JP4477541B2 - Circuit board, manufacturing method thereof, and electronic component using the same - Google Patents

Description

  The present invention relates to a circuit board, a method for manufacturing the circuit board, and an electronic component using the circuit board. In particular, the present invention relates to an electronic component with improved airtightness, a circuit board useful for manufacturing the electronic component, and a manufacturing method thereof.

  As a conventional electronic component, electrodes and external terminals are formed on the outer surface of the bottom plate portion of the ceramic base having the bottom plate portion and the frame portion, and the lid is fixed and sealed on the upper surface of the frame portion through low melting point glass. (See, for example, Patent Document 1 below).

  FIG. 4 is a cross-sectional view showing a conventional electronic component package described in Patent Document 1. In FIG.

  In FIG. 4, reference numeral 101 denotes a ceramic bottom plate portion, and reference numeral 102 denotes a ceramic frame body portion, which are integrally formed to constitute a ceramic base. The bottom plate portion 101 and the frame portion 102 are made of alumina ceramic.

On the first main surface in the vicinity of one end in the longitudinal direction of the bottom plate 101 (the horizontal direction in FIG. 4), tungsten or molybdenum paste is applied and fired before the ceramic frame 102 is formed. Thus, electrodes 103 and 104 are formed. An electronic element 108 such as a semiconductor element is provided on the electrodes 103 and 104 via a conductive support 107. One electrode 103 passes between the bottom plate portion 101 and the frame body portion 102 and is led out of one end in the longitudinal direction of the bottom plate portion 101, and the other electrode 104 is also connected to the bottom plate portion 101 and the frame body. Between the first and second portions 102 and led to the outside of the other end of the bottom plate portion 101, and tungsten or molybdenum paste is passed through the end surfaces of the bottom plate portion 101 to the second main surfaces at both ends in the longitudinal direction of the bottom plate portion 101. It is connected to terminals 105 and 106 formed by coating and baking. Then, the lid body 110 was bonded and sealed to the upper surface of the frame body portion 102 through the low melting point glass 109.
Japanese Utility Model Publication No. 07-16421

  However, in the conventional configuration, a ceramic material which is a powder sintered body is used, and the thickness of the bottom plate portion is required to be 0.3 mm or more in order to maintain airtightness. For this reason, it cannot respond to an ultra-thin package having a package thickness of 0.6 mm or less. In addition, even when glass is used for the sealing part in order to hermetically seal the hole through which the lead wire passes through the metal plate thickness direction using a metal plate as the bottom plate part material, and to seal the hole through the lead wire. In the case where the sealing direction is taken in the vertical direction of the package, a plate thickness of about 0.8 mm is necessary to ensure airtight reliability, and it cannot be applied to an ultra-thin package.

  The present invention solves the above-described conventional problems, and provides an ultra-thin surface-mount type electronic component sealed in a package having excellent airtightness, a circuit board suitably used for the electronic component, and a manufacturing method thereof. The purpose is to do.

In order to solve the above-described conventional problems, a circuit board according to the present invention includes a conductive portion formed of a sheet-like metal thin plate provided substantially along a surface direction of a glass thin plate, and an electrode portion formed on the conductive portion. And the terminal portion is exposed from the first main surface of the glass thin plate, and the terminal portion is exposed from the second main surface of the glass thin plate.

  In the circuit board according to the present invention, it is preferable that the conductive portion is disposed at a substantially center between the first main surface and the second main surface of the glass thin plate.

  In the circuit board of the present invention, it is preferable that the conductive part has a plurality of bent parts.

  In the circuit board of the present invention, it is preferable that the bent portion is formed at a connection portion between the conductive portion and the electrode portion and between the conductive portion and the terminal portion.

The circuit board manufacturing method of the present invention includes a sandwiching step of sandwiching the front and back surfaces of a sheet-like metal thin plate with a glass thin plate, a joining step of joining the metal thin plate and the glass thin plate, and a first step of the glass thin plate. And a polishing step of polishing the one main surface and the second main surface to expose the electrode portion and the terminal portion.

  In the method for manufacturing a circuit board according to the present invention, in the joining step, the metal thin plate and the glass thin plate are heated and pressed at a glass transition point or more and a softening point or less of the glass thin plate, and the metal thin plate is attached to the glass plate. It is preferable to comprise a step of joining and molding in a state of being internally provided in the thin plate.

  Further, in the method for manufacturing a circuit board according to the present invention, the heating and pressing are an upper mold contacting the first main surface side of the glass thin plate, and a lower mold contacting the second main surface side of the glass thin plate. The upper mold has a concave part for forming the electrode part and a convex part for forming the terminal part, and the lower mold corresponds to the concave part of the upper mold. A convex portion for forming the electrode portion that can be fitted with the concave portion at a position to be formed, and a concave portion for forming the terminal portion that can be fitted with the convex portion at a position corresponding to the convex portion of the upper mold. A mold is preferred.

Further, the electronic component of the present invention, the conductive portion made of a sheet-like metal thin plate provided substantially along the surface direction in the glass thin plate, the electrode portion exposed from the first main surface of the glass thin plate, The terminal part exposed from the second main surface of the glass thin plate, the electronic element connected to the electrode part via a conductive adhesive, and the electronic element covering the electronic element via the bonding material on the first main surface of the glass thin plate The electrode part and the terminal part are connected by the conductive part.

  This configuration consists of a package body made of glass, which is a solid material, and a lead terminal made of a metal material. Sealing the lead terminal in the thickness direction of the package bottom plate makes it airtight. It is possible to provide a circuit board such as an ultra-thin surface-mounting type airtight terminal that can be maintained and has high airtightness, a manufacturing method thereof, and an electronic component using the circuit board.

In the circuit board of the present invention, a sheet-like metal thin plate serving as a conductive portion is embedded (embedded) in the glass thin plate substantially along the surface direction and sealed between the thickness directions of the glass thin plate. Can be exposed to the outside while maintaining the airtightness of the terminal part surface, and is suitable for the manufacture of electronic parts sealed with an ultra-thin package having high airtightness. A thin circuit board can be provided.

  Further, in the circuit board of the present invention, the conductive portion is arranged at a substantially central position between the first main surface and the second main surface of the glass thin plate, thereby exposing the electrode portion; Except for the terminal portion and the like, it is possible to reduce the possibility that the portion of the conductive portion that should not be exposed to the outside so as not to cause a short circuit is exposed to the outside, and it is preferable because the conductive portion can be formed with high reliability.

  In the circuit board according to the present invention, the conductive portion has a plurality of bent portions, whereby the bonding area between the glass substrate and the conductor portion is increased, and each bent portion has an anchor effect. This is preferable because a circuit board having excellent bonding strength can be formed.

  Further, in the circuit board of the present invention, the bent portion is formed in a preferable mode in which the bent portion is formed at a connection portion between the conductive portion and the electrode portion and between the conductive portion and the terminal portion. As the bonding area between the substrate and the conductor increases, each bent portion has an anchor effect, and a circuit substrate with excellent bonding strength can be formed. Can be easily exposed.

  In addition, according to the circuit board manufacturing method of the present invention, it is possible to easily manufacture a thin circuit board suitable for manufacturing an electronic component or the like sealed with the above-described ultra-thin package having high airtightness. It becomes.

Further, in the method for manufacturing a circuit board according to the present invention, the joining step includes heating and pressurizing the sheet-like metal thin plate and the glass thin plate at a glass transition point or more and a softening point or less of the glass thin plate, By adopting a preferred embodiment of the present invention comprising the step of joining and molding in a state of being internally provided in the glass thin plate, a thin circuit board having excellent adhesion between the sheet-like metal thin plate and the glass thin plate, and thus excellent in airtightness, is obtained. It becomes possible to manufacture more simply.

  Further, in the method for manufacturing a circuit board according to the present invention, the heating and pressurization includes an upper mold contacting the first main surface side of the glass thin plate, and a lower mold contacting the second main surface side of the glass thin plate. The upper mold has a concave part for forming the electrode part and a convex part for forming the terminal part, and the lower mold corresponds to the concave part of the upper mold. A gold having the electrode part forming convex part that can be fitted with the concave part at a position and the terminal part forming concave part that can be fitted with the convex part at a position corresponding to the convex part of the upper mold. By forming a preferred embodiment of the present invention that is a mold, it is easy to form an electrode portion and a terminal portion, and a plurality of bent portions can be formed in a conductive portion. Therefore, adhesion between a metal thin plate and a glass thin plate is excellent, and thus airtightness It is possible to more easily manufacture a thin circuit board that is superior to the above.

  The electronic component of the present invention can also provide an electronic component sealed with a thinner package while maintaining airtightness with the electronic component sealed with the package. Therefore, it is possible to provide electronic components suitable for reducing the thickness and size of various electronic devices.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1A is a perspective view of a circuit board according to Embodiment 1 of the present invention, and FIG. 1B is a cross-sectional view taken along the line XX ′ of FIG. This circuit board is a circuit board suitably used as a bottom plate for a hollow package for a semiconductor device.

  1A and 1B, 1 is a circuit board, 2 is a conductive portion provided in the circuit board 1, and 3 is a surface exposed from the first main surface 1a of the circuit board 1. Reference numeral 4 denotes an electrode portion, 4 is a terminal portion whose surface is exposed from the second main surface 1b of the circuit board 1, and 5 is a conductor portion in which the electrode portion 3 and the terminal portion 4 are electrically connected.

  A detailed configuration will be described below.

  The circuit board 1 is made of an insulating glass plate 7 such as borosilicate glass or soda glass, and has a conductor portion 5 made of a thin metal plate such as iron or iron alloy. The glass plate 7 used for the circuit board 1 is not particularly limited, but a thin thing such as 0.1 mm to less than 0.3 mm is thinned as the entire thickness of the circuit board 1 in FIG. Preferred above. A thin metal plate such as 20 μm to 200 μm is also preferable. In the first embodiment, the total thickness of the circuit board 1 shown in FIG. 1B is used, and the glass plate 7 has a thickness of 0.15 mm, and the conductor 5 has a thickness of 50 μm.

At this time, it is preferable that the glass plate used for the circuit board 1 and the metal thin plate used for the conductor part 5 are close in thermal expansion coefficient, and glass made of borosilicate glass of 45 to 50 × 10 ⁻⁷ / K. A combination of a plate and an iron alloy of 45-50 × 10 ⁻⁷ / K iron-nickel-cobalt (composition is iron 45-60 wt%, nickel 25-35 wt%, cobalt 15-20 wt%) Is preferred.

  According to this, the circuit board which is excellent in the adhesiveness of a glass plate and an electroconductive part and is hard to produce a crack of a glass part etc. can be obtained, and it is preferable.

  The conductor part 5 provided in the circuit board 1 has an electrode part 3 exposed from the first main surface 1a of the circuit board 1 at one end, and the second main part of the circuit board 1 at the other end. It has the terminal part 4 exposed from the surface 1b.

  The conductor part 5 is located in a substantially central part (substantially central part between the first main surface and the second main surface) in the thickness direction of the glass substrate in a cross-sectional view, and faces the electrode part 3 (the electrode part 3 and And a bent portion 6b toward the terminal portion 4 (connecting the terminal portion 4).

  The presence of the bent portion is preferable because the bonding area between the glass substrate and the conductor portion 5 is increased, and each bent portion has an anchor effect, so that a circuit substrate having excellent bonding strength can be formed.

 Thus, in the circuit board of the present invention, the metal thin plate serving as the conductive portion is provided (embedded) in the glass thin plate substantially along the surface direction and sealed between the thickness directions of the glass thin plate. Even when used as a bottom plate part, the surface of the terminal part can be exposed to the outside while maintaining airtightness, and is a thin circuit suitable for manufacturing electronic parts sealed with an ultra-thin package having high airtightness A substrate can be provided.

(Embodiment 2)
2 (a) to 2 (d) are cross-sectional views showing a manufacturing process flow of the circuit board according to Embodiment 2 of the present invention.

  2A to 2D, the same components as those in FIGS. 1A and 1B are denoted by the same reference numerals, and description thereof is omitted.

2A to 2D, the front and back surfaces of the thin metal plate 8 made of iron-nickel-cobalt are sandwiched between a plurality of glass plates 7 (7a, 7b) made of borosilicate glass (FIG. 2A). ). The thickness of each glass plate 7a, 7b is not particularly limited,
A thin material such as 0.1 mm to 0.5 mm is preferable for reducing the thickness. In the second embodiment, each glass plate 7a, 7b has a thickness of 0.15 mm. The type and thickness of the thin metal plate 8 are the same as those in the first embodiment.

  Next, using the molds (upper mold 10a, lower mold 10b), the metal thin plate 8 and the glass thin plates 7a and 7b are heated and pressurized at a glass transition point or more and a softening point or less of the glass thin plate, The upper mold is a mold 10a in contact with the first main surface side (glass thin plate 7a) of the glass thin plate, and the lower mold is in contact with the second main surface side (glass thin plate 7b) of the glass thin plate. The mold 10b is meant.

  A concave portion 11a for forming the electrode portion 3 and a convex portion 11b for forming the terminal portion 4 are formed on the surface of the upper mold 10a that is in contact with the first main surface side (glass thin plate 7a) of the glass thin plate. The lower mold 10b is fitted to the concave portion 11a at a position corresponding to the concave portion 11a of the upper mold on the surface of the lower mold 10b on the side of the second main surface (glass thin plate 7b) of the glass thin plate. A protrusion 11c for forming the electrode part 3 to be obtained and a recess 11d for forming the terminal part 4 that can be fitted to the protrusion 11b are formed at positions corresponding to the protrusion 11b of the upper mold. Yes.

  Using such molds 10a and 10b, a temperature range from the glass transition point of the glass plate 7 (550 ° C. for this borosilicate glass) to the softening point (770 ° C. for this borosilicate glass) or less (this embodiment) 2 is heated to 620 ° C. while applying pressure to the glass plates 7a and 7b to embed the thin metal plate 8, and the glass plates 7a and 7b and the thin metal plate 8 are joined to form the circuit board 1 and the circuit. Projections 9 a and 9 b are formed on the first main surface 1 a and the second main surface 1 b of the substrate 1. (FIGS. 2B and 2C).

  The glass sheet 7a and 7b are heated and pressed between the glass plate 7 and the softening point, and the thin metal plate 8 is embedded at a temperature lower than the glass transition point. Molding is difficult because it is not plasticized, it cannot be joined to a thin metal plate, and at temperatures above the softening point, the glass has high fluidity and difficult to mold, so the heating temperature softens from a temperature above the glass transition point. A temperature range below the point is preferred.

  Next, a liquid abrasive containing, for example, alumina or cerium oxide fine particles as an abrasive is used for the molded article formed above using a polishing member (not shown) having a planar shape that can be rotated by a polishing apparatus. The polishing member is pressed against the surfaces of the first main surface 1a and the second main surface 1b of the circuit board 1 while the circuit board 1 is sandwiched between the polishing members. The surfaces of the first main surface 1a and the second main surface 1b of the circuit board 1 are simultaneously polished by rotating the main surface 1a and the second main surface 1b in opposite directions (in the example of Embodiment 2). The first main surface and the second main surface were each polished by 0.1 mm in thickness), and the electrode portion 3 and the terminal portion 4 were exposed to the protruding portion 9a (FIG. 2D).

  A metal film (not shown) is formed on the exposed surfaces of the electrode portion 3 and the terminal portion 4. The metal film (not shown) preferably has a metal composition excellent in rust prevention and bondability to an external circuit (not shown), and a structure in which a gold plating film is formed on an electroless nickel plating film is suitable. is there.

  It is also possible to form a plurality of circuit boards 1 into a large sheet, and in that case, the circuit board 1 is cut into a predetermined size using, for example, a dicing cutter equipped with a rotary cutting blade (not shown).

In addition, before joining the glass plate 7 and the metal thin plate 8, the metal thin plate 8 is heat-treated at 600 to 900 ° C. for 10 to 30 minutes in the atmosphere or in an atmosphere of a mixed gas of H ₂ O and N _2. By forming an oxide film on the surface, the formation of this oxide film is preferably diffusion-bonded to the glass surface, which enables stronger bonding and is preferable.

  According to the method for manufacturing a circuit board of the present invention, it is possible to easily manufacture a thin circuit board suitable for manufacturing an electronic component or the like sealed with the above-described ultra-thin package having high airtightness. Become.

(Embodiment 3)
FIG. 3 is a cross-sectional view of an electronic component according to Embodiment 3 of the present invention.

  3, the same components as those in FIGS. 1A and 1B and FIGS. 2A to 2D are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 3, an electronic component 11 is formed by electrically bonding an electronic element 12 such as a crystal piece or a semiconductor element to the electrode portion 3 exposed on the first main surface 1a of the circuit board 1 described in the first embodiment of the present invention. It connects via the agent 13, covers on the 1st main surface 1a side of the circuit board 1 with the cover body 14 which consists of a glass material or a metal material which protects the electronic element 12, and joins 15 such as a low melting glass or a metal brazing material. It is joined via.

  The bonding material 15 is preferably a material that has a melting temperature of 280 ° C. to 380 ° C. and hardly generates outgas. Tin-phosphate glass is preferable for low-melting glass, and gold-tin alloy is preferable for metal brazing material. According to these, when the bonding material is heated and melted, the generation of outgas is small, the performance of the electronic element 12 due to the outgas is prevented from being deteriorated, the airtightness is excellent, and the performance of the electronic component 11 over a long period of time. Can be held.

  Thus, in the present invention, it is also possible to provide an electronic component sealed with an ultra-thin package having high airtightness, and depending on the size and type of the electronic component to be mounted, as the thickness of the package, For example, an ultra-thin package sealed electronic component having a minimum thickness of 0.3 mm can be provided.

  The ultra-thin circuit board according to the present invention, the manufacturing method thereof, and the surface-mounted airtight electronic component using the circuit board have been described above, but can be appropriately changed without departing from the technical idea of the present invention.

  The present invention relates to a circuit board, a method for manufacturing the circuit board, and an electronic component using the circuit board, and is particularly useful for improving the airtightness of a miniaturized electronic component, and is an ultra-thin circuit board, a method for manufacturing the circuit board, and the circuit board. It can be applied to electronic parts using

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the circuit board in Embodiment 1 of this invention, (a) is a perspective view, (b) is sectional drawing. Sectional view of the manufacturing process flow of the circuit board in the second embodiment of the present invention Sectional drawing of the electronic component in Embodiment 3 of this invention Cross-sectional view of a package containing a conventional electronic component

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit board 1a 1st main surface 1b 2nd main surface 2 Conductive part 3 Electrode part 4 Terminal part 5 Conductor part 6a Bending part 6b Bending part 7 Glass plate 7a Glass plate 7b Glass plate 8 Metal thin plate 9a Protruding part 9b Protruding part 10a Upper mold 10b Lower mold 11a, 11d Recess 11b, 11c Protrusion 12 Electronic element 13 Conductive adhesive 14 Lid 15 Bonding material 101 Bottom plate part 102 Frame part 103 Electrode 104 Electrode 105 Terminal 106 Terminal 107 Support part 108 Electron Element 109 Low melting point glass 110 Lid

Claims (8)

A conductive portion made of a sheet-like metal thin plate provided substantially along the surface direction of the glass thin plate, and an electrode portion and a terminal portion formed on the conductive portion, wherein the electrode portion is the first of the glass thin plate. A circuit board, wherein the circuit board is exposed from a main surface, and the terminal portion is exposed from a second main surface of the glass thin plate. The circuit board according to claim 1, wherein the conductive portion is disposed substantially at the center between the first main surface and the second main surface of the glass thin plate. The circuit board according to claim 1, wherein the conductive portion has a plurality of bent portions. The circuit board according to claim 3, wherein the bent portion is formed at a connection portion between the conductive portion and the electrode portion and between the conductive portion and the terminal portion. A sandwiching step for sandwiching the front and back surfaces of the sheet-like metal thin plate with a glass thin plate, a joining step for joining the metal thin plate and the glass thin plate, and polishing and polishing the first main surface and the second main surface of the glass thin plate A circuit board manufacturing method comprising: a polishing step for exposing the portion and the terminal portion. The joining step includes a step of heat-pressing the metal thin plate and the glass thin plate at a glass transition point or more and a softening point or less of the glass thin plate, and joining and forming the metal thin plate in a state of being internally provided in the glass thin plate. Item 6. A circuit board manufacturing method according to Item 5. The heating and pressing is a heating and pressing step using an upper mold that contacts the first main surface side of the glass sheet and a lower mold that contacts the second main surface side of the glass sheet, and the upper mold The electrode part formation in which a mold has a concave part for forming the electrode part and a convex part for forming the terminal part, and the lower mold can be fitted to the concave part at a position corresponding to the concave part of the upper mold. The method for manufacturing a circuit board according to claim 6, wherein the mold has a convex portion for use and a concave portion for forming the terminal portion that can be fitted to the convex portion at a position corresponding to the convex portion of the upper mold. . Exposed from the second main surface of the glass thin plate, the conductive portion made of a sheet-like metal thin plate provided substantially along the surface direction of the glass thin plate, the electrode portion exposed from the first main surface of the glass thin plate A terminal part, an electronic element connected to the electrode part via a conductive adhesive, and a lid body that covers the electronic element and is joined to the first main surface of the glass thin plate via a joining material, An electronic component, wherein the electrode portion and the terminal portion are connected by the conductive portion.

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