JP2013045880A - Manufacturing method of electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an electronic device which stably maintains conduction between an electronic component and an external electrode and enables through electrodes to be easily formed.SOLUTION: A manufacturing method of an electronic device includes the steps of: (a) forming dents on one of an upper surface and a lower surface of a base material 9; (b) filling metal particles 21 into the dents; (c) heating and melting metal particles 21 having a melting point lower than that of glass; (d) polishing the base material 9 so that at least bottom surfaces of the dents are exposed to the exterior and thereby forming a base 10 that includes through electrodes 20 based on the metal particles 21, at the base material 9 after the polishing.

Description

  The present invention relates to a method for manufacturing an electronic device typified by a crystal resonator or a piezoelectric element.

  Since a crystal resonator is excellent in frequency characteristics, it is frequently used as a device, specifically, one of printed circuit board mounting components. Here, in order to stabilize the characteristics of the crystal resonator, it is necessary to block the influence of outside air. As an example of such a package structure, a “glass-ceramic composite and a flat package type piezoelectric component using the same” described later is known (Patent Document 1).

  In the package described in Patent Document 1, a ceramic resonator piece, which is a material having substantially the same thermal expansion coefficient as that of a quartz resonator piece, is mixed in an electronic device in which a quartz resonator piece is placed in a base and a cap is put on the base. A package is constructed using a thing. However, since this package is a glass-ceramic composite, it is made by single-piece production by placing a crystal resonator piece on one base and covering the cap, so the productivity is extremely low. In addition, this package is difficult to process the glass-ceramic composite, which increases production costs.

  In order to eliminate these drawbacks, a method of manufacturing a package with glass that is easy to process has been proposed. As an example, an “electronic component package” described later is known (Patent Document 2).

  The outline of the electronic component package described in Patent Document 2 will be described with reference to FIG. In the electronic component package, a step (a) of forming a through hole in the base 110, a step (b) of pouring low melting glass into the through hole and fitting the metal pin 120, pushing the metal pin 120 and making the glass plate concave Step (c) for processing, step (d) for forming electrode 130 by printing, step (e) for mounting component 140 such as a crystal resonator on metal pin 120, cap 160 and base 110 via sealing material 150 The electronic device 100 is manufactured through the step (f) of sealing and bonding the components. Here, in the step (c), the metal pin 120 adhered and fixed to the base 110 can be obtained by welding the glass at a heating temperature equal to or higher than the softening point temperature (about 1000 ° C.) of the glass. In step f), confidentiality can be reliably maintained, and the electronic device 100 can be manufactured at low cost.

  Further, as another example of manufacturing a package with glass that can be easily processed, an “electronic device and manufacturing method” described later is known (Patent Document 3).

  The outline | summary of the electronic device of patent document 3 is demonstrated using FIG. In the electronic device 200, as the through electrodes 206a and 206b formed in the through holes 203a and 203b of the insulating substrates 208a and 208b, mixed members 204a and 204b made of a metal and an inorganic material, and alloy members 205a and 205b made of gold tin, The mixing members 204a and 204b are covered with alloy members 205a and 205b. Thereby, the sealing performance of the through electrodes 206a and 206b is improved, the bonding property between the mixing members 204a and 204b and the side walls of the through holes 203a and 203b is improved, and the holes of the mixing members 204a and 204b are improved. Since it is satisfied and the entry of impurities and moisture from the outside is prevented, the sealing performance is improved.

JP-A-11-302034 JP 2003-209198 A JP2011-40499A

  However, the above package has the following problems. First, in the package described in Patent Document 2, when the metal pin 120 is short or the amount of pushing is small, the metal pin 120 is wrapped in the low melting point glass. For this reason, there exists a problem that electrical connection with the electrode 130 and metal pin 120 which are formed at a process (d) cannot fully be ensured. Even if the metal pin 120 is pushed in as designed, the glass may cover the tip of the metal pin 120 because the base 110 is exposed to a temperature equal to or higher than the softening point of the glass. Furthermore, as a result of the metal pin 120 being exposed to a temperature of about 1000 ° C., an oxide film grows around the metal pin 120, and there is a problem that the electrode 130 and the electronic component 140 are not conductive. Further, the package described in Patent Document 3 has a problem that resistance increases because the mixed members 204a and 204b made of metal and an inorganic material are used for the through electrodes 206a and 206b. Therefore, an object of the present invention is to solve these problems.

In order to solve the above-described problems, the present invention provides the following means.
The invention according to claim 1 is a method of manufacturing an electronic device, the step of forming a depression on one of the upper and lower surfaces of a glass base material, the step of filling the depression with metal particles, A process of heating and melting metal particles having a melting point lower than that of glass, and polishing the base material so that at least the bottom surface of the recess is exposed to the outside, thereby penetrating the base material after polishing based on the metal particles A step of forming a base provided with electrodes, a step of forming internal wiring on one of upper and lower surfaces of the base so as to contact one end of the through electrode, and electrical conduction with the internal wiring And a step of mounting an electronic component on the base.

  A second aspect of the present invention is the electronic device manufacturing method according to the first aspect, wherein the metal particles are composed of a plurality of types of metals.

  Invention of Claim 3 is manufacture of the electronic device of Claim 1 or 2, Comprising: The metal particle consists of the particle | grains which consist of multiple types of particle diameters, It is characterized by the above-mentioned.

  Invention of Claim 4 is a manufacturing method of the electronic device of Claim 3, Comprising: The said metal particle contains the particle | grains which have a particle diameter of diameter 1-100 nanometer, The metal which comprises the said metal particle Has a melting point higher than that of the glass.

  The invention according to claim 5 is the method for manufacturing the electronic device according to any one of claims 1 to 4, wherein after the plurality of electronic devices are collectively formed on one of the bases, the electronic devices are individually separated. It is characterized by comprising a step of separating. Thereby, the electronic device which concerns on this invention can be manufactured collectively, and the shortening of the manufacturing time and process in mass production of an electronic device, and cost reduction can be achieved.

  The invention according to claim 6 is the method for manufacturing an electronic device according to any one of claims 1 to 5, wherein the electronic device can be joined to the base, and is shielded from outside air together with the base in the joined state. A step of bonding a cover forming a hollow portion to the base and sealing the electronic component in the hollow portion; and a surface of the base opposite to the surface on which the internal wiring is formed, And a step of forming an external electrode so as to abut the end.

  According to the present invention, when forming the through electrode, a process is used in which the metal particle is filled in the recess formed in the base material, and then the metal particle is heated and melted. No process is used. Therefore, in the present invention, it is possible to avoid a situation in which the metal pin is encased in the low melting point glass or an oxide film is formed around the metal pin, so that the electrical conduction between the electronic component and the external electrode is stable. Can be kept. Furthermore, in the present invention, since the metal particles having a melting point lower than that of glass are used, the glass base material is not exposed to a temperature higher than the softening point of the glass. In addition, according to the present invention, the through electrode can be easily formed simply by filling the recess with the metal particles and melting them and polishing the base material.

  Therefore, the present invention has an effect that it is possible to provide a method of manufacturing an electronic device that can stably maintain conduction between the electronic component and the external electrode and can easily form a through electrode.

It is sectional drawing of the electronic device which concerns on this invention. It is a figure which shows the manufacturing process of the electronic device which concerns on this invention. It is an expanded sectional view of the penetration electrode part of the electronic device concerning the present invention. It is an expanded sectional view of the penetration electrode part of the electronic device concerning the present invention. It is a figure which shows another manufacturing process of the electronic device which concerns on this invention. It is a figure which shows the manufacturing process of the electronic device of a prior art example. It is sectional drawing of the electronic device of a prior art example.

  Hereinafter, a first embodiment of an electronic device manufacturing method according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an electronic device according to the present invention. In the electronic device 1, the electronic component 50 is mounted in a hollow portion surrounded by the glass base 10 and the cover 60 and shielded from the outside air. The electronic component 50 is electrically connected to the external electrode 70 that is a terminal mounted on the substrate via the mounting portion 40, the internal wiring 30, and the through electrode 20. Here, the cover 60 is not limited to glass. For example, when the electronic device 1 is a MEMS device such as a pressure sensor, a cover made of silicon or the like can be used. The cover 60 can be made of aluminum.

  An electronic device 1 shown in FIG. 1 includes various electronic components that can be mounted on a base 10, such as a water vibrator, a piezoelectric element, a semiconductor circuit, an LED, and various sensors each having a tuning fork-type crystal resonator piece as an electronic component 50. Including those equipped with. Moreover, the electronic device 1 does not need to have the cover 60, when mounting LED etc. as an electronic component.

  The through electrode 20 is, for example, an alloy such as AuSn. The through electrode 20 is provided so as to penetrate the base 10 up and down over the height direction of the base 10, and electrically connects the internal wiring 30 and the external electrode 70 connected to both ends.

  The internal wiring 30 and the external electrode 70 are each formed of a metal film, and the outermost surface has a layer shape using a noble metal such as gold, silver, or platinum. Here, since the noble metal has a small ionization tendency and has corrosion resistance, it is possible to suppress long-term deterioration of the internal wiring 30 and the external electrode 70, so that the reliability of the electronic device 1 using the present invention is improved. be able to. The internal wiring 30 and the external electrode 70 are respectively disposed at the upper and lower ends of the base 10 (and the through electrode 20). In addition, as a diffusion preventing layer for preventing metal diffusion, a metal layer such as nickel may be formed under the surface layer formed of a noble metal. Further, the internal wiring 30 and the external electrode 70 can be formed using the same material, but may be formed using different materials.

  Incidentally, a sputtering method is generally used as a method of forming the internal wiring 30 and the external electrode 70. However, the internal wiring 30 and the external electrode 70 may be formed using a plating method.

  Moreover, the mounting part 40 formed on the upper surface of the internal wiring 30 and connecting the internal wiring 30 and the electronic component 50 can use a conductive adhesive such as silver paste, for example. In that case, the internal wiring 30 and the electronic component 50 are bonded by baking a conductive adhesive (mounting portion 40) such as a silver paste as a connection portion. However, depending on the configuration of the electronic component 50, the conductive adhesive may not be used as the connection portion. For example, when a gold film (gold film) is formed on the outermost surface of the internal wiring 30, gold bumps (not shown) formed on the electronic component 50 can be used as the mounting portion 40. In that case, the gold bump formed on the electronic component 50 and the gold film of the internal wiring 30 can be bonded together by using a gold-gold bonding or the like instead of the conductive adhesive.

  The external electrode 70 can also be formed of a conductive adhesive such as a silver paste that relieves stress during board mounting.

(Electronic device manufacturing method)
Next, a method for manufacturing the electronic device 1 according to the present embodiment will be described with reference to FIGS. 2 to 4 are diagrams showing a method for manufacturing an electronic device that is manufactured at a wafer level and is finally cut by dicing or the like. The electronic device 1 according to the present embodiment is not limited to this, and may be formed as an individual package from the beginning.

FIG. 2 is a diagram illustrating a manufacturing process of the electronic device 1 according to the present embodiment.
FIG. 2A is a view for explaining a process of forming a concave recess in the base material 9. The recess is manufactured by sandblasting, laser processing, drilling, hot pressing, or the like.

  FIG. 2B is a view for explaining a process of filling the concave shape with the metal particles 21. In this step, two kinds of particles of Au and Sn are filled as the metal particles 21. The type of metal used for the metal particles 21 is not limited to Au and Sn, and for example, Zn, In, Pb, Ge, Si, and the like can also be used. Further, the number of metal particles 21 to be filled is not limited to two, but may be three or more. Moreover, the size (particle diameter) of the metal particles does not have to be single, and a plurality of sizes may be used. In this case, since the depression can have a structure close to the close-packing, it is possible to prevent a decrease in volume when the metal particles 21 are melted in the next step. Further, by mixing the metal particles 21 having a size of 1 to 100 nm, even when the metal particles 21 made of a high melting point metal are used, the metal particles 21 have a low melting point due to the size effect. Can be used.

  FIG. 2C is a view for explaining a process of obtaining the alloy 22 by heating the metal particles 21. In this step, the alloy 22 is obtained by melting a metal lower than the melting point of the glass as the metal particles 21. This alloy 22 only needs to have a melting point higher than the temperature at which the electronic device 1 is mounted, and an AuSn alloy is an example.

  FIG. 2D is a diagram for explaining a polishing process of the base material 9. At least the bottom surface of the depression is exposed to the outside (specifically, the upper and lower surfaces of the base material 9 and the upper and lower end surfaces of the alloy 22 are the same height and parallel surfaces). By polishing, the alloy 22 filled in the depression functions as the through electrode 20. Further, the base material 9 after polishing provided with the through electrode 20 becomes the base 10. Here, FIGS. 3 and 4 are enlarged views of a portion that becomes the through electrode 20 in the state of FIG. Specifically, FIG. 3 is a diagram showing a state in which a part of the alloy 22 filled in the depression protrudes upward from the upper surface of the base material 9. On the other hand, FIG. 4 is a view showing a state in which the upper end surface of the alloy 22 filled in the depression is formed in a concave shape with respect to the upper surface of the base material 9. 3 or 4, the upper and lower surfaces of the base material 9 and the upper and lower end surfaces of the alloy 22 are at the same height and are parallel to each other. By polishing the base material 9 from the upper and lower surfaces to a position, it is possible to form an excellent through electrode 20 regardless of the state of the alloy 22 (how it is formed in the depression).

  FIG. 2E shows the internal wiring 30 on one surface (upper or lower surface) of the base 10 of the through electrode 20. Here, the base 10 shown in FIG. It is formed on the end surface on the upper surface) side and on the one surface of the base 10 by using the sputtering method, the electronic component 50 is installed, and the internal wiring 30 and the electronic component 50 are connected via the mounting portion 40. It is a figure for demonstrating an electronic component connection process. Here, the mounting part 40 which connects the internal wiring 30 and the electronic component 50 can use conductive adhesives, such as a silver paste, for example. In that case, the internal wiring 30 and the electronic component 50 are bonded by baking a conductive adhesive such as silver paste as a connecting portion. In addition, depending on the configuration of the electronic component 50, the conductive adhesive may not be used as the connection portion. For example, when gold is used for the outermost surface of the internal wiring 30, gold bumps formed on the electronic component 50 can be used as the mounting portion 40. In that case, the gold bump formed on the electronic component 40 and the gold film of the internal wiring 30 can be bonded by using thermo-compression bonding instead of the conductive adhesive.

  FIG. 2F is a diagram for explaining a cap joining step for joining the cover 60 processed into a concave shape to the base 10 in order to protect the electronic component 50 mounted on the base 10. In this step, a hollow portion that is blocked from outside air is formed by the one surface of the base 10 and the concave portion of the cover 60. Thereby, it can arrange | position in the state which sealed the electronic component in the cavity part. In addition, the material of the cover 60 may be appropriately selected from, for example, silicon, glass, aluminum, and the like in consideration of the bonding method and specifications required for the electronic component 50 such as the degree of vacuum and cost. For example, when the electronic component 50 is a quartz crystal piece and the frequency is adjusted after the base 10 and the cover 60 are joined, it is desirable to select a glass member for the cover 60. Moreover, as a method for joining the cover 60 and the base 10, for example, adhesion, anodic bonding, gold-gold bonding, or the like can be used. In addition, when the base 10 is processed into a concave shape, the cover 60 does not need to be formed into a concave shape. In this case, since the hollow portion is formed by the concave portion of the base 10 and one surface (lower surface) of the cover 60, the electronic component only needs to be provided in the hollow portion.

  In FIG. 2G, the external wiring 70 is sputtered on the end surface of the base 10 opposite to the end surface on the one surface side and on the surface (lower surface) opposite to one surface of the base 10. It is a figure for demonstrating the process formed using. Here, the internal wiring 30 and the external electrode 70 may be formed by combining a sputtering method, a vapor deposition method, and a photolithography method, respectively.

  FIG. 2H is a diagram for explaining the process of dividing the package into individual pieces. That is, the step suggested by FIG. 2H is a step of forming a plurality of electronic devices on one base 10 and then separating the electronic devices. In this process, depending on the material of the cover 60. Although the method of dividing into individual pieces varies, as an example, the electronic device can be divided into pieces by dicing or laser cutting.

  As described above, according to the method for manufacturing the electronic device 1 according to the present embodiment, when forming the through electrode 20, the metal particle 21 is heated after filling the recess formed in the base material 9 with the metal particle 21. The process of melting is used, and the process of inserting / pressing the metal pin is not used. Therefore, in the electronic device 1, it is possible to avoid a situation in which the metal pin is encased in the low melting point glass or an oxide film is formed around the metal pin. Therefore, the electrical connection between the electronic component 50 and the external electrode 70 can be avoided. Conductivity can be kept stable. Further, in the electronic device 1, since the metal particles 21 having a melting point lower than that of glass are used, the glass base material 9 is not exposed to a temperature higher than the softening point of the glass. Furthermore, in the electronic device 1, the through electrode 20 can be easily formed simply by filling the recess with the metal particles 21 and melting them, and polishing the base material 9.

  Therefore, the present invention can be said to be a method for manufacturing an electronic device that can stably maintain conduction between the electronic component and the external electrode and can easily form a through electrode.

  Moreover, according to the manufacturing method of the electronic device 1 which concerns on this embodiment, the metal particle 21 can be comprised from multiple types of metals like Au and Sn. In other words, since the melting point of gold is 1064 ° C, it is higher than the melting point of the base material and it is difficult to melt and use gold alone, but for example, the eutectic temperature of gold 80wt% tin 20wt% is about 280 ° C Since the electronic device 1 can be melted at a temperature higher than the reflow temperature (about 260 ° C.) when mounted on the substrate and lower than the melting point of the base material, a practical electronic device can be manufactured. Further, the proportion of gold tin is not limited to gold 80 wt% tin 20 wt%, and may be gold 50 wt% tin 50 wt%, for example.

  In the electronic device 1, the metal particles 21 can be a mixture of particles having a plurality of types of particle sizes. In this case, since the depression can have a structure close to the close-packing, it is possible to prevent a decrease in volume when the metal particles 21 are melted in the next step.

  Moreover, according to the manufacturing method of the electronic device 1 which concerns on this embodiment, a metal particle contains the particle | grains which have a particle diameter of 1-100 nanometer in diameter, and the metal which comprises the said metal particle 21 has melting | fusing point higher than glass. Use things. That is, even when the metal particles 21 made of a high melting point metal are used, the metal particles 21 have a low melting point due to the size effect, so that they can be used for filling the depressions.

  In addition, according to the method for manufacturing the electronic device 1 according to the present embodiment, as shown in FIG. 2 (h), after a plurality of electronic devices 1 are collectively formed on one base 10, the electronic devices 1 are separated into pieces. Can be Therefore, the electronic devices according to the present invention can be manufactured in a lump, and the manufacturing time and process in the mass production of electronic devices can be shortened and the cost can be reduced.

(Second Embodiment)
Next, a second embodiment of the electronic device manufacturing method according to the present invention will be described with reference to FIG. Since steps other than FIG. 5E are the same as the steps described in FIG. 2, the description thereof will be omitted below, and only the steps different from FIG. 2 will be described. FIG. 5 is a diagram illustrating a manufacturing process of the electronic device according to the present embodiment.

  FIG. 5E shows that the internal wiring 30 is sputtered on the end surface of the through electrode 20 on one surface of the base 10 (the surface opposite to that in FIG. 2E) and on the one surface of the base 10. It is a figure for demonstrating the electronic component connection process which forms using a method, installs the electronic component 50, and connects the internal wiring 30 and the electronic component 50 via the mounting part 40. FIG. FIG. 5E differs from FIG. 2E in that the surface on which the internal wiring 30 is formed is different (upside down). From the relationship of layout and characteristics, the surface on which the internal wiring 30 is formed may be configured as shown in either FIG. 2 (e) or FIG. 5 (e).

  The electronic device of the present invention includes, for example, an oscillator or a clock using the electronic device of the present invention as an oscillator, a portable information device including the electronic device of the present invention in a timekeeping unit, and an electronic device of the present invention as a radio wave such as time information. Can be used for an electronic device such as a radio timepiece provided in the receiver.

DESCRIPTION OF SYMBOLS 1 Electronic device 9 Base material 10 Base 11 Sacrificial material 20 Through electrode 21 Metal particle 22 Alloy 30 Internal wiring 40 Mounting part 50 Electronic component 60 Cover 70 External electrode 100 Electronic device 110 Base 120 Metal pin 130 Electrode 140 Electronic component 150 Sealing material 160 cap

Claims (6)

Forming a depression on one of the upper and lower surfaces of the glass base material;
Filling the hollow with metal particles;
Heating and melting metal particles having a melting point lower than that of the glass;
Polishing the base material so that at least the bottom surface of the recess is exposed to the outside, thereby forming a base including a through electrode based on the metal particles in the base material after polishing;
Forming an internal wiring on one of upper and lower surfaces of the base so as to be in contact with one end of the through electrode;
Mounting an electronic component on the base so as to be electrically connected to the internal wiring;
The manufacturing method of the electronic device characterized by the above-mentioned.   The method of manufacturing an electronic device according to claim 1, wherein the metal particles are composed of a plurality of types of metals.   The method for manufacturing an electronic device according to claim 1, wherein the metal particles are a mixture of particles having a plurality of particle sizes.   The electronic device according to claim 3, wherein the metal particles include particles having a particle diameter of 1 to 100 nanometers, and the metal constituting the metal particles has a melting point higher than that of the glass. Method.   5. The method of manufacturing an electronic device according to claim 1, further comprising a step of separating the electronic devices after forming a plurality of electronic devices collectively on one of the bases. A step of joining the base to form a cavity portion that can be joined to the base and is shielded from outside air together with the base, and sealing the electronic component to the cavity portion;
Forming an external electrode on the surface of the base facing the surface on which the internal wiring is formed so as to contact the other end of the through electrode;
The method for manufacturing an electronic device according to any one of claims 1 to 5, further comprising:

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