A thin and light flexible circuit board

Abstract

The present invention discloses a light and thin flexible circuit board, comprising an upper PET layer, an upper circuit, an upper insulating UV layer, an upper jumper, an upper waterproof glue layer, a middle spacer, a lower waterproof glue layer, a lower jumper, a lower insulating UV layer, a lower circuit and a lower PET layer, which are arranged in sequence from top to bottom; wherein the thickness of the upper PET layer is 0.05-0.06mm, the thickness of the lower PET layer is 0.05-0.06mm, the thickness of the middle spacer is 0.025-0.038mm, and the total thickness of the flexible circuit board is 0.15-0.22mm; the upper waterproof glue fully covers the upper circuit, the upper insulating UV layer and the upper jumper; the lower waterproof glue fully covers the lower circuit, the lower insulating UV layer and the lower jumper; a layer of exhaust groove is printed on the upper waterproof glue or the lower waterproof glue. The light and thin flexible circuit board provided by the present invention makes the flexible circuit board lighter and thinner, the pressing force is more comfortable, the hand feel is better, and it has excellent waterproof function and exhaust function.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible circuit boards, and in particular to a light and thin flexible circuit board. Background Art

[0002] Flexible circuit boards are mainly used in home appliance buttons, computer buttons and various key function equipment. They realize electrical functions by printing conductive silver paste, insulating UV, carbon, waterproof glue, etc. on PET.

[0003] Normally, flexible circuit boards are divided into three major components, namely the upper layer, the middle layer and the lower layer. The thickness of the upper and lower PET layers is usually 0.075mm-0.1mm, the thickness of the middle layer PET is usually 0.05-0.075mm, and the total thickness of the product is between 0.3-0.35mm. Due to the overall thickness of the flexible circuit board, there are defects such as poor pressing performance and insufficient functionality.

[0004] In addition, the prior art has the problem of poor waterproof performance because waterproof glue is printed locally at locations such as circuits and jumpers, which can easily lead to circuit short circuits; moreover, exhaust grooves are usually opened locally on the waterproof glue, so the exhaust performance is poor and the feel when pressing the buttons is poor. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a thin and light flexible circuit board, comprising an upper layer of PET, an upper layer of circuit, an upper layer of insulating UV, an upper layer of jumper, an upper layer of waterproof glue, a middle layer of spacer, a lower layer of waterproof glue, a lower layer of jumper, a lower layer of insulating UV, a lower layer of circuit and a lower layer of PET, which are arranged in sequence from top to bottom; wherein the thickness of the upper layer of PET is 0.05-0.06mm, the thickness of the lower layer of PET is 0.05-0.06mm, the thickness of the middle layer of spacer is 0.025-0.038mm, and the total thickness of the flexible circuit board is 0.15-0.22mm.

[0006] The thin and light flexible circuit board provided by the present invention uses PET with a thickness of 0.05-0.06mm for the upper and lower layers, and uses PET with a thickness of 0.025-0.038mm for the middle layer. According to this design process, the total thickness of the product is between 0.15-0.22mm, making the flexible circuit board thinner and lighter, with more comfortable pressing force and better hand feel. Any design process in which the upper or lower layer of the flexible circuit board is designed to use PET with a thickness of 0.05-0.06mm, and the middle layer is designed to use PET with a thickness of 0.025-0.038mm, is within the protection scope of the present invention.

[0007] Among them, the upper circuit, upper insulating UV, upper jumper and upper waterproof glue are printed on the upper PET in sequence, and the upper waterproof glue fully covers the upper circuit, upper insulating UV and upper jumper; the lower circuit, lower insulating UV, lower jumper and lower waterproof glue are printed on the lower PET in sequence, and the lower waterproof glue fully covers the lower circuit, lower insulating UV and lower jumper.

[0008] The present invention can effectively prevent liquid and moisture from contacting the circuits of the flexible circuit board by completely wrapping the upper and lower circuits with waterproof glue, avoid liquid and moisture from damaging the electrical function of the flexible circuit board, achieve excellent waterproof function, and effectively solve the problem of poor moisture-proof and waterproof performance caused by setting waterproof glue locally on the circuit in the conventional way.

[0009] Among them, an upper layer of exhaust grooves is printed on the upper layer of waterproof glue; or, a lower layer of exhaust grooves is printed on the lower layer of waterproof glue; or, an upper layer of exhaust grooves is printed on the upper layer of waterproof glue and a lower layer of exhaust grooves is printed on the lower layer of waterproof glue.

[0010] The present invention prints a whole layer of exhaust grooves on the upper layer of waterproof glue or the lower layer of waterproof glue to ensure normal exhaust function when a key is pressed, thereby effectively solving the problem of poor exhaust caused by setting the exhaust grooves locally on the waterproof glue in the conventional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0012] Figure 1 This is a schematic diagram of the decomposed structure of the flexible circuit board disclosed in Example 1 of the present invention.

[0013] In the figure: 1. upper layer PET; 2. upper layer circuit; 3. upper layer insulation UV; 4. upper layer jumper; 5. upper layer waterproof glue; 6. upper layer exhaust groove; 7. middle layer spacer; 8. lower layer waterproof glue; 9. lower layer jumper; 10. lower layer insulation UV; 11. lower layer circuit; 12. lower layer PET. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0015] Embodiment 1:

[0016] refer to Figure 1The present invention provides a thin and light flexible circuit board, comprising an upper PET layer 1, an upper circuit layer 2, an upper insulating UV layer 3, an upper jumper wire 4, an upper waterproof glue layer 5, an upper exhaust groove 6, a middle spacer layer 7, a lower waterproof glue layer 8, a lower jumper wire 9, a lower insulating UV layer 10, a lower circuit layer 11 and a lower PET layer 12, which are arranged in sequence from top to bottom; wherein the thickness of the upper PET layer 1 is 0.05-0.07mm, the thickness of the lower PET layer 12 is 0.05-0.07mm, the thickness of the middle spacer layer 7 is 0.025-0.039mm, and the total thickness of the flexible circuit board is 0.15-0.22mm.

[0017] The thin and light flexible circuit board provided in the present embodiment 1 is designed to use PET with a thickness of 0.05-0.07mm for the upper and lower layers, and PET with a thickness of 0.025-0.039mm for the middle layer. According to this design process, the total thickness of the product is between 0.15-0.22mm, making the flexible circuit board thinner and lighter, with more comfortable pressing force and better hand feel. Any design process in which the upper or lower layer of the flexible circuit board is designed to use PET with a thickness of 0.05-0.07mm, and the middle layer is designed to use PET with a thickness of 0.025-0.039mm, is within the protection scope of the present invention.

[0018] Among them, the upper circuit 2, the upper insulation UV3, the upper jumper 4 and the upper waterproof glue 5 are printed on the upper PET1 in sequence, and the upper waterproof glue 5 fully covers the upper circuit 2, the upper insulation UV3 and the upper jumper 4; the lower circuit 11, the lower insulation UV10, the lower jumper 9 and the lower waterproof glue 8 are printed on the lower PET12 in sequence, and the lower waterproof glue 8 fully covers the lower circuit 11, the lower insulation UV10 and the lower jumper 9.

[0019] In this embodiment 1, by completely wrapping the upper and lower layers of circuits 11 with waterproof glue, liquid and moisture can be effectively prevented from contacting the circuits of the flexible circuit board, thereby preventing liquid and moisture from damaging the electrical functions of the flexible circuit board and achieving excellent waterproof function.

[0020] In this embodiment 1, a layer of upper exhaust groove 6 is printed on the upper waterproof adhesive 5 to ensure that the exhaust function is normal when the key is pressed.

[0021] Embodiment 2:

[0022] The difference between the second embodiment and the first embodiment is that a layer of lower exhaust grooves is printed on the lower waterproof adhesive 8 .

[0023] Embodiment 3:

[0024] The difference between the present embodiment 3 and the embodiments 1 and 2 is that an upper exhaust groove 6 is printed on the upper waterproof adhesive 5, and a lower exhaust groove is printed on the lower waterproof adhesive 8.

[0025] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to the above embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A light and thin flexible circuit board, comprising an upper PET layer (1), an upper circuit layer (2), an upper insulating UV layer (3), an upper jumper wire (4), an upper waterproof glue layer (5), a middle spacer (7), a lower waterproof glue layer (8), a lower jumper wire (9), a lower insulating UV layer (10), a lower circuit layer (11) and a lower PET layer (12) arranged in sequence from top to bottom; characterized in that: The thickness of the upper PET layer (1) is 0.05-0.06 mm, the thickness of the lower PET layer (12) is 0.05-0.06 mm, the thickness of the middle spacer (7) is 0.025-0.038 mm, and the total thickness of the flexible circuit board is 0.15-0.22 mm; The upper circuit (2), the upper insulating UV (3), the upper jumper (4) and the upper waterproof glue (5) are printed on the upper PET (1) in sequence, and the upper waterproof glue (5) fully covers the upper circuit (2), the upper insulating UV (3) and the upper jumper (4); The lower layer circuit (11), the lower layer insulating UV (10), the lower layer jumper (9) and the lower layer waterproof glue (8) are printed on the lower layer PET (12) in sequence, and the lower layer waterproof glue (8) fully covers the lower layer circuit (11), the lower layer insulating UV (10) and the lower layer jumper (9); A layer of exhaust grooves is printed on the upper layer of waterproof glue (5) and / or the lower layer of waterproof glue (8).

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