CN201263268Y

CN201263268Y - Constant temperature crystal oscillator suitable for surface installation

Info

Publication number: CN201263268Y
Application number: CNU2008200503674U
Authority: CN
Inventors: 黄恭义; 林旭; 李晓云; 刘桂华
Original assignee: GUANGZHOU TIANMA TELECOM TECHNOLOGY Co Ltd
Current assignee: GUANGZHOU TIANMA TELECOM TECHNOLOGY Co Ltd
Priority date: 2008-07-08
Filing date: 2008-07-08
Publication date: 2009-06-24
Anticipated expiration: 2018-07-08

Abstract

The utility model discloses a constant temperature crystal oscillator applicable to surface mounting, which comprises a main board, a bottom board, a shield box and a contact pin; wherein the main board is connected with the bottom board through the contact pin; the shield box is arranged at the outside of the main board; components with large weight such as a crystal and a power tube are welded on the top surface of the main board; the contact pin is a tower-typed contact pin, which comprises a plurality of mounting sections with cross sections of different sizes. The constant temperature crystal oscillator is greatly improved in assembly structure, solves the problems of the existing structure that the main board is easy to slip when going through a reflow oven and the components with larger weight such as the crystal and the like separate from a heat conducting bonding pad, obviously reduces the reject rate of the product, improves the production stability better, produces more reliable products, facilitates batch production and improves production efficiency.

Description

Be applicable to the constant-temperature crystal oscillator of mounted on surface

Technical field

The utility model relates to the constant-temperature crystal oscillator technology, particularly a kind of constant-temperature crystal oscillator that is applicable to mounted on surface.

Background technology

Crystal oscillator (XO) is the indispensable main devices of modern communications equipment, for adapting to the growth requirement of modern communication technology, various types of crystal oscillators are (as temperature compensating crystal oscillator-TCXO, voltage controlled crystal oscillator-VCXO, voltage-controlled compensation crystal oscillator-VCTCXO) is chip type all, but high stable crystal oscillator one class is (as constant-temperature crystal oscillator, voltage-controlled constant-temperature crystal oscillator, the temperature compensation constant-temperature crystal oscillator, the voltage-controlled constant-temperature crystal oscillator of temperature compensation) bigger because of its volume, power consumption is big, the temperature height, all adopt copper lid or printed board (PCB) to be the plug-in mounting structure of base traditionally, wherein Fig. 1 is a copper cover base structure, Fig. 2 is the printed board understructure, principal character is: crystal, power tube, heavier components and parts such as potentiometer are welded on the bottom surface (non-surface) of mainboard, the contact pin that supports mainboard is the policy or the round needle of orthoscopic, contact pin one end passes pad hole on the mainboard, soldering connects then, the contact pin other end is welded on the base plate contact pin pad, this kind structure generally is applied to non-mounted on surface (as plug-in mounting), as this structure is directly applied in the mounted on surface, when crossing reflow ovens, because of contact pin two ends scolding tin can melt, the weight of mainboard makes it the landing phenomenon can occur when crossing reflow ovens, the pad phenomenon also can appear breaking away from the heavier components and parts such as crystal of mainboard bottom surface, so product reliability is relatively poor.Along with the development of electron surface mounting technique with popularize, increasing communications equipment manufacturer has proposed the mounted on surface requirement to the high stable crystal oscillator as constant-temperature crystal oscillator (OCXO), voltage-controlled constant-temperature crystal oscillator (VCOCXO), temperature compensation constant-temperature crystal oscillator (TCOCXO), the voltage-controlled constant-temperature crystal oscillator of temperature compensation (TCVCOCXO) etc.In order to improve the reliability of assembling, need do bigger improvement to existing constant-temperature crystal oscillator package assembly.

The utility model content

The shortcoming that the purpose of this utility model is to overcome prior art provides a kind of rational in infrastructure, easy for installation, reliability height, the constant-temperature crystal oscillator of being convenient to produce in batches that is applicable to mounted on surface with not enough.

The purpose of this utility model is achieved through the following technical solutions: a kind of constant-temperature crystal oscillator that is applicable to mounted on surface, comprise mainboard, base plate, shielding box, contact pin, mainboard is connected by contact pin with base plate, shielding box is arranged at the mainboard outside, it is characterized in that: the components and parts dress that weight such as crystal, power tube, potentiometer are big is welded in described mainboard end face; Described contact pin is tower contact pin, comprises a plurality of construction sections that cross-sectional sizes is different.

Described tower contact pin is the round needle of tower structure, comprise top fine needle, middle part, bottom fine needle, described bottom fine needle inserts in the pad hole of base plate, and the top fine needle is inserted in the pad hole of mainboard, the diameter of middle part is bigger than upper and lower pad hole, guarantees that mainboard can landing.The bottom fine needle of tower contact pin and the pad hole of base plate are interference fits or interference fit, must firmly be pressed into, and make the bottom fine needle be close to the base plate pad, with flatiron both are welded again; The pad hole of described top fine needle and mainboard is a matched in clearance, and mainboard easily is inserted in.

Be to adapt to the SMT packaging technology, change the PCB base of traditional copper cover base or plug-in mounting structure into sheet PCB base plate, the bottom surface of described sheet PCB base plate is provided with the PCB pad, and the function of constant-temperature crystal oscillator brings out pin and is connected with the PCB pad; When the user used this constant-temperature crystal oscillator, welding (promptly realizing mounted on surface) can fit described PCB pad and the corresponding pad of its product (as clock board).

Every limit of one group of opposite side of described shielding box is provided with salient point and spill mouth, and described salient point stretches out the edge of shielding box, is used for and the welding of base plate location; Described spill mouth is convenient to pin pad cabling, this design is greatly simplified the design of the base plate (PCB) that is mated, and has both avoided the multi-layer sheet design, makes things convenient for shielding box fixed point soldering and silica gel sealing again, the shielding box displacement played position-limiting action to it in the time of also can preventing reflow ovens.

This surface installation structure is applicable to various high stable crystal oscillators, as OCXO, and VCOCXO, TCOCXO, TCVCOCXO etc.

The utility model has following advantage and beneficial effect with respect to prior art: (1) the utility model is done bigger improvement on package assembly, solved existing structure the phenomenon that mainboard landing and crystal break away from thermal land has taken place when crossing reflow ovens easily, the percent defective of product is obviously reduced, improved the stability of producing preferably, the product reliability of being produced is better.(2) the utility model is handled the same SMT technology that all adopts of pliotron, crystal and other electron component, can conveniently produce in batches, enhance productivity, and high conformity.

Description of drawings

Fig. 1 is the copper cover base plug-in mounting structure schematic diagram of existing constant-temperature crystal oscillator.

Fig. 2 is the printed board base plug-in mounting structure schematic diagram of existing constant-temperature crystal oscillator.

Fig. 3 is the structural representation of the utility model constant-temperature crystal oscillator.

Fig. 4 is that the mainboard end face thermostat device of constant-temperature crystal oscillator shown in Figure 3 pastes weldering figure.

Fig. 5 is that the mainboard bottom surface components and parts of constant-temperature crystal oscillator shown in Figure 3 paste weldering figure.

Fig. 6 is that the plate top surface components and parts of constant-temperature crystal oscillator shown in Figure 3 paste weldering figure.

Fig. 7 is that the base plate bottom surface of constant-temperature crystal oscillator shown in Figure 3 goes out pin pad figure.

Fig. 8 is the tower contact pin structural representation of constant-temperature crystal oscillator shown in Figure 3.

Fig. 9 is the tower contact pin structure end view of constant-temperature crystal oscillator shown in Figure 8.

Figure 10 is the shielding box structure schematic diagram of constant-temperature crystal oscillator shown in Figure 3.

Embodiment

Below in conjunction with drawings and Examples the utility model is described in further detail.

Embodiment 1

Fig. 3～Figure 10 shows concrete structure of the present utility model, and as seen from Figure 3, this constant-temperature crystal oscillator comprises mainboard 1, base plate 2, shielding box 3, contact pin 4, and mainboard 1 is connected by contact pin 4 with base plate 2, and shielding box 3 is arranged at mainboard 1 outside.

The structure of described mainboard 1 is seen Fig. 4 and Fig. 5, and mainboard 1 is a pcb board, adorns at the end face of mainboard 1 and is welded with the bigger components and parts of weight: crystal 5, pliotron 6, potentiometer 7; The (see figure 4)s such as debugging element that also have temperature-control circuit, main vibration circuit and temperature compensation network in the weldering of mainboard 1 end face dress; The components and parts that weld are pasted in mainboard 1 bottom surface the components and parts of the non-debugging element of main vibration circuit and temperature compensation network, frequency-selecting amplification, voltage stabilizing circuit, also has the (see figure 5)s such as part components and parts of shaping output stage; This structure has improved reliability, has avoided the phenomenon of heavier components and parts disengaging such as crystal 5 and pliotron 6 thermal land when crossing reflow ovens to take place.

The structure of described base plate 2 is seen Fig. 6 and Fig. 7, wherein: Fig. 6 is that base plate 2 end face elements paste weldering figure, the components and parts that paste weldering have the output IC and the EMI circuit element of shaping output stage, sheet base plate (PCB) replaces the traditional copper cover base or the PCB base of plug-in mounting structure, and base plate 2 is provided with pad hole 9, the semicircle plated-through hole 10 of contact pin pad hole 8, shielding box salient point insertion base plate; Fig. 7 is base plate 2 bottom surface pad figure, crystal oscillator goes out footnote and knows the bottom surface that is arranged on base plate 2, go out the PCB pad that pin pad 11 adopts the bar shaped of half round cut, each goes out pin pad 11 and brings out pin by semicircle plated-through hole 10 with the function of the constant-temperature crystal oscillator of the end face of base plate 2 and be connected.

Described contact pin 4 is the round needle of tower structure, structure is seen Fig. 8, wherein Fig. 9 is the tower contact pin structure end view of constant-temperature crystal oscillator shown in Figure 8, comprise a plurality of construction sections that cross-sectional sizes is different, be respectively top fine needle 4-1, middle part 4-2, bottom fine needle 4-3, described bottom fine needle 4-3 inserts in the contact pin pad hole 8 of base plate 2, and top fine needle 4-1 is inserted in the pad hole of mainboard 1, the diameter of middle part 4-2 is bigger than upper and lower pad hole, guarantees that mainboard 1 can landing; The bottom fine needle 4-3 of tower contact pin and the contact pin pad hole 8 of base plate 2 are interference fits or interference fit, must firmly be pressed into, and make bottom fine needle 4-3 be close to the base plate pad, with flatiron both are welded again; The pad hole of described top fine needle 4-1 and mainboard 1 is a matched in clearance, makes mainboard 1 be easy to be inserted in, the convenient installation.

Described shielding box 3 as shown in figure 10, every limit of one group opposite side is provided with salient point 3-1 and spill mouth 3-2, described salient point 3-1 stretches out the edge of shielding box 3, is used for location, pad hole 9 welding with base plate; Described spill mouth 3-2 is convenient to pin pad cabling, this design is greatly simplified the design of the base plate (PCB) that is mated, both avoided the multi-layer sheet design, made things convenient for shielding box 3 fixed point soldering and silica gel sealings again, the phenomenon of shielding box 3 displacements in the time of also can avoiding reflow ovens took place.

The foregoing description is the utility model preferred implementation; but execution mode of the present utility model is not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present utility model and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within the protection range of the present utility model.

Claims

1, a kind of constant-temperature crystal oscillator that is applicable to mounted on surface, comprise mainboard, base plate, shielding box, contact pin, mainboard is connected by contact pin with base plate, and shielding box is arranged at the mainboard outside, it is characterized in that: crystal, power tube, potentiometer dress are welded in described mainboard end face; Described contact pin is tower contact pin, comprises a plurality of construction sections that cross-sectional sizes is different.

2, the constant-temperature crystal oscillator that is applicable to mounted on surface according to claim 1, it is characterized in that: described tower contact pin is the round needle of tower structure, comprise top fine needle, middle part, bottom fine needle, described bottom fine needle inserts in the pad hole of base plate, the top fine needle is inserted in the pad hole of mainboard, and the diameter of middle part is bigger than upper and lower pad hole.

3, the constant-temperature crystal oscillator that is applicable to mounted on surface according to claim 2 is characterized in that: the pad hole of described bottom fine needle and base plate is interference fits or interference fit.

4, the constant-temperature crystal oscillator that is applicable to mounted on surface according to claim 2 is characterized in that: the pad hole of described top fine needle and mainboard is a matched in clearance.

5, the constant-temperature crystal oscillator that is applicable to mounted on surface according to claim 1 and 2 is characterized in that: every limit of one group of opposite side of described shielding box is provided with salient point and spill mouth, and described salient point stretches out the edge of shielding box, with the welding of base plate location.

6, the constant-temperature crystal oscillator that is applicable to mounted on surface according to claim 1 and 2, it is characterized in that: described base plate is a sheet PCB base plate, the bottom surface of described sheet PCB base plate is provided with the PCB pad, and the function of constant-temperature crystal oscillator brings out pin and is connected with the PCB pad.