Circuit board

Abstract

A circuit board according to an embodiment of the present invention may comprise: a heat-generating element disposed on one side of the circuit board; first thermal epoxy disposed on one side of the circuit board and covering at least a portion of the side surface and at least a portion of the lower surface of the heat-generating element; second thermal epoxy disposed on the other side of the circuit board; and a via disposed on the circuit board and connecting the first thermal epoxy and the second thermal epoxy.

Description

circuit board

[0001] The present invention relates to a circuit board, and more specifically, to a circuit board having a heating element arranged thereon.

[0002] A circuit board is a substrate containing circuit patterns on an electrically insulating substrate, serving as a board for mounting electronic components. Various electronic components can be mounted on a circuit board, some of which are heat-generating elements that release heat during operation. For example, driver ICs (Integrated Circuits) are heat-generating elements. These heat-generating elements emit a significant amount of heat. If the heat generated by these elements is not sufficiently dissipated externally, it can raise the temperature of the circuit board and the components placed on it, potentially causing malfunctions and reliability issues in the product containing the circuit board. This is particularly difficult when the product itself is small, as it makes it even harder to remove internal heat to the outside.

[0003] Heat dissipation methods for circuit boards must consider various factors ranging from the design stage to manufacturing and the operating environment of the final product. Specifically, heat dissipation methods include optimizing the design and layout of the circuit board, utilizing thermal interface materials, attaching heat dissipation devices, and actively cooling with fans or liquids.

[0004] The technical problem that the embodiments of the present invention aim to solve is to provide a circuit board with improved heat dissipation effect.

[0005] The technical problem that the embodiments of the present invention aim to solve is to provide a circuit board capable of rapidly dissipating heat generated from a heat-generating element disposed on the circuit board to the outside.

[0006] The technical problem that the embodiments of the present invention aim to solve is to provide a circuit board that further includes a thermal path through which heat can be released.

[0007] The technical problem that the embodiments of the present invention aim to solve is to provide a circuit board with enhanced heat dissipation effect so that circuit components disposed on the circuit board can operate normally.

[0008] The problems to be solved in the embodiments of the present invention are not limited thereto, and may also include objectives or effects that can be identified from the means for solving the problems or embodiments described below.

[0009] A circuit board according to an embodiment of the present invention may include a heating element disposed on one side of the circuit board, a first thermal epoxy disposed on one side of the circuit board and covering at least a portion of the side surface and at least a portion of the bottom surface of the heating element, a second thermal epoxy disposed on the other side of the circuit board, and a via disposed on the circuit board and connecting the first thermal epoxy and the second thermal epoxy.

[0010] A circuit board according to an embodiment of the present invention further includes at least one via, and the at least one via may be disposed below the heating element.

[0011] In a circuit board according to an embodiment of the present invention, a photo solder resist (PSR) may be further disposed between the second thermal epoxy and the at least one via.

[0012] A circuit board according to an embodiment of the present invention further comprises a back yoke composed of a thermally conductive material, and the back yoke may be further disposed in the second thermal epoxy.

[0013] A circuit board according to an embodiment of the present invention further includes a bracket, and the bracket may be further disposed at the lower part of the back yoke.

[0014] A circuit board according to an embodiment of the present invention may be characterized in that the vias are filled with a thermally conductive material or coated with a thermally conductive material.

[0015] In a circuit board according to an embodiment of the present invention, the thermally conductive material may be at least one of epoxy resin, copper, and gold.

[0016] In a circuit board according to an embodiment of the present invention, the first thermal epoxy and the second thermal epoxy may be the same material.

[0017] A circuit board according to an embodiment of the present invention may further include a thermal pad between the first thermal epoxy and the circuit board.

[0018] A circuit board according to an embodiment of the present invention includes a heating element disposed on one side of the circuit board, a first thermal epoxy, a second thermal epoxy disposed on the other side of the circuit board, and a via penetrating the circuit board, wherein the first thermal epoxy covers at least a portion of the side and at least a portion of the bottom of the heating element, and the via can connect the first thermal epoxy and the second thermal epoxy.

[0019] According to an embodiment of the present invention, heat generated from a heat-generating element disposed on a circuit board can be rapidly released to the outside.

[0020] According to an embodiment of the present invention, the heat dissipation effect of the circuit board is enhanced so that circuit components placed on the circuit board can operate within a temperature range where normal operation is possible.

[0021] According to an embodiment of the present invention, a heat path can be further provided through which heat generated in a circuit board can be released to the outside.

[0022] The various and beneficial advantages and effects of the present invention are not limited to those described above and may be more easily understood in the process of explaining specific embodiments of the present invention.

[0023] Figure 1 is an example of a cross-sectional view of a portion of a circuit board where a heating element is placed.

[0024] Figures 2a and 2b are examples of text captured at different times using a camera module that includes a circuit board with the same configuration as Figure 1.

[0025] FIG. 3 is a cross-sectional view of a portion in which a heating element is arranged on a circuit board according to one embodiment of the present invention.

[0026] FIG. 4 is a drawing showing, as an example, a part of a camera module to which the circuit board of FIG. 3 is applied, and

[0027] FIG. 5 is a cross-sectional view of the portion (410) in FIG. 4 where the circuit board is placed.

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0029] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0030] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0031] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0032] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0033] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0034] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0035] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0036] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0037] The present invention relates to heat dissipation of a circuit board in which a heating element is disposed, and a detailed description of the electrical connection between the heating element and the circuit board is omitted. In the following description, the circuit board is described as a single-layer circuit board, but is not limited thereto.

[0038] Figure 1 is an example of a cross-sectional view of a portion of a circuit board where a heating element is placed.

[0039] Specifically, this shows a structural diagram of a circuit board considering heat dissipation when a heat-generating element is placed on the circuit board. Various design techniques can be applied to the circuit board to dissipate heat emitted from the heat-generating element to the outside. For example, the circuit pattern can be designed so that the heat-generating elements are not adjacent to each other, or the heat-generating elements can be placed at the edges of the circuit board to facilitate heat diffusion. Alternatively, a heat sink can be attached to the heat-generating element, or / and a cooling fan can be attached. Figure 1 shows an example in which a thermal via (or hole) is placed on the circuit board to dissipate heat emitted from the heat-generating element to the outside through the thermal via. The heat generated by the heat-generating element can be transferred to the side of the circuit board opposite to the side where the heat-generating element is placed through the thermal via of the circuit board.

[0040] Referring to FIG. 1, a heating element (120) may be disposed on one side of a circuit board (110), and a plurality of thermal vias (130) may be disposed on the lower side of the heating element (120). According to one embodiment, the thermal vias (130) may be filled with a thermally conductive material or the thermally conductive material may be applied to the surface of the thermal vias (130). Examples of thermally conductive materials may include epoxy resin, copper, gold, etc. The number and / or density of the thermal vias (130) may vary depending on the heat emitted from the heating element (120). Generally, the thermal conductivity efficiency may be higher as the number and density of the thermal vias (130) increase, but this may increase manufacturing costs and time, and weaken the mechanical strength of the circuit board (110). Also, if the size of the thermal vias (130) is too small, it may be difficult to manufacture and the thermal conductivity efficiency may be poor. However, if the size of the thermal via (130) is too large, the problem of liquid solder being sucked into the via during soldering may occur.

[0041] Meanwhile, the circuit board (110) may further include vias (140) in addition to the lower surface of the heating element (120). Vias are arranged on the circuit board (110) to transfer heat, but vias can also be arranged to transfer electrical signals.

[0042] According to one embodiment, a photo solder resist (PSR) (150) may be applied to both sides of a circuit board (110) with a certain thickness. The PSR (150) may be, for example, an indegradable ink and can prevent electrical short circuits or pattern damage from occurring in the exposed parts of the circuit board (110). However, heat transfer may be blocked by the PSR (150) applied to the circuit board (110). In FIG. 1, heat generated from a heat-generating element (120) may not be released to the outside through a thermal via (130) due to the PSR applied to the lower surface of the circuit board (110).

[0043] According to one embodiment, if heat generated from a heat-generating element placed on a circuit board is not sufficiently released to the outside, the heat may affect the performance of other circuit elements in addition to the heat-generating element and / or the performance of a device including the circuit board.

[0044] Figures 2a and 2b are examples of text captured at different times using a camera module that includes a circuit board with the same configuration as Figure 1.

[0045] FIGS. 2A and FIGS. 2B show the same text captured by a single camera module. That is, FIGS. 2A and FIGS. 2B are drawings in which all conditions related to the camera module are identical, differing only in the time at which the camera module is operated and captured. Specifically, FIGS. 2A shows text captured 5 seconds after the camera module is operated, and FIGS. 2B shows text captured 3 minutes after the camera module is operated.

[0046] Comparing Fig. 2a and Fig. 2b, it can be seen that the resolution of the text shown in Fig. 2a is better than the resolution of the text shown in Fig. 2b. Shortly after the camera module is activated, the camera module operates normally and the resolution of the captured text is good; however, after a certain amount of time has passed since the camera module began operation, it can be judged that the performance of the camera module has deteriorated. This is due to heat generation in the camera module, or more precisely, because the heat from the heat-generating elements included in the camera module's circuit board is not sufficiently dissipated to the outside, causing the operating temperature of the electronic components included in the camera module to rise. Although various techniques for heat dissipation are applied within the camera module, these techniques alone may not be sufficient for heat dissipation.

[0047] FIG. 3 is a cross-sectional view of a portion in which a heating element is arranged on a circuit board according to one embodiment of the present invention.

[0048] Referring to FIG. 3, a heating element (120) may be disposed on one side of a circuit board (110) as in FIG. 1. Additionally, a plurality of vias (130, 140) may be disposed on the circuit board (110). At least some of these vias may be thermal vias for discharging heat generated from the heating element (120). For example, a via (130) disposed on the lower surface of the heating element (120) on the circuit board (110) may be a thermal via. According to one embodiment, the thermal via (130) may be filled with a thermally conductive material, or a thermally conductive material may be applied to the surface of the thermal via (130). Examples of thermally conductive materials may include epoxy resin, copper, gold, etc. The number and / or density of the thermal vias (130) may vary depending on the heat emitted from the heating element (120). Generally, the more thermal vias (130) there are and the higher the density, the higher the thermal conductivity efficiency may be, but this increases manufacturing costs and time, and may also weaken the mechanical strength of the circuit board (110). Also, if the size of the thermal vias (130) is too small, it may be difficult to manufacture and the thermal conductivity efficiency may be poor. However, if the size of the thermal vias (130) is too large, a problem may occur where liquid solder is sucked into the vias during soldering.

[0049] According to one embodiment, a PSR (150) may be applied to the lower surface of a circuit board (110) with a certain thickness. The PSR (150) may be, for example, an indegradable ink and can prevent electrical short circuits or pattern damage from occurring in the exposed portion of the circuit board (110). However, heat transfer may be blocked by the PSR (150) applied to the circuit board (110).

[0050] In FIG. 3, since the heat generated from the heating element (120) cannot be released to the outside through the thermal via (130) by the PSR (150) applied to the lower surface of the circuit board (110), a configuration for releasing the heat generated from the heating element (120) may be further included. Specifically, in FIG. 3, a thermal epoxy (310) may be further included to release the heat generated from the heating element (120). Here, the thermal epoxy (310) may refer to an epoxy capable of effectively transferring heat, which has excellent thermal conductivity. The thermal epoxy (310) may be placed on the upper surface of the circuit board (110) to directly receive the heat generated from the heating element (120). Additionally, the thermal epoxy (310) may directly receive heat by contacting at least a part of the heating element (120). The thermal epoxy (310) can come into direct contact with the thermal vias (140) of the circuit board (110) to release heat more quickly. At this time, the thermal vias (140) of the circuit board (110) may be located at a place other than the bottom surface of the heat-generating element (120).

[0051] According to one embodiment, thermal epoxy (310) may be further disposed (or applied) on the lower surface of the circuit board (110) to dissipate heat transferred to the lower surface of the circuit board (110) through the thermal via (140) of the circuit board (110). Since PSR (150) is disposed first and then thermal epoxy (310) is further disposed on the part where the pattern is disposed on the lower surface of the circuit board (110), electrical short circuits or pattern damage can be prevented.

[0052] According to one embodiment, a back yoke (320) may be further included on the lower surface of the circuit board (110). The back yoke (320) may perform the same or similar function as a heat sink. The back yoke (320) may release heat transferred to the thermal epoxy (310) to the outside.

[0053] As described above, FIG. 3 further discloses an additional path for discharging heat generated from a heating element (120), which follows the sequence from the heating element (120) to the thermal epoxy (310), the via (140) of the circuit board (110), the thermal epoxy (310), and the back yoke (320). Through the additional path disclosed in FIG. 3, heat generated from the heating element (120) can be rapidly discharged to the outside.

[0054] FIG. 4 is a plan view of a camera module with the cover removed, on which a circuit board is placed as an example, and FIG. 5 is a cross-sectional view of the portion (410) on which the circuit board is placed in FIG. 4.

[0055] For example, a camera module may include a cover, a first camera actuator, a second camera actuator, and a circuit board. The cover may cover the first camera actuator and the second camera actuator. The cover may improve the coupling force between the first camera actuator and the second camera actuator and may block electromagnetic waves. The first camera actuator may be an OIS (Optical Image Stabilizer) actuator. The first camera actuator may move an optical member in a direction perpendicular to the optical axis. The second camera actuator may be a zoom actuator or an AF (Auto Focus) actuator. The second camera actuator supports one or more lenses and may perform an auto-focusing function or a zoom function by moving the lenses according to a control signal from a predetermined control unit. The circuit board may be placed at the rear end of the second camera actuator. As a result, the circuit board may be placed close to the lens of the second camera actuator and the Hall sensor for moving the lens. Heat generated from the heat-generating element placed on the circuit board may affect the lens of the second camera actuator and the Hall sensor. This may cause the second camera actuator of the camera module to malfunction, resulting in reduced resolution.

[0056] Referring to FIG. 4, a circuit board may be placed on one side of a camera module (400) with the cover removed. The circuit board may be placed so as to be exposed for heat dissipation. FIG. 4 shows the circuit board in an upright position, and the portion (410) where the circuit board is placed is shown in enlarged detail. FIG. 5 shows a cross-sectional view taken along A-A' in the portion (410) where the circuit board is placed in FIG. 4 for more detailed examination.

[0057] Referring to FIG. 5, a heating element (510) may be disposed on one side of a circuit board (530). In a camera module, the heating element (510) may be, for example, a driver IC. To dissipate heat generated from the heating element (510) to the outside, a thermal epoxy (520) may be disposed to contact the heating element (510) and the circuit board (530). The thermal epoxy (520) may be in contact with at least a portion of the heating element (510), and heat dissipation may be easier as the contact surface area is larger. According to one embodiment, a thermal pad may be disposed on one side and the other side of the circuit board (530), and a thermal via (not shown) may be included. The thermal via may contact the thermal epoxy (520) to transfer heat generated from the heating element (510) to the opposite side of the circuit board (530). A back yoke (540) of a second camera actuator may be disposed on the other side of the circuit board (530). The back yoke (540) of the second camera actuator may be disposed such that the other side of the circuit board (530) contacts the back yoke (540) of the second camera actuator, such that the back yoke (540) of the second camera actuator has a thermal conductivity or is a component included in the second camera actuator. The camera module may include a bracket (560) for securing internal components. The bracket (560) may generally be made of a metal material (e.g., aluminum) and may have high thermal conductivity. In the camera module, thermal epoxy (550) may be further disposed between the back yoke (540) of the second camera actuator and the bracket (560) to further facilitate heat dissipation. According to the above configuration, heat generated from the heat-generating element (510) can be transferred in the order of thermal epoxy (520), circuit board (530), back yoke (540), thermal epoxy (550), and bracket (560) and released to the outside. In particular, if the bracket (560) is made of aluminum, it can function as a heat sink, allowing heat inside the camera module to be effectively released to the outside.According to one embodiment, if a metal component and thermal epoxy are utilized around a circuit board (530) in which a heating element (510) is placed within a camera module, a heat transfer path for discharging heat generated from the heating element (510) may be further configured.

[0058] Although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. In a circuit board, A heating element disposed on one side of the above circuit board; A first thermal epoxy disposed on one side of the circuit board and covering at least a portion of the side and at least a portion of the bottom of the heating element; A second thermal epoxy disposed on the other side of the circuit board; and A circuit board disposed on the circuit board and comprising a via connecting the first thermal epoxy and the second thermal epoxy.

2. In Paragraph 1, It includes at least one additional via, The above at least one via is a circuit board disposed below the heating element.

3. In Paragraph 2, A circuit board having a PSR (photo solder resist) further disposed between the second thermal epoxy and the at least one via.

4. In Paragraph 1, It further includes a back yoke composed of a thermally conductive material, and The above back yoke is a circuit board further disposed on the above second thermal epoxy.

5. In Paragraph 4, Includes additional brackets, The above bracket is a circuit board further positioned at the lower part of the above back yoke.

6. In Paragraph 1, A circuit board characterized in that the above vias are filled with a thermally conductive material or coated with a thermally conductive material.

7. In Paragraph 6, The above thermally conductive material is at least one of epoxy resin, copper, and gold, and is a circuit board.

8. In Paragraph 1, A circuit board in which the first thermal epoxy and the second thermal epoxy are of the same material.

9. In Paragraph 1, A circuit board further comprising a thermal pad between the first thermal epoxy and the circuit board.

10. In a circuit board, A heating element disposed on one side of the above circuit board and a first thermal epoxy; A second thermal epoxy disposed on the other side of the circuit board; and It includes vias penetrating the circuit board, and The first thermal epoxy above covers at least a portion of the side and at least a portion of the bottom of the heating element, and The above via is a circuit board connecting the first thermal epoxy and the second thermal epoxy.

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