TWI396311B - Manufacturing Method of Wafer - level Packaging Structure for Through - hole Oscillator - Google Patents

Description

Method for manufacturing wafer level package structure of through-hole vibrator device

The invention relates to a method for manufacturing a vibrator device, which is applied to various electronic products such as a mobile phone, a notebook computer, an automobile electronic device, and the like, and particularly to a manufacturing method of a wafer-level package structure of a through-hole vibrator device.

Quartz components have stable piezoelectric characteristics, providing accurate and wide reference frequency, clock control, timing functions and filtering noise. In addition, quartz components can also be used as sensors for motion and pressure, as well as important Optical components; therefore, for electronic products, quartz components play a pivotal role.

For the encapsulation of quartz crystal oscillator crystals, many proposals have been made in the prior art, such as the "sacrificial quartz-crystal mount" of the US Patent Publication No. 5030875, which belongs to the early metal cap (Metal Cap). The package method has a complicated package structure and cannot be reduced in size. U.S. Patent No. 6,654,392, "Package structure for a piezoelectric resonator", which mainly uses a ceramic package to encapsulate a quartz tuning fork vibrator, and improves the ceramic package and the lid structure. Therefore, the quartz tuning fork vibrator has better shock resistance, however, the package is costly and the size cannot be further reduced.

U.S. Patent No. 6,531,807, "Piezoelectric Device", which is mainly used for encapsulating a quartz crystal oscillator and an oscillating circuit chip on ceramic pedestals in different regions, and electrically connecting the wires on the ceramic pedestal while oscillating The circuit chip is packaged in resin, and the quartz vibrator is covered by the above cover; however, since the two wafers are placed in different blocks and the ceramic base is used as the package, the area is increased and the manufacturing cost is high. No less.

In addition, the "Piezoelectric Oscillator" of the Japanese Patent Publication No. 7098580, which mainly encapsulates a quartz wafer and an integrated circuit in a ceramic package, and then performs an electrical connection operation, can effectively reduce the area problem. However, the overall volume cannot be effectively reduced, and the manufacturing cost of the packaging method is relatively high.

The US Patent Publication No. 7608986 "Quartz crystal resonator" is mainly a wafer-level package form, which mainly uses a blue plate glass upper cover and a lower base, and a quartz wafer. Anode bonding completes a sandwich structure. However, this sandwich structure differs in thermal expansion coefficient between the substrate and the quartz, so that when the temperature changes, the internal quartz wafer generates thermal stress, so that the frequency shifts with temperature. Therefore, it is necessary to specifically select the chamfer angle of the quartz wafer and the thermal expansion coefficient of the upper and lower base materials in order to overcome this difficulty, but it is laborious in terms of production and cost.

The prior art of the above patents cannot escape the current dilemma of using a ceramic pedestal package, which not only has high product cost and unstable supply, but also the thermal stress problem caused by the sandwich-like package structure cannot be effectively solved.

In view of the above problems, the main object of the present invention is to provide a method for manufacturing a wafer-level package structure of a through-hole vibrator device, which is suitable for the current use of a ceramic pedestal package, which has reduced product cost and stable supply, and improves the sandwich package structure. The thermal stress problem caused by the through-hole connection method enables the process to be batch-produced and complete packaged on the wafer. At the same time, the design of the outer edge without groove plane greatly reduces the accumulation of pollutants, and borrows The use of a package ring as an etch mask not only simplifies the process, but also reduces the cost of the process.

Therefore, in order to achieve the above object, a method for manufacturing a wafer level package structure of a through-hole type oscillator device disclosed in the present invention first provides an upper cover and forms a package ring layer on the upper cover, and the manufacturing method thereof is different depending on the material property; When the ring layer is made of a metal material, such as copper, tin, gold, silver, indium, and an alloy of the above metals, it can be produced by sputtering or evaporation; when the encapsulating ring layer is an organic polymer When the material is made, it can be made by spin coating; or when the package ring layer is made of oxide, it can be anode by chemical vapor deposition (CVD) or thermal oxidation (thermal Oxidation). Anodic bonding is achieved.

Next, patterning the package ring layer to form a package ring, and etching the groove on the upper cover by using the package ring as a mask; then providing a pedestal having at least one conductive via and bonding the vibrator unit to the base The socket is electrically connected with the conductive through hole; then the upper cover and the base are combined, and the outer ring of the package is aligned with the package ring of the base, and the outer edge of the package ring is aligned with the upper cover and the base to form a complete grooveless The plane of the groove to reduce the accumulation of contaminants; the encapsulation ring is aligned with the edge of the groove of the upper cover or the base, and the area of the encapsulation ring is increased to improve the joint strength and sealing effect; finally, the bottom of the base is made The base metal pad completes the overall packaging process.

In order to further understand the purpose, features and functions of the present invention, the drawings are described in detail as follows:

According to the manufacturing method of the wafer-level package structure of the through-hole type vibrator device disclosed in the present invention, first, referring to FIG. 1 , a first embodiment of the wafer-level package structure of the through-hole type vibrator device of the present invention is shown.

The wafer-level package structure of the through-hole type oscillator device according to the present invention includes the vibrator unit 20, the upper cover 10, the base 40, the package ring 30, and the conductive via 50. The vibrator unit 20 can be a temperature stable chamfer (AT- Cut) a quartz crystal vibrator such as a quartz crystal vibrator or a tuning fork quartz crystal vibrator or other mechanical resonance type vibrator, and the upper surface and the lower surface of the vibrator unit 20 have an upper surface electrode 21 and a lower surface electrode 22, respectively (see FIG. 2). The vibrator unit 20 is excited and electrically connected to the base metal pad 41 of the bottom base 40 through the conductive bumps 23. The upper surface electrode 21 and the lower surface electrode 22 are respectively located on opposite sides of the vibrator unit 20, and the conductive bumps 23 may be conductive rubber materials or metal bumps composed of silver powder particles and resin, wherein the metal bumps may be gold or copper. One of tin, silver, indium or one of its alloys.

Therefore, the vibrator unit 20 is disposed on the base 40, and the outer edge of the base 40 is provided with a package ring 30. The package ring 30 can be made of copper, tin, gold, silver, indium, and an alloy of the above metals, an organic polymer. If the encapsulation ring 30 is made of a metal material and the upper cover 10 and the susceptor 40 are electrically conductive, a layer of insulation must be provided between the two to prevent the upper cover 10 and the susceptor 40 from being electrically connected. The package ring 30 is provided for providing the upper cover 10, and the upper cover 10 has a recess 11 for accommodating the vibrator unit 20. Therefore, the upper cover 10 and the base 40 are transmitted through the sealing ring 30, and the vibrator unit 20 can be hermetically sealed, and the internal environment can be vacuum or filled with nitrogen; the upper cover 10 can be made of bismuth, glass, quartz, ceramic, or metal. Materials, etc., the material of the susceptor 40 may also be non-conductive materials such as enamel, glass, quartz, ceramics, etc. Further, if the two materials (the upper cover 10 and the susceptor 40) are selected from the same material, the problem of thermal stress can be further prevented. .

The outer edge of the encapsulation ring 30 is aligned with the upper cover 10 and the base 40 to form a complete groove-free plane to reduce the accumulation of contaminants; and the inner edge of the encapsulation ring 30 is cut from the edge of the recess 11 of the upper cover 10. Together, the area of the package ring 30 can be increased to improve the joint strength and sealing effect.

The conductive vias 50 are vertically disposed through the susceptor 40 and may be made of a metal conductive material such as copper, tungsten, aluminum, silver, gold, or an alloy of the above metals. Alternatively, the conductive vias 50 may be polysilicon or conductive. Molecules, as long as they can conduct electricity, are formed by using a through silicon via (TSV) technique. The conductive via 50 is electrically connected to the upper surface electrode 21 and the lower surface electrode 22 of the vibrator unit 20, and is electrically connected to the pedestal metal pad 41 so as to be electrically connected to the outside to provide electrical energy. Signal input and output.

Please refer to FIGS. 3A-3E , which are schematic diagrams showing the manufacturing process of the upper cover of the first embodiment of the wafer level package structure of the through-hole vibrator device of the present invention.

First, the upper cover 10 is provided (see FIG. 3A), and a layer of the package ring 301 (see FIG. 3B) is formed on the upper cover 10. The manufacturing method varies depending on the material properties; when the package ring layer 301 is made of a metal material, for example. The alloy of copper, tin, gold, silver, indium and the above metal can be produced by a sputtering method or an evaporation method; when the encapsulating ring layer 301 is made of an organic polymer material, It is produced by spin coating; or when the encapsulation ring layer 301 is made of an oxide material, it can be anodized by chemical vapor deposition (CVD) or thermal Oxidation (anodic bonding). ) to reach.

Next, the package ring layer 301 is patterned by a yellow light developing process to form the package ring 30, and the opening is exposed to expose a portion of the upper cover 10 (see FIG. 3C). Next, a recess 11 (see FIG. 3D) is formed on the upper cover 10 by a wet etching process, such as etching with an etchant such as KOH or TMAH solution; at this time, the patterned package ring 30 can be used as a mask for the process. In order to further simplify the production process and reduce production costs. On the other hand, as shown in FIG. 3E, the groove 11 can also be formed by a dry etching process, such as an Inductively Coupled Plasma Reactive Ion Etching process.

Please refer to FIGS. 4A-4G for a manufacturing process diagram of the susceptor of the first embodiment of the wafer level package structure of the through-hole type vibrator device of the present invention.

First, a susceptor 40 is provided (see FIG. 4A), and then a metal layer 60 is formed on the susceptor 40 (see FIG. 4B), which can be fabricated by sputtering or evaporation. The metal layer 60 can be made of a metal such as aluminum, silver or gold. Then, the metal layer 60 is patterned by a yellow light developing process, and the opening is exposed to expose a portion of the susceptor 40 (see FIG. 4C); then, referring to FIG. 4D, the cavity is etched by a dry etching process. 401, such as an Inductively Coupled Plasma Reactive Ion Etching process, followed by a wet etch process to remove the metal layer 60.

As shown in FIG. 4E, the recess 401 is filled and a plating layer 70 is formed thereon by an electroplating process; the upper surface of the plating layer 70 is polished by a precision polishing process until the susceptor 40 is exposed (see 4F). Figure).

Next, as shown in FIG. 4G, a package ring 30 is formed on the susceptor 40, and the manufacturing method thereof is different depending on the material property; when the package ring 30 is made of a metal material, for example, copper, tin, gold, silver, indium, and The metal alloy may be formed by a sputtering method or an evaporation method; when the sealing ring 30 is made of an organic polymer, it may be formed by spin coating; or When the package ring 30 is made of an oxide material, the package can be achieved by anodic bonding such as chemical vapor deposition (CVD) or thermal oxidation (thermal Oxidation); and by yellow light development and etching processes. The package ring 30 is patterned.

Next, the package of the vibrator unit 20 is performed. Referring to FIGS. 5A-5D, the vibrator unit 20 is first auto-mounted on the conductive via 50 by means of dispensing and automatic clamping, and the conductive bump is passed through a high temperature baking process. The block 23 is cured, and the fixed vibrator unit 20 is on the conductive via 50 while completing the electrical connection, as shown in FIG. 5A.

Referring to FIG. 5B, the alignment and bonding process of the susceptor 40 and the upper cover 10 are performed. Similarly, the packaging process is completed by metal fusion bonding, gluing technique or anodizing bonding technology depending on the material characteristics of the package ring 30. Next, using a precision polishing technique, the wafer is thinned and the conductive vias 50 are exposed, and the upper cover 10 determines whether or not the thinning process is performed depending on the application and size specifications (see FIG. 5C). Finally, the susceptor metal pad 41 is fabricated by a metal deposition process, a yellow light developing process, and an electroplating process, as shown in FIG. 5D; the figure is illustrated as a double component, and therefore needs to be cut and used. The thinning process (see FIG. 5C) can also be performed when the upper cover 10 and the base 40 are completed, without having to wait for the combination to be thinned.

On the other hand, in addition to the above-described upper surface electrode 21 and lower surface electrode 22 being located on opposite sides of the vibrator unit 20, they may be designed to be located on the same side. Please refer to FIG. 6 , which is a schematic diagram of a second embodiment of a wafer level package structure of a through-hole vibrator device according to the present invention; wherein the upper surface electrode 21 and the lower surface electrode 22 are located on the same side of the vibrator unit 20 (see section 7). Figure).

Similarly, the recess 11 of the upper cover 10 is designed to accommodate the vibrator unit 20, so that the base 40 can also be designed with a recess 42 and the upper cover 10 is designed to be flat, and the same effect can be achieved. 8A, 8B, respectively, corresponding to the first embodiment and the second embodiment; in this case, the inner edge of the encapsulation ring 30 is aligned with the edge of the recess 42 of the base 40, too, It can also serve as a mask for forming the recess 42 of the susceptor 40. The groove 11, the metal layer 60, and the plating layer 70 are formed on the susceptor 40, and the upper cover 10 only needs to be combined with the package ring 30.

Please refer to FIGS. 9 and 10, which are schematic diagrams showing a third embodiment of a wafer level package structure of a through-hole vibrator device according to the present invention. In the above embodiment, the conductive vias 50 are designed to extend under the conductive bumps 23 of the vibrator unit 20; in this embodiment, the conductive vias 50 are designed to penetrate vertically below the package ring 30 due to the conductive vias. 50 is formed by the via via technology, and the via is one of the factors affecting the internal airtightness. Therefore, in this embodiment, the conductive via 50 is opened in the package ring 30 by way of routing. Below, when the packaging process is performed, the factors affecting the hermeticity of the package are left, and only the bonding of the package ring 30 is left, and the internal package gas is not exchanged with the outside through the via hole. Therefore, the airtightness of the overall package structure will be more easily controlled. Of course, the change of the groove 11 and the relative position of the upper surface electrode 21 and the lower surface electrode 22 can also be changed as shown in the above embodiment (not shown).

The manufacturing method of the wafer-level package structure of the through-hole vibrator device disclosed in the present invention is to electrically connect the vibrator unit to the bottom base metal pad by vertically penetrating through the conductive via hole opened in the pedestal. , the current dip environment of ceramic base package (including high product cost and unstable supply), and improve the thermal stress caused by the sandwich package structure; at the same time, reduce the use of precious metal materials and further shrinkage, reduce the connection line The length, which reduces the parasitic capacitance/inductance effect due to high frequency. And through the wafer bonding technology, quartz crystal oscillators can be batch-produced, reducing labor and production time and reducing production costs. At the same time, the outer edge of the encapsulation ring is aligned with the upper cover and the base to form a complete groove-free plane to reduce the accumulation of contaminants; the inner edge of the encapsulation ring is aligned with the edge of the groove of the upper cover to increase the package. The area of the ring improves the joint strength and sealing effect. And the package ring can be used as a mask for the subsequent etching process, which will greatly simplify the process.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

10. . . Upper cover

11. . . Groove

20. . . Vibrator unit

twenty one. . . Upper surface electrode

twenty two. . . Lower surface electrode

twenty three. . . Conductive bump

30. . . Package ring

301. . . Package ring layer

40. . . Pedestal

401. . . pit

41. . . Base metal pad

42. . . Groove

50. . . Conductive through hole

60. . . Metal layer

70. . . Plating

FIG. 1 is a schematic view showing a first embodiment of a method for manufacturing a wafer level package structure of a through-hole type vibrator device according to the present invention.

2 is a schematic view of the upper and lower electrodes of the vibrator unit in the first embodiment of the method for fabricating the wafer level package structure of the through-hole vibrator device of the present invention.

3A-3E are schematic diagrams showing the manufacturing process of the upper cover of the first embodiment of the wafer level package structure of the through-hole type vibrator device of the present invention.

4A to 4G are schematic diagrams showing the manufacturing process of the susceptor of the first embodiment of the wafer-level package structure of the through-hole type vibrator device of the present invention.

5A-5D are schematic diagrams showing the manufacturing process of the assembly of the first embodiment of the wafer level package structure of the through-hole vibrator device of the present invention.

FIG. 6 is a schematic view showing a second embodiment of a method for manufacturing a wafer level package structure of a through-hole type vibrator device according to the present invention.

FIG. 7 is a schematic view showing the upper and lower electrodes of the vibrator unit in the second embodiment of the method for fabricating the wafer level package structure of the through-hole vibrator device of the present invention.

FIG. 8A is a schematic view showing a variation of the groove in the first embodiment of the method for manufacturing the wafer level package structure of the through-hole type vibrator device of the present invention.

FIG. 8B is a schematic view showing a variation of the groove in the second embodiment of the method for manufacturing the wafer level package structure of the through-hole vibrator device of the present invention.

FIG. 9 is a schematic view showing a third embodiment of a method for manufacturing a wafer level package structure of a through-hole type vibrator device according to the present invention.

FIG. 10 is a schematic view showing the upper and lower electrodes and the package ring of the vibrator unit in the third embodiment of the method for manufacturing the wafer level package structure of the through-hole vibrator device of the present invention.

10. . . Upper cover

11. . . Groove

20. . . Vibrator unit

twenty one. . . Upper surface electrode

twenty two. . . Lower surface electrode

twenty three. . . Conductive bump

30. . . Package ring

40. . . Pedestal

41. . . Base metal pad

50. . . Conductive through hole

Claims (14)

A method for manufacturing a wafer-level package structure of a through-hole vibrator device, comprising the steps of: providing an upper cover; forming a package ring layer on the upper cover; patterning the package ring layer to form a package ring; using the package The ring is used as a mask to etch a recess in the upper cover; a base is provided, the base has at least one conductive through hole vertically disposed on the base; and a vibrator unit is bonded to the base and electrically connected thereto The hole constitutes an electrical connection; the upper cover and the base are combined, and the package ring of the upper cover is aligned with the package ring of the base; and a base metal pad is formed on the bottom of the base. The manufacturing method of the wafer-level package structure of the through-hole vibrator device according to the first aspect of the invention, wherein the vibrator unit is a quartz crystal vibrator or a mechanical resonance type vibrator, and the quartz crystal vibrator is temperature-stable. An angle (AT-cut) quartz crystal vibrator or a tuning fork type quartz crystal vibrator. The method for manufacturing a wafer-level package structure of a through-hole vibrator device according to claim 1, wherein the upper cover is made of one of bismuth, glass, quartz, ceramic or metal material, and the package ring is made of copper. Or tin, gold, silver, indium or one of the above alloys, organic polymers or oxide materials, the base is composed of one of bismuth, glass, quartz or ceramic materials, and the conductive through hole is selected A combination of free copper, silver, gold, tungsten, or alloys thereof. The manufacturing method of the wafer-level package structure of the through-hole type vibrator device according to the first aspect of the invention, wherein the vibrator unit comprises an upper surface electrode and a lower surface electrode, wherein the upper surface electrode and the lower surface electrode system respectively The conductive bump is electrically connected to the conductive via, and the conductive bump is formed by one of a mixed conductive paste or a metal bump of silver powder particles and a resin, and the metal bump can be made of gold, copper, tin, One of silver, indium or one of its alloys. The method for manufacturing a wafer-level package structure of a via-type vibrator device according to claim 4, wherein the upper surface electrode and the lower surface electrode are disposed on the same side or opposite sides of the vibrator unit. The manufacturing method of the wafer-level package structure of the through-hole type vibrator device according to claim 1, wherein the package ring of the upper cover, the outer edge of the package ring of the base, and the upper cover and the base Cut together. The manufacturing method of the wafer-level package structure of the through-hole vibrator device according to claim 1, wherein the inner edge of the package ring is aligned with the groove. The manufacturing method of the wafer-level package structure of the through-hole vibrator device of claim 1, wherein the conductive via is disposed under the package ring of the upper cover. The method for manufacturing a wafer-level package structure of a through-hole vibrator device according to claim 1, further comprising the step of thinning the upper cover. The manufacturing method of the wafer-level package structure of the through-hole type vibrator device according to claim 9, wherein the step of thinning the upper cover is performed after etching the groove. The method for manufacturing a wafer-level package structure of a through-hole vibrator device according to claim 9, wherein the step of thinning the upper cover is performed after bonding the upper cover and the base. The method for manufacturing a wafer-level package structure of a via-type vibrator device according to claim 1, further comprising the step of thinning the susceptor. The manufacturing method of the wafer-level package structure of the through-hole vibrator device according to claim 12, wherein the step of thinning the pedestal is performed when the susceptor is provided. The method for manufacturing a wafer-level package structure of a through-hole vibrator device according to claim 12, wherein the step of thinning the pedestal is performed after bonding the upper cover and the pedestal.