It can reflow formula Thermal Cutoffs
Technical field
The present invention relates to one kind can reflow formula Thermal Cutoffs, metal surface pasting type electronic device, especially it is a kind of pressing-
Activation can reflow formula Thermal Cutoffs.
Background technique
Circuit protecting assembly is often brought protection power electronic product at present, enable the circuits of these products in due course with mistake
The current circuit of miss effect, which disconnects, to be protected.Under the premise of the circuit protection demand of these products, many excess temperatures or excessively electric
Stream protection device is come in by application.This measure is also the guarantee that power electronic product brings safety and reliability.For example, this protection electricity
Road can be used to protect and avoid the failure of automotive engine control mould group, or even prevent fire caused by power circuit failure.
Thermal Cutoffs is one kind of circuit protecting element.The somewhat similar traditional glass tube of the function of Thermal Cutoffs is protected
Dangerous silk.In a normal operating conditions, Thermal Cutoffs fusible portion connection both ends form conducting, and super in erroneous condition
When crossing critical-temperature, the fusible portion of the Thermal Cutoffs disconnects forming open-circuit.When temperature is lower than or is more than stagnation temperature
When spending, Thermal Cutoffs is just converted in conducting with two states are disconnected.That is, due to overcurrent or neighbouring component failure
Heating will be so that the Thermal Cutoffs will switch to non-conduction or disconnected when temperature reaches specific critical temperature from state
Line state.
Facilitate this conversion, it can seem conducting wire or connection cover that Thermal Cutoffs, which has to comprising a conduct piece,
The metal or other metals that are in contact of cap or immersion tin, these conduct pieces can be converted into from state it is non-conduction or
Off state.The structure of Thermal Cutoffs also contains temperature sensing part.The physical state of this temperature sensing part changes meeting and its
Operating temperature is related.For example, what this temperature sensing part can be melted by the metal or discrete (discrete) of a kind of low melting point
Organic compound is constituted, and can be melted in a specific critical temperature.When this temperature sensing part, which melts, changes its physical state, can allow
The conductive path of Thermal Cutoffs disconnects so that switching to non-conduction or off state from state.
In actual use operation, electric current can flow through fuse fusible portion, face once temperature sensing part reaches specific
Boundary's melting temperature can make Thermal Cutoffs be converted into open circuit or nonconducting state from state.The one of existing Thermal Cutoffs
Item is the disadvantage is that the factor in relation to heat.Temperature sensing part especially careful must be avoided to reach when being assembled in circuit board and change its physics
The melting temperature of state.Using traditional glass tube fuse just without the puzzlement of this heat, because fuse holder is to weld in advance
Up, it is inserted into fuse and fuse holder itself and the heat for not being afraid of wave crest or fluid welding.But if being in the Reflow Soldering of SMT technology
Thermal Cutoffs, the temperature sensing part that just especially careful must avoid Thermal Cutoffs reach the melting temperature for changing its physical state
Degree.As a result, old Thermal Cutoffs can not become reflowable weldering, it is because being assembled into the mistake on plank in Reflow Soldering
Journey, temperature can be more than the specific critical melting temperature of temperature sensing part, disconnect Thermal Cutoffs and nothing too early from state
Method uses.
The implementation method of Thermal Cutoffs is usually made pin form and needs special be handled with care and also uncomfortable
Close Reflow Soldering mode, thus can reflow formula Thermal Cutoffs be in response to and give birth to.In general, Thermal Cutoffs includes a conduction
Element can hold current-carrying flowing and an elastic element is suitable for applied force in transport element.In some embodiments, the conduction
Element can combine a sensing element.When temperature is more than sensing element threshold value or fusion temperature, sensing element, which can soften, loses bullet
Property, it is allowed to become easily-deformable or fracture by the power for being applied to transport element by elastic element.Finally, the transport element is in machinery
It can be disconnected under the action of power and lead to open-circuit condition.The heat born in reflow process may be such that sensing element loses
It goes elasticity and disconnects.So to allow sensing element not turn off in reflow process, and produced from neighbouring device failure or overcurrent
Raw heat and sensing element must be allowed to disconnect, this is conflicting.It, then can reflow formula temperature guarantor in order to overcome the above problem
Dangerous silk is developed.
Application number: 201310112330.5, which provide a kind of leakproofness by improving Thermal Cutoffs, to minimize
Thermal Cutoffs.Thermal Cutoffs includes: basement membrane;By a pair arranged opposite in such a way that interval is arranged in top end part on basement membrane
Band-like portion of terminal;The fusable links engaged in a manner of bridge joint between a pair of end sub-portion;Coated in the fluxing agent in fusable links;With
And the covering film being arranged in a manner of covering the fusable links for being coated with fluxing agent, at least on the length direction of Thermal Cutoffs
The encapsulation part of extension is cut off between the interior acies and outer edge of encapsulation part, also, the basement membrane on its section and covering are thin
Film carries out welding again.
United States Patent (USP) US8,289,122 and US 8,581,686 disclose one kind can reflow formula Thermal Cutoffs, apply
One group of suppressing part, the pulling force of the suppressing part can ensure that the position for keeping the elastic component to be fixed on script during reflux is welded process
It sets, elastic component when Reflow Soldering is avoided to force in conducting piece and disconnect.The shortcomings that this design is must be after Reflow Soldering assembling again
This Thermal Cutoffs could be activated by carrying out the step of once electrification disconnects suppressing part, thus will increase the complexity of OEM processing procedure.
Summary of the invention
Present invention aims at: provide one kind can reflow formula Thermal Cutoffs, do not need suppressing part come when preventing Reflow Soldering
It causes fuse to disconnect, blows this suppressing part without galvanization after the completion of Reflow Soldering.
The object of the invention pass through following proposal realize: one can reflow formula Thermal Cutoffs, belong to Thermal Cutoffs, include:
Conducting element contains first end and the second end;
One sensing element is connect with an end of conducting element, and when temperature is more than critical threshold values, softening or molten occurs
Change deformation;
One elastic element, is made of conductive material, applied to conducting element is forced in, at nominal conditions, makees according to elastic force
It is electrically connected with conducting element;
Activator button, for exerting a force to elastic element, when filling state at the beginning of Thermal Cutoffs, activator button is not first with elasticity
Part contact;After finishing assembly, activator button is pressed and forces on elastic element, and Thermal Cutoffs is made to be in activation shape
State, and in failure conditions, conducting element is disconnected by elastic element;
With the several weld pads for forming electrical connection with external circuitry, such as two or more, at least the first weld pad and the second weldering
Pad is separately connected first end, the second end of conducting element, and it is empty that the accommodating that the cover is formed in conjunction with pedestal inside one is arranged in
In;
Wherein, the sensing element is more than a critical threshold values when being looped around Thermal Cutoffs ambient temperature, is pressed by activation
Button is depressed into elastic element and is transmitted through the elastic force come so that transport element disconnects.
The present invention realizes the activation of Thermal Cutoffs by an activator button, can not only simplify weld pad design and packaging technology
Fabrication steps, and device reliability can be improved.
The working principle of the invention is: elastic element in active state can applied force in transport element, the elasticity
Element normal condition in Reflow Soldering assembling process can apply a power, and the conducting element is combined;And it is different
The transport element of Thermal Cutoffs of the separating force under state of activation can be applied in the elastic element used in the prior art.
After Reflow Soldering, activator button is just pressed and applied force is in the elastic element, and making can reflow formula Thermal Cutoffs
Into state of activation.When heating up under encountering such as high temperature or overcurrent generation or adjoining device due to fault condition, activation is pressed
The power of the be applied to elastic element of button can be allowed to disconnect with the first and second ends of conducting element and be electrically connected.
On the basis of above scheme, the elastic element is the reed lifted up or arch bridge shape, and one end, which is fixedly connected, leads
One end of electric device, the other end are supported with sensing element elasticity, and the end through sensing element and another conducting element is electrical
Connection.
On the basis of above scheme, scolding tin or other gold of the sensing element by fusing point between 70 DEG C~250 DEG C
Belong to composition of alloy.
On the basis of above scheme, the weld pad is fixed on the base, and the pedestal be also used to carry it is electrical with weld pad
Conducting element, elastic element and the sensing element of connection, constitute shell by pedestal and the cover, with the cover come with external insulation and prop up
Support activator button.
On the basis of above scheme, the pedestal is via nail hook, gluing and/or supersonic welding in conjunction with the cover.
On the basis of above scheme, the activator button that supports in the cover is to be separately implantable, or through two support arm edges
Groove extends or is directly built in inside the cover on the inside of the cover.
On the basis of above scheme, the activator button includes the protrusion or intaglio of two fragment positions, to be fixed on
Two states, i.e. assembled state and state of activation.
On the basis of above scheme, the weld pad at least partially exposes shell, is welded on pcb board or panel.
On the basis of above scheme, the first end of the conducting element and the first weld pad are electrically connected;The second end
With and the second weld pad be electrically connected.
On the basis of above scheme, first weld pad and the second weld pad extend external metallization electrode.
If high temperature fault condition leads to the fusing of sensing element, this will disconnect the first end and of elastic conductive component
Connection between two ends, and can therefore disconnect the connection between the first weld pad and the second weld pad.
After Reflow Soldering, activator button can be pressed via thumb or tool or certain mechanically actuateds, therefore not need
The operating procedure of the similar straining element that fused in the past by electric current.
It is of the invention to be advantageous in that: can effectively to simplify the assembling process of reflow formula Thermal Cutoffs, and also mention
The high reliability of product.
Detailed description of the invention
Fig. 1 first embodiment of the invention can reflow formula Thermal Cutoffs in the section view of assembled state (activate it
Before);
Fig. 2 first embodiment of the invention can reflow formula Thermal Cutoffs in the section view of state of activation (press activation
After button);
Fig. 3 first embodiment of the invention can reflow formula Thermal Cutoffs its elastic element off-state in failure conditions
Section view;
Fig. 4 can reflow formula Thermal Cutoffs be assembled on pcb board and press activator button come activate can reflow formula temperature protect
The flow chart of dangerous silk;
Fig. 5 first embodiment of the invention can use in reflow formula Thermal Cutoffs activator button and elastic element block with
And elastic element disconnects situation in failure conditions;
Fig. 6 second embodiment of the invention can reflow formula Thermal Cutoffs its pedestal section view;
Fig. 7 second embodiment of the invention can reflow formula Thermal Cutoffs layered structure explanatory diagram;
Fig. 8 third embodiment of the invention can reflow formula Thermal Cutoffs its elastic element off-state in failure conditions
Section view, farther out, the break distance of elastic component is also longer for distance sensing part link position at activator button pushing;
Fig. 9 fourth embodiment of the invention can the section view of reflow formula Thermal Cutoffs its activator button extend two
Support arm can advance along inner wall trench, wherein Fig. 9 a, Fig. 9 b and Fig. 9 c are that activator button is in un-activation, activation but bullet respectively
Property part it is undeformed, and activation and elastic component deformation status diagram, the A-A diagrammatic cross-section of Fig. 9 aA-A system Fig. 9 a;
Figure 10 fourth embodiment of the invention can reflow formula Thermal Cutoffs dimensional decomposition structure signal;
Figure 11 fifth embodiment of the invention can reflow formula Thermal Cutoffs section view, wherein Figure 11 a, Figure 11 b and
Figure 11 c be respectively activator button be in un-activation, activation but elastic component it is undeformed or deformation it is smaller, and activation and elastic component become
Shape is greatly to the status diagram of open circuit;
Figure 12 fifth embodiment of the invention can reflow formula Thermal Cutoffs dimensional decomposition structure signal.
Specific embodiment
Below in conjunction with attached drawing be described in further detail can reflow formula Thermal Cutoffs, however, discussed in specific embodiment only
Illustrate specific product and manufacturing method, and how using the present invention, but is not used to limitation protection scope of the present invention.
Embodiment 1
As shown in Figure 1 for first embodiment of the invention can reflow formula Thermal Cutoffs assembled state section view.
One can reflow formula Thermal Cutoffs 100 include: the first end 110 and the second end 120 of conducting element;One sensing element 180,
It is connect with the first end 110 of conducting element, softening or fusing deformation occurs when temperature is more than critical threshold values;One elastic element
150, it is made of conductive material, applied to conducting element is forced in, at nominal conditions, is acted on according to elastic force conducting element is electrical
Connection;One activator button 130, for exerting a force to elastic element, when filling state at the beginning of Thermal Cutoffs, activator button 130 is not
It is contacted with elastic element 150, after finishing assembly, activator button 130 is pressed and forces on elastic element 150, makes temperature
Fuse is active, and in failure conditions, disconnects conducting element by elastic element 150;Have and external circuitry
Formed electrical connection first and second weld pad 141,142 respectively with the first end of conducting element 110 and the second end 120
Electrical connection;Wherein, the sensing element 180 is more than a critical threshold values when being looped around Thermal Cutoffs ambient temperature, by swashing
Button 130 living is depressed into elastic element 150 and is transmitted through the elastic force come so that transport element disconnects.150 one end of elastic element is fixed
The second end 120 of conducting element is connected, the other end is supported with 180 elasticity of sensing element, through sensing element 180 and conducting element
First end 110 be electrically connected.Sensing element 180 can be by leading with opposite low melting point or what specific temperature can follow the string
Electric material is made.Such as scolding tin or alloying metal.Can reflow formula Thermal Cutoffs 100 further include the cover 160 and pedestal 170,
Described first and second weld pad 141,142 is fixed to constitute shell by pedestal 170 and the cover 160 on the base, with the cover come
With external insulation and support activator button 130, which is also used to carry the conducting element first end with weld pad electrical connection
110 and the second end 120, elastic element 150 and sensing element 180.Pedestal 170 can be done via ejection formation or PCB technology
At.Pedestal 170 can be combined via nail hook, gluing and/or supersonic welding with the cover 160.The activator button supported in the cover 160
130 is are separately implantable, and activator button 130 includes the protrusion or intaglio of two fragment positions are assembled to be fixed on two states
State and state of activation.In following embodiments, the first and second end of conducting element 110,120, elastic element 150 also accordingly can be with
It is arranged on pedestal or circuit board.First, second weld pad 141,142 can be used to can reflow formula Thermal Cutoffs 100 be welded to
On pcb board or panel (not shown), the first, second end of conducting element 110,120 is also connected to outside the cover 160 by this simultaneously
Face and and circuit connection, and extensible external metallization electrode.Can be in reflow formula Thermal Cutoffs real work, load current stream
Through the first, second end of conducting element 110,120, for example, load current can be generated by power supply unit, conductive element is flowed through
Part is again on other circuits.Elastic element 150 can be made of an electrically conducting material, such as copper, nickel, stainless steel or other metals.Its
As long as his material or structure can this suitable function can apply can also be used for strength on conducting element.In the present embodiment, bullet
Property element 150 and conducting element the second end 120 be identity element, not only had the function of conductive capability again completion application strength.
Fig. 2 show first embodiment of the invention can reflow formula Thermal Cutoffs state of activation section view,
After Reflow Soldering, activator button 130 be pressed so that can reflow formula Thermal Cutoffs 100 be under state of activation.This activation
Button 130 can apply strength on elastic element 150, while the internal stress generated can be transmitted to sensing element 180 and generate one
Isolated strength, thus having activated this can reflow formula Thermal Cutoffs 100.
Fig. 3 show first embodiment of the invention can reflow formula Thermal Cutoffs its elastic element disconnect in failure conditions
The section view of state, in this case, can reflow formula Thermal Cutoffs 100 pressed activator button 130 in advance, be in sharp
Under state living, as shown in Figure 2 above.When 100 environment temperature of Thermal Cutoffs for being centered around reflowable weldering reaches a stagnation temperature
Degree, for example, it is 200 DEG C Celsius when, cause sensing element 180 to follow the string and/or be to become easy deformation or fusing.When this situation
After generation, sensing element 180 can be made to disconnect by the strength that elastic element 150 is passed to sensing element 180, to prevent electric current
Sensing element 180 is flowed through, is also just disconnected the first, second end of conducting element 110,120 on circuit, be also just disconnected first,
Second weld pad 141,142.
Fig. 4 show can reflow formula Thermal Cutoffs be assembled on pcb board and press activator button can reflow formula temperature to activate
Spend the flow chart of fuse.In process square, can reflow formula Thermal Cutoffs be placed on pcb board or panel and passed through by piece
Cross reflow soldering, for example, Fig. 1 can reflow formula Thermal Cutoffs 100 be placed on pcb board or panel in the assembling stage by piece, so
Afterwards by reflow soldering.Scolding tin can be added on pcb board or panel through steel mesh printing in advance can the weldering of reflow formula Thermal Cutoffs 100
Pad corresponding position.Place can reflow formula Thermal Cutoffs, then make the melts soldering tin on weld pad and cooling by reflow soldering.
In process square, can as Fig. 2 reflow formula Thermal Cutoffs 100 above activator button 130 be pressed so that in process side
In block, can reflow formula Thermal Cutoffs 100 be active.This activator button 130 can apply strength in elastic element 150
On, while the internal stress generated can be transmitted to the strength that sensing element 180 generates a separation, completing activation can reflow formula temperature
Fuse 100.Refering to shown in above-mentioned Fig. 2, in next application, if there is excessive heat be loaded into can reflow formula temperature protect
Dangerous 100 the inside of silk, sensing element 180 are pressed in activator button 130 and convey power caused by strength to elastic element 150
It under effect, can follow the string, and or become easy deformation and or fracture.By above description it can be seen that the present invention can return
Weldering formula Thermal Cutoffs 100 overcomes old Thermal Cutoffs in surface patch technique by Reflow Soldering problem often encountered.And
The innovation concept of activator button make can reflow formula Thermal Cutoffs 100 be easy to be activated, it is conductive under subsequent fault condition
Element just will disconnect.
Fig. 5 display first embodiment of the invention can use activator button and elastic element in reflow formula Thermal Cutoffs
Block and elastic element disconnect the conceptual schematic view of situation in failure conditions, in the schematic diagram of Fig. 5,150 quilt of elastic element
It is designed to that arch bridge shape uses, and it can also be taken as the conducting element the second end 120 of carrying operating current to use simultaneously,
The rear end of conducting element the second end 120 also contains sensing element 180, it all bears as conducting element carrys out own elasticity
The elastic force of element 150 acts on.Under normal assembled state, this elastic force is conducting element the second end 120 and first end
110 are combined together.Activator button 130 can provide a force herein can reflow formula Thermal Cutoffs 100 to activate.When sharp
Button 130 living is pressed, can reflow formula Thermal Cutoffs 100 be just activated, but the first, second end of conducting element
110,120 and sensing element 180 or combined.Under subsequent malfunction or overheat condition, sensing element
180 follow the string and or become easy deformation and or be broken and lose conducting element the first, second end 110,120 knots
The ability being combined just is will disconnect later shown in dotted line part as shown in Figure 5.
The present invention proposes the innovation concept of activator button, can be completed at the same time the purpose of assembling process and state of activation.In group
During dress, the direction of stress produced by elastic element can allow transport element to tend to be combined together.
Can be after reflow formula Thermal Cutoffs be mounted on pcb board or panel by reflow soldering, this activator button
It can be pressed down, it can be applied force on elastic element.This step has been activated by can reflow formula Thermal Cutoffs.
Embodiment 2
Fig. 6 show second embodiment of the invention can reflow formula Thermal Cutoffs its pedestal section view.In this reality
It applies in a structure chart, elastic element 250 can be made into the reed shape being bent upwards before manufacture, remaining structure and implementation
Example 1 is consistent, so elastic element 250, which can apply a strength, to lead when it is bent under conducting element first end 210
Electric device first end 210, sensing element 280 weld together during Reflow Soldering.
Fig. 7 show second embodiment of the invention can reflow formula Thermal Cutoffs layered structure explanatory diagram.Wherein show respectively
Show, activator button 230, the cover 260, carries the first, second end of conducting element 210,220, elastic element 250,
The pedestal of sensing element 280.
Embodiment 3
Fig. 8 show third embodiment of the invention can reflow formula Thermal Cutoffs its elastic element disconnect in failure conditions
The section view of state.In nonserviceabling, can the activator button 330 of reflow formula Thermal Cutoffs 300 pressed in advance
It is active, as the description of Fig. 2.Apart from conducting element first end at 330 pushing of the present embodiment activator button
310 position of portion farther out, so 350 end break distance of elastic element is also longer, can be resistant to higher operating voltage without
Arcing.When be centered around can 300 environment temperature of reflow formula Thermal Cutoffs reach a critical-temperature, such as 200 DEG C Celsius, cause to sense
Element 380 follows the string and/or is to become easy deformation or fusing.After this situation occurs, it is passed to by elastic element 350
The strength of sensing unit 380 can be such that sensing element 380 disconnects, so that electric current be prevented to flow through sensing element 380, that is, be disconnected conductive element
The first, second end of part 310,320, the first, second weld pad 341,342 being also just disconnected on pedestal 370.
Embodiment 4
Fig. 9 show fourth embodiment of the invention can reflow formula Thermal Cutoffs section view, in the present embodiment,
Activator button 430 extends two support arms and can advance along inner wall trench.To help activator button 430 more smoothly to consolidate past move down
It is dynamic.Activator button 430 is respectively illustrated in figure, the cover 460 contains the first, second end of conducting element 410,420, elasticity member
Part 450, the pedestal of sensing element 480.Fig. 9 a show can reflow formula Thermal Cutoffs in the state in assembling stage, activation presses
Button 430 is not by lower by state of activation, and as shown in Fig. 9 aA-A, activator button 430 is not supported with elastic element 450;In Fig. 9 b
In, activator button 430 be pressed make can reflow formula Thermal Cutoffs 400 be in state of activation, but sensing element 480 does not occur greatly
Deformation, circuit still locates on state;And in Fig. 9 c, nonserviceable or the heat that exceeds make sensing element 480 disconnect or
It deforms, disconnects circuit.
Figure 10 show fourth embodiment of the invention can reflow formula Thermal Cutoffs dimensional decomposition structure diagram,
In, activator button 430, the cover 460 and conducting element first end, the second end 410,420 are carried, elastic element 450 passes
The pedestal of sensing unit 480.
Embodiment 5
Figure 11 show fifth embodiment of the invention can reflow formula Thermal Cutoffs section view.It is respectively illustrated in figure
The cover 560 and the activator button 530 integrated with the cover 560 contain the first, second end of conducting element 510,520, elasticity member
Part 550, the pedestal of sensing element 580.In fig. 11 a, it is shown that can reflow formula Thermal Cutoffs assembling the stage state;?
In Figure 11 b, activator button 530 be pressed make can reflow formula Thermal Cutoffs 500 be in state of activation;And in Figure 11 c, in event
Barrier state or the heat exceeded make sensing element 580 disconnect the connection with circuit.In the present embodiment, activator button 530 is solid
It is scheduled among the cover 560.So the movement for pressing the cover 560 is equivalent to press activator button 530 simultaneously after Reflow Soldering assembling
Make can reflow formula Thermal Cutoffs 500 be active.
Figure 12 show fifth embodiment of the invention can reflow formula Thermal Cutoffs dimensional decomposition structure signal.It can reflow
Formula Thermal Cutoffs 500 includes the cover 560, and carries the first, second end of conducting element 510,520, elastic element
550, the pedestal of sensing element 580.Activator button 530 is located within the cover 560 herein, therefore not shown.
Based on the explanation of above each embodiment, activator button can have various design forms to realize, as long as it can be in bullet
Property element on apply mechanical force and belong to scope of the invention.Is activated after Reflow Soldering formula Thermal Cutoffs is completed
Button is pressed and is active the Temperature protection of reflowable weldering.It is different from the past can reflow formula Thermal Cutoffs must
Must galvanization blow restriction element, simple and mechanical design of the invention can easily activationary temperature fuse, therefore mention
The high reliability of device and simplifies technique and reduce production cost.
Only be above the present invention it is it is related can reflow formula Thermal Cutoffs embodiment exposure, and the range limit of non-present invention
System.Different methods can make elastic element be bonded together using mechanical force such as, and can utilize mechanical force after fluid welding assembling
It is applied on elastic element the Temperature protection person of being active for enabling reflowable weldering, is still covered by the present invention.