Transformer circuit and substrate including same

Abstract

A transformer circuit according to an embodiment of the present invention comprises: a power input unit; and a transformer for transforming a voltage input from the power input unit and including a primary-side transformer unit and a secondary-side transformer unit, wherein a moisture-proofing agent is applied to an EMI filter, a bridge diode, a flyback transformer, a flyback IC, and a photo coupler included in the primary-side transformer unit.

Description

Transformer circuit and substrate including the same

[0001] The present invention relates to a transformer circuit and a substrate including the same.

[0002] In general, a printed circuit board is a circuit board in which many different types of components, such as integrated circuits (ICs) or resistors, are densely mounted on a flat plate made of paper phenol resin or glass epoxy resin, and the circuits connecting each component are densely packed and fixed on the surface of the resin plate.

[0003] The circuit board is composed of a pattern layer on which the actual circuit diagram is drawn, a solder layer on which electronic components are soldered using surface mount technology (SMT), and a silk layer laminated at the very top to enable the circuit diagram to be recognized by the naked eye. These printed circuit boards have been gradually becoming more dense in recent years due to the advancement of electronic technology.

[0004] Electronic devices used in environments prone to humidity and moisture typically have their printed circuit boards coated to protect the circuitry within. This coating is necessary because if water, a polar substance, comes into contact with the exposed copper foil, the water acts as a conductor between the copper foil and causes a short circuit, ultimately leading to failure of the electronic device.

[0005] The technical problem to be solved by the present invention is to provide a transformer circuit and a substrate including the same.

[0006] In order to solve the above technical problem, a transformer circuit according to an embodiment of the present invention includes a power input unit; and a transformer that transforms a voltage input from the power input unit and includes a primary-side transformer unit and a secondary-side transformer unit, and a desiccant is applied to an EMI filter, a bridge diode, a flyback transformer, a flyback IC, and a photocoupler included in the primary-side transformer unit.

[0007] The viscosity of the above desiccant can satisfy 2500 cP or more and 3500 cP or less at 25°C.

[0008] The above-mentioned desiccant can satisfy a coating thickness of 45 um or more and 55 um or less.

[0009] The desiccant includes a first region for applying the EMI filter and the bridge diode, a second region for applying the flyback transformer and the flyback IC, and a third region for applying the photocoupler, and the first region, the second region, and the third region can be spaced apart from each other.

[0010] In order to solve the above technical problem, a substrate including a transformer circuit according to an embodiment of the present invention includes a substrate including a plurality of solder masks spaced apart from each other; and a primary-side transformer and a secondary-side transformer arranged on the substrate, wherein the primary-side transformer includes an EMI filter, a bridge diode, a flyback transformer, a flyback IC, and a photocoupler, and the secondary-side transformer includes first and second diodes, an inductor, and a driver IC connected to an output terminal of the flyback transformer, and a desiccant is applied to the primary-side transformer.

[0011] The desiccant may be applied to the first diode of the secondary side transformer, and the first diode may be placed on a solder mask where the photo coupler is placed.

[0012] A solder mask including a ground is formed in a corner area of ​​the substrate, and at least a portion of a component constituting the secondary side transformer can be placed on the solder mask including the ground.

[0013] At least some of the components constituting the primary side transformer may not be placed on the solder mask including the ground.

[0014] The viscosity of the above-mentioned desiccant satisfies 2500 cP or more and 3500 cP or less at 25°C, and the above-mentioned desiccant satisfies a coating thickness of 45 um or more and 55 um or less.

[0015] The above desiccant may be applied so as to extend from the center of the area corresponding to the plurality of solder masks to the edge portion or to cover a predetermined distance from the edge portion in the outer direction of the solder mask.

[0016] The above desiccant may be applied to each area corresponding to a plurality of solder masks on which components constituting the primary side transformer are arranged, and the desiccant corresponding to each area may be arranged to be spaced apart from each other.

[0017] The above desiccant may be applied to each area corresponding to a plurality of solder masks on which components constituting the primary side transformer are arranged, and the desiccant corresponding to each area may be arranged to be partially connected.

[0018] According to the present embodiments, a desiccant can be applied to a portion of a substrate vulnerable to surge voltage to strengthen insulation and prevent damage to components due to ESD (Electrostatic Discharge).

[0019] Additionally, the desiccant covers the solder area, protecting the components from external impact.

[0020] Figure 1 is a drawing for explaining a technique for applying a desiccant on a substrate.

[0021] Figure 2 illustrates an area where a desiccant is applied in a transformer circuit according to the present embodiment.

[0022] FIGS. 3 and 4 illustrate an area where a desiccant is applied on a substrate including a transformer circuit according to the present embodiment.

[0023] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0024] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0025] In addition, terms (including technical and scientific terms) used in this embodiment may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which this embodiment belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0026] Additionally, the terms used in this embodiment are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0027] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0028] Additionally, in describing the components of this embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0029] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0030] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0031]

[0032] FIG. 1 is a drawing for explaining a technique for applying a desiccant on a substrate, FIG. 2 illustrates an area where a desiccant is applied in a transformer circuit according to the present embodiment, and FIGS. 3 and 4 illustrate an area where a desiccant is applied in a substrate including a transformer circuit according to the present embodiment.

[0033] Referring to Fig. 1(a), the exposed portion of the solder (20) of the substrate (10) is not separately insulated, and the spaced solders (20) can be insulated with air. However, when a high surge voltage is momentarily applied, the insulation of the air may be destroyed, potentially resulting in damage to the components. Furthermore, for electronic devices used in environments where they may be easily exposed to humidity or moisture, it is necessary to protect the components and circuits contained therein.

[0034] Referring to Fig. 1(b), a desiccant (30) can be applied to the exposed portion of the solder (20) of the substrate (10) to strengthen insulation. This can strengthen insulation between solders (20) that are spaced apart from each other, and prevent damage to components vulnerable to surge voltage and damage to components caused by external impact.

[0035] The transformer circuit and the substrate including the same according to the present embodiment may include a power input unit (11) and a transformer including a primary side transformer unit and a secondary side transformer unit.

[0036] External power can be applied to the transformer circuit through the power input unit (11). The power applied through the power input unit (11) can be AC ​​90 V to AC 264 V. The power applied through the power input unit (11) can vary depending on the characteristics of the load connected to the transformer circuit.

[0037] The primary side transformer of the transformer may include a filter (12), a bridge diode (13), a flyback transformer (15), a flyback IC (14), and a photocoupler (16).

[0038] The filter (12) may be an EMI filter. The filter (12) may be connected to the power input section (11) to reduce noise from AC power. The bridge diode (13) is an electronic component used to rectify AC power and convert AC power into DC power. The bridge diode (13) may be connected between the output terminal of the filter (12) and the input terminal of the flyback transformer (15).

[0039] A flyback transformer (15) is used to convert low-voltage DC power into high-voltage DC power or to convert AC power into DC power of various voltages. The flyback transformer (15) can form insulation between the primary side transformer and the secondary side transformer for safety in a flyback circuit.

[0040] The photo coupler (16) is a component that prevents electrical interference when transmitting signals between high-voltage and low-voltage circuits, and transmits the output signal status to the driving IC outside the board while satisfying insulation. The photo coupler (16) is a component placed between the primary side transformer and the secondary side transformer and may be vulnerable to surge voltage. Through the photo coupler (16)

[0041] The voltage output from the flyback transformer (15) is sensed, and the flyback IC (14) monitors the sensed voltage to ensure that the voltage remains constant, and adjusts the operation of the flyback transformer (15) as needed to maintain a stable output.

[0042] The secondary side transformer of the transformer may include a first diode (D1) and a second diode (D2) connected to the output terminal of the flyback transformer (15), an inductor (18), and a driver IC (19).

[0043] The first diode (D1) may be placed between the output terminal of the flyback transformer (15) and an LED placed in an external area of ​​the substrate. The second diode (D2) may be connected to the output terminal of the flyback transformer (15), and a photo coupler (16) may be connected to the output terminal of the second diode (D2). The first diode (D1) and the second diode (D2) may be diodes that prevent reverse voltage.

[0044] An inductor (18) and a driver IC (19) can control the brightness of an LED (17) placed in an external area of ​​a substrate. The inductor (18) can store energy and transfer it to an external load to maintain a stable output voltage. The inductor (18) may be a buck inductor. The driver IC (19) can control a driving signal that controls the brightness of the LED (17).

[0045]

[0046] The substrate may include a plurality of spaced apart solder masks. The solder masks are polymer-coated areas used to protect circuit patterns on the substrate, and solder may be formed on the solder masks to which electronic components are soldered. Electronic components that are connected to each other may be placed on one solder mask area. Electronic components placed on the spaced apart solder masks may be insulated from each other. Unsoldered areas may be placed between the spaced apart solder masks. A solder mask including a ground (G) may be formed on a corner area of ​​the substrate.

[0047] A desiccant may be applied to components included in the primary side transformer. The desiccant may be applied to the filter (12), bridge diode (13), flyback transformer (15), flyback IC (14), and photocoupler (16) included in the primary side transformer. Additionally, the desiccant may be applied to the first diode (D1) of the secondary side transformer. The first diode (D1) may be arranged adjacent to the photocoupler (16) on the substrate.

[0048] At least some of the components constituting the secondary-side transformer may be placed on a solder mask including a ground (G). Components constituting the secondary-side transformer, excluding the first diode (D1), may be placed on a solder mask including a ground (G). At least some of the components constituting the primary-side transformer may not be placed on a solder mask including a ground (G). Not all of the components constituting the primary-side transformer may be placed on a solder mask including a ground (G).

[0049]

[0050] Referring to FIGS. 2 to 4, in the transformer circuit and the substrate including the same according to the present embodiment, a desiccant may be applied to an area A where a filter (12) and a bridge diode (13) are placed, an area B where a flyback transformer (15) and a flyback IC (14) are placed, and an area C where a photocoupler (16) is placed. The area C may extend to an area where a first diode (D1) adjacent to the photocoupler (16) is placed. An area E where components included in the secondary transformer are placed may be formed on a solder mask including a ground (G). The area E and areas A to C may be physically separated through an area that is not solder masked.

[0051]

[0052] The desiccant material may be made of silicone or epoxy. The viscosity of the desiccant may be 2500 cP or more and 3500 cP or less at 25°C, and preferably, the viscosity of the desiccant may be 2800 cP or more and 3200 cP or less at 25°C. When the viscosity of the desiccant satisfies the above numerical range, the process cost and material cost can be reduced by applying an appropriate amount of the desiccant, and sufficient insulation effect can be provided in areas vulnerable to surge voltage.

[0053] If the desiccant content exceeds the upper limit of the above-mentioned numerical range, the desiccant application process becomes difficult. If the desiccant content falls below the lower limit of the above-mentioned numerical range, the viscosity of the desiccant may be excessively thin, making it difficult to maintain the desired shape.

[0054] Specifically, a jig such as a nozzle machine is used to pour the desiccant into the center of the solder mask where the desiccant is to be applied, and the desiccant can be spread and applied to the edge area of ​​the solder mask according to the flowability based on the viscosity of the desiccant.

[0055] In other words, the amount of desiccant can be determined based on the viscosity of the desiccant and the size of the solder mask to which the desiccant is to be applied, and the desiccant can be poured onto the substrate.

[0056] The desiccant may be applied to extend from the center of an area corresponding to a plurality of solder masks to cover an edge portion or an outer distance from the edge portion to the solder mask.

[0057] The above preset interval may be within 2 cm.

[0058] As an example, the desiccant may be applied to each area corresponding to a plurality of solder masks on which components constituting the primary side transformer are arranged, and the desiccant corresponding to each area may be spaced apart from each other.

[0059] For example, a desiccant may be poured onto an area corresponding to a solder mask, and the desiccant may be applied to an area corresponding to the solder mask or an area exceeding a preset interval from the area corresponding to the solder mask.

[0060] Accordingly, the desiccant may include a first region where a filter (12) and a bridge diode (13) are applied, a second region where a flyback transformer (15) and a flyback IC (14) are applied, and a third region where a photo coupler (16) is applied, and the first region, the second region, and the third region may be spaced apart from each other.

[0061] The first region can correspond to region A, the second region can correspond to region B, and the third region can correspond to region C. The first region can be formed larger than region A. The second region can be formed larger than region B. The third region can be formed larger than region C.

[0062] Alternatively, as another embodiment, the desiccant may be applied to each region corresponding to a plurality of solder masks on which components constituting the primary transformer are arranged, such that the desiccant corresponding to each region is partially connected. Two regions adjacent to each other among the first to third regions may be connected. The first to third regions may be connected to each other as a single region.

[0063] A desiccant may be poured into an area corresponding to a solder mask, and the desiccant may be applied to an area exceeding a predetermined distance from the area corresponding to the solder mask. If the substrate is small, some areas of the desiccant applied in the excess area may come into contact.

[0064] Therefore, the viscosity of the desiccant is adjusted to a specific value based on room temperature, so that the desiccant can be applied to each desired circuit area.

[0065] The coating thickness of the desiccant can satisfy a range of 45 um to 55 um, and preferably, the coating thickness of the desiccant can satisfy a range of 48 um to 52 um. The coating thickness of the desiccant can mean the thickness from the upper surface of the substrate in the direction penetrating the substrate. When the coating thickness of the desiccant satisfies the above numerical range, it can have a sufficient insulating effect in an area vulnerable to surge voltage, and can prevent damage to the desiccant and damage to components due to external impact.

[0066] If the thickness of the desiccant coating exceeds the upper limit of the above numerical range, the amount of desiccant applied increases, leading to increased material costs. If the thickness of the desiccant coating falls below the lower limit of the above numerical range, sufficient insulation is not achieved, and the desiccant may fall off or crack due to external impact.

[0067]

[0068] Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from the essential characteristics of the above-described description. Therefore, the disclosed methods should be considered illustrative rather than restrictive. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

1. Power input; and It includes a transformer that transforms the voltage input from the power input section and includes a primary side transformer section and a secondary side transformer section, A transformer circuit in which a desiccant is applied to an EMI filter, a bridge diode, a flyback transformer, a flyback IC, and a photocoupler included in the primary side transformer section.

2. In paragraph 1, A transformer circuit that satisfies the viscosity of the above desiccant of 2500 cP or more and 3500 cP or less at 25℃.

3. In paragraph 1, The above desiccant is a transformer circuit that satisfies a coating thickness of 45 um or more and 55 um or less.

4. In paragraph 1, The above desiccant includes a first region for applying the EMI filter and the bridge diode, a second region for applying the flyback transformer and the flyback IC, and a third region for applying the photocoupler. A transformer circuit in which the first region, the second region, and the third region are spaced apart from each other.

5. A substrate comprising a plurality of solder masks spaced apart from each other; and It includes a primary side transformer and a secondary side transformer arranged on the above substrate, The above primary side transformer includes an EMI filter, a bridge diode, a flyback transformer, a flyback IC, and a photocoupler. The secondary side transformer includes first and second diodes, an inductor, and a driver IC connected to the output terminal of the flyback transformer, A substrate including a transformer circuit in which a desiccant is applied to the primary transformer section.

6. In paragraph 5, The desiccant is applied to the first diode of the secondary transformer, A substrate including a transformer circuit disposed on a solder mask on which the photocoupler is disposed, wherein the first diode is disposed.

7. In paragraph 5, A solder mask including a ground is formed in the corner area of ​​the above substrate, A substrate including a transformer circuit, wherein at least a portion of the components constituting the secondary side transformer are arranged on a solder mask including the ground.

8. In paragraph 7, A substrate including a transformer circuit in which at least some of the components constituting the primary side transformer are not placed on a solder mask including the ground.

9. In paragraph 5, The viscosity of the above desiccant satisfies 2500cP or more and 3500cP or less at 25℃, The above desiccant is a substrate including a transformer circuit that satisfies a coating thickness of 45 um or more and 55 um or less.

10. In paragraph 5, A substrate in which the desiccant is applied so as to extend from the center of an area corresponding to the plurality of solder masks and cover an edge portion or a predetermined distance from the edge portion toward the outside of the solder mask.

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