CN206807850U

CN206807850U - PCB radiator structures based on QFN encapsulation

Info

Publication number: CN206807850U
Application number: CN201720603237.8U
Authority: CN
Inventors: 贯均; 林峰; 阴陶; 戴荣
Original assignee: CHENGDU FOURIER ELECTRONIC TECHNOLOGY Co Ltd; Shenzhen SDG Information Co Ltd
Current assignee: CHENGDU FOURIER ELECTRONIC TECHNOLOGY Co Ltd; Shenzhen SDG Information Co Ltd
Priority date: 2017-05-26
Filing date: 2017-05-26
Publication date: 2017-12-26
Anticipated expiration: 2027-05-26

Abstract

The utility model discloses a kind of PCB radiator structures based on QFN encapsulation, it includes PCB, pad and chip；The pad is arranged in the PCB one sides；The chip is arranged on the pad；The PCB is provided with through hole；Hot weld disk is provided with the PCB another sides；When the PCB is the PCB without radiator structure or without sealing conductive structure；Radiator is provided with the hot weld disk；Conversely, it is provided with radiating rubber cushion on the hot weld disk；Heat conduction is attached using the structural member of radiate rubber cushion and radiator structure or sealing conductive structure, rubber cushion will realize radiating by radiating in the heat transfer on PCB hot weld disks to the structural member.The first heat radiation structure design simple possible of the utility model, radiating do not interfere with the size of pcb board effectively, under rational design yet.Second of radiator structure can be suitably used for the PCB radiatings of most of sealing QFN packagings.

Description

PCB radiator structures based on QFN encapsulation

Technical field

It the utility model is related to radiator structure technical field, and in particular to a kind of PCB radiator structures based on QFN encapsulation.

Background technology

PCB (Printed Circuit Board), Chinese is printed circuit board, also known as printed substrate, is important Electronic unit, be electronic component supporter, be electronic component electrical connection carrier.

QFN (Quad Flat No-lead Package, quad flat non-pin package) is that a kind of pad size is small, body Product emerging surface mount chip encapsulation technologies small, using plastics as material.The bottom device center big exposure of QFN encapsulation Pad can be soldered on PCB hot weld disk, and caused heat can be direct by chip bottom hot weld disk at work for device Be transmitted on PCB and radiated, there is preferably electrically and thermally performance, can meet general cooling requirements, but due to power consumption compared with Big device can produce amount of heat when working, and the heat-sinking capability of pcb board in itself is limited, and heat will when device works long hours Constantly accumulation rises whole system temperature on pcb board, and high temperature can not only cause that system operation is unstable, component uses the longevity Life shortens, it could even be possible to making thrashing.So directly it is generally adapted by the PCB methods to radiate smaller or short for power consumption The device of time service.

The effect of radiator is to absorb the heat of heat generating components, then diffuses to outside, keeps the temperature of heat generating components In a relatively low stability range.The radiating efficiency of the radiator and pyroconductivity of radiator, radiator material and heat eliminating medium Hot melt and the relating to parameters such as the effective area of dissipation of radiator.

Utility model content

The utility model overcomes the deficiencies in the prior art, there is provided a kind of PCB radiator structures based on QFN encapsulation.To The heat dissipation problem of big power consumption QFN packagings to be solved.

To solve above-mentioned technical problem, the utility model uses following technical scheme：

A kind of PCB radiator structures based on QFN encapsulation, it includes PCB, pad and chip；The pad is arranged on institute State in PCB one sides；The chip is arranged on the pad；The PCB is provided with through hole；Heat is provided with the PCB another sides Pad；

When the PCB is the PCB without radiator structure or without sealing conductive structure；Set on the hot weld disk There is radiator；

When the PCB is to have the PCB of radiator structure or sealing conductive structure；It is provided with the hot weld disk Radiate rubber cushion；Heat conduction is attached using the structural member of radiate rubber cushion and radiator structure or sealing conductive structure, passes through thermal paste Pad will radiate in the heat transfer on PCB hot weld disks to the structural member to realize.

Further technical scheme is that welding manner is provided with radiator on described hot weld disk.

Further technical scheme is that boss is provided with described structural member, and the boss connects with the radiating rubber cushion Touch, for heat transfer.

Further technical scheme is that described radiator back is interdigitated electrode structure structure.

Compared with prior art, one of beneficial effect of the utility model embodiment is：The utility model is directed to big power consumption Heat dissipation problem of the QFN packagings under two kinds of different use environments solved.The first heat sink conception is not for tying The pcb board of component or sealing device, weld one again on the basis of PCB conducts heat through hole and PCB hot weld disks and be of moderate size, tie Structure, the radiator of compatible materials increase the area of dissipation of pcb board, are effectively radiated for the big QFN packagings of caloric value. The design and implementation simple possible of the program, radiating do not interfere with the size of pcb board effectively, under rational design yet, can fitted PCB for most of QFN packagings radiates.Second heat sink conception, which is directed to, itself has structural member or sealing device Pcb board, QFN is made full use of to encapsulate good hot property i.e. chip bonding pad, heat transfer through hole and hot weld disk to carry out heat transfer, then profit Effectively radiated with structural member boss and radiating rubber cushion.The design and implementation simple possible of the heat sink conception, radiating effect Well, being radiated in itself using structural member does not influence the size of structural member and PCB, can be suitably used for most of sealing QFN encapsulation The PCB radiatings of device.

Brief description of the drawings

Fig. 1 is QFN packaging positive structure schematics in the utility model embodiment 1.

Fig. 2 is the utility model Fig. 1 A-A to sectional view.

Fig. 3 is the heat spreader structures schematic diagram of the utility model embodiment 1.

Fig. 4 is QFN packaging positive structure schematics in the utility model embodiment 2.

Fig. 5 is the utility model Fig. 4 A-A to sectional view.

Embodiment

All features disclosed in this specification, or disclosed all methods or during the step of, except mutually exclusive Feature and/or step beyond, can combine in any way.

Any feature disclosed in this specification (including any accessory claim, summary and accompanying drawing), except non-specifically chatting State, can alternative features equivalent by other or with similar purpose replaced.I.e., unless specifically stated otherwise, each feature It is an example in a series of equivalent or similar characteristics.

Below in conjunction with the accompanying drawings and specific embodiment of the present utility model is described in detail embodiment.

In the following detailed description, many specific descriptions are described for illustrative purposes so as to thoroughly understand institute Disclosed embodiment, it is clear, however, that one or more embodiments can be in the case of without using these specific descriptions Implement, in other instances, known structure and device are schematically shown, to simplify accompanying drawing.

Embodiment 1

As shown in Figure 1 to Figure 3, according to one embodiment of the present utility model, the present embodiment discloses a kind of based on QFN encapsulation PCB radiator structures, QFN is a kind of leadless packages, and there is the exposed pad of a large area package bottom middle position, had The effect of heat conduction, the conductive welding disk for realizing electrical connection is with outside the encapsulation of big pad.Because QFN is encapsulated unlike traditional SOIC and TSOP encapsulation have gull wing lead like that, and the conductive path between internal pin and pad is short, electrodynamic capacity and Routing resistance is very low in packaging body, so, it can provide the electrical property of brilliance.In addition, it is also welded by exposed lead frame Disk provides outstanding heat dispersion, and the pad has the passage directly to radiate, for discharging the heat in encapsulation.By hot weld disk Be directly welded on circuit board, the dissipating vias on PCB by device work caused by heat be transmitted to the hot weld disk at the PCB back sides.

Specifically, as shown in Figure 1 to Figure 3, PCB1, weldering should be included based on the foundation structure of the PCB radiator structures of QFN encapsulation Disk 2 and chip 3；The pad 2 is arranged in the PCB1 one sides；The chip 3 is arranged on the pad 2；The PCB Provided with through hole 5；Hot weld disk 4 is provided with the PCB1 another sides；When the PCB is without radiator structure or without sealing conductive structure PCB when；The present embodiment is provided with radiator 6 on the hot weld disk；Preferably, the present embodiment welds radiator 6 It is connected on hot weld disk 4, radiator is directly welded on hot weld disk, is caused using this mode is welded between radiator and pad Thermal resistance is minimum, and the heat on hot weld disk rapidly can be directly transferred on radiator, recycles radiator to be radiated.Welding Radiator there is the characteristics of small volume area of dissipation is big, heat can be dissipated rapidly by convection current and radiation two ways, Make the temperature of hot weld disk reduce, so that the temperature of QFN packagings reduces, avoid the too fast temperature of big power consuming devices heating too high Cause device job insecurity or failure.

It can be seen from figure 1 that the QFN packagings do not have gull wing leads, device center has what large area exposed Pad, there is corresponding hot weld disk in PCB bottom designs, the via for having heat transfer between PCB bottoms and chip bonding pad can Rapidly to conduct heat, the present embodiment is welded with radiator on hot weld disk, is radiated rapidly eventually through radiator.

Further, as shown in Figure 3, it is preferred that radiator is interdigitated electrode structure structure in the present embodiment, and program chips are produced Raw heat can be transmitted to pcb board by the pad of chip bottom, heat can also be transmitted into PCB bottoms by the via that conducts heat Hot weld disk, then heat is transmitted to by pcb board and connected radiator by hot weld disk.Improving radiating efficiency can be to high-power QFN packagings are effectively radiated.

Embodiment 2

As shown in Figure 4 and Figure 5, it is a kind of in the present embodiment to be encapsulated based on QFN according to another embodiment of the present utility model PCB radiator structures, PCB1, pad 2 and chip 3 should be included based on foundation structure of PCB radiator structures of QFN encapsulation；Institute Pad 2 is stated to be arranged in the PCB1 one sides；The chip 3 is arranged on the pad 2；The PCB is provided with through hole 5；It is described Hot weld disk 4 is provided with PCB1 another sides；When the PCB is to have the PCB of radiator structure or sealing conductive structure；This Confined space in the case of kind where pcb board is detrimental to radiating, typically to carry out heat loss through conduction using structural member.At this moment Pcb board be in sealing or relatively closed space in, rely only on air radiating, or by pcb board directly and structural member Contact can all have larger thermal resistance so that heat conduction is slow and is easily accumulated on pcb board, causes the too high influence device of heat Part and system work.So radiating method will be considered simultaneously in design structure.

The present embodiment is provided with radiating rubber cushion 7 on the hot weld disk；Using radiating, rubber cushion is led with radiator structure or sealing The structural member of heat structure is attached heat conduction, by the rubber cushion that radiates by the heat transfer on PCB hot weld disks to the structural member To realize radiating.Further, boss is provided with structural member, the boss contacts with the radiating rubber cushion, for heat transfer. Specifically, structural member described in the present embodiment is encapsulating housing 8, radiating boss 9, radiating boss 9 are provided with encapsulating housing 8 Contacted with radiating rubber cushion, by the heat transfer of radiate rubber cushion and radiating boss, realize good radiating effect.

The present embodiment designs boss on the corresponding structural member of the larger QFN packagings of power consumption, then passes through thermal paste Connection PCB Base Heat pad and structural member boss are padded, is radiated using structural member.QFN encapsulation inherently has preferably heat Performance, what the pad of its chip bottom can be quickly conducts heat to pcb board, and the hot weld disk and can of pcb board is rapidly by dissipating Hot glue pad conducts heat to the boss of structural member, and heat can be transmitted to whole knot by boss well as a part for structural member Component.The area of dissipation of structural member in itself, can be good at conducting heat caused by big power consuming devices much larger than PCB, QFN device is effectively radiated, ensures stabilization, the effective and lasting work of device and system.

The first heat sink conception of the utility model above-described embodiment 1, for no structural member or the PCB of sealing device Plate, welded again on the basis of PCB conducts heat through hole and PCB hot weld disks one be of moderate size, the radiator of structure, compatible materials increases Add the area of dissipation of pcb board, effectively radiated for the big QFN packagings of caloric value.The design and implementation letter of the program Single feasible, radiating does not interfere with the size of pcb board effectively, under rational design yet, can be suitably used for most of QFN packagings PCB radiating.

Second of heat sink conception of the utility model above-described embodiment 2, for itself having structural member or sealing device Pcb board, make full use of QFN to encapsulate good hot property i.e. chip bonding pad, heat transfer through hole and hot weld disk to carry out heat transfer, then Effectively radiated using structural member boss and radiating rubber cushion.The design and implementation simple possible of the heat sink conception, radiating effect Fruit is good, and being radiated in itself using structural member does not influence the size of structural member and PCB, can be suitably used for most of sealing QFN envelopes Fill the PCB radiatings of device.

" one embodiment " for being spoken of in this manual, " another embodiment ", " embodiment " etc., refer to combining Specific features, structure or the feature of embodiment description are included at least one embodiment of the application generality description. It is not necessarily to refer to same embodiment that statement of the same race, which occur, in multiple places in the description.Furthermore, it is understood that with reference to any When individual embodiment describes a specific features, structure or feature, what is advocated is this to realize with reference to other embodiment Feature, structure or feature also fall in the scope of the utility model.

Although reference be made herein to the utility model is described multiple explanatory embodiments of utility model, still, should The understanding, those skilled in the art can be designed that a lot of other modifications and embodiment, and these modifications and embodiment will Fall within spirit disclosed in the present application and spirit.More specifically, in the model of disclosure, drawings and claims In enclosing, a variety of variations and modifications can be carried out to the building block and/or layout of theme combination layout.Except to building block And/or outside the variations and modifications of layout progress, to those skilled in the art, other purposes also will be apparent.

Claims

1. a kind of PCB radiator structures based on QFN encapsulation, it includes PCB (1), pad (2) and chip (3)；The pad (2) it is arranged in the PCB (1) one side；The chip (3) is arranged on the pad (2)；The PCB (1) is provided with through hole (5)；Hot weld disk (4) is provided with PCB (1) another side；It is characterized in that：

When the PCB (1) is the PCB without radiator structure or without sealing conductive structure；Set on the hot weld disk (4) It is equipped with radiator (6)；

When the PCB (1) is to have the PCB of radiator structure or sealing conductive structure；Set on the hot weld disk (4) There is radiating rubber cushion (7)；Heat conduction is attached using the structural member of radiate rubber cushion and radiator structure or sealing conductive structure, by dissipating Hot glue pad will radiate in the heat transfer on PCB hot weld disks to the structural member to realize.

2. the PCB radiator structures according to claim 1 based on QFN encapsulation, it is characterised in that on described hot weld disk (4) Radiator (6) is provided with by welding manner.

3. the PCB radiator structures according to claim 1 based on QFN encapsulation, it is characterised in that set on described structural member Boss (9) is equipped with, the boss (9) contacts with the radiating rubber cushion, for heat transfer.

4. the PCB radiator structures according to claim 1 based on QFN encapsulation, it is characterised in that described radiator back For interdigitated electrode structure structure.