CN201535862U

CN201535862U - Thick-film circuit of crystal oscillator with real time clock RTC chip

Info

Publication number: CN201535862U
Application number: CN200920260434XU
Authority: CN
Inventors: 石林国
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-18
Filing date: 2009-11-18
Publication date: 2010-07-28
Anticipated expiration: 2019-11-18

Abstract

A thick-film circuit of a crystal oscillator with a real time clock RTC chip includes a quartz crystal resonator for controlling oscillating frequency, a real time clock RTC chip, a printed circuit board PCB and multiple pins, wherein a circuit of the RTC chip includes a digital temperature compensation oscillator DTCX0 having a temperature sensor; the crystal resonator and the RTC chip are all arranged on the PCB and connected with the PCB electrically, the crystal resonator is connected with the RTC chip electrically, and each pin is connected with the PCB electrically and then guided out from the PCB; the crystal resonator, the RTC chip, the PCB and the root of each pin are integrated to form a device. By means of slickly employing the printed circuit board to connect and providing the RTC chip and the crystal resonator, the thick-film circuit of the crystal oscillator has advantages of low cost, good performance-price ratio, high utility value, high reliability, high compensation precision, etc.

Description

Include the crystal oscillator thick film circuit of real-time clock RTC chip

[technical field]

The utility model relates to electric solid state device, particularly relates to the assembly of being made up of a plurality of single semiconductors or other solid state device, relates in particular to real-time clock RTC Chip Packaging crystal oscillator thick film circuit together.

[background technology]

Devices such as electronic clock or electrician's measuring instrument all need crystal oscillator to provide the high accuracy clock frequency signal source for them.But the output of the frequency of crystal oscillator tends to change along with environment temperature, its output frequency can occurrence temperature drift about in other words, therefore must carry out temperature compensation, reach the high-precision requirement of devices such as electronic clock or electrician's measuring instrument frequency to be provided at frequency output constant relatively in the wider temperature range.

The method that prior art addresses this problem comprises (the Real Time Clock with RTC, real-time clock) chip is electrically connected with crystal oscillator, utilization is in the frequency drift of different temperatures test, at reverse compensated curve of RTC chip internal design, when crystal oscillator is in different temperatures, the temperature sensor of RTC chip internal is measured the temperature of crystal oscillator, and the offset data of calling the RTC chip internal compensates the frequency of crystal oscillator, reach the purpose of proofreading and correct crystal oscillator frequency, thereby make the crystal oscillator output frequency more accurate; The frequency of crystal oscillator output is handled through the RTC chip, obtains clock frequency, and then obtains time value, and the RTC chip supplies external circuit to regulate and uses with this time value storage within it.

Prior art is electrically connected with two kinds of technical schemes with RTC chip and crystal oscillator:

1, separately with the RTC Chip Packaging, then it is electrically connected with crystal oscillator, RTC chip and crystal oscillator are two electronic devices and components independently, and this technical scheme has following weak point:

A, can not carry out fine compensation to the temperature curve of each crystal oscillator, can only do the reverse compensated curve of a representative value at the RTC chip internal, so the compensation degree of accuracy is very low, the frequency output accuracy of the crystal oscillator of this technical scheme generally can only reach in-40 ℃ to 85 ℃ temperature range ± 40ppm (40/1000000ths);

B, because two electronic devices and components that adopt to separate cause bigger inconvenience to follow-up assembling, increased follow-up working time and cost;

C, because two electronic devices and components that adopt to separate have reduced reliability;

2, RTC chip, crystal oscillator are carried out integrated encapsulation; Because what adopt is disposable encapsulation technology, does not have the centre part transition, this disposable packaging technology requires very high to environment, mould and equipment etc., its encapsulating mould cost is very high, cause whole packaging cost very high, be unfavorable for that manufacturing enterprise reduces cost, general enterprise is difficult to produce.

[utility model content]

The technical problems to be solved in the utility model is to avoid above-mentioned the deficiencies in the prior art part and a kind of crystal oscillator thick film circuit that includes real-time clock RTC chip is provided, this crystal oscillator thick film circuit is used printed circuit board (PCB) connection and carrying RTC chip and crystal resonator dexterously, has advantages such as low cost, good cost performance, high practical value, high reliability and high compensation precision.

The technical scheme that the utility model solve the technical problem employing is:

A kind of crystal oscillator thick film circuit that includes real-time clock RTC chip is provided, comprise the quartz-crystal resonator and the real-time clock RTC chip that are used to control oscillation frequency, the circuit of this RTC chip is formed and is comprised the digital temperature compensated oscillator DTCXO that contains temperature sensor; This crystal oscillator thick film circuit also comprises printing board PCB and many pieces of pins; Described crystal resonator and RTC chip all are arranged on the described PCB, and are electrically connected with it and are electrically connected mutually, and described each pin is then drawn after this PCB is electrically connected respectively; The root of described crystal resonator, RTC chip, PCB and each pin all is packaged into the one device with engineering plastics.

Described RTC chip is arranged on the PCB, is that the nude film with this RTC chip is welded on the described PCB, and its surface is sprayed protective seam that organic material forms and covered.

Described pin comprise at least SCL, FOUT output frequency, Vdd, FOE, SDA, GND ,/INT and VBACK.

After packed, described each pin is shaped to the SOP type.Or, packed after, described each pin is shaped to the SOJ type.

Described crystal resonator and RTC chip all are arranged on described PCB with one side.

Or described crystal resonator and RTC chip are separately positioned on the positive and negative two sides of described PCB.

Or described PCB is provided with the through hole that holds described crystal resonator, and described crystal resonator is arranged in the through hole of described PCB.

Compare with prior art, the beneficial effect that the utility model includes the crystal oscillator thick film circuit of real-time clock RTC chip is:

1, connects and carrying RTC chip and crystal resonator by printed circuit board (PCB), its packaging technology is not very high to requirements such as environment, mould and equipment, its encapsulating mould cost is low, though increased the very low printed circuit board (PCB) of cost, but carrying out integrated encapsulation with RTC chip, crystal resonator compares, whole cost is much lower, and general enterprise all can produce, and has advantages such as low cost, good cost performance and high practical value;

2, compensation precision height, the frequency output accuracy of the utility model crystal oscillator thick film circuit can reach ± 5ppm (5/1000000ths) between temperature-40 is ℃ to 85 ℃, with RTC chip and crystal resonator is that independently two electronic devices and components are compared, its frequency output accuracy height about 8 times;

3, reliability height and since earlier with the RTC Chip Packaging on printed circuit board (PCB), the whole encapsulation of RTC chip, crystal resonator and printed circuit board (PCB) that will encapsulate again improves its reliability greatly;

4, follow-up easy to assembly, follow-up assembling is equivalent to only assemble the element of an integral body.

[description of drawings]

Fig. 1 is the axonometric projection synoptic diagram that the utility model includes the crystal oscillator thick film circuit embodiment one of real-time clock RTC chip;

Fig. 2 is the axonometric projection synoptic diagram of described crystal oscillator thick film circuit embodiment two;

Fig. 3 is the horizontal cross-sectional schematic of the described crystal oscillator thick film circuit of Fig. 1 embodiment one;

Fig. 4 is vertical cross-sectional schematic of the described crystal oscillator thick film circuit of Fig. 1 embodiment one;

Fig. 5 is vertical cross-sectional schematic of described crystal oscillator thick film circuit embodiment three;

Fig. 6 is vertical cross-sectional schematic of described crystal oscillator thick film circuit embodiment four;

Fig. 7～Figure 12 is the axonometric projection synoptic diagram of described crystal oscillator thick film circuit assembling technology procedure;

Figure 13 is the electric functional-block diagram of described crystal oscillator thick film circuit;

Figure 14 is the internal electrical functional-block diagram of described crystal oscillator thick film circuit.

[embodiment]

Below in conjunction with each accompanying drawing the utility model is described in further detail.

Embodiment one:

Referring to Fig. 1, Fig. 3, Fig. 4, Figure 13 and Figure 14, a kind of crystal oscillator thick film circuit that includes real-time clock RTC chip, comprise the quartz-crystal resonator 15 and the real-time clock RTC chip 20 that are used to control oscillation frequency, the circuit of this RTC chip 20 is formed and is comprised the digital temperature compensated oscillator DTCXO that contains temperature sensor, these RTC chip 20 typical models are the EM3027 that is produced by Swatch Group (Swatch Group) at present, and some other company of RTC chip of this EM3027 model also produces; This crystal oscillator thick film circuit also comprises printing board PCB 30 and many pieces of pins 40; Described crystal resonator 15 and RTC chip 20 all are arranged on described printing board PCB 30 with one side, and are electrically connected with it and are electrically connected mutually; 40 of described each pins are drawn after this printing board PCB 30 is electrically connected respectively; Described RTC chip 20 is arranged on the described printing board PCB 30, be that nude film with this RTC chip 20 is welded on the described PCB30, protective seam 50 coverings that organic material forms are sprayed on its surface, the material of this protective seam 50 mainly is the glue class, also can not establish protective seam, decide on production environment and requirement; The root 41 of described crystal resonator 15, RTC chip 20, printing board PCB 30 and each pin 40 all is packaged into the one device with engineering plastics, and promptly the root 41 at described crystal resonator 15, RTC chip 20, printing board PCB 30 and each pin 40 has all been wrapped up one deck engineering plastics protective seam 60 by integral body.Described printing board PCB 30 comprises that material is common single or multiple lift wiring board, FPC (flexible PCB, the abbreviation of F1exible Printed Circuit) and ceramic wafer etc.

Described pin 40 comprise at least SCL, FOUT output frequency, Vdd, FOE, SDA, GND ,/INT and VBACK.Pin described in the present embodiment 40 has 14 pieces, except SCL, FOUT, Vdd, FOE, SDA, GND ,/INT and eight pieces of pins of VBACK, also have six pieces of empty pins, i.e. NC pin.After packed, described each pin 40 is shaped to SOP (little profile shell encapsulation, the abbreviation of small out-line package) type.

Embodiment two:

Referring to Fig. 2, a kind of crystal oscillator thick film circuit that includes real-time clock RTC chip, basic identical with embodiment one, difference is: after packed, described each pin 40 is shaped to SOJ (the little external form encapsulation of plastics J-shaped pin, the abbreviation of small out-line J-Leaded package, pin are drawn from the encapsulation both sides and are the J font downwards) type.

Embodiment three:

Referring to Fig. 1 and Fig. 5, a kind of crystal oscillator thick film circuit that includes real-time clock RTC chip, basic identical with embodiment one, difference is: described crystal resonator 15 and RTC chip 20 are separately positioned on the positive and negative two sides of described printing board PCB 30.

Embodiment four:

Referring to Fig. 1 and Fig. 6, a kind of crystal oscillator thick film circuit that includes real-time clock RTC chip, basic identical with embodiment one, difference is: described printing board PCB 30 is provided with the through hole 31 that holds described crystal resonator 15, described crystal resonator 15 is arranged in the through hole 31 of described printing board PCB 30, promptly adopt broken board-like printing board PCB, crystal resonator 15 is placed on the centre that this breaks board-like printing board PCB, can reduces the whole height H in packed back like this.Described RTC chip 20 can be arranged on any one side on described printing board PCB 30 positive and negative two sides.

The technological process that the utility model includes the crystal oscillator thick film circuit of real-time clock RTC chip is described below simply:

One; the fixed described RTC chip 20 of nation on described printing board PCB 30: referring to Fig. 3; Fig. 4; Fig. 7 and Fig. 8; make a printed circuit board PCB 30; the fixed described RTC chip 20 of nation on this printing board PCB 30; nation is the transliteration of English " bonding " surely; it is the mode of a kind of routing in the chip production technology; the flow process of technology is that good after tested described RTC chip 20 is implanted on the described printing board PCB 30; use gold (or other metal) line that each pin of described RTC chip 20 is connected on the described printing board PCB 30 then; the organic material that will have the special protection function after will melting again covers on the described RTC chip 20; form protective seam 50, in order to protect described RTC chip 20.

Two, the described crystal resonator 15 of welding on described printing board PCB 30: referring to Fig. 3 to Fig. 6 and Fig. 9, the described crystal resonator 15 of welding perhaps makes the pin of described crystal resonator 15 be electrically connected with described RTC chip 20 by nation surely on described printing board PCB 30; Described crystal resonator 15 is according to the design attitude of described printing board PCB 30 and the thickness needs of whole finished product, can be welded on one side (seeing Fig. 3, Fig. 4 and Fig. 9) with described RTC chip 20, or positive and negative two sides (see figure 5), also can adopt brokenly board-like printed circuit board (PCB) 30, crystal resonator 15 is placed on the middle (see figure 6) that this breaks board-like printed circuit board (PCB), can reduces the whole height H in packed back like this.

Three, described each pin 40 of welding on described printing board PCB 30:, dual mode is arranged referring to Fig. 3, Figure 10 and Figure 11:

First kind is to adopt the downhand welding mode, referring to Fig. 3 and Figure 11, is about to described each pin 40 and lies on the described printing board PCB 30, makes them be fixed on the described printing board PCB 30 by welding then and forms path;

The second way be with described each pin 40 insert perforate described printing board PCB 30 on, make them be fixed on the described printing board PCB 30 by welding then and form path, referring to Figure 11.

Four, encapsulation: referring to Fig. 3 and Figure 12, the whole element of described each pin 40 will be welded, be placed on and carry out plastic packaging in the mould, the root 41 of described crystal resonator 15, RTC chip 20, printing board PCB 30 and each pin 40 all is packaged into the one device with engineering plastics, and promptly the root 41 at described crystal resonator 15, RTC chip 20, printing board PCB 30 and each pin 40 has all been wrapped up one deck engineering plastics protective seam 60 by integral body;

Five, described each pin 40 moulding: referring to Fig. 1 and Fig. 2, packaged element is carried out pin be shaped, the pin after general the shaping has following two kinds of forms, SOP type (referring to Fig. 1) and SOJ shape (referring to Fig. 2), certainly also can be pin being configured as other shape, so that meet client's needs.

The above embodiment has only expressed preferred implementation of the present utility model, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the utility model claim; Should be pointed out that for the person of ordinary skill of the art, under the prerequisite that does not break away from the utility model design, can also make some distortion and improvement, for example pin is configured as other shape, these all belong to protection domain of the present utility model; Therefore, all equivalents and modifications of being done with the utility model claim scope all should belong to the covering scope of the utility model claim.

Claims

1. crystal oscillator thick film circuit that includes real-time clock RTC chip, comprise the quartz-crystal resonator (15) and the real-time clock RTC chip (20) that are used to control oscillation frequency, the circuit of this RTC chip (20) is formed and is comprised the digital temperature compensated oscillator DTCXO that contains temperature sensor; It is characterized in that:

Also comprise printing board PCB (30) and many pieces of pins (40); Described crystal resonator (15) and RTC chip (20) all are arranged on the described PCB (30), and are electrically connected with it and are electrically connected mutually, and described each pin (40) is then drawn after this PCB (30) is electrically connected respectively; The root (41) of described crystal resonator (15), RTC chip (20), PCB (30) and each pin (40) all is packaged into the one device with engineering plastics.

2. the crystal oscillator thick film circuit that includes real-time clock RTC chip according to claim 1 is characterized in that:

Described RTC chip (20) is arranged on the PCB (30), is that the nude film with this RTC chip (20) is welded on the described PCB (30), and its surface is sprayed protective seam (50) that organic material forms and covered.

3. the crystal oscillator thick film circuit that includes real-time clock RTC chip according to claim 1 is characterized in that:

Described pin (40) comprise at least SCL, FOUT output frequency, Vdd, FOE, SDA, GND ,/INT and VBACK.

4. the crystal oscillator thick film circuit that includes real-time clock RTC chip according to claim 1 is characterized in that:

After packed, described each pin (40) is shaped to the SOP type.

5. the crystal oscillator thick film circuit that includes real-time clock RTC chip according to claim 1 is characterized in that:

After packed, described each pin (40) is shaped to the SOJ type.

6. according to each described crystal oscillator thick film circuit that includes real-time clock RTC chip of claim 1 to 5, it is characterized in that:

Described crystal resonator (15) and RTC chip (20) all are arranged on described PCB (30) with one side.

7. according to each described crystal oscillator thick film circuit that includes real-time clock RTC chip of claim 1 to 5, it is characterized in that:

Described crystal resonator (15) and RTC chip (20) are separately positioned on the positive and negative two sides of described PCB (30).

8. according to each described crystal oscillator thick film circuit that includes real-time clock RTC chip of claim 1 to 5, it is characterized in that:

Described PCB (30) is provided with the through hole (31) that holds described crystal resonator (15), and described crystal resonator (15) is arranged in the through hole (31) of described PCB (30).