Dual-chip parallel surface-mount quartz crystal resonator and preparation method

Abstract

The present invention provides a dual-chip parallel surface-mount quartz crystal resonator and a preparation method, belonging to the technical field of electronic components. The resonator comprises a tube shell, wherein a first conductor and a second conductor are disposed within the tube shell. The first conductor is higher than the second conductor. A first resonant crystal is fixed to the first conductor; a second resonant crystal is fixed to the second conductor. The first resonant crystal and the second resonant crystal are connected in parallel via the first and second conductors of different heights. The first resonant crystal and the second resonant crystal are parallel to each other. The dual-chip parallel surface-mount quartz crystal resonator provided by the present invention can reduce equivalent resistance, improve load-pulling force, and meet the needs of tube shell miniaturization.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic components, and more specifically, relates to a dual-chip parallel surface-mount quartz crystal resonator and a preparation method thereof. Background Art

[0002] A quartz crystal resonator (also known as an Xtal, External Crystal Osillator, or external crystal oscillator, as the crystal oscillator unit is often connected externally to a circuit) is a passive electronic component that utilizes the piezoelectric effect of a quartz crystal (also known as crystal) to generate a high-precision oscillation frequency. It primarily consists of a quartz wafer, a tube and case, an outer shell, silver glue, and other components. Depending on the lead configuration, it can be categorized as either a direct-insert (with leads) or surface-mount (without leads). Commonly available packages include HC-49U, HC-49 / S, GLASS, UM-1, UM-4, UM-5, and SMD.

[0003] SMD is the abbreviation of surface mounted devices. This series has dimensions of 7×5mm, 6×3.5mm, 5×3.2mm, 4×2.5mm, 3×2.5mm, 2.5×2.0mm, 2×1.6mm, etc.

[0004] A quartz crystal resonator is a resonant component made using the piezoelectric effect of quartz crystal. Its core is the quartz crystal. Because the crystal is thin and easily oxidized, the manufacturing process typically places the crystal inside a tube shell, which is then sealed under nitrogen or vacuum. The crystal is secured by connecting the crystal electrodes to the tube shell electrodes using conductive adhesive. When used, the customer directly solders the outer electrodes of the tube shell to the circuit board.

[0005] Currently, see Figure 22 Surface-mount quartz crystal resonators all use a single quartz resonator chip. As the package size of surface-mount quartz crystal resonators continues to shrink, the chip size is limited by the packaging, resulting in a relatively high equivalent resistance and low load-pulling force. This is particularly true for overtone crystals. Summary of the Invention

[0006] The present invention aims to provide a dual-chip parallel surface-mount quartz crystal resonator, aiming to solve the problems of large equivalent resistance and low load pulling force of current surface-mount quartz crystal resonators.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a dual-chip parallel surface-mount quartz crystal resonator, including: a tube shell, a first conductor and a second conductor are provided in the tube shell, the height of the first conductor is higher than the height of the second conductor, a first resonant chip is fixed on the first conductor; a second resonant chip is fixed on the second conductor, the first resonant chip and the second resonant chip are connected in parallel via the first conductor and the second conductor of different heights, and the first resonant chip is parallel to the second resonant chip.

[0008] As another embodiment of the present application, the first conductor includes a first solder pad and a second solder pad not connected to the first solder pad, and the second conductor includes a first lead connected to the first solder pad and a second lead connected to the second solder pad; the first resonant chip is fixed on the first solder pad and the second solder pad, and the second resonant chip is fixed on the first lead and the second lead.

[0009] As another embodiment of the present application, the height difference between the first solder pad and the first lead is 0.2±0.05mm, and the height difference between the second solder pad and the second lead is 0.2±0.05mm; the first solder pad and the second solder pad have the same height, and the first lead and the second lead have the same height.

[0010] As another embodiment of the present application, the front side of the first resonant chip is provided with a metallized electrode area A1, a metallized electrode area B1 and a metallized electrode area C1, the metallized electrode area A1 is located in the middle of the first resonant chip, the metallized electrode area B1 and the metallized electrode area C1 are located at the same end of the first resonant chip, and the metallized electrode area A1 is connected to the metallized electrode area B1; the back side of the first resonant chip is correspondingly provided with a metallized electrode area A2, a metallized electrode area B2 and a metallized electrode area C2, the metallized electrode area A2 is connected to the metallized electrode area C2; the metallized electrode area B2 and the metallized electrode area C2 are respectively connected to the first pad and the second pad.

[0011] As another embodiment of the present application, the front side of the second resonant chip is provided with a metallized electrode area D1, a metallized electrode area E1 and a metallized electrode area F1, the metallized electrode area D1 is located in the middle of the second resonant chip, the metallized electrode area E1 and the metallized electrode area F1 are located at the same end of the second resonant chip, and the metallized electrode area D1 is connected to the metallized electrode area E1; the back side of the second resonant chip is correspondingly provided with a metallized electrode area D2, a metallized electrode area E2 and a metallized electrode area F2, the metallized electrode area D2 is connected to the metallized electrode area F2; the metallized electrode area E2 and the metallized electrode area F2 are respectively connected to the first lead and the second lead.

[0012] As another embodiment of the present application, a first solder pad glue point is provided on the first solder pad, a second solder pad glue point is provided on the second solder pad, a first lead glue point is provided on the first lead, and a second lead glue point is provided on the second lead. Two parts of the first resonant chip are fixedly connected to the first solder pad glue point and the second solder pad glue point, respectively, and two parts of the second resonant chip are connected to the first lead glue point and the second lead glue point, respectively.

[0013] As another embodiment of the present application, the first solder pad and the second solder pad are arranged at the same end of the tube shell.

[0014] As another embodiment of the present application, the fixed end of the second resonant chip and the fixed end of the first resonant chip are located at the same end.

[0015] As another embodiment of the present application, the upper surfaces of the first pad and the second pad are respectively provided with a metallization layer, and the first lead and the second lead are respectively connected to the metallization layers on the first pad and the second pad.

[0016] The present invention also provides a method for preparing the dual-chip parallel surface-mount quartz crystal resonator, comprising the following steps:

[0017] Metallization treatment of the front and back surfaces of the first resonant wafer and the second resonant wafer;

[0018] In the tube shell, the first pad is connected to the first lead, and the second pad is connected to the second lead;

[0019] Dispense glue on the first pad, the second pad, the first lead, and the second lead;

[0020] bonding the metallized area of the first resonant wafer to the first pad and the second pad;

[0021] The metallized area of the second resonant chip is bonded to the first lead and the second lead; the first resonant chip and the second resonant chip are connected in parallel;

[0022] Shell cap.

[0023] The dual-chip parallel surface-mount quartz crystal resonator provided by the present invention has the following beneficial effects: Compared with the prior art, the dual-chip parallel surface-mount quartz crystal resonator of the present invention, based on the surface-mount tube shell structure, utilizes the connection relationship between the internal wiring and the solder pad of the tube shell, and places a quartz resonant chip at the wiring position and the solder pad position respectively, so that the two quartz resonant chips form a parallel relationship, reducing the equivalent resistance of the quartz crystal resonator and improving the load-pulling force. Because the two parallel resonant chips are in a parallel relationship in the vertical direction, and because the cavity of the tube shell originally has a certain amount of space in the height direction, the two parallel resonant chips in the vertical direction do not cause the outer dimensions of the tube shell to increase in width, length, and height. While reducing the equivalent resistance and improving the load-pulling force, it can meet the needs of miniaturization of the tube shell.

[0024] The present invention, based on the existing small-sized tube shell, can achieve the effects of small equivalent resistance and large load pulling force by adopting upper and lower parallel-connected mirror chips.

[0025] The invention provides a method for preparing a dual-chip parallel surface-mounted quartz crystal resonator. The prepared resonator comprises two resonant chips connected in parallel, and has the effects of small equivalent resistance and large load pulling force. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 Schematic diagram of the structure of the dual-chip parallel surface-mount quartz crystal resonator provided in the embodiment of the present invention Figure 1 ;

[0028] Figure 2 for Figure 1 Schematic diagram of the three-dimensional structure of the dual-chip parallel surface-mount quartz crystal resonator provided;

[0029] Figure 3 for Figure 1 Schematic diagram of the internal structure of the provided dual-chip parallel surface-mount quartz crystal resonator;

[0030] Figure 4 Schematic diagram of the structure of the dual-chip parallel surface-mount quartz crystal resonator provided in the embodiment of the present invention Figure 2 ;

[0031] Figure 5 for Figure 4 Schematic diagram of the three-dimensional structure of the dual-chip parallel surface-mount quartz crystal resonator provided;

[0032] Figure 6 for Figure 4 Schematic diagram of the internal structure of the provided dual-chip parallel surface-mount quartz crystal resonator;

[0033] Figure 7 Schematic diagram of the structure of the dual-chip parallel surface-mount quartz crystal resonator provided in the embodiment of the present invention Figure 3 ;

[0034] Figure 8 for Figure 7 Schematic diagram of the three-dimensional structure of the dual-chip parallel surface-mount quartz crystal resonator provided;

[0035] Figure 9 for Figure 7 Schematic diagram of the internal structure of the provided dual-chip parallel surface-mount quartz crystal resonator;

[0036] Figure 10 Schematic diagram of the structure of the dual-chip parallel surface-mount quartz crystal resonator provided in the embodiment of the present invention Figure 4 ;

[0037] Figure 11 for Figure 10 Schematic diagram of the three-dimensional structure of the dual-chip parallel surface-mount quartz crystal resonator provided;

[0038] Figure 12 for Figure 10 Schematic diagram of the internal structure of the dual-chip parallel surface-mount quartz crystal resonator provided;

[0039] Figure 13 for Figure 10 The internal main structure diagram of the provided dual-chip parallel surface-mount quartz crystal resonator;

[0040] Figure 14 A schematic diagram of the front three-dimensional structure of the second resonant chip provided by an embodiment of the present invention;

[0041] Figure 15 A schematic diagram of the back three-dimensional structure of the second resonant chip provided in an embodiment of the present invention;

[0042] Figure 16 A schematic diagram of the front three-dimensional structure of a first resonant chip provided by an embodiment of the present invention;

[0043] Figure 17 A schematic diagram of the back three-dimensional structure of a tube shell provided by an embodiment of the present invention;

[0044] Figure 18The structure of the dual-chip parallel surface-mount quartz crystal resonator provided by the embodiment of the present invention is simple. Figure 1 ;

[0045] Figure 19 The structure of the dual-chip parallel surface-mount quartz crystal resonator provided by the embodiment of the present invention is simple. Figure 2 ;

[0046] Figure 20 A schematic diagram of the structure of a dual-chip parallel surface-mount quartz crystal resonator provided in an embodiment of the present invention;

[0047] Figure 21 An oscillation circuit diagram of the dual-chip parallel surface-mount quartz crystal resonator provided by the present invention;

[0048] Figure 22 The structural principle diagram of the quartz crystal resonator provided as background technology.

[0049] In the figure: 1. tube shell; 2. first solder pad; 3. first lead; 4. second lead; 5. second solder pad; 6. second solder pad glue point; 7. first solder pad glue point; 8. first lead glue point; 9. second lead glue point; 10. metallized electrode area F1; 11. second resonant chip; 12. metallized electrode area D1; 13. metallized electrode area E1; 14. metallized electrode area B1; 15. metallized electrode area A1; 16. first resonant chip; 17. metallized electrode area C1; 18. metallized electrode area F2; 19. metallized electrode area D2; 20. metallized electrode area E2; 21. back solder pad. DETAILED DESCRIPTION

[0050] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] Please also refer to Figures 1 to 20 The dual-chip parallel surface-mount quartz crystal resonator provided by the present invention is now described. The dual-chip parallel surface-mount quartz crystal resonator includes a tube shell 1, within which a first conductor and a second conductor are disposed. The first conductor is higher than the second conductor. A first resonant crystal 16 is fixed to the first conductor; a second resonant crystal 11 is fixed to the second conductor. The first resonant crystal 16 and the second resonant crystal 11 are connected in parallel via the first conductor and the second conductor of different heights. The first resonant crystal 16 is parallel to the second resonant crystal 11.

[0052] Compared to the prior art, the dual-chip parallel surface-mount quartz crystal resonator provided by the present invention utilizes the structure of a surface-mounted tube shell 1 and utilizes the connection relationship between the internal wiring and pads of the tube shell 1 to place a quartz resonant chip at the wiring position and the pad position, respectively, so that the two quartz resonant chips are connected in parallel, reducing the equivalent resistance of the quartz crystal resonator and improving the load-pulling force. Because the two parallel resonant chips are in a parallel relationship in an upper and lower position, and because the cavity of the tube shell 1 originally has a certain amount of space in the height direction, the two parallel resonant chips in the upper and lower positions do not increase the external dimensions of the tube shell 1 in width, length, and height. While reducing the equivalent resistance and improving the load-pulling force, it can meet the demand for miniaturization of the tube shell 1.

[0053] Based on the existing small-sized tube shell 1, the present invention can achieve the effects of small equivalent resistance and large load pulling force by adopting upper and lower parallel-connected mirror chips.

[0054] Compared with the quartz crystal resonator of the traditional structure, the characteristics of the present invention, such as the external dimensions, power consumption, assembly process, practicality, and reliability, remain consistent.

[0055] For example, see Figures 18 to 20 The static capacitance, dynamic capacitance, equivalent resistance, dynamic inductance and pulling force of the first resonant chip 16 are C 01 、C 11 , R1, L 11 , Among them, C L is the load capacitance, generally 10-22pF.

[0056] The static capacitance, dynamic capacitance, equivalent resistance, dynamic inductance and pulling force of the second resonant chip 11 are C 02 、C 12 , R2, L 12 , Among them, C L is the load capacitance, generally 10-22pF.

[0057] The static capacitance C0, dynamic capacitance C1, equivalent resistance R, dynamic inductance L, and pulling force Ts of the two resonant chips in parallel are:

[0058] C0≈C 01 +C 02

[0059] C1≈C 11 +C 12

[0060]

[0061]

[0062]

[0063] If the specifications of the two resonant crystals are the same, that is, the static capacitance, dynamic capacitance, equivalent resistance and dynamic inductance are all the same, then the crystal equivalent resistance R is reduced by 50% and the load pulling force Ts is increased by 50%.

[0064] As a specific implementation of the embodiment of the present invention, please refer to Figures 1 to 12 The first conductive body includes a first pad 2 and a second pad 5 not connected to the first pad 2. The second conductive body includes a first lead 3 connected to the first pad 2 and a second lead 4 connected to the second pad 5. The first resonant chip 16 is fixed to the first pad 2 and the second pad 5, and the second resonant chip 11 is fixed to the first lead 3 and the second lead 4. A backside pad 21 is also provided on the backside of the tube case 1.

[0065] As a specific embodiment of the dual-chip parallel surface-mount quartz crystal resonator provided by the present invention, please refer to Figure 3 The height difference between the first pad 2 and the first lead 3 is 0.2±0.05mm, and the height difference between the second pad 5 and the second lead 4 is 0.2±0.05mm. The first pad 2 and the second pad 5 are of the same height, and the first lead 3 and the second lead 4 are of the same height. This embodiment utilizes the height difference between the pads and the leads to achieve parallel connection of two resonant chips, making manufacturing simple and convenient. This structural design ensures that the pads are connected to the corresponding leads and that the subsequent assembly of the two resonant chips does not affect each other.

[0066] As a specific implementation of the embodiment of the present invention, see Figures 7 to 16 The front of the first resonant chip 16 is provided with a metallized electrode area A1, a metallized electrode area B1, and a metallized electrode area C1. The metallized electrode area A1 is located in the middle of the first resonant chip 16, and the metallized electrode area B1 and the metallized electrode area C1 are located at the same end of the first resonant chip 16. The metallized electrode area A1 is connected to the metallized electrode area B1. The back of the first resonant chip 16 is correspondingly provided with a metallized electrode area A2, a metallized electrode area B2, and a metallized electrode area C2. The metallized electrode area A2 is connected to the metallized electrode area C2. The metallized electrode area B2 and the metallized electrode area C2 are connected to the first soldering pad 2 and the second soldering pad 5, respectively. Electrical connection is achieved by metallizing the front and back of the resonant chip. The front side referred to herein is the side away from the bottom surface of the cavity of the tube shell 1, and the back side is in direct contact with the soldering pad or lead. Regarding the metallized areas on the front and back sides, with the front side as a reference, when the resonant chip is flipped 180°, the metallized area on the back side overlaps or is consistent with the original metallized area on the front side, that is, the position and shape are consistent.

[0067] The explanation of this embodiment is as follows: Figure 14 and Figure 15 The shapes and positions of the metallized electrode areas A1 and A2 on the front and back sides are opposite, the metallized electrode area B1 on the front side is opposite to the metallized electrode area B2 on the back side, and the metallized electrode area C1 on the front side is opposite to the metallized electrode area C2 on the back side.

[0068] As a specific implementation of the embodiment of the present invention, please refer to 7 to Figure 16 The front surface of the second resonant chip 11 is provided with a metallized electrode region D1, a metallized electrode region E1, and a metallized electrode region F1. The metallized electrode region D1 is located in the middle of the second resonant chip 11, and the metallized electrode region E1 and the metallized electrode region F1 are located at the same end of the second resonant chip 11. The metallized electrode region D1 is connected to the metallized electrode region E1. The back surface of the second resonant chip 11 is correspondingly provided with a metallized electrode region D2, a metallized electrode region E2, and a metallized electrode region F2. The metallized electrode region D2 is connected to the metallized electrode region F2. The metallized electrode region E2 and the metallized electrode region F2 are respectively connected to the first lead 3 and the second lead 4. The structural explanation of the second resonant chip 11 is the same as that of the first resonant chip 16 described above and will not be repeated here.

[0069] As a specific implementation of the embodiment of the present invention, please refer to Figures 4 to 12 The first pad 2 is provided with a first pad glue point 7, the second pad 5 is provided with a second pad glue point 6, the first lead 3 is provided with a first lead glue point 8, the second lead 4 is provided with a second lead glue point 9, two parts of the first resonant chip 16 are respectively fixedly connected to the first pad glue point 7 and the second pad glue point 6, and two parts of the second resonant chip 11 are respectively connected to the first lead glue point 8 and the second lead glue point 9. The present invention can fix the two resonant chips with four glue points, and the fixed connection is simple and convenient.

[0070] As a specific implementation of the embodiment of the present invention, please refer to Figures 1 to 12 The first pad 2 and the second pad 5 are arranged at the same end of the tube shell 1. That is, one end of the first resonant chip 16 is fixed and the other end is suspended.

[0071] As a specific implementation of the embodiment of the present invention, please refer to Figures 1 to 12 The fixed end of the second resonant chip 11 is located at the same end as the fixed end of the first resonant chip 16. One end of the second resonant chip 11 is fixed, and the other end is also suspended.

[0072] As a specific implementation of the embodiment of the present invention, please refer to Figures 1 to 3 The upper surfaces of the first pad 2 and the second pad 5 are respectively provided with a metallization layer, and the first lead 3 and the second lead 4 are respectively connected to the metallization layers on the first pad 2 and the second pad 5.

[0073] The present invention also provides a method for preparing the dual-chip parallel surface-mount quartz crystal resonator, comprising the following steps:

[0074] The first step is to metallize the front and back surfaces of the first resonant chip 16 and the second resonant chip 11, see Figures 14 to 16 ;

[0075] In the second step, inside the tube shell 1, the first pad 2 is connected to the first lead 3, and the second pad 5 is connected to the second lead 4. Figures 1 to 3 ;

[0076] The third step is to apply glue on the first pad 2, the second pad 5, the first lead 3 and the second lead 4. Figures 4 to 6 ;

[0077] Step 4: Bond the metallized area of the first resonant chip 16 to the first pad 2 and the second pad 5, see Figures 7 to 9 ;

[0078] Step 5: The metallized area of the second resonant chip 11 is bonded to the first lead 3 and the second lead 4; the first resonant chip 16 and the second resonant chip 11 are connected in parallel. Figures 10 to 13 ;

[0079] Step 6: Cap the tube shell 1. Figure 21 After the tube shell 1 is capped, it is installed in the oscillation circuit as a frequency-selective component. By adjusting the tuning voltage, the tuning capacitance value CL is changed, thereby achieving the output power of the oscillation circuit.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dual-chip parallel surface-mount quartz crystal resonator, characterized by: include: A tube shell, wherein a first conductor and a second conductor are disposed within the tube shell, wherein the first conductor is higher than the second conductor, a first resonant chip is fixed to the first conductor, and a second resonant chip is fixed to the second conductor, wherein the first resonant chip and the second resonant chip are connected in parallel via the first conductor and the second conductor of different heights, and the first resonant chip is parallel to the second resonant chip; The first conductive body includes a first pad and a second pad not connected to the first pad, and the second conductive body includes a first lead connected to the first pad and a second lead connected to the second pad; the first resonant chip is fixed on the first pad and the second pad, and the second resonant chip is fixed on the first lead and the second lead; The front surface of the first resonant chip is provided with a metallized electrode area A1, a metallized electrode area B1 and a metallized electrode area C1. The metallized electrode area A1 is located in the middle of the first resonant chip, the metallized electrode area B1 and the metallized electrode area C1 are located at the same end of the first resonant chip, and the metallized electrode area A1 is connected to the metallized electrode area B1. The back side of the first resonant chip is correspondingly provided with a metallized electrode area A2, a metallized electrode area B2 and a metallized electrode area C2, and the metallized electrode area A2 is connected to the metallized electrode area C2; The metallized electrode area B2 and the metallized electrode area C2 are connected to the first pad and the second pad respectively; The front surface of the second resonant chip is provided with a metallized electrode area D1, a metallized electrode area E1 and a metallized electrode area F1. The metallized electrode area D1 is located in the middle of the second resonant chip. The metallized electrode area E1 and the metallized electrode area F1 are located at the same end of the second resonant chip. The metallized electrode area D1 is connected to the metallized electrode area E1. The back side of the second resonant chip is correspondingly provided with a metallized electrode area D2, a metallized electrode area E2 and a metallized electrode area F2, and the metallized electrode area D2 is connected to the metallized electrode area F2; The metallized electrode region E2 and the metallized electrode region F2 are connected to the first lead and the second lead respectively.

2. The dual-chip parallel surface-mount quartz crystal resonator according to claim 1, characterized in that: The height difference between the first pad and the first lead is 0.2±0.05 mm, and the height difference between the second pad and the second lead is 0.2±0.05 mm; the first pad and the second pad have the same height, and the first lead and the second lead have the same height.

3. The dual-chip parallel surface-mount quartz crystal resonator according to claim 1, characterized in that: A first solder pad glue point is provided on the first solder pad, a second solder pad glue point is provided on the second solder pad, a first lead glue point is provided on the first lead, a second lead glue point is provided on the second lead, two parts of the first resonant chip are fixedly connected to the first solder pad glue point and the second solder pad glue point respectively, and two parts of the second resonant chip are connected to the first lead glue point and the second lead glue point respectively.

4. The dual-chip parallel surface-mount quartz crystal resonator according to claim 1, wherein: The first pad and the second pad are disposed on the same end of the tube shell.

5. The dual-chip parallel surface-mount quartz crystal resonator according to claim 4, characterized in that: The fixed end of the second resonant chip is located at the same end as the fixed end of the first resonant chip.

6. The dual-chip parallel surface-mount quartz crystal resonator according to claim 1, wherein: A metallization layer is provided on the upper surface of the first pad and the upper surface of the second pad, respectively. The first lead and the second lead are connected to the metallization layers on the first pad and the second pad, respectively.

7. A method for preparing a dual-chip parallel surface-mount quartz crystal resonator according to any one of claims 1 to 6, characterized in that: The following steps are involved: Metallization treatment of the front and back surfaces of the first resonant wafer and the second resonant wafer; In the tube shell, the first pad is connected to the first lead, and the second pad is connected to the second lead; Dispense glue on the first pad, the second pad, the first lead, and the second lead; bonding the metallized area of the first resonant wafer to the first pad and the second pad; The metallized area of the second resonant chip is glued to the first lead and the second lead; the first resonant chip and the second resonant chip are connected in parallel; Shell cap.

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