CN109392261B

CN109392261B - Assembling method for preparing intelligent power optimizer device capable of enhancing creepage distance

Info

Publication number: CN109392261B
Application number: CN201710653170.3A
Authority: CN
Inventors: 张永; 虞红峰
Original assignee: Fonrich Shanghai New Energy Technology Co ltd
Current assignee: Fonrich Shanghai New Energy Technology Co ltd
Priority date: 2017-08-02
Filing date: 2017-08-02
Publication date: 2020-08-04
Anticipated expiration: 2037-08-02
Also published as: CN109392261A

Abstract

The invention mainly relates to an assembling method for preparing an intelligent power optimizer device capable of enhancing creepage distance, which comprises the steps of providing a metal shell with a cavity, covering a layer of first flexible insulating film on the inner wall of the cavity, pressing an insulating tray on the first flexible insulating film, placing a metal sheet in a window formed in the tray, covering a layer of second flexible insulating film on the metal sheet, mounting a circuit board on the tray, enabling a heating electronic element to be close to and attached to the second flexible insulating film, pressing one or more elastic members on the circuit board, and covering a rear cover on the back side of the metal shell. After the assembling steps, reasonable electric insulation is realized between the printed circuit board and the metal shell, and the creepage distance can be increased to a higher degree so as to ensure the safety and reliability of the whole power electronic device.

Description

Assembling method for preparing intelligent power optimizer device capable of enhancing creepage distance

Technical Field

The invention mainly relates to an assembling method of a power device, in particular to an internal assembling method for setting a reinforced creepage distance on a printed circuit board suitable for a high-voltage environment, which advocates that the heat of electronic elements and other heat sources on the circuit board is led out to a metal shell to be used as a heat dissipation path, and the creepage distance is increased to a higher degree under the reasonable assembling method between the printed circuit board and the metal shell so as to ensure the safety and reliability of the whole power electronic device.

Background

With the rapid development of electronic technology, printed circuit boards are widely used in various fields, and almost all electronic devices cannot leave the corresponding printed circuit boards. In order to ensure the normal operation of electronic equipment, reduce mutual electromagnetic interference and reduce the adverse effect of electromagnetic pollution, the electromagnetic compatibility design cannot be ignored. The present application relates to printed circuit board design methods and techniques. In the design of a printed circuit board, the layout of components and the wiring of circuit connection are two key links. Printed circuit boards, also known as printed circuit boards, are providers of electrical connections for electronic components in the field of electronic circuits. The development of circuit boards has been in history for over a hundred years, and the adoption of printed circuit boards has the main advantages of greatly reducing errors of wiring and assembly, greatly improving the automation level and the production labor rate of circuit design, and mainly adopting layout design. The circuit board can be divided into a single-sided board, a double-sided board, a four-layer board, a six-layer board and other multi-layer circuit boards according to the number of the layers of the circuit board. One of the important parameters of a printed circuit board is mechanical strength, which refers to the maximum load that the printed circuit board can bear per unit area when the material is subjected to an external force. Printed circuit boards are generally described in terms of bending/flexural strength, tensile/tensile strength, compressive strength, impact strength, etc., with more layers of the circuit board indicating greater/higher mechanical strength, but at a higher corresponding cost. The circuit board substrate is generally classified by the insulation part of the substrate, the most common raw materials are bakelite board, glass fiber board and various plastic boards, etc., and the manufacturers of the printed circuit board generally press the insulation part composed of glass fiber, fabric material and resin and then press the epoxy resin and copper foil into the bonding sheet for use. The copper foil laminated inside the printed circuit board is easy to cause the problem that the printed circuit board is delaminated to cause delamination between layers.

The photovoltaic junction box is used as a matched outer shell and internally integrated with a power optimizer, and is arranged on a connector between the solar cell module and the solar charging control device. One drawback of the conventional photovoltaic junction box is that the terminal assembly is firstly fixed on the mounting plate and then is mounted in the base of the photovoltaic junction box through the mounting plate, so that the structure is complex and the mounting is complicated, the cost is high due to the mounting plate, and the heat dissipation performance of the whole photovoltaic junction box is affected due to the fact that the mounting plate occupies a certain convection space. The current also some structures adopt the terminal subassembly with the tight design of clamping on the base after two working of plastics are wrapped up, though saved the mounting panel, the tight parcel of working of plastics also causes the inside heat dispersion of whole box body not good. Another disadvantage of the conventional photovoltaic junction box is that there is no thermal isolation between the upper or lower cover of the photovoltaic junction box and the anti-reflection diode, so that the upper cover of the photovoltaic junction box is easily burned by heat generated by the diode.

The printed circuit board is used in the power industry, an internal assembly scheme for enhancing the creepage distance is adopted on the printed circuit board suitable for the high-voltage environment, heat of heat sources such as electronic elements and the like on the printed circuit board is led out to the metal shell to be used as a heat dissipation path, and the creepage distance is increased to a higher degree between the printed circuit board and the metal shell under a reasonable assembly technology so as to ensure the safety and reliability of the whole power electronic device.

Disclosure of Invention

In one non-limiting alternative embodiment of the present invention, an intelligent power optimizer apparatus for enhancing creepage distance is disclosed, which essentially comprises: a metal housing with a cavity; a first flexible insulating film covering an inner wall of the cavity; an insulating tray laminated on the first flexible insulating film; the metal sheet is arranged in a window formed in the tray; a second flexible insulating film covering the metal sheet; a circuit board mounted on the tray, wherein the heating electronic element on the circuit board is close to and attached to the second flexible insulating film; and the back cover is fixedly held at the back side of the metal shell, and the elastic component in the cavity is pressed between the back cover and the circuit board.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: one or more raised positioning pins are arranged on the inner wall of the cavity of the metal shell; one or more positioning holes are formed in the first flexible insulating film; each positioning pin penetrates through a corresponding positioning hole when the first flexible insulating film covers the inner wall of the cavity so as to realize positioning of the first flexible insulating film.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: the tray is provided with one or more cap-shaped positioning sleeves with the front ends being open parts and the rear ends being sealed; each positioning pin is inserted from the open part of a corresponding one of the positioning sleeves when the tray is laminated on the first flexible insulation film to realize the positioning of the tray.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: and a heat-conducting glue is coated between the metal sheet and the first flexible insulating film.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: and a heat-conducting glue is coated between the metal sheet and the second flexible insulating film.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: the cavity is filled with an insulating pouring sealant material which is in a liquid state before curing and in a solid state after curing.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: the edge of the tray is provided with a side edge or a side wing which is vertical to the flat-plate-shaped body part of the tray; the circuit board is close to the flat-plate-shaped body part of the tray and is enclosed inside the side edge or the side wing.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: one or more positioning upright posts are arranged on the flat-plate-shaped body part of the tray; one or more positioning holes are formed in the circuit board; when the circuit board is installed on the tray, each positioning upright post penetrates through a corresponding positioning hole on the circuit board so as to realize the positioning of the circuit board on the tray.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: the patch area used for mounting the heating electronic element on the circuit board is aligned and superposed with the window; the elastic member is pressed against the circuit board in a manner of offsetting the patch area.

The aforesaid can strengthen creepage distance's intelligent power optimizer device, its characterized in that: the elastic member presses the circuit board and the tray against the front wall of the metal shell opposite to the rear cover, and meanwhile, the metal sheet props against the heating electronic element through the second flexible insulating film, so that the elastic deformation force of the circuit board ensures that the heating electronic element is not pressed by the metal sheet to cause structural damage.

In one non-limiting alternative embodiment of the present invention, an assembly method for preparing an intelligent power optimizer device capable of enhancing creepage distance is disclosed, which mainly comprises: step S1 providing a metal housing with a cavity; step S2 of covering a layer of first flexible insulating film onto the inner wall of the cavity; step S3 of pressing an insulated tray against the first flexible insulating film; step S4, a metal sheet is placed in a window formed in the tray; step S5 of covering a second flexible insulating film on the metal sheet; step S6 of mounting the circuit board on the tray so that the heat generating electronic component is close to and bonded to the second flexible insulating film; step S7 presses one or more elastic members against the circuit board and covers the back cover on the back side of the metal case.

The above method is characterized in that: one or more raised positioning pins are arranged on the inner wall of the cavity of the metal shell; one or more positioning holes are formed in the first flexible insulating film; in step S2: each positioning pin is aligned with and passes through a corresponding one of the positioning holes to achieve positioning of the first flexible insulating film.

The above method is characterized in that: the tray is provided with a cap-shaped positioning sleeve with only one open part; and in step S3: each positioning pin is inserted from the open part of a corresponding positioning sleeve to realize the positioning of the tray.

The above method is characterized in that: in step S4: coating heat-conducting glue on the metal sheet or coating the heat-conducting glue on the region of the first flexible insulating film exposed to the window; then the metal sheet is placed at the window; so that a thermally conductive paste is disposed between the metal sheet and the first flexible insulating film.

The above method is characterized in that: in step S5: firstly coating heat-conducting glue on the metal sheet or coating heat-conducting glue on the second flexible insulating film; then covering a second flexible insulating film on the metal sheet; so that a thermally conductive paste is disposed between the metal sheet and the second flexible insulating film.

The above method is characterized in that: in step S6: firstly coating heat-conducting glue on the heating electronic element or coating heat-conducting glue on the second flexible insulating film; then the circuit board is arranged on the tray; so that a thermally conductive paste is disposed between the heat generating electronic component and the second flexible insulating film.

The above method is characterized in that: prior to step S7: filling liquid insulating pouring sealant material in the cavity, and then solidifying the liquid insulating pouring sealant material.

The above method is characterized in that: the edge of the tray is provided with a side edge which is vertical to the flat-plate-shaped body part of the tray; the circuit board is close to the flat-plate-shaped body part of the tray and is enclosed inside the flat-plate-shaped body part by the side edge.

The above method is characterized in that: one or more positioning upright posts are arranged on the flat-plate-shaped body part of the tray; one or more positioning holes are formed in the circuit board; in step S6: each positioning column is aligned with and penetrates through a corresponding positioning hole in the circuit board to realize the positioning of the circuit board on the tray.

The above method is characterized in that: in step S6: aligning and superposing a patch area for mounting the heating electronic element on the circuit board with the window; and in step S7: the elastic member is pressed against the circuit board in a manner of offsetting the patch area.

The above method is characterized in that: after completion of step S7: the elastic component presses the circuit board and the tray to the front wall of the metal shell opposite to the rear cover, and the metal sheet is pressed against the heating electronic element through a second flexible insulating film; the elastic deformation force of the circuit board ensures that the heating electronic element is not extruded by the metal sheet to cause structural damage.

Drawings

To make the above objects, features and advantages more comprehensible, embodiments accompanied with figures are described in detail below, and features and advantages of the present application will become apparent upon reading the following detailed description and upon reference to the following figures.

FIG. 1 is an exemplary diagram of the various components within the power optimizer in an exploded view.

Fig. 2 is an exemplary view of the interior cavity defined by the front wall and side walls of the metal shell within the shell.

Fig. 3 is an exemplary view of a layer of a first flexible insulating film applied to the inner wall of the cavity of the housing.

Fig. 4 is an exemplary top view of a tray carrying printed circuit boards and mounting metal sheets.

Fig. 5 is an exemplary view of the tray placed inside the cavity and pressed against the first flexible insulating film.

Fig. 6 is an exemplary view of a bird's eye view of a tray carrying a printed circuit board and mounting a metal sheet.

Fig. 7 is an exemplary view of a tray placed into the cavity and a metal sheet placed in a window of the tray.

Fig. 8 is an exemplary illustration of a covering of a second flexible insulating film over a metal sheet in a window.

Fig. 9 is an exemplary view of the circuit board mounted to the tray with the electronics proximate the second flexible insulating film.

Fig. 10 is an exemplary view of pressing one or more elastic members against the circuit board in advance.

Fig. 11 is an exemplary view of the cover after pressing the elastic member against the circuit board and then covering.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below with reference to various embodiments, but the described embodiments are only used for describing and illustrating the present invention and not for describing and describing all embodiments, and the solutions obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

The power optimizer is a dc-to-dc current-controlled buck-boost converter, in other words a single-component level battery maximum power tracking power device. And the power optimizer carries out maximum power optimization on the single component, transmits the single component to a terminal inverter for direct current to alternating current processing, and supplies the single component for local use or power generation internet access. The terminal inverter can be generally a pure inverter device without maximum power tracking or an inverter device equipped with two-stage maximum power tracking. The power optimizers which are more mainstream in the market at present are generally divided into a series type and a parallel type, and the adopted control topological structures are also different.

The design concept of fixed voltage is adopted by the series type power optimizer. In brief, the inverter control board determines a stable voltage of a direct current bus according to the alternating-current voltage, summarizes the maximum power collected by each serially-connected optimizer, and further calculates the bus current and transmits the bus current to the optimizer through wireless or power carrier. The voltage at the output of each optimizer is then equal to the power of the maximum power of the collected component divided by the bus current. When the assembly is blocked, the optimizer can re-determine the maximum output power value according to the volt-ampere curve and transmit the maximum output power value to the inverter control panel through wireless or power carrier waves. On the premise of maintaining the voltage of the direct current bus unchanged, the control board recalculates the bus current (becomes smaller) and feeds the bus current back to each optimizer. At this point, the power of the shielded components is reduced, and the optimizer also steps down to confirm that the output current is up to standard. The optimizers for other non-occluded components are boosted to meet the output current. If a component is too heavily shaded, the power optimizer bypasses the heavily shaded component until it returns to a workable state, and this regulation is essentially a voltage-balancing process, thereby providing the most stable and optimized dc-side bus voltage to the inverter.

The parallel type power optimizer also uses a fixed voltage mode. The inverter determines the bus voltage from the closed loops of the direct and alternating currents, where each optimizer boosts the voltage at the respective output to a specified value, where the current input to the inverter is equal to the sum of the maximum power collected by each optimizer divided by the rated voltage. Since the shielding of the thick cloud layer has little influence on the voltage of the component and mainly influences the output current, the parallel optimizer basically does not have frequent voltage mismatch regulation, and the output currents do not influence each other due to the parallel relationship, so that the parallel optimizer is indeed regarded as an advantage compared with the serial optimizer. Meanwhile, if the individual components are seriously shielded and cannot start the boosting equipment, the optimizer automatically disconnects and sends a fault reporting signal, and restarts until the shielding problem is removed. However, compared with the series topology, the parallel topology also has the same defects as the micro-inverter, and the boost span is larger. The open circuit voltage of the current popular component is about 38V, the working voltage is about 30V, the voltage increasing and reducing range of the serial topological structure is controlled to be about 10% to 30% under the normal condition, and the variation range is increased to be 10% to 90% under the condition of insufficient voltage. However, both the parallel topology and the micro-inverter require boosting the component input voltage to a relatively high value, typically around 400V, which is equivalent to a 10-fold increase. This is a challenging duty cycle for boost devices that do not use a transformer, but are only switch controlled.

One of the biggest topological features of the power optimizer is to separate the components and the inverter functionality, which is different from the traditional photovoltaic system. It appears that the components are connected to the inverter through the optimizer, and in fact the components are only used to start the optimizer, and the optimizer collects the maximum power of the components and then cooperates with each other to give the inverter function. Due to the technology of fixing the voltage, the problem of partial shielding of the photovoltaic power generation system is solved, the number of the components in each group of strings does not need to be equal for a system with a plurality of groups of strings, and even the orientation of the components in the same group of strings does not need to be the same. For the series type optimizer, the open-circuit voltage after the circuit breaking is only a tiny voltage such as 1V, and for the parallel type optimizer, the open-circuit voltage after the circuit breaking is at most the open-circuit voltage of the component, so the safety performance and the reliability of the power generation system are also a leap-type improvement.

Besides the advantages of the circuit topology on the structure, the power optimizer has inherent advantages on the maximum power point tracking algorithm. The traditional tracking algorithm of the maximum power point is basically based on two types: hill climbing method and logic measurement algorithm. Methods for tracking points of advance these also use a combination of: for example, a hill climbing method is combined with a constant range method, and a full scanning method with a fixed time interval is matched to find a maximum power point; the maximum power point is also found by combining a slope polarity method and a conductance increment method and matching with a detection step control method. Under ideal test conditions, the accuracy of the algorithms can reach over 99 percent, and actually, the biggest current challenge is the situation of multiple peaks and steep illumination increase. By multi-peaked is meant that multiple power peaks occur in the power-current or power-voltage graph of an array. The formation reasons of the array are various, one of the reasons is that a bypass diode is deflected in the forward direction due to shielding of part of assemblies, one third of batteries are bypassed, the working voltage of the string is reduced, and further, the voltage mismatch of the array occurs, so that the multi-wave peak condition occurs. Or a multi-peak condition caused by current mismatch in the same string due to blocking and the bypass diode is still in a reverse deflected inactive state. Multiple peaks and steep increases in illumination have a huge impact on many maximum power point algorithms, which can confuse the tracker's decision on the direction of detection and on which peak is the maximum power point due to its uncontrollable and variable nature. In fact, the root cause of the problem is that too many components are accessed. It is contemplated that if each optimizer is connected with only one component, each component is only provided with two to three bypass diodes, and the components are not affected with each other, so that the difficulty in analyzing and tracking the maximum power point is greatly reduced, and the logic editing of the controller is very simple and accurate. Because only one IV curve of 38 v, 8.9 a, the maximum power point tracking of the optimizer does not need to use the traditional algorithm to track the maximum power point, and there are two common methods currently, namely, the tangent point tracking method, and the combination of the resistance control method and the voltage control method with two-stage tracking. Based on the advantages, the capacity of the optimizer can be improved by about 30% compared with the traditional inverter. In addition to limiting the ac power of the micro-inverter, the power optimizer may fully transfer the collected power to the inverter.

The power optimizer is compatible with all silicon cells and can be matched with part of thin film battery systems, and efforts are being made to make the optimizer have a wider compatibility range. However, most micro-inverters are incompatible or self-functionally grounded, which makes them incompatible with some mainstream components currently on the market. At the same time, the input voltage range of the power optimizer is between about 5 volts and 50 volts, which ensures that the optimizer can remain on and continue to operate even if the components are heavily covered. The power optimizer can also be matched with a third-party inverter, and communication with the third-party inverter and regulation and control of a system are carried out through an additional control box.

Referring to fig. 1, in a non-limiting alternative embodiment of the present invention, an intelligent power optimizer apparatus for enhancing creepage distance is disclosed, comprising essentially: a metal housing 100 with a cavity. It can be seen from the figures that the metal housing comprises side walls 105a-105d etc. and comprises a front wall 105e etc., in connection with fig. 2: the left side wall 105b and the right side wall 105c and the lower side wall 105c are perpendicular to the front wall 105e, and again, as viewed in fig. 1, the upper side wall 105a is not perpendicular to the front wall 105e in fig. 2, the side wall 105a is a smooth curved portion that forms an obtuse angle with the plane of the front wall, and the side wall 105a is substantially inclined with respect to the front wall 105e rather than vertical. Referring to fig. 1-2, the side wall 105a is smoothly curved from its intersection with the front wall 105e to a holding portion 103 of the metal shell, which corresponds to a tab with a fastening hole through which a fastener such as a screw can fasten the metal shell or the optimizer device at a location where the optimizer is to be installed. The plane of the holding portion 103 and the plane of the front wall are substantially parallel, and the rear end surfaces of the

side walls

105b, 105c and 105c are substantially flush with the holding portion 103. The side walls 105a-105d and the front wall 105e of the metal casing 100 thus enclose a slot or cavity 101 for receiving the printed circuit board PCB, with an opening 109 or notch located opposite the front wall, from which the various components inside the power optimizer are placed into the cavity inside the power optimizer, and with a back cover located opposite the front wall, which is also inserted in the opening 109. The respective side walls and front wall of the metal housing and even the holding part can be produced as one piece in an integrally molded manner.

Referring to fig. 1 in conjunction with fig. 2, the metal housing 100 is provided with one or more raised pins 102 on the inner wall of the cavity 101, which are substantially needle-shaped pins on the inner side of the front wall. It will also be observed that inside the chamber there are provided a plurality of threaded studs 106 with threaded holes, which can also be provided on the inner side of the front wall 105e, also on the previously inclined side wall 105a, or on the inner side of the vertical side walls 105b-105c-105d, but which must be limited in the direction towards the opening 109 provided by the threaded studs in order to facilitate the locking of the rear cover.

Referring to fig. 1 in conjunction with fig. 3, the first flexible insulating film 110 is insulating and highly isolating from electricity, and may be folded or bent like cloth or paper to embody a flexible characteristic. The first flexible insulating film 110 itself is provided with one or more positioning holes 110a, and the positioning holes 110a penetrate through the entire thickness of the first flexible insulating film and mainly serve to align positioning, and when the first flexible insulating film 110 is covered on the inner wall of the chamber or on the inner side of the front wall, each positioning pin 102 on the inner wall of the chamber 101 passes through a corresponding one of the positioning holes to position the first flexible insulating film and prevent it from sliding on the inner side of the front wall 105 e. The first flexible insulating film 110 can secure at least electrical insulation of the circuit board subsequently placed into the cavity from the front wall of the metal housing.

Referring to fig. 1 in conjunction with fig. 4, the tray 120 is insulating and highly isolated from electricity, it cannot be folded or bent like cloth or paper, the tray 120 should have a certain hardness/rigidity, and various plastics can be used as the raw material for preparing the tray. The tray 120 is substantially irregularly rectangular in shape. The tray can be provided with one or more notches 120C at the peripheral edge, the purpose of the notches being: when the tray 120 is placed inside the cavity of the metal shell, the threaded posts 106 with the threaded holes previously provided in the cavity may be aligned with the cutouts to avoid the tray from shielding the threaded posts 106. In addition, a window 120A is opened at a central position of the tray 120, and one or more openings 120B may be opened at other positions of the tray, wherein the purpose of the opening 120B is to reduce the hardness of the tray so that at least a portion of the tray can exhibit the characteristic of elastic deformation. The primary purpose of the window 120A is to receive and position a metal sheet as will be described. In connection with fig. 6, it must be noted that: assuming that the tray 120 has a front side and a rear side, the front side of the tray will face the front wall 105e or the insulating film 110 when the tray is placed inside the cavity, and the rear side will face the open portion 109 of the cavity or the rear cover 300 or the circuit board. Referring to fig. 1-4-6, it is observed that the tray 120 is provided with one or more cap-shaped positioning sleeves 121 having an open front end and a closed rear end, the open end of the cap-shaped positioning sleeve 121 is located at one side of the front side of the tray, and the closed rear end of the cap-shaped positioning sleeve 121 is located at one side of the rear side of the tray. The main function of the cap-shaped positioning sleeve is to align and position the positioning pin 102 as described above with reference to fig. 3, and when the positioning pin 102 is inserted into the cap-shaped positioning sleeve 121 from the opening of the cap-shaped positioning sleeve located at the front side of the tray, the positioning of the tray 120 on the metal shell or on the front wall of the shell can be realized, and the tray is prevented from sliding. The rear side of the tray 120 is also provided with one or more positioning pins 122 belonging to the tray, and the positioning pins 122 are mainly used for positioning the circuit board. The positioning pins 122 of the tray, the above cap-shaped positioning sleeve 121 and the like can be integrally formed as a whole. The cap-shaped positioning sleeve 121 with the open front end and the sealed rear end has another structural function as follows: since the positioning pin 102 directly connected to the inner side of the front wall 105e or inside the cavity is also made of metal and is integrated with the metal shell, considering that the printed circuit board is mounted on the rear side of the tray, when the positioning pin 102 is inserted into the cap-shaped positioning sleeve 121 from the front end of the positioning pin 102, the rear end of the cap-shaped positioning sleeve is sealed/closed, thereby ensuring electrical isolation between the positioning pin 102 and the printed circuit board, which is another electrical isolation means from the insulating film to the electrical isolation, and the creepage distance is increased by several orders of magnitude.

Referring to fig. 1 in conjunction with fig. 5, each of the positioning pins passes through a corresponding one of the positioning holes when the first flexible insulating film 110 is covered on the inner wall of the cavity to achieve positioning of the first flexible insulating film 110, but the insulating film 110 is flexible and easily falls off or bulges/folds from the inner side of the inner wall or the front wall of the cavity, which is a phenomenon that is negative to electrical isolation. Since the tray is provided with one or more cap-shaped positioning sleeves 121 having an open front end and a closed rear end, when the tray is placed in the cavity of the metal shell, the tray 120 is laminated/pressed against the first flexible insulating film 110, and each positioning pin 102 is inserted through the opening of a corresponding one of the positioning sleeves 121 to position the tray 120. The positioning of the tray 120 is completed, and at least the first flexible insulating film 110 can be sandwiched between the tray 120 and the front wall.

Referring to fig. 1 in conjunction with fig. 6, the tray 120 has a front side that faces the front wall 105e when the tray is placed inside the cavity and a rear side that faces the open portion 109 of the cavity. The tray 120 is provided with one or more cap-shaped positioning sleeves 121 having an open front end and a closed rear end, the open front end of the cap-shaped positioning sleeve 121 is located at one side of the front side of the tray, and the closed rear end of the cap-shaped positioning sleeve 121 is located at one side of the rear side of the tray. The rear side of the tray 120 is also provided with one or more alignment pins 122 protruding from the tray. A window 120A is formed through the thickness of the tray 120 at a central position of the tray, and a plurality of openings 120B may be formed at other positions of the tray. The edge of the tray is further provided with a lateral edge 128 perpendicular to the flat-plate-shaped body of the tray, with reference to fig. 4, the lateral edge 128 extends and folds along the flat-plate-shaped body of the tray to form a ring-shaped structure, the flat-plate-shaped body of the tray 120 is provided with one or more cap-shaped positioning sleeves 121 with front ends being open and rear ends being sealed, the opening of each cap-shaped positioning sleeve 121 is located on one side of the front side surface of the flat-plate-shaped body of the tray, and the sealed rear end of the opposite cap-shaped positioning sleeve 121 is located on one side of the rear side surface of the flat-plate-shaped. In addition, one or more positioning pins 122 protruding from the flat plate-shaped body of the tray are disposed on the rear side of the flat plate-shaped body of the tray 120. The flat plate-like body portion is provided with a window 120A and an opening 120B.

Referring to fig. 1 in conjunction with fig. 7, the metal sheet 130 is placed in the window 120A formed in the tray 120, the metal sheet is preferably made of aluminum, and the shape of the metal sheet should be consistent with the shape of the window 120A, such as circular, oval, triangular, square, or any polygon, and the metal sheet can be placed in the window in a matching manner. Because the tray is rigid, but should have elasticity that can be deformed when the tray is subjected to a squeezing force and can restore to its original shape after the squeezing force disappears, the window 120A on the tray, in addition to accommodating the metal sheet 130, and the additional opening 120B, etc., can also satisfy the capability of allowing the tray to deform. In the process of placing the metal sheet into the window, in an alternative embodiment, the heat conductive adhesive may be coated on the first flexible insulating film 110 from the window 120A, and then the metal sheet is placed on the window, so that the heat conductive adhesive is coated between the metal sheet and the first flexible insulating film.

Referring to fig. 1 in conjunction with fig. 8, a second flexible insulating film 140 is coated on the metal sheet 130, and the second flexible insulating film 140 is insulating and highly isolating, and can be folded or bent arbitrarily like cloth or paper to exhibit a flexible characteristic, and the material and the insulating film 110 are similar to those of the insulating tape. In the process of covering the second flexible insulating film on the metal sheet, in an alternative embodiment, the heat conductive adhesive may be coated on the metal sheet first, or the heat conductive adhesive may be coated on the second flexible insulating film, so that when the second flexible insulating film is covered on the metal sheet, the heat conductive adhesive is coated between the metal sheet and the second flexible insulating film. The heat-conducting glue has excellent heat-conducting performance/heat-radiating performance, the heat-conducting coefficient after curing can reach 1.1-1.5, a high-guarantee heat-radiating coefficient is provided for electronic products, a guarantee effect is played for the stability of the electronic products, particularly products needing high heat radiation in the using process, the using performance of the products is improved, and the service life of the products is prolonged. The high-power electronic product has excellent electrical property, ageing resistance, cold and heat alternation resistance, moisture resistance, no swelling, electrical insulation property, power recession rate, shock resistance, water resistance, shock absorption and stability, and the safety coefficient of the electronic product in the using process is increased. The adhesive has excellent bonding strength, particularly has good adhesive force to electronic components, aluminum, PVC, PBT and other plastics, and simultaneously has excellent sealing property and excellent bonding and heat conducting effects. The curing speed is high, the extrusion is easy, the flowing is avoided, the operation is convenient, the glue can be applied manually or mechanically, the glue does not leak, and the requirements of any working environment and any working condition place are met. The paste is nontoxic and nonirritant gas release, and has no solvent, no corrosion and no pollution, and meanwhile, the paste is safe for operating personnel and consumers using electronic products, and double guarantees are provided for safety and environmental protection. Has excellent high and low temperature resistance.

Referring to fig. 1 in conjunction with fig. 9, a printed circuit board 150 is mounted on the tray such that the heat generating electronic components mounted or attached or soldered on the printed circuit board are adjacent to and bonded to the second flexible insulating film 140 of fig. 8. In connection with fig. 6, it must be noted that: assuming that the circuit board 150 has a front side and a back side, the front side of the circuit board will face the front wall 105e or tray when placed inside the cavity, and the back side will face the open portion 109 or back cover 300 of the cavity. It can be observed that the step of mounting the printed circuit board on the tray entails aligning the chip area 155 for mounting the heat-generating electronic components with the so-called window 120A, on which there may be many areas on which various areas like capacitors or resistors or transformers or inductors can be mounted/soldered, but here the chip area 155 is dedicated to mounting those heat-generating electronic components on the PCB, typically for example power semiconductor switching transistors, common thyristors, mosfets, igbts, transistors, microprocessors, etc., which are defined in this application as those electronic components that are considered as heat sources during the working phase of power-on. The meaning of the alignment registration of the chip area 155 on the front side of the circuit board 150 and the window 120A on the tray is that: so that the electronic component is close to and attached to the second flexible insulating film 140. In fact, electronic components which can generate heat during the working stage when electrified are mainly the plastic package shell contacting the second flexible insulating film 140, the silicon substrate which is sealed inside the plastic package shell and is provided with the integrated circuit/discrete circuit is not directly contacted with the second flexible insulating film 140, and certainly, those electronic components which allow the silicon substrate to be exposed can also directly contact the silicon substrate with the second flexible insulating film 140. In the process of mounting the circuit board on the tray, in an alternative embodiment, the heat conductive adhesive may be coated on the second flexible insulating film 140, or the electronic component in the patch area 155, so that when the circuit board is mounted on the tray, the heat conductive adhesive is coated between the electronic component and the second flexible insulating film. The circuit board 150 has one or more positioning holes 152, and as described above, the rear side of the tray 120 has one or more positioning pins or posts 122 belonging to the tray, and the positioning pins/posts 122 are mainly used for positioning the printed circuit board. When the circuit board is mounted on the tray, each positioning post 122 passes through a corresponding one of the positioning holes 152 in the circuit board to achieve positioning of the circuit board 150 on the tray. The circuit board 150 is close to the flat body of the tray and is enclosed inside the side edge 128 by the side edge 128, and the circuit board is located inside the side edge 128, which is a very important measure for enhancing the creepage distance: electrical isolation between the circuit board and the front wall of the housing may be achieved by the insulating film 110 and the insulating tray, while electrical isolation between the circuit board and the side walls of the metal housing is partially afforded by the side edges 128.

Referring to fig. 1 in conjunction with fig. 10, one or more insulating elastic members 200 are pressed against the circuit board 150 and then covered/assembled/mounted on the back side of the metal housing with a back cover 300, as shown in conjunction with fig. 1-11. The back cover fixed at the backside of the metal housing causes the elastic member 200 to be pressed between the back cover 300 and the circuit board 150. Although springs or the like may be used as the elastic member 200, it is preferable to use an insulating plastic column, a rubber pad, an eraser, or the like. The elastic member 200 is pressed between the rear cover 300 and the circuit board 150 to cause slight deformation of the circuit board, and even the tray is deformed, so as to avoid damaging each electronic component on the circuit board, the elastic member 200 is pressed on the circuit board in a manner of offsetting the patch area 155, that is, the placement position of the elastic member 200 is not allowed to be directly between the rear cover 300 and the patch area of the circuit board 150, but is allowed to be between the rear cover 300 and the non-patch area of the circuit board 150. The non-chip area may not be provided with any components, and the non-chip area may also be welded/provided with other components, but the deformation capability of the printed circuit board itself is such that the other components in the non-chip area are not directly crushed or damaged by the elastic member. However, since the patch area is aligned and overlapped with the metal plate 130, if the elastic member 200 directly presses against the patch area 155, the heat-generating electronic components at the so-called patch area 155 on the front side of the circuit board are clamped by the circuit board and the metal plate pressed by the elastic member, and the clamping is rigid pressing, so that the electronic components at the patch area 155 may be physically/mechanically damaged under the clamping force, and since most components such as power switch tubes are integrated or discrete circuits in an integrated form prepared by using a silicon material as a substrate, such an abnormal situation is absolutely not allowed. However, the metal sheet is pressed against the heating electronic component through the second flexible insulating film as a necessary condition for constructing a heat dissipation path of the component, and the elastic deformation force of the circuit board itself prevents the electronic component from being pressed by the metal sheet to cause structural damage. One of the problems that must be considered in addition is: although the metal sheet has excellent heat dissipation effect, the expansion and contraction characteristics of the metal sheet cannot be overcome, it is known that the heating electronic component at the patch area 155 can cause the metal sheet to expand with heat in an operating stage, and the heating electronic component at the patch area 155 can cause the metal sheet to shrink in an inoperative stage, so as to avoid indirect or continuous interference force between the metal sheet and the heating electronic component caused by the situation, the elastic member is pressed against the circuit board in a manner of offsetting the patch area, and the elastic deformation force of the circuit board is added, so that the requirements of the expansion and contraction of the metal sheet on precise mutual extrusion contact between the metal sheet and the component can be met, but the metal sheet does not periodically damage the component. To sum up, in the assembling process of mounting the tray and the circuit board, the metal sheet can not shift back and forth at the window, and the circuit board and the tray are slightly elastically deformed back and forth by the metal sheet at the window 120A, so that the safety of the device in the assembling process and the reliability of the durability of the electronic component after the assembling process is completed are guaranteed.

Referring to fig. 1, in one embodiment, an intelligent power optimizer apparatus that can enhance creepage distance includes: a metal housing 100 with a cavity, a first flexible insulating film 110 covering the inner wall of the cavity, an insulating tray 120 laminated on the first flexible insulating film, a metal sheet 130 disposed in a window 120A formed in the tray, a second flexible insulating film 140 covering the metal sheet, a circuit board 150 mounted on the tray and a heat generating electronic component on the circuit board close to and attached to the second flexible insulating film, and, referring to fig. 11, a rear cover 300 fixed at the back side of the metal housing and an elastic member 200 disposed in the cavity is pressed between the rear cover 300 and the circuit board 150.

Referring to fig. 2, in one embodiment, the metal housing 100 is provided with one or more protruding positioning pins 102 on the inner wall of the cavity 101, and the first flexible insulating film 110 is provided with one or more positioning holes 110a, and when the first flexible insulating film 110 covers the inner wall of the cavity 101, as also shown in fig. 3, each positioning pin 102 passes through a corresponding one of the positioning holes 110a to achieve positioning of the first flexible insulating film 110.

Referring to fig. 4, in one embodiment, the tray 120 is provided with one or more cap-shaped positioning sleeves 121 having an open front end and a closed rear end, and when the tray is laminated on the first flexible insulating film 110, as shown in fig. 5 to 6, any one of the positioning pins 102 is inserted through the open end of a corresponding one of the cap-shaped positioning sleeves 121 to achieve positioning of the tray.

Referring to fig. 7, in one embodiment, a thermally conductive paste is coated between the metal sheet 130 and the first flexible insulating film 110.

Referring to fig. 8, in one embodiment, a heat conductive adhesive is coated between the metal sheet 130 and the second flexible insulating film 140 and/or a heat conductive adhesive is coated between the second flexible insulating film 140 and the heat generating electronic component, as shown in fig. 9.

Referring to fig. 8, in an embodiment, a side edge 128 perpendicular to the flat-plate-shaped body portion of the tray 120 is disposed at the edge of the tray 120, and as shown in fig. 6 and 9, the circuit board 150 is proximate to the flat-plate-shaped body portion of the tray 120 and the side edge 128 encloses the circuit board 150 inside the ring-shaped structure formed by the side edge 128. The flat body portion of the tray 120 is provided with one or more positioning posts 122, and the circuit board is provided with one or more positioning holes 152. When the circuit boards are mounted on the tray, each of the positioning posts 122 passes through a corresponding one of the positioning holes 152 in the circuit board 150 to effect positioning of the circuit board on the tray, and the circuit board and the front wall also clamp the tray therebetween.

Referring to fig. 10, in one embodiment, and also in conjunction with fig. 9, the alignment of the chip area 155 on the circuit board 150 for mounting the heat generating electronic components to the window 120A must be such that: the resilient member 200 interposed between the circuit board 150 and the plastic back cover 300 is pressed between the circuit board and the back cover in a manner to bias the patch area 155 apart. The elastic member presses the circuit board and the

tray

150 and 120 toward the front wall 105e of the metal housing opposite to the rear cover 300, and simultaneously the metal sheet presses against the heat generating electronic element in the region 155 through the second flexible insulation film 140, so that the elastic deformation force of the circuit board itself prevents the heat generating electronic element from causing damage on its physical structure due to the pressing of the metal sheet, such as abnormal physical damage phenomena like crushing or cracking of internal silicon wafer. As an optional but not necessary embodiment, after the above-mentioned packaging or assembling process is completed, the cavity 101 may be filled with an insulating potting material which is in a liquid state before curing and in a solid state after curing, and since the liquid state is relatively easy to be poured into the cavity, the electrical insulating wire may be further enhanced after the subsequent curing. As an alternative, but not required, an adhesive may be attached to the front end of the elastic member 200 to interface/adhere with the circuit board 150. As an alternative, but not necessary, embodiment, the plastic-type tray 120 has a better elastic deformation force in the initial state, repeatedly pressing the rear cover at the stage of mounting the elastic member between the circuit board and the rear cover (S7) repeatedly deforms and restores the circuit board and the tray, and after the operation of pressing-releasing the rear cover is repeated for several times, the deformation or elastic tolerance of the tray is worse than that of the circuit board, that is, the tray can not recover after being deformed by a plurality of external forces, but the circuit board can recover the original elastic force and deformation capability under the same condition, it is noted that the implementation means is not necessary, but the original elastic recovery capability is lost because the tray becomes loose after adopting the method, although it is directly close to and in contact with the circuit board, it does not cause free deformation of the toggle circuit board, so that it is a better measure for protecting the device during the stage of heating of the electronic component. It is indeed necessary that the tray has a good original elastic deformability before it is relaxed, for example the first flexible insulating film 110 is very soft, it must rely on a rigid tray for pressing and it must also carry the circuit board during its assembly. After steps S1 to S7 are completed, it is necessary to align the positioning holes 306 of the rear cover 300 and the threaded posts 106 with screw holes in a one-to-one manner, and to lock or fix the plastic rear cover and the metal shell by using fasteners such as screws screwed into the positioning holes 306.

While the present invention has been described with reference to the preferred embodiments and illustrative embodiments, it is to be understood that the invention as described is not limited to the disclosed embodiments. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above description. Therefore, the appended claims should be construed to cover all such variations and modifications as fall within the true spirit and scope of the invention. Any and all equivalent ranges and contents within the scope of the claims of the present application should be considered to be within the intent and scope of the present invention.

Claims

1. An assembly method for making an intelligent power optimizer device with enhanced creepage distance comprising:

step S1, providing a metal shell with a cavity;

step S2, covering a layer of first flexible insulating film on the inner wall of the cavity;

step S3, pressing an insulated tray on the first flexible insulating film;

step S4, placing a metal sheet into a window formed in the tray;

step S5, covering a layer of second flexible insulating film on the metal sheet;

step S6, mounting the circuit board on the tray to make the heating electronic element close to and joint with the second flexible insulating film;

aligning and superposing a patch area for mounting the heating electronic element on the circuit board with the window;

step S7, pressing one or more elastic components on the circuit board and covering the back cover on the back side of the metal shell;

pressing the elastic component on the circuit board in a manner of offsetting the patch area;

repeatedly pressing the rear cover to repeatedly deform and restore the circuit board and the tray, wherein the elastic tolerance force of the tray is poorer than that of the circuit board, so that the tray becomes loose and loses the original elastic restoring capability but the circuit board restores the original elastic force;

after completion of step S7:

the elastic component presses the circuit board and the tray to the front wall of the metal shell opposite to the rear cover, and the metal sheet is pressed against the heating electronic element through a second flexible insulating film;

the metal sheet does not move back and forth at the window, and the circuit board and the tray are elastically deformed back and forth by means of the metal sheet at the window, so that the elastic deformation force of the circuit board ensures that the heating electronic element is not extruded by the metal sheet to cause structural damage.

2. The method of claim 1, wherein:

one or more raised positioning pins are arranged on the inner wall of the cavity of the metal shell;

one or more positioning holes are formed in the first flexible insulating film;

in step S2:

each positioning pin is aligned with and passes through a corresponding one of the positioning holes to achieve positioning of the first flexible insulating film.

3. The method of claim 2, wherein:

the tray is provided with a cap-shaped positioning sleeve with only one open part;

in step S3:

each positioning pin is inserted from the open part of a corresponding positioning sleeve to realize the positioning of the tray.

4. The method of claim 1, wherein:

in step S4:

coating heat-conducting glue on the metal sheet or coating the heat-conducting glue on the region of the first flexible insulating film exposed to the window; then the metal sheet is placed at the window;

so that a thermally conductive paste is disposed between the metal sheet and the first flexible insulating film.

5. The method of claim 1, wherein:

in step S5:

firstly coating heat-conducting glue on the metal sheet or coating heat-conducting glue on the second flexible insulating film;

then covering a second flexible insulating film on the metal sheet;

so that a thermally conductive paste is disposed between the metal sheet and the second flexible insulating film.

6. The method of claim 1, wherein:

prior to step S7:

filling liquid insulating pouring sealant material in the cavity, and then solidifying the liquid insulating pouring sealant material.

7. The method of claim 1, wherein:

the edge of the tray is provided with a side edge which is vertical to the flat-plate-shaped body part of the tray;

the circuit board is close to the flat-plate-shaped body part of the tray and is enclosed inside the flat-plate-shaped body part by the side edge.

8. The method of claim 7, wherein:

one or more positioning upright posts are arranged on the flat-plate-shaped body part of the tray;

one or more positioning holes are formed in the circuit board;

in step S6:

each positioning column is aligned with and penetrates through a corresponding positioning hole in the circuit board to realize the positioning of the circuit board on the tray.