CN216057610U

CN216057610U - Circuit board

Info

Publication number: CN216057610U
Application number: CN202121682656.8U
Authority: CN
Inventors: 朱泽春; 胡建卫; 张小川
Original assignee: Joyoung Co Ltd
Current assignee: Joyoung Co Ltd
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2022-03-15
Anticipated expiration: 2031-07-23

Abstract

The utility model relates to the field of electric appliances, in particular to a circuit board. It includes the plate body and sets up the silicon controlled rectifier on the plate body, and the silicon controlled rectifier includes the main part and sets up the pin in the main part, the plate body is including copper foil layer, the basic unit that from top to bottom piles up, the main part passes through the pin to be fixed on the copper foil layer, is equipped with naked tin face on the copper foil layer, and naked tin face is arranged around the silicon controlled rectifier and is exposed outside the copper foil layer in order to dispel the heat to the silicon controlled rectifier. The utility model improves and designs the heat dissipation structure on the circuit board, so that the circuit board can also utilize the limited space on the circuit board to carry out high-efficiency heat dissipation under the condition of omitting a radiator.

Description

Circuit board

Technical Field

The utility model relates to the field of electric appliances, in particular to a circuit board.

Background

The circuit board is an essential part on many electrical appliances, and liquid heaters such as electric kettles, health preserving kettles and the like all use the circuit board, and the circuit board comprises a board body and a silicon controlled rectifier arranged on the board body. The silicon controlled rectifier can produce a large amount of heat when working, has set up the radiator on the general product and dispels the heat to the silicon controlled rectifier. For example, chinese patent No. CN206293431U, entitled "a rapid mounting structure for a silicon controlled rectifier radiator" discloses a mounting structure of a circuit board, a heat dissipation aluminum base, and a silicon controlled rectifier, wherein the silicon controlled rectifier is electrically connected to the circuit board, the heat dissipation aluminum base is disposed on the circuit board and connected to one side of the silicon controlled rectifier, the mounting structure further includes a heat dissipation aluminum pressing sheet, the heat dissipation aluminum pressing sheet is disposed on the other side of the silicon controlled rectifier, and the heat dissipation aluminum base and the heat dissipation aluminum pressing sheet are mutually clamped and connected to clamp the silicon controlled rectifier.

However, the heat sink has a high cost and occupies a large space, and is not suitable for a modern liquid heater, and how to effectively dissipate heat by using the limited space of the circuit board is a problem to be solved.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects of high cost and large occupied space of the prior art caused by the fact that the circuit board utilizes a radiator to radiate the silicon controlled rectifier, the utility model aims to provide the circuit board, and the radiating structure on the circuit board is improved, so that the circuit board can also utilize the limited space on the circuit board to radiate heat efficiently under the condition of omitting the radiator.

In order to achieve the purpose, the utility model provides the following technical scheme: the utility model provides a circuit board, includes the plate body and sets up the silicon controlled rectifier on the plate body, and the silicon controlled rectifier includes the main part and sets up the pin in the main part, the plate body is including copper foil layer, the basic unit that from top to bottom piles up, the main part passes through the pin to be fixed on the copper foil layer, is equipped with naked tin face on the copper foil layer, and naked tin face is arranged around the silicon controlled rectifier and is exposed outside the copper foil layer in order to dispel the heat to the silicon controlled rectifier.

Among this technical scheme, thereby through soldering tin with pin welded fastening make the main part laminating fix on the copper foil layer, the heat transfer direction mainly has following several kinds of ways: the main part to copper foil layer, copper foil layer to basic unit, main part to pin, pin to soldering tin, copper foil layer to naked tin face to and the convection current between main part, pin, soldering tin, naked tin face and the air. Under this kind of mounting means, the silicon controlled rectifier has great area of contact with the copper foil layer, has good heat transfer effect, has arranged the naked tin face of large tracts of land around the silicon controlled rectifier simultaneously and has strengthened the radiating effect, has established the silicon controlled rectifier and has reached the fast heat transfer route of naked tin face to air to the copper foil layer, has saved the radiator, utilizes the finite space on the circuit board to dispel the heat high-efficiently to reduce silicon controlled rectifier weight volume, reduce cost.

The utility model is further configured to: the bare tin surface is formed by arranging dotted bare tin. Through this setting, sufficient clearance can be arranged each other to punctiform naked tin when arranging to strengthen the air convection between the naked tin, make the radiating effect of naked tin face better.

The utility model is further configured to: the bare tin surface is formed by arranging strip-shaped bare tin. Through this setting, banding naked tin is convenient for weld, also can guarantee when arranging that naked tin has certain clearance each other to strengthen the air convection between the naked tin, make the radiating effect of naked tin face better.

The utility model is further configured to: the bare tin is arranged into a plurality of rows from the controllable silicon to two sides, and the adjacent rows are mutually staggered. Through this setting, the texture of naked tin face is the brick wall formula, can arrange as much naked tin as possible on the finite space on the copper foil layer, can also guarantee to have the heat dissipation clearance between the naked tin simultaneously.

The utility model is further configured to: the bare tin is arranged in a vortex shape from the controlled silicon to the periphery. Through this setting, the texture of naked tin face is the vortex formula, except can guaranteeing the heat dissipation clearance between the naked tin, also has the gain effect to the hot convection of the cold and hot air in naked tin top.

The utility model is further configured to: the ratio of the area of the bare tin surface to the area of the copper foil layer is 0.5-0.8. Through this setting, the bigger naked tin face area, the heat dissipation income that brings is higher, but the corresponding production consumptive material expense that brings is also higher, simultaneously because of the arrangement of other components and parts and the consideration in naked tin heat dissipation clearance, naked tin face also can not be covered with whole copper foil layer, therefore the area of naked tin face should be optimizing in a suitable scope.

The utility model is further configured to: the plate body is provided with a convection groove or a convection hole which is arranged around the controllable silicon. The heat dissipation thermal resistance from the silicon controlled rectifier to the base layer to the air is the largest, the convection groove or the convection hole can solve the problem that the heat transfer efficiency is low due to the thermal resistance of the PCB base layer in the heat dissipation process of the silicon controlled rectifier, and in addition, the convection of cold air and hot air can be increased to form heat convection to improve the heat dissipation effect.

The utility model is further configured to: the convection groove or the convection hole extends along the current output direction of the thyristor. Through this setting, because the output direction of perpendicular fluting or other direction fluting easy blocking currents in the current direction, further lead to the temperature rise of silicon controlled rectifier, consequently to the chute or to the current output direction fluting of convection current hole along the silicon controlled rectifier, reasonable layout prevents to interfere with the output direction of current.

The utility model is further configured to: the convection grooves or the convection holes are symmetrically distributed on two sides of the current output direction of the controllable silicon. Through this setting, a plurality of convection grooves or convection hole increase radiating heat transfer, the thermal convection of silicon controlled rectifier, have promoted the radiating efficiency.

The utility model is further configured to: the distance between the convection groove or the convection hole and the silicon controlled rectifier is 0-1 mm. Through this setting, to the chute or press close to the silicon controlled rectifier to the convection current hole, guarantee the thermal convection effect.

The utility model has the advantages that: 1) thereby it fixes on the copper foil layer to make the main part laminating through soldering tin welding pin, under this kind of mounting means, the silicon controlled rectifier has great area of contact with the copper foil layer, good heat transfer effect has, simultaneously arranged the naked tin face of large tracts of land around the silicon controlled rectifier and strengthened the radiating effect, silicon controlled rectifier to copper foil layer to the fast heat transfer route of naked tin face to air has been established, the radiator has been saved, utilize the finite space on the circuit board to dispel the heat high-efficiently, with the volume of reducing silicon controlled rectifier weight, reduce cost. 2) The structure and the layout form of the bare tin surface are provided, and certain gaps can be ensured among the bare tin surfaces by the dotted or banded bare tin, so that the air convection among the bare tin surfaces is enhanced, and the heat dissipation effect of the bare tin surfaces is better. The layout of brick wall formula or vortex formula can arrange naked tin as much as possible on the finite space on the copper foil layer, can also guarantee to have the heat dissipation clearance between the naked tin simultaneously, also has the gain effect to the hot convection of naked tin top cold and hot air. 3) The convection groove or the convection hole is arranged on the circuit board to solve the problem that the heat transfer efficiency is low due to the thermal resistance of the PCB base layer in the heat dissipation process of the controllable silicon, and in addition, the convection of cold air and hot air can be increased to form heat convection to improve the heat dissipation effect. The convection groove or the convection hole is grooved along the current output direction of the silicon controlled rectifier, and the reasonable layout prevents the interference with the current output direction.

Drawings

Fig. 1 is a schematic structural diagram of a circuit board in embodiment 1 of the present invention;

FIG. 2 is a schematic diagram showing heat transfer of a wiring board in example 1 of the present invention;

FIG. 3 is a schematic structural view of a bare tin surface in example 1 of the present invention;

FIG. 4 is a schematic structural view of the bare tin surface in example 2 of the present invention;

fig. 5 is a structural view of a convection cell in example 3 of the present invention.

Reference numerals: the structure comprises a plate body 100, a copper foil layer 101, a base layer 102, bare tin 103, a convection groove 104, a thyristor 200, a main body 201 and pins 202.

Detailed Description

In the description of the present embodiment, it should be noted that, as the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "rear", etc. appear, their indicated orientations or positional relationships are based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" as appearing herein are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The utility model is further described with reference to the drawings and the specific embodiments in the following description.

Example 1: as shown in fig. 1 to 3, a circuit board includes a board body 100 and a thyristor 200 disposed on the board body 100, the thyristor 200 includes a main body 201 and a pin 202 disposed on the main body 201, the board body 100 includes a copper foil layer 101 and a base layer 102 stacked from top to bottom, the main body 201 is fixed on the copper foil layer 101 through the pin 202, the copper foil layer 101 is provided with a bare tin surface, and the bare tin surface is disposed around the thyristor 200 and exposed outside the copper foil layer 101 to dissipate heat of the thyristor 200.

In this embodiment, the lead 202 is fixed by soldering so that the main body 201 is attached to the copper foil layer 101, as shown in fig. 2, the arrow represents the heat transfer direction, and the heat transfer direction mainly includes the following ways: the main body 201 to the copper foil layer 101, the copper foil layer 101 to the base layer 102, the main body 201 to the pin 202, the pin 202 to the solder, the copper foil layer 101 to the bare tin surface, and convection between the main body 201, the pin 202, the solder, the bare tin surface and air. Under the installation mode, the controllable silicon 200 and the copper foil layer 101 have larger contact area and good heat transfer effect, meanwhile, a large-area bare tin surface is arranged around the controllable silicon 200 to enhance the heat dissipation effect, a rapid heat transfer path from the controllable silicon 200 to the copper foil layer 101 to the bare tin surface to the air is established, a heat radiator is omitted, limited space on a circuit board is utilized to efficiently dissipate heat, so that the weight and the volume of the controllable silicon 200 are reduced, and the cost is reduced.

The area of the copper foil layer 101 in contact with the thyristor 200 should be the maximum value within the allowable space range, which can bring the maximum heat dissipation gain improvement, but due to factors such as the shape, the space reserved for the circuit board cannot be increased greatly. After the heat sink is removed, the area of the copper foil layer 101 for assisting heat dissipation should be the minimum value in order to ensure the heat dissipation efficiency.

The minimum value of the heat dissipation area of the copper foil layer 101 is positively correlated with the power of the heating tube, so that the following area design scheme can be obtained:

S＝γ·P。

s is the minimum heat dissipation area of the copper foil layer 101.

Gamma is a defined proportion parameter, and is generally 1.25-1.4 mm²/W。

P is the power of the heating tube, and the commonly defined high power is 800-1200W.

The bare tin surface is formed by arranging the dotted bare tin 103 and can also be formed by arranging the banded bare tin 103, the dotted bare tin 103 is taken as an example in the embodiment, and enough gaps can be arranged between the dotted bare tin 103 when the dotted bare tin 103 is arranged, so that the air convection between the bare tin 103 is enhanced, and the heat dissipation effect of the bare tin surface is better.

Specifically, the larger the area of the bare tin surface, the higher the heat dissipation benefit is brought, but the higher the corresponding production consumable cost is brought, and meanwhile, in consideration of the arrangement of other components and the heat dissipation gap of the bare tin 103, the bare tin surface cannot be spread over the whole copper foil layer 101, so the area of the bare tin surface should be optimized in a proper range.

Here, the area of the bare tin surface can be correlated with the area of the copper foil layer 101: s_{Bare tin surface}＝(0.5-0.8)×S_{Copper foil layer 101}。

On the basis, the layout mode of the bare tin surface is related, the bare tin 103 is arranged into multiple rows from the controllable silicon 200 to two sides, the two adjacent rows are staggered mutually, brick wall textures are formed, the proportionality coefficient of the brick wall textures can be close to 0.8, poor processes such as tin connection reduction and tin eating prevention can be achieved in the circuit board production wave soldering process link to the maximum extent, the bare tin 103 can be arranged on the limited space on the copper foil layer 101 as much as possible, and meanwhile, the heat dissipation gap between the bare tin 103 can be guaranteed.

Example 2: based on the structure in the above embodiment, the difference lies in the layout form of the bare tin surface, as shown in fig. 4, in this embodiment, the bare tin 103 is arranged from the controllable silicon 200 to the periphery in a vortex shape to form a vortex diffusion texture, and this texture not only can ensure the heat dissipation gap between the bare tin 103, but also has a gain effect on the heat convection of the cold and hot air above the bare tin 103.

Example 3: based on the structure in the above-mentioned embodiment, the difference is that, as shown in fig. 5, a convection groove 104 or a convection hole is provided on the plate body 100 in this embodiment, and the convection groove 104 or the convection hole is arranged around the thyristor 200. The thermal resistance of the thyristor 200 to the substrate 102 to the air is the largest, and on the basis, a reasonable open-hole and open-slot structure is involved to increase the heat dissipation efficiency, and the convection slot 104 or the convection hole can solve the problem of low heat transfer efficiency caused by the thermal resistance of the PCB substrate 102 in the heat dissipation process of the thyristor 200, and can also increase the convection of cold and hot air to form heat convection to improve the heat dissipation effect.

The position of the slot or the hole of the plate 100 determines the heat dissipation gain effect, because the vertical slot or the other slots in the current direction easily block the output direction of the current, further resulting in the temperature rise of the thyristor 200, therefore the convection slot 104 or the convection hole is slotted along the current output direction of the thyristor 200 (the arrow direction in fig. 5 is the current output direction of the thyristor 200), and is located at both sides of the thyristor 200, and the heat dissipation efficiency is improved by the heat transfer and the heat convection of the heat dissipation of the thyristor 200 increased by the convection slots 104 or the convection holes, which are reasonably arranged and prevented from interfering with the current output direction.

Because of the higher thermal resistance of the substrate 102, the slots or openings can provide the benefits of increased air convection and increased heat transfer between the thyristors 200 and the air. But at the same time, the notching or opening position is also located in the area of the copper foil layer 101, which brings the negative benefit of losing the heat conduction of the copper foil layer 101.

The design of the slots or openings can thus be optimized, taking runner 104 as an example:

convection groove 104 width: generally, the diameter is 1.0mm-2.5 mm.

Convection groove 104 length: equal to the plastic package size length of the thyristor 200.

Distance between convection groove 104 and thyristor 200: preferably 0-1 mm.

The above embodiments are only for further illustration of the present invention, and should not be construed as limiting the scope of the present invention, and the technical engineers in the art can make insubstantial modifications and adaptations of the present invention based on the above disclosure and disclosure of the utility model.

Claims

1. The utility model provides a circuit board, includes the plate body and sets up the silicon controlled rectifier on the plate body, and the silicon controlled rectifier includes the main part and sets up the pin in the main part, its characterized in that: the plate body is including copper foil layer, the basic unit that from top to bottom piles up, the main part passes through the pin to be fixed on the copper foil layer, is equipped with naked tin face on the copper foil layer, and naked tin face is arranged around the silicon controlled rectifier and is exposed outside the copper foil layer in order to dispel the heat to the silicon controlled rectifier.

2. A wiring board according to claim 1, wherein: the bare tin surface is formed by arranging dotted bare tin.

3. A wiring board according to claim 1, wherein: the bare tin surface is formed by arranging strip-shaped bare tin.

4. A wiring board according to claim 2 or 3, characterized in that: the bare tin is arranged into a plurality of rows from the controllable silicon to two sides, and the adjacent rows are mutually staggered.

5. A wiring board according to claim 2 or 3, characterized in that: the bare tin is arranged in a vortex shape from the controlled silicon to the periphery.

6. A circuit board according to claim 1, 2 or 3, wherein: the ratio of the area of the bare tin surface to the area of the copper foil layer is 0.5-0.8.

7. A wiring board according to claim 1, wherein: the plate body is provided with a convection groove or a convection hole which is arranged around the controllable silicon.

8. A circuit board according to claim 7, wherein: the convection groove or the convection hole extends along the current output direction of the thyristor.

9. A wiring board according to claim 7 or 8, wherein: the convection grooves or the convection holes are symmetrically distributed on two sides of the current output direction of the controllable silicon.

10. A wiring board according to claim 7 or 8, wherein: the distance between the convection groove or the convection hole and the silicon controlled rectifier is 0-1 mm.