Thin film circuit board

Abstract

To provide a thin film circuit board.SOLUTION: A thin film circuit board 100 includes a substrate and a heat dissipation sheet 120. The heat dissipation sheet 120 is attached to the substrate, and includes: a first heat dissipation part 121; a second heat dissipation part 122; and a third heat dissipation part 123. Since the contour of the heat dissipation sheet 120 has a non-rectangular polygonal shape, a stress generated by the heat dissipation sheet 120 and the substrate may be reduced, thereby preventing wrapping of the thin film circuit board 100. A first chip shadow 200a is formed on the first heat dissipation part 121. An imaginary line Y passes through the first heat dissipation part 121, the second heat dissipation part 122, and the third heat dissipation part 123. A third width W3 of the third heat dissipation part 123 is not smaller than a first width W1 of the first heat dissipation part 121 and a second width W2 of the second heat dissipation part 122. The heat dissipation sheet 120 includes a first notch part 124 located at the first heat dissipation portion 121 and exposing the substrate, and the first chip shadow 200a is located between the first notch part 124 and the third heat dissipation part 123.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a thin-film circuit board, and more particularly to a thin-film circuit board provided with a non-rectangular polygonal heat dissipation sheet.

Background Art

[0002] Conventional thin-film flip-chip package processes adopt a roll-to-roll transport method to perform various processes (e.g., heat dissipation sheet attachment and flip-chip bonding processes), cut a circuit board tape into a plurality of thin-film flip-chip packages, sandwich each of the thin-film flip-chip packages with a jig, and bond each of the thin-film flip-chip packages to an electronic element (e.g., a display panel or a circuit board).

Summary of the Invention

Problems to be Solved by the Invention

[0003] A conventional thin-film circuit board 10 includes a substrate 11 and a heat dissipation sheet 12 (see FIGS. 1 and 2). The heat dissipation sheet 12 is attached to the surface 11a of the substrate 11 by an adhesive 13, a chip 20 is bonded to the other surface 11b of the substrate 11, and the heat dissipation sheet 12 is used to reduce the temperature during the operation of the chip 20. However, since the material properties (e.g., plasticity, ductility, thermal expansion coefficient, etc.) of the substrate 11, the heat dissipation sheet 12, and the adhesive 13 are different, when the substrate 11, the heat dissipation sheet 12, and the adhesive 13 are affected by the process environment temperature or clamped by a jig, warpage or bending occurs in the thin-film circuit board 10, and the thin-film circuit board 10 cannot be accurately bonded to an electronic element.

[0004] The inventor of the present invention considered that the above-mentioned drawbacks could be improved, and as a result of intensive studies, the present invention was proposed to effectively improve the above-mentioned problems through a rational design.

[0005] As a result of intensive studies, the inventors of the present invention have found that the above object can be achieved by adopting a configuration of a thin film circuit board that prevents warping and bending of the thin film circuit board by attaching a non-rectangular polygon heat dissipation sheet to a substrate, and have completed the present invention.

Means for Solving the Problems

[0006] In order to solve the above problems, a thin film circuit board according to an aspect of the present invention includes a substrate and a heat dissipation sheet. The substrate has a first surface and a second surface, and the second surface is used for bonding a first chip and a second chip. The heat dissipation sheet is attached to the first surface of the substrate, and the contour of the heat dissipation sheet presents a non-rectangular polygon. The heat dissipation sheet has a first heat dissipation portion, a second heat dissipation portion, and a third heat dissipation portion. The third heat dissipation portion is located between the first heat dissipation portion and the second heat dissipation portion, and the third heat dissipation portion is connected to the first heat dissipation portion and the second heat dissipation portion. The first chip and the second chip are installed on the heat dissipation sheet, and a first chip shadow and a second chip shadow are respectively formed. The first chip is installed in a first region of the second surface, the second chip is installed in a second region of the second surface, the first chip and the second chip are alternately arranged on the second surface and expose a third region located between the first region and the second region. The first chip is located directly above the first heat dissipation portion and forms the first chip shadow on the first heat dissipation portion. The second chip is located directly above the second heat dissipation portion and forms the second chip shadow on the second heat dissipation portion. The third region is located above the third heat dissipation portion. A virtual line passes through the first heat dissipation portion, the second heat dissipation portion, and the third heat dissipation portion. Along a direction perpendicular to the virtual line, the third width of the third heat dissipation portion is not smaller than the first width of the first heat dissipation portion and the second width of the second heat dissipation portion. The heat dissipation sheet has a first notch portion that is located in the first heat dissipation portion and exposes the substrate, and the first chip shadow is located between the first notch portion and the third heat dissipation portion.

Advantages of the Invention

[0007] The contour of the heat dissipation sheet according to the present invention presents a non-rectangular polygon, and the third heat dissipation part is connected to the first heat dissipation part and the second heat dissipation part. Thereby, the bending resistance strength of the substrate is increased, and the stress generated in the heat dissipation sheet and the substrate is reduced, preventing warping and bending of the thin film circuit board, and at the same time increasing the area of the heat dissipation sheet to enhance the heat dissipation effect.

[0008] From the descriptions in the following specification and drawings, at least the following matters will become clear.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the thin-film circuit board of the present invention will be described with reference to the drawings. The present invention is not limited to these embodiments, and the members, materials, etc. described below can be variously modified within the scope of the gist of the present invention. The fourth embodiment corresponds to a mode for carrying out the invention described in the claims.

[0011] (First Embodiment) The configuration of the first embodiment of the present invention is shown in FIGS. 3 to 5. The circuit board tape 100A has a plurality of thin-film circuit boards 100, and each of the thin-film circuit boards 100 has a substrate 110 and a heat dissipation sheet 120. The contour of the heat dissipation sheet 120 presents a non-rectangular polygon, and the heat dissipation sheet 120 is adhered to the first surface 110a of the substrate 110 by an adhesive 130. Each of the thin-film circuit boards 100 is used to bond the first chip 200 and the second chip 300. In the cutting process, the thin-film circuit boards 100 are separated into individual ones, and each thin-film circuit board 100, the first chip 200, and the second chip 300 are formed as a thin-film flip-chip package.

[0012] As shown in FIGS. 4 and 5, the first chip 200 and the second chip 300 are installed on the second surface 110b of the substrate 110 and are alternately arranged in different regions of the second surface 110b. In this embodiment, the first chip 200 is installed in the first region 110b1 of the second surface 110b, the second chip 300 is installed in the second region 110b2 of the second surface 110b, and the third region 110b3 located between the first region 110b1 and the second region 110b2 is exposed.

[0013] As shown in FIGS. 4 and 5, in this embodiment, the contour of the heat dissipation sheet 120 approximates an inverted A shape. The heat dissipation sheet 120 has a first heat dissipation portion 121, a second heat dissipation portion 122, and a third heat dissipation portion 123. The third heat dissipation portion 123 is located between the first heat dissipation portion 121 and the second heat dissipation portion 122, and the third heat dissipation portion 123 is connected to the first heat dissipation portion 121 and the second heat dissipation portion 122. The first chip 200 is located directly above the first heat dissipation portion 121 and forms a first chip shadow 200a on the first heat dissipation portion 121. The second chip 300 is located directly above the second heat dissipation portion 122 and forms a second chip shadow 300a on the second heat dissipation portion 122. The third region 110b3 is located directly above the third heat dissipation portion 123.

[0014] As shown in FIGS. 3 and 4, along the direction of transporting the circuit board tape 100A, the virtual line Y passes through the first heat dissipation portion 121, the second heat dissipation portion 122, and the third heat dissipation portion 123. Along the direction perpendicular to the virtual line Y, the first heat dissipation portion 121 has a first corner A1 and a first side surface 121a connected to the first corner A1, and the second heat dissipation portion 122 has a second corner B1 and a second side surface 122a connected to the second corner B1.

[0015] As shown in FIGS. 3 and 4, the third heat dissipation portion 123 is connected to the first corner A1 and the second corner B1, and the third heat dissipation portion 123 exposes the first side surface 121a and the second side surface 122a. In this embodiment, along the direction perpendicular to the virtual line Y, the third width W3 of the third heat dissipation portion 123 is smaller than the first width W1 of the first heat dissipation portion 121 and the second width W2 of the second heat dissipation portion 122. Preferably, the third heat dissipation portion 123 has a third side surface 123a, and the first virtual line Y1 extending outward along the third side surface 123a passes through the first chip shadow 200a, increasing the warping resistance and bending resistance strength of the third heat dissipation portion 123.

[0016] Referring to FIG. 4, the heat dissipation sheet 120 has a first notch portion 124 located on one side of the third heat dissipation portion 123. In this embodiment, the first side surface 121a, the second side surface 122a, and the third side surface 123a are also the side surfaces of the first notch portion 124. The first notch portion 124 exposes the first surface 110a of the substrate 110. When the substrate 110, the heat dissipation sheet 120, and the adhesive 130 generate stress due to differences in material properties (e.g., plasticity, ductility, or coefficient of thermal expansion), the first notch portion 124 is used to release the stress, preventing the warping of the circuit board tape 100A.

[0017] In this embodiment, the heat dissipation sheet 120 further includes a fourth heat dissipation portion 125 located between the first heat dissipation portion 121 and the second heat dissipation portion 122. The third region 110b3 is located directly above the first notch portion 124 and the fourth heat dissipation portion 125 (see FIG. 4). The fourth heat dissipation portion 125 is connected to the third corner portion A2 of the first heat dissipation portion 121 and the fourth corner portion B2 of the second heat dissipation portion 122, and the fourth heat dissipation portion 125 exposes the first side surface 121a and the second side surface 122a. The first notch portion 124 is located between the third heat dissipation portion 123 and the fourth heat dissipation portion 125, and the first notch portion 124 is a closed notch portion. Preferably, the fourth heat dissipation portion 125 has a fourth side surface 125a, and the second virtual line Y2 extending outward along the fourth side surface 125a passes through the second chip shadow 300a, enhancing the warping resistance and bending resistance strength of the fourth heat dissipation portion 125.

[0018] In this embodiment, the heat dissipation sheet 120 further has a second notch portion 126 located on the first heat dissipation portion 121. The second notch portion 126 exposes the first surface 110a of the substrate 110. The second notch portion 126 is an open notch portion and is used to release stress, preventing the warping of the circuit board tape 100A (see FIG. 4). The first chip shadow 200a is located between the first notch portion 124 and the second notch portion 126.

[0019] As shown in FIGS. 4 and 6, the first heat radiating part 121 and the second heat radiating part 122 are integrally connected by the third heat radiating part 123 and / or the fourth heat radiating part 125, thereby increasing the bending resistance strength of the substrate 110 and preventing the thin film circuit board 100 from bending. When the jig 400 clamps the first part 111 of the thin film circuit board 100, the second part 112 of the thin film circuit board 100 can be accurately joined to the electronic element 500 (for example, a display panel or a circuit board), solving the problem that a conventional thin film circuit board is bent under the influence of gravity and cannot be accurately joined to the electronic element.

[0020] (Second Embodiment) The configuration of the second embodiment of the present invention is shown in FIG. 7. Regarding the differences between this embodiment and the first embodiment, along the direction perpendicular to the virtual line Y, the third heat radiating part 123 is located between the first notch part 124 and the second notch part 126, and the first notch part 124 and the second notch part 126 are open notch parts. In this embodiment, the contour of the heat radiating sheet 120 approximates a Z shape, the third heat radiating part 123 is connected to the first corner part A1 and the second corner part B1, and the first side surface 121a and the second side surface 122a are exposed. The first side surface 121a is also the side surface of the first notch part 124, and the second side surface 122a is also the side surface of the second notch part 126. Similarly, the third width W3 is smaller than the first width W1 and the second width W2.

[0021] (Third Embodiment) The configuration of the third embodiment of the present invention is shown in FIG. 8. Regarding the differences between this embodiment and the first embodiment, the contour of the heat radiating sheet 120 approximates an inverted H shape, along the direction perpendicular to the virtual line Y, the third heat radiating part 123 is located between the first notch part 124 and the second notch part 126, and the first notch part 124 and the second notch part 126 are open notch parts. Along the direction perpendicular to the virtual line Y, the third virtual line X1 passes through the first chip shadow 200a, the fourth virtual line X2 passes through the second chip shadow 300a, and the third heat radiating part 123 is located between the third virtual line X1 and the fourth virtual line X2. Similarly, the third width W3 is smaller than the first width W1 and the second width W2.

[0022] (Fourth Embodiment) The configuration of the fourth embodiment of the present invention is shown in FIG. 9. Regarding the differences from the first embodiment of this embodiment, the contour of the heat dissipation sheet 120 approximates an H shape, the third width W3 is not smaller than the first width W1 and the second width W2, the first notch 124 and the second notch 126 are respectively located in the first heat dissipation portion 121 and the second heat dissipation portion 122, and the first notch 124 and the second notch 126 expose the substrate 110. Along the direction perpendicular to the virtual line Y, the first chip shadow 200a is located between the first notch 124 and the third heat dissipation portion 123, the second chip shadow 300a is located between the second notch 126 and the third heat dissipation portion 123, and the first chip shadow 200a and the second chip shadow 300a are located between the first notch 124 and the second notch 126.

[0023] The contour of the heat dissipation sheet 120 presents a non-rectangular polygon, and the first notch 124 and / or the second notch 126 reduce or release the stress generated due to the difference in material properties. The first heat dissipation portion 121 and the second heat dissipation portion 122 are integrally connected by the third heat dissipation portion 123 and / or the fourth heat dissipation portion 125, so as to increase the heat dissipation area of the heat dissipation sheet 120 to enhance the heat dissipation effect, and to increase the bending resistance strength of the substrate 110 to prevent warping and bending of the thin film circuit board 100.

[0024] As described above, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the gist thereof.

Explanation of Signs

[0025] 10 Thin film circuit board 100 Thin film circuit board 11 Substrate 110 Substrate 11a Surface 11b Surface 12 Heat dissipation sheet 120 Heat dissipation sheet 13 Adhesive 130 Adhesive 20 Chip 100A Circuit board tape 110a First surface Second side of 110b First area of 110b1 Second area of 110b2 Third area of 110b3 First part of 111 Second part of 112 First heat dissipation part of 121 First side of 121a Second heat dissipation part of 122 Second side of 122a Third heat dissipation part of 123 Third side of 123a First notch part of 124 Fourth heat dissipation part of 125 Fourth side of 125a Second notch part of 126 First chip of 200 First chip shadow of 200a Second chip of 300 Second chip shadow of 300a Fixture of 400 Electronic component of 500 First corner of A1 Third corner of A2 Second corner of B1 Fourth corner of B2 Third virtual line of X1 Fourth virtual line of X2 Virtual line of Y First virtual line of Y1 Second virtual line of Y2 First width of W1 Second width of W2 Third width of W3

Claims

1. A substrate (110) having a first surface (110a) and a second surface (110b), wherein the second surface is used for bonding a first chip (200) and a second chip (300), a heat dissipation sheet (120) adhered to the first surface of the substrate, wherein the contour of the heat dissipation sheet presents a non-rectangular polygon, and the heat dissipation sheet has a first heat dissipation portion (121), a second heat dissipation portion (122), and a third heat dissipation portion (123), the third heat dissipation portion is located between the first heat dissipation portion and the second heat dissipation portion, the third heat dissipation portion is connected to the first heat dissipation portion and the second heat dissipation portion, and the first chip and the second chip are installed directly above the heat dissipation sheet and are used to form a first chip shadow (200a) and a second chip shadow (300a) respectively, the first chip is installed in a first region (110b1) of the second surface, the second chip is installed in a second region (110b2) of the second surface, the first chip and the second chip are arranged alternately on the second surface and expose a third region (110b3) located between the first region and the second region, the first chip is located directly above the first heat dissipation portion and forms the first chip shadow on the first heat dissipation portion, the second chip is located directly above the second heat dissipation portion and forms the second chip shadow on the second heat dissipation portion, and the third region is located above the third heat dissipation portion, a virtual line (Y) passes through the first heat dissipation portion, the second heat dissipation portion, and the third heat dissipation portion, and along a direction perpendicular to the virtual line, the third width (W3) of the third heat dissipation portion is not smaller than the first width (W1) of the first heat dissipation portion and the second width (W2) of the second heat dissipation portion, the heat dissipation sheet has a first notch portion (124) located in the first heat dissipation portion and exposing the substrate, and the first chip shadow is located between the first notch portion and the third heat dissipation portion. A thin-film circuit board characterized by this.

2. The heat dissipation sheet has a second notch portion (126) located in the second heat dissipation portion and exposing the substrate, and the second chip shadow is located between the second notch portion and the third heat dissipation portion. The thin-film circuit board according to claim 1, characterized by this.

3. The thin film circuit board according to claim 2, wherein the first chip shadow and the second chip shadow are located between the first notch and the second notch.

Images