated under the condition that an overlapping jig is allocated thereon. The metal base component and terminal component are sealed with the sealing glass. Consequently, a plurality of metal bases 23 can be formed simultaneously. The coupling portion is cut away after a piezoelectric vibrating piece 25 is mounted to each metal base under this condition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to piezoelectric vibrators / oscillators, surface acoustic wave (SAW) devices used in various electronic devices, surface mounted electronic devices such as semiconductor devices, and in particular piezoelectric elements such as piezoelectric vibrating pieces and SAW elements, The present invention relates to a method for manufacturing a metal package in which an electronic component such as a semiconductor integrated circuit (IC) chip is mounted and hermetically sealed, and further relates to a method for manufacturing an electronic device using the metal package.

  2. Description of the Related Art As a surface-mount type piezoelectric device that has been widely used with downsizing and thinning electronic devices, a box-type package in which sheet materials made of an insulating material such as ceramic are laminated is widely used. However, generally, a ceramic package requires many steps for its production, and the production cost tends to increase. On the other hand, surface mount type metal packages have been developed that are made of relatively inexpensive metal materials that can realize products with better processability and formability, less dimensional variation and fewer manufacturing processes. .

  For example, since it is difficult to reduce the thickness of a conventional cylindrical airtight terminal in which a cylindrical metal case is fitted to a metal outer ring sealed with glass with a metal lead inserted, one end of the metal base of the box-type housing Alternatively, a metal package has been proposed in which a metal lead is inserted into an opening provided on a side wall and sealed with sealing glass, and a metal cap is put on and sealed (see Patent Document 1). A certain surface-mount type piezoelectric vibrator has a device terminal penetrated through a through-hole at the bottom of a metal shell and is fixed in an electrically independent state with an insulating material made of ceramic glass to form a metal package. Are sealed by seam welding (see Patent Document 2). Also known is a thin metal package in which a metal lead is inserted into a through-hole on the lower surface of the metal base, a high melting point glass insulating material is fused to form a united base, and a metal (or glass) cap is joined and sealed. (See Patent Document 3). Another thin metal package is a metal base having a frame-like structure, a metal lead in which a cylindrical electrode is joined to a metal flat plate is fused with an insulating material such as refractory glass to form a united base, and a crystal vibrating piece And sealed with a metal cap (see Patent Document 4).

JP 2003-158209 A JP 2002-84159 A JP 2003-86723 A JP 2002-124382 A

  However, these metal packages have a large number of components because the metal base component, the glass tablet for sealing glass, and the plurality of terminal components are each composed of a single component. Accordingly, it is becoming more difficult to assemble a metal package by positioning these many parts individually as the electronic device becomes smaller.

  In the conventional automatic parts assembly technology, each terminal part is aligned and transferred to an assembly jig in an automatic assembly machine, and then the glass tablet is similarly aligned and transferred to the assembly jig, and further the metal base part is aligned. The assembly is transferred to an assembly jig, and finally a weight jig is set, and then the metal base is sealed by heating and fusing the glass. Therefore, the assembly process is complicated and requires a lot of man-hours, the shape of each assembly jig is complicated, and an automatic assembly machine having a complicated structure is required for each different assembly process, resulting in an increase in the number of manufacturing and the manufacturing cost.

  Therefore, the present invention has been made in view of the above-described conventional problems, and its purpose is to simplify the assembly process and reduce the number of steps, and to position each component in the manufacture of an electronic device and its metal package. An object of the present invention is to provide a manufacturing method capable of improving assembly accuracy and improving productivity and quality.

According to the present invention, in order to achieve the above object, a plurality of metal base components each defining a cavity for accommodating an electronic component and having a terminal hole at the bottom of the cavity are integrated with each other via a connecting portion. Place the formed metal base lead frame on the jig with the cavity side facing down,
A plurality of glass tablets for sealing glass having through holes corresponding to the terminal holes are arranged on the metal base parts of the metal base lead frame, respectively, and the through holes are aligned with the terminal holes,
A plurality of sets of terminal parts each having an external electrode part and a mount electrode part erected on the external electrode part are each formed as a terminal part lead frame integrally formed through a connecting part, with the mount electrode part side facing downward. On the glass tablet, the mount electrode portions of the terminal parts of each set are inserted through the corresponding through holes of the glass tablet and the terminal holes of the metal base part, and are arranged.
Place a weight jig on the terminal component lead frame,
A manufacturing method of a metal package including a step of fusing the glass tablet by heating in this state, sealing the metal base component and the terminal component with sealing glass, and simultaneously forming a plurality of metal bases. Provided.

  With this configuration, the present invention can reduce the number of parts required for assembling and manufacturing a metal package, thereby simplifying the manufacturing process and reducing the number of steps, thereby realizing a reduction in manufacturing cost. it can. Furthermore, regardless of the miniaturization of electronic devices and metal packages, positioning of individual parts is easy, assembly accuracy is improved, and quality and yield are improved.

  In one embodiment, the metal base component has a peripheral wall portion projecting downward from the lower surface opposite to the cavity, and a glass tablet is fitted inside the peripheral wall portion to thereby heat the sealed glass melted by heating. A welding area can be expanded and peeling with a metal base component or a terminal member can be prevented.

  Further, the metal base lead frame and / or the terminal component lead frame can be easily formed at a low cost by press punching a metal material.

  In another embodiment, after forming a plurality of metal bases, the method further includes a step of cutting the connection parts of the metal base parts and the connection parts of the terminal parts, whereby a plurality of metal bases can be manufactured simultaneously.

  According to another aspect of the present invention, there is a step of mounting electronic components such as piezoelectric elements and IC chips in the plurality of metal-based cavities thus formed, and sealing the cavities with a lid. A method for manufacturing an electronic device is provided.

  In one embodiment, after the metal package is hermetically sealed with a lid, the method further includes the step of cutting the connection portion of the metal base component and the connection portion of the terminal component, thereby performing the mounting process of the electronic device in the state of the lead frame. It can be done, is easy to work and can be automated.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 schematically shows a process of assembling a metal base of a metal package of a piezoelectric vibrator by the method of the present invention. The process of the present embodiment will be described in detail with reference to FIG. First, the metal base lead frame 2 is set on the rectangular flat carbon jig 1 (FIG. 2-1 (A)).

  The metal base lead frame 2 is formed with a large number of metal base components 3 arranged at regular intervals along the longitudinal direction thereof. As shown in FIGS. 3A and 3B, the metal base part 3 has a generally rectangular box shape that defines a cavity 4 for mounting the piezoelectric vibrating piece. Terminal holes 5 are provided in the vicinity of each corner. Furthermore, a peripheral wall portion 6 that extends continuously over the entire circumference of the lower surface of the metal base part 3 projects downward, and a shallow concave portion 7 is defined on the inner side thereof. Because of the peripheral wall 6, the metal base component 3 is formed in an H shape in cross section, so that the bending strength and the adhesion strength of the glass are improved.

  Each metal base component 3 is integrally coupled with frame portions 9 on both sides extending in the longitudinal direction of the metal base lead frame 2 by a relatively thin and thin connecting portion 8 in the vicinity of the center of both ends in the longitudinal direction. . Positioning holes 10 are formed in the frame portion 9 at regular intervals along the longitudinal direction. The metal base lead frame 2 is formed by press-punching a hoop material to form the outer shape of the metal base component 3, rolling the cavity 4 and the like, and cutting to a predetermined length. For the hoop material, a material having an expansion coefficient close to that of a glass tablet, such as Kovar, which is a nickel-cobalt-iron alloy, is used.

  The metal base lead frame 2 is arranged on the carbon jig 1 with the cavity 4 side facing downward, that is, the recessed portion 7 side facing upward. A plurality of positioning pins 11 are erected on the upper surface of the carbon jig 1 and are inserted into the corresponding positioning holes 10 so that the metal base lead frame 2 is accurately positioned at a predetermined position on the carbon jig 1. The

  Next, the glass tablets 12 are fitted into the recessed portions 7 of the metal base components 3 of the metal base lead frame 2 (FIG. 2-1 (B)). As shown in FIGS. 4A and 4B, the glass tablet 12 has a generally rectangular outer shape that fits into the recessed portion 7 and a thickness that is slightly larger than the height of the peripheral wall portion 6. In the glass tablet 12, four through holes 13 are formed at positions corresponding to the terminal holes 5 of the metal base part 3. The glass tablet 12 can be formed, for example, by pressing and baking a hard glass powder such as borosilicate glass with a press machine or by molding with a mold.

  The terminal lead frame 14 is placed on this (FIG. 2-1 (C)). The terminal lead frame 14 has the same number of sets as the number of metal base components 3 of the metal base lead frame 2, and one set of four terminal members 15 are arranged at regular intervals along the longitudinal direction thereof. As shown in FIGS. 5A and 5B, the terminal member 15 includes an external terminal portion 16 having a generally rectangular flat plate shape, and a columnar mount terminal portion 17 erected on the external terminal portion.

  Each set of terminal members 15 is such that each mount terminal portion 17 is aligned with the corresponding terminal hole 5 of the metal base component 3, and each external terminal portion 16 is aligned with each corner of the metal base component 3. Each of them is integrally coupled with a frame portion 18 in the width direction crossing the terminal lead frame 14 and a relatively thin and thin connecting portion 19. A large number of positioning holes 21 are formed in the longitudinal frame portion 20 of the terminal lead frame 14 so as to be aligned with the positioning holes 10 of the metal base lead frame 2 at regular intervals in the longitudinal direction.

  Similarly to the metal base lead frame 2, the terminal lead frame 14 is formed by press punching a hoop material and cutting it into a predetermined length. The hoop material is preferably the same metal material as that of the metal base lead frame 2 so that the thermal expansion coefficient is the same or approximate. Similarly, the hoop material is a material having an expansion coefficient close to that of a glass tablet such as Kovar, which is a nickel-cobalt-iron alloy. Can be formed.

  The terminal lead frame 14 has the mount terminal portion 17 side facing downward, aligns each set of terminal members 15 with the corresponding metal base component 3, and each mount member portion 17 of each terminal member 15 corresponds to a corresponding glass tablet. 12 are inserted into the through holes 13 and the terminal holes 5 of the metal base part 3 and placed on the glass tablet 12. At this time, by inserting each positioning pin 11 protruding from the positioning hole 10 of the metal base lead frame 2 into the corresponding positioning hole 21, the terminal lead frame 14 can be accurately aligned with the metal base lead frame 2. Positioned.

  A weight carbon jig 22 having the same dimensions and shape as the lower carbon jig 1 is placed thereon (FIG. 2-1 (D)). In a state where all the parts constituting the metal base of the metal package are assembled in this way, the whole is heated to an appropriate temperature in a heating furnace or the like, and the glass tablet 12 is semi-melted to form the metal base part 3 and the terminal member 15. To fuse. The semi-molten glass flows due to the weight and surface tension of the upper carbon jig 22, is in close contact with the external terminal portion 16 of each terminal member 15, and flows evenly into the recessed portion 7 of the metal base part 3. Thus, the metal base part 3 is in close contact with the lower surface of the metal base part 3 and the inner side surface of the peripheral wall part 6, and the space between each terminal hole 5 and the mount terminal part 17 is airtightly closed.

  At this time, if the surfaces of the terminal member 15 and the metal base part 3 for welding the glass are oxidized in advance, the adhesion of the glass is improved. Further, in order to prevent distortion generated between the components due to thermal expansion during heating, the metal base lead frame 2 (metal base component 3), the terminal lead frame 14 (terminal member 15), and the glass tablet 12 are thermally expanded. It is preferable to select materials with substantially the same coefficients or as close as possible. Further, since each of the lead frames 2 and 14 made of a metal material extends with respect to the carbon jig 22 by the heating, it is preferable that the positioning holes 10 and 21 through which the positioning pins 11 are inserted have a long hole shape extending in the longitudinal direction. .

  After the semi-molten glass is cooled and solidified, when both the upper and lower carbon jigs 1 and 22 are removed, a large number of metal bases 24 in which the metal base part 3 and the terminal member 15 are electrically insulated by the insulating material 23. However, it is completed in a state where it is coupled to the frame portions of the metal base lead frame 2 and the terminal lead frame 14, respectively. In the present embodiment, the glass welded area increases due to the presence of the peripheral wall portion 6, and therefore, the peeling of the insulating material 23 from the metal base 24 due to the influence of thermal expansion or the like is effectively suppressed.

  Next, these metal bases 24 have their cavities 4 facing upward (FIG. 2-2 (E)), and a piezoelectric vibrating piece 25 such as an AT-cut quartz vibrating piece is mounted with a conductive adhesive or the like (FIG. 2-). 2 (F)). The terminal member 15 of each metal base 24 is used to electrically connect a pair of terminals disposed on one end side in the longitudinal direction to a connection electrode provided at the base end portion of the piezoelectric vibrating piece 25. The The pair on the opposite side can be used as a so-called dummy electrode, for example, to stably support the tip of the piezoelectric vibrating piece 25 on the mount terminal portion 17. The terminal member 15 for connecting to the connection electrode of the piezoelectric vibrating piece 25 is preferably subjected to electrolytic nickel plating on the surface in advance and electrolytic gold plating on the surface in order to enhance conductivity.

  Next, a flat lid 26 is joined to the upper end of each metal base 24 to hermetically seal the cavity 4, thereby completing the piezoelectric vibrator 27 made of a surface-mount type metal package. If the lid 26 is formed of the same metal material as that of the metal base part 3 or the terminal member 15, it is advantageous that the lid 26 can be easily joined to the metal base 24 and is not distorted by thermal expansion. The lid 26 can also be formed of a transparent glass plate in order to adjust the frequency of the piezoelectric vibrating reed 25 by a laser beam or the like after sealing the metal package.

  Finally, the connecting portion 8 between the metal base 3 and the metal base lead frame 2 and the connecting portion 19 between the terminal member 15 and the terminal lead frame 14 are fused by laser beam or mechanically cut by dicing or the like. Divide into pieces. In order to facilitate this cutting process, it is preferable to form the connecting portions 8 and 19 of the lead frames thinly. Thereby, a large number of piezoelectric vibrators 27 shown in FIG. 6 can be manufactured simultaneously.

  Although the preferred embodiments of the present invention have been described above, the present invention can be implemented by adding various modifications and changes to the above embodiments within the technical scope thereof. For example, the present invention can be applied to manufacture of a metal package for mounting a piezoelectric element such as a SAW element or an electronic component such as a semiconductor integrated circuit (IC) chip in addition to the piezoelectric vibrating piece. Further, the metal base lead frame 2 and the terminal lead frame 14 can be formed by various conventionally known methods such as cutting and wet etching in addition to the press punching process. Further, in the above embodiment, the metal base lead frame and the terminal lead frame have the metal base components and the set of four terminal materials arranged in one row, but may be arranged in a plurality of rows, or a set of terminals. The number is not limited to four, and can be increased or decreased to an appropriate number of two or more according to product specifications. Further, the carbon jig can be replaced with a metal jig, and the expansion coefficient thereof can be made comparable to that of the lead frame. In the manufacturing process of the above embodiment, the metal base lead frame is set on the carbon jig first, but the order can be reversed and the terminal lead frame can be set upside down first.

The perspective view which shows schematically the process of manufacturing a metal package by the method of this invention. FIGS. 1A to 1D are cross-sectional views taken along the line II-II in FIG. FIGS. 5E to 5G are cross-sectional views similar to FIGS. 2A and 2B, each showing a process of manufacturing a crystal resonator in succession to the process of FIGS. (A) is a plan view showing a partially enlarged base lead frame, and (B) is a sectional view taken along line III-III. (A) The figure is a top view which expands and shows a glass tablet, (B) The figure is sectional drawing in the IV-IV line. (A) The figure is a top view which expands and shows a terminal lead frame partially, (B) The figure is sectional drawing in the VV line. The longitudinal cross-sectional view of the piezoelectric vibrator manufactured by the method of the present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,22 ... Carbon jig, 2 ... Metal base lead frame, 3 ... Metal base component, 4 ... Cavity, 5 ... Terminal hole, 6 ... Perimeter wall part, 7 ... Recessed part, 8, 19 ... Connection part, 9, 18 , 20 ... Frame part, 10, 21 ... Positioning hole, 11 ... Positioning pin, 12 ... Glass tablet, 13 ... Through hole, 14 ... Terminal lead frame, 15 ... Terminal member, 16 ... External terminal part, 17 ... Mount terminal part , 23 ... insulating material, 24 ... metal base, 25 ... piezoelectric vibrating piece, 26 ... lid, 27 ... piezoelectric vibrator.

Claims (6)

A metal base lead frame in which a plurality of metal base components each defining a cavity for accommodating electronic components and having a terminal hole at the bottom of the cavity are integrally formed via a connecting portion, with the cavity side facing downward. Placed on the jig,
A plurality of glass tablets for sealing glass having through holes corresponding to the terminal holes are arranged on the metal base parts of the metal base lead frame, respectively, and the through holes are aligned with the terminal holes,
A plurality of sets of terminal parts each having an external electrode part and a mount electrode part erected on the external electrode part are each formed as a terminal part lead frame integrally formed through a connecting part, with the mount electrode part side facing downward. On the glass tablet, the mount electrode portions of the terminal parts of each set are inserted through the corresponding through holes of the glass tablet and the terminal holes of the metal base part, and are arranged.
Place a weight jig on the terminal component lead frame,
The metal comprising the steps of fusing the glass tablet by heating in this state, sealing the metal base component and the terminal component with sealing glass, and simultaneously forming a plurality of metal bases Package manufacturing method. 2. The metal package according to claim 1, wherein the metal base component has a peripheral wall portion that protrudes downward from a lower surface opposite to the cavity, and the glass tablet is fitted inside the peripheral wall portion. Manufacturing method. 3. The method of manufacturing a metal package according to claim 1, wherein the metal base lead frame and / or the terminal component lead frame are formed by press punching of a metal material. The metal package according to any one of claims 1 to 3, further comprising a step of cutting the connecting portion of the metal base component and the connecting portion of the terminal component after forming the plurality of metal bases. Production method. An electronic device comprising: mounting electronic components in the cavities of the plurality of metal bases formed by the method according to claim 1, and sealing the cavities hermetically with a lid. Device manufacturing method. 6. The method of manufacturing an electronic device according to claim 5, further comprising a step of cutting the connecting portion of the metal base component and the connecting portion of the terminal component after hermetically sealing with the lid.

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