A high-temperature-resistant thermistor crystal resonator without a sealing cover

Abstract

The present invention relates to a high-temperature-resistant thermistor crystal resonator without a sealing cover, comprising a lower base, a quartz chip, and a thermistor. The upper end of the lower base is mounted with an upper base, and a groove is formed in the middle of the upper end of the lower base and the middle of the lower end of the upper base. The two grooves are connected to form an inner cavity, and the quartz chip is mounted in the lower groove, and the thermistor is mounted in the upper groove. The lower end of the lower base is provided with external electrodes connected to the quartz chip and the thermistor in a one-to-one correspondence. The present invention uses an upper base instead of a metal upper cover for sealing to effectively reduce the thermal stress of the thermistor crystal resonator, solves the problem of overflow of the gold-tin alloy caused by traditional metal upper cover packaging, and simultaneously improves the sealing of the resonator and can provide an accurate real-time temperature signal, achieving the purpose of stable operation in a high temperature environment.

Description

Technical Field

[0001] The invention relates to the technical field of quartz crystal frequency components, in particular to a high-temperature resistant and thermosensitive crystal resonator without a sealing cover. Background Art

[0002] A thermistor crystal resonator typically consists of a piezoelectric quartz chip, a thermistor, conductive adhesive, a ceramic base, and a metal cover. The piezoelectric quartz chip is typically rectangular or circular, and the ceramic base typically requires a portion of the backside of the chip to be sacrificed for solder pads to create a recessed groove for the thermistor. Electrodes are plated on both sides of the piezoelectric quartz chip and secured to the package with conductive adhesive. The electrodes are connected to the base pins of the package via leads within the sealed package. AC voltage is applied to the upper and lower electrodes of the quartz chip through the pins, causing the chip to oscillate by the inverse piezoelectric effect. Simultaneously, the thermistor senses the ambient temperature and transmits the temperature signal to the IC. The IC, through its internal circuitry, adjusts the frequency output of the crystal oscillator circuit to maintain a stable and controllable range.

[0003] The continuous development of microelectronic products has also put forward stringent requirements for thermistor crystal resonators. First, the ceramic base and the metal cover are made of different materials, which will generate large thermal stress during the thermal process. At the same time, due to the structure of the metal cover, overflow of the gold-tin alloy will occur during packaging, causing the risk of short circuit. Secondly, the chip is fixed to the base with conductive glue. With the miniaturization of glue points, the conductive particles in the conductive glue are also getting smaller. Smaller conductive particles cannot provide better support, resulting in highly unstable chip mounting and fluctuating glue thickness between the quartz chip and the glue pad. Finally, the thermistor and quartz chip are designed separately in different grooves, resulting in a certain lag between the thermistor sensing temperature and the quartz chip. The area of ​​the tin pad is sacrificed for the groove design, resulting in poor welding strength. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-temperature resistant thermistor crystal resonator without a sealing cover, which can reduce the thermal stress of the thermistor crystal resonator and improve the impact resistance of the resonator. At the same time, it completely solves the overflow problem in the gold-tin alloy and can provide accurate real-time temperature signals, so as to achieve the purpose of stable operation in harsh temperature environments.

[0005] The technical solution adopted by the present invention to solve its technical problem is: providing a high-temperature resistant thermistor crystal resonator without a sealing cover, comprising a lower base, a quartz chip and a thermistor, wherein an upper base is mounted on the upper end of the lower base, a groove is provided in the middle of the upper end of the lower base and the middle of the lower end of the upper base, the two grooves are butted up and down to form an inner cavity, a quartz chip is mounted in the interior of the lower groove, and a thermistor is mounted in the interior of the upper groove, and an external electrode is provided at the lower end of the lower base, which is connected to the quartz chip and the thermistor in a one-to-one correspondence.

[0006] As a supplement to the technical solution described in the present invention, the upper end of the lower base is located inside the groove and has two glue pads arranged in parallel. The quartz chip is fixed on the glue pads by conductive glue.

[0007] As a supplement to the technical solution described in this invention, a support portion is provided in the middle of the upper end of each adhesive pad. This support portion is an isosceles trapezoidal block structure, and its width gradually increases from top to bottom. The conductive adhesive contains several conductive particles, which together with the support portion support the quartz chip. The adhesive thickness between the quartz chip and the adhesive pad is 13 to 15 μm.

[0008] As a supplement to the technical solution described in the present invention, the lower end of the upper base is located inside the groove and has two tin pads arranged side by side. The thermistor is mounted on the two tin pads through solder paste, and the two tin pads are respectively connected to the corresponding external electrodes.

[0009] As a supplement to the technical solution described in the present invention, the upper base is provided with an upper conductive hole connected one-to-one with the two tin soldering pads, and the lower base is provided with a lower conductive hole for connecting the upper conductive hole and the external electrode. The upper conductive hole and the lower conductive hole are filled with conductive material, and the two tin soldering pads are respectively connected to the corresponding external electrodes through the conductive material in the upper conductive hole and the conductive material in the lower conductive hole.

[0010] As a supplement to the technical solution of the present invention, the lower base and the upper base are sealed by a gold-tin alloy.

[0011] As a supplement to the technical solution described in the present invention, a circle of convex rings is arranged on the inner side of the groove opening around the lower end of the upper base, and the convex rings form a stepped structure with the end face of the upper base. The upper end face of the lower base is provided with a boss structure inserted into the corresponding convex ring.

[0012] As a supplement to the technical solution described in the present invention, the distance between the thermistor and the quartz chip ranges from 60um to 90um.

[0013] As a supplement to the technical solution described in the present invention, the upper and lower surfaces of the quartz chip are both covered with an electrode surface, which overlaps with the upper or lower surface of the quartz chip to form a main vibration area, and the two electrode surfaces are respectively connected to the corresponding external electrodes.

[0014] Beneficial effects: The present invention relates to a high-temperature resistant thermistor crystal resonator without a sealing cover, which is sealed by replacing the traditional metal upper cover with an upper base, which can effectively reduce the thermal stress of the product, greatly improve the high-temperature resistance of the thermistor crystal resonator, and meet the customer's demanding use environment; at the same time, the upper base is provided with a convex ring around the inner side of the groove opening to prevent the internal overflow of the gold-tin alloy, which solves the problem of internal overflow of the gold-tin alloy caused by the traditional metal upper cover, and completely solves the problem of short circuit caused by internal overflow of gold-tin; the thickness of the glue between the quartz chip and the glue pad is effectively controlled by the conductive particles in the conductive glue on the glue pad, thereby improving the impact resistance of the product; by The thermistor and quartz chip are designed in the same cavity, which can accurately measure the real-time temperature of the quartz chip and provide precise temperature data for IC compensation. Through the optimization of the lower and upper base structures, the lower end surface of the upper base is designed into a stepped structure, and the lower base is designed with a boss structure that matches the stepped structure, which can effectively improve the positioning accuracy between the lower and upper bases and enhance their welding strength. By designing the quartz chip groove and the thermistor groove separately, the existing series production process of first mounting the quartz chip and then the thermistor is optimized to a parallel production process of mounting the quartz chip and the thermistor at the same time, effectively shortening the product production cycle and increasing production capacity benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of the present invention in the main viewing direction;

[0016] Figure 2 is a top view of the lower base of the present invention;

[0017] Figure 3 is a top view of the upper base of the present invention;

[0018] Figure 4 This invention Figure 1 A partial enlarged view of middle A;

[0019] Figure 5 It is a bottom view of the lower base of the present invention.

[0020] Diagram: 1. Lower base, 2. Glue pad, 3. Support part, 4. Lower conductive hole, 5. Boss structure, 6. External electrode, 7. Conductive glue, 8. Conductive particles, 9. Quartz chip, 10. Electrode surface, 11. Upper base, 12. Tin pad, 13. Upper conductive hole, 14. Boss ring, 15. Solder paste, 16. Thermistor, 17. Gold-tin alloy, 18. Inner cavity. DETAILED DESCRIPTION

[0021] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0022] The embodiment of the present invention relates to a high temperature resistant thermosensitive crystal resonator without a sealing cover, such as Figure 1-5 As shown, it includes a lower base 1, a quartz chip 9 and a thermistor 16. The upper end of the lower base 1 is installed with an upper base 11. A groove is provided in the middle of the upper end of the lower base 1 and the middle of the lower end of the upper base 11. The two grooves are connected to each other to form an inner cavity 18. The quartz chip 9 is installed in the lower groove, and the thermistor 16 is installed in the upper groove. The lower end of the lower base 1 is provided with an external electrode 6 connected to the quartz chip 9 and the thermistor 16 in a one-to-one correspondence. The lower base 1 and the upper base 11 are sealed together by a gold-tin alloy 17 to replace the traditional metal cover. The thermal stress generated by the product after the thermal process mainly comes from the dissimilar materials, which can effectively reduce the thermal stress of the product.

[0023] The traditional quartz chip 9 is fixed on the glue pad 2 by the conductive glue 7. Due to the influence of the structure, the glue thickness between the quartz chip 9 and the glue pad 2 can only be controlled by the conductive particles 8 in the conductive glue 7. However, with the miniaturization of the product, the particle size of the conductive particles 8 is also constantly miniaturized. The smaller conductive particles 8 cannot play a better supporting effect, which will cause the glue thickness between the quartz chip 9 and the glue pad 2 to be smaller, and it will not play a good buffering role when the product is impacted by external force, which will eventually lead to a large change in RR when subjected to mechanical impact. The upper end of the lower base 1 of the present invention is located inside the groove and two Glue pad 2, the quartz chip 9 is fixed on the glue pad 2 by conductive glue 7, and a support part 3 is provided in the middle of the upper end of each glue pad 2. A support part 3 is designed on the glue pad 2. The advantage is that the quartz chip 9 can be completely controlled according to the height of the support part 3 and the particle size of the conductive particles 8, ensuring that the glue thickness between the quartz chip 9 and the glue pad 2 is 13um~15um. When the product is subjected to mechanical impact, the conductive glue 7 can play a good buffering role, reduce internal stress, effectively reduce the RR change during impact, and greatly improve the stability of the product's conductivity and impact resistance.

[0024] As a preferred embodiment of the support portion 3, the support portion 3 is an isosceles trapezoidal block structure, and the width of the support portion 3 gradually increases from one end where the support portion 3 is connected to the conductive glue 7 to the other end where the support portion 3 is connected to the glue pad 2. Such a shape design of the support portion 3 can increase the contact area with the conductive glue 7, thereby effectively improving the bonding strength of the quartz chip 9.

[0025] As an illustration of the installation method of the thermistor 16, the lower end of the upper base 11 is located inside the groove and has two tin pads 12 arranged side by side. The thermistor 16 is mounted on the two tin pads 12 through solder paste 15, and the two tin pads 12 are respectively connected to the corresponding external electrodes 6; the upper base 11 is provided with an upper conductive hole 13 connected one-to-one with the two tin pads 12, and the lower base 1 is provided with a lower conductive hole 4 for connecting the upper conductive hole 13 with the external electrode 6. The upper conductive hole 13 and the lower conductive hole 4 are both filled with conductive material. When the lower base 1 and the upper base 11 are sealed, the two tin pads 12 are respectively connected to the corresponding external electrodes 6 through the conductive material in the upper conductive hole 13 and the conductive material in the lower conductive hole 4, thereby realizing circuit conduction between the thermistor 16 and the external electrode 6.

[0026] As an installation instruction for the lower base 1 and the upper base 11, the lower end of the upper base 11 is provided with a convex ring 14 around the inner side of the groove opening, and the convex ring 14 forms a step structure with the open end face of the upper base 11. The upper end of the lower base 1 is provided with a boss structure 5 inserted into the corresponding convex ring 14; the lower base 1 and the upper base 11 are sealed by a gold-tin alloy 17; high-precision positioning is achieved by cooperating with the boss structure 5 and the step structure. At the same time, this structure can also improve the welding strength. After positioning, the gold-tin alloy 17 is used to achieve Sealed, and at the same time, the convex ring 14 can prevent the gold-tin alloy 17 from overflowing during sealing; the height of the gold-tin alloy 17 is 8~10um; the thickness of the lower base 1 is 0.22~0.24mm; the thickness of the upper base 11 is 0.25~0.27mm, and the total thickness of the resonator is 0.46~0.48mm; the boss structure 5 and the step structure can also avoid the short circuit problem between the conductive material of the lower conductive hole 4 and the gold-tin alloy 17 when the lower base 1 and the upper base 11 are sealed.

[0027] As an explanation of the arrangement of the thermistor 16 and the quartz chip 9, the spacing between the thermistor 16 and the quartz chip 9 is in the range of 60um to 90um. Within this spacing range, the real-time temperature signal of the quartz chip 9 can be sensed relatively closely. At the same time, the thermistor is sealed in the cavity to reduce damage to the thermistor 16 and the solder paste 15 by the external environment.

[0028] The upper and lower surfaces of the quartz chip 9 are both covered with an electrode surface 10 , which overlaps with the upper or lower surface of the quartz chip 9 to form a main vibration area. The two electrode surfaces 10 are respectively connected to the corresponding external electrodes 6 .

[0029] On the one hand, the present invention separates the groove for carrying the quartz chip and the groove for carrying the thermistor into independent lower bases 1 and upper bases 11. The upper base 11 replaces the traditional metal cover to play a sealing role and greatly reduces the thermal stress of the product. At the same time, the upper base 11 is provided with a circle of raised rings 14 around the inner side of the groove opening, which can effectively prevent the problem of internal overflow of the gold-tin alloy 17 during packaging. By designing the lower base 1 and the upper base 11 separately, during the assembly process of the product, the process of fixing the quartz chip 9 to the lower base 1 and the process of fixing the thermistor 16 to the upper base 11 can be carried out simultaneously, which greatly shortens the production cycle and improves production efficiency. On the other hand, the support portion 3 on the dispensing pad 2 is designed in combination with the conductive particles 8 in the conductive glue 7, which effectively controls the glue thickness between the quartz chip 9 and the dispensing pad 2, thereby improving the impact resistance of the product. At the same time, the thermistor 16 and the quartz chip 9 are designed in the same cavity. This arrangement can accurately obtain the real-time temperature signal of the quartz chip 9, providing an accurate temperature signal for the IC to achieve a precise compensation effect. In summary, the present invention can reduce the thermal stress of the thermistor crystal resonator and improve the shock resistance of the resonator. At the same time, it can completely solve the overflow problem in the gold-tin alloy and provide an accurate real-time temperature signal, thereby achieving the purpose of stable operation in a high-temperature environment.

[0030] As an illustration of the separate arrangement of the upper base 11 and the lower base 1, the base structure of a traditional thermistor crystal resonator is H-shaped, with two grooves formed on the upper and lower sides for carrying a quartz chip and a thermistor. The groove for carrying the quartz chip is sealed with a metal cover, while the groove for carrying the thermistor is exposed. At the same time, the external electrode is arranged around the end face of the thermistor groove. Due to the influence of the thermistor groove, the area of ​​the external electrode is small, which will reduce the welding strength between the product and the PCB board. The advantages of designing the upper base 11 and the lower base 1 separately are: first, the upper base 11 replaces the metal cover to achieve sealing, while greatly reducing thermal stress; second, the thermistor 16 is arranged inside the cavity, improving the sealing of the product; third, the external electrode 6 is designed on the bottom platform of the lower base 1, which increases the area of ​​the external electrode 6 and effectively improves the welding strength between the product and the PCB board; fourth, the series production process of first carrying the quartz chip 9 and then the thermistor 16 is optimized to a parallel production process in which the quartz chip 9 and the thermistor 16 are carried out simultaneously, greatly shortening the production cycle and improving production efficiency.

[0031] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0032] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0033] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0034] The above is a detailed introduction to a high-temperature resistant thermistor resonator without a sealing cover provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A high-temperature resistant thermistor crystal resonator without a sealing cover, comprising a lower base (1), a quartz chip (9) and a thermistor (16), characterized in that: The upper end of the lower base (1) is equipped with an upper base (11), and a groove is provided in the middle of the upper end of the lower base (1) and the middle of the lower end of the upper base (11). The two grooves are connected to form an inner cavity (18). A quartz chip (9) is installed in the lower groove, and a thermistor (16) is installed in the upper groove. The lower end of the lower base (1) is provided with an external electrode (6) connected to the quartz chip (9) and the thermistor (16) in a one-to-one correspondence; the lower end of the upper base (11) is located inside the groove and has two tin pads (12) arranged side by side. The thermistor (16) is connected to the quartz chip (9) and the thermistor (16) by solder paste (15). The device is carried on two tin solder pads (12), and the two tin solder pads (12) are respectively connected to the corresponding external electrodes (6); the upper base (11) is provided with an upper conductive hole (13) connected to the two tin solder pads (12) in a one-to-one correspondence, and the lower base (1) is provided with a lower conductive hole (4) for connecting the upper conductive hole (13) and the external electrode (6); the upper conductive hole (13) and the lower conductive hole (4) are filled with conductive material, and the two tin solder pads (12) are respectively connected to the corresponding external electrodes (6) through the conductive material in the upper conductive hole (13) and the conductive material in the lower conductive hole (4).

2. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 1, characterized in that: The upper end of the lower base (1) is located inside the groove and has two glue pads (2) arranged in parallel. The quartz chip (9) is fixed on the glue pads (2) by conductive glue (7).

3. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 2, characterized in that: A support portion (3) is provided in the middle of the upper end of each glue dispensing pad (2), and the support portion (3) is an isosceles trapezoidal block structure, and the width of the support portion (3) gradually increases from top to bottom.

4. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 2, characterized in that: The glue thickness between the quartz chip (9) and the glue pad (2) is 13um to 15um.

5. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 1, characterized in that: The lower base (1) and the upper base (11) are sealed by a gold-tin alloy (17).

6. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 1 or 5, characterized in that: A convex ring (14) is arranged on the inner side of the groove opening around the lower end of the upper base (11), and the convex ring (14) and the end face of the upper base (11) form a stepped structure. The upper end face of the lower base (1) is provided with a boss structure (5) inserted into the corresponding convex ring (14).

7. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 1, characterized in that: The distance between the thermistor (16) and the quartz chip (9) ranges from 60um to 90um.

8. The high-temperature resistant thermosensitive crystal resonator without a sealing cover according to claim 1, characterized in that: The upper and lower surfaces of the quartz chip (9) are both covered with a layer of electrode surface (10), and the electrode surface (10) overlaps with the upper surface or the lower surface of the quartz chip (9) to form a main vibration area, and the two electrode surfaces (10) are respectively connected to the corresponding external electrodes (6).

Images