Film circuit board with anti-vulcanization function

Abstract

The utility model discloses a film circuit board with an anti-sulfuration function, which comprises an upper circuit layer, a lower circuit layer, a middle interlayer, an upper anti-sulfuration coating and a lower anti-sulfuration coating, and is characterized in that the upper anti-sulfuration coating made of anti-sulfuration materials hermetically covers an upper circuit on the lower side of the upper circuit layer; a lower anti-vulcanization coating made of an anti-vulcanization material covers the lower circuit on the upper side of the lower circuit layer in a sealing manner, and the upper anti-vulcanization coating and the lower anti-vulcanization coating are respectively provided with an upper fracture and a lower fracture for exposing the upper-layer metal contact point and the lower-layer metal contact point; when the film circuit board is used in various environments, the positions, right opposite to the positions of the upper layer metal contact points, on the upper circuit layer are pressed, so that the upper layer metal contact points penetrate through the avoiding hollow-out hole positions in the middle interlayer and move downwards to be in contact with the lower layer metal contact points, and then trigger signals are generated. The operation stability of the film circuit board is effectively improved, and the service life of the film circuit board is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to a keyboard circuit board, especially a thin film circuit board with anti-sulfuration function. BACKGROUND

[0002] The thin film circuit board is used in different environments, and the surface of the thin film circuit board is corroded to different degrees. When the thin film circuit board is used in a harsh environment, a large amount of sulfur in the environment reacts with the metal circuit on the thin film circuit board to form sulfide, and the sulfide covers the surface of the metal circuit. The sulfide can cause oxidation of the metal circuit, reduce the resistance value of the metal circuit, and reduce the signal transmission efficiency of the thin film circuit board. Even worse, the thin film circuit board can be damaged, resulting in poor signal stability and short service life of the thin film circuit board. SUMMARY

[0003] To make up for the above shortcomings, the utility model provides a thin film circuit board with anti-sulfuration function, which can be used in various environments and prevent the surface of the thin film circuit board from being damaged by sulfuration, effectively improving the operation stability of the thin film circuit board and prolonging the service life of the thin film circuit board.

[0004] The utility model discloses a thin film circuit board with anti-sulfuration function, which comprises an upper circuit layer, a lower circuit layer, a middle separation layer, an upper anti-sulfuration coating and a lower anti-sulfuration coating. The upper anti-sulfuration coating made of anti-sulfuration material is arranged on the lower side surface of the upper circuit layer, and can seal and cover the upper circuit on the lower side of the upper circuit layer. The lower anti-sulfuration coating made of anti-sulfuration material is arranged on the upper side surface of the lower circuit layer, and can seal and cover the lower circuit on the upper side of the lower circuit layer. The upper anti-sulfuration coating has an upper break on the surface, which exposes the upper metal contact point on the lower side surface of the upper circuit layer. The lower anti-sulfuration coating has a lower break on the surface, which exposes the lower metal contact point on the upper side surface of the lower circuit layer. The middle separation layer is fixedly clamped between the upper circuit layer, the upper anti-sulfuration coating above the upper circuit layer, the lower circuit layer and the lower anti-sulfuration coating above the lower circuit layer. The middle separation layer has a relief hole position. The upper metal contact point on the lower side surface of the upper circuit layer is opposite to the lower metal contact point through the relief hole position. When the upper circuit layer is pressed at the position opposite to the relief hole position, the upper metal contact point can contact the lower metal contact point, and a trigger signal is generated.

[0005] As a further improvement of the present application, the upper anti-sulfuration coating is a film structure formed on the lower side of the upper circuit layer by printing or coating, and the lower anti-sulfuration coating is a film structure formed on the upper side of the lower circuit layer by printing or coating, which can prevent the formation of sulfides on the surface of the circuits on the upper and lower circuit layers.

[0006] As a further improvement of the present application, the upper anti-sulfuration coating extends along the upper circuit on the lower side of the upper circuit layer, and completely covers the surface of the upper circuit and the electronic components thereon; and the lower anti-sulfuration coating extends along the lower circuit on the lower side of the lower circuit layer, and completely covers the surface of the lower circuit and the electronic components thereon.

[0007] As a further improvement of the present application, the width of the upper circuit on the lower side of the upper circuit layer and the lower circuit on the lower side of the lower circuit layer is 0.2 mm, and the width of the upper anti-sulfuration coating and the lower anti-sulfuration coating is 0.2 mm larger than that of the upper circuit on the lower side of the upper circuit layer and the lower circuit on the lower side of the lower circuit layer respectively.

[0008] As a further improvement of the present application, the circuit in the middle partition layer only leads out from the upper and lower directions, and the avoiding hollow hole position of the middle partition layer is a special-shaped hole with a large middle size and small end sizes.

[0009] As a further improvement of the present application, the upper side of the middle partition layer is fixedly connected with the lower side of the upper circuit layer and the upper anti-sulfuration coating thereon through a hot melt adhesive layer, and the lower side of the middle partition layer is fixedly connected with the upper side of the lower circuit layer and the lower anti-sulfuration coating thereon through a waterproof adhesive layer, and the hot melt adhesive layer and the waterproof adhesive layer are respectively provided with an upper avoiding hole and a lower avoiding hole corresponding to the avoiding hollow hole position.

[0010] As a further improvement of the present application, the avoiding hole on the hot melt adhesive layer is consistent with the avoiding hollow hole in size and is arranged in alignment, the avoiding hole of the waterproof adhesive layer is larger in size than the avoiding hollow hole, the center of the avoiding hole of the waterproof adhesive layer is opposite to the center of the avoiding hollow hole, and the four sides of the avoiding hole of the waterproof adhesive layer are arranged in a symmetrical outward expansion state with the four sides of the avoiding hollow hole.

[0011] As a further improvement of the present application, the thickness of the upper circuit layer is 0.060±0.001 mm, the thickness of the lower circuit layer is 0.075±0.001 mm, the thickness of the upper anti-sulfuration coating and the lower anti-sulfuration coating is 0.009±0.001 mm, the thickness of the middle partition layer is 0.038±0.001 mm, the thickness of the hot melt adhesive layer is 0.013±0.001 mm, and the thickness of the waterproof adhesive layer is 0.018±0.001 mm.

[0012] As a further improvement of the present application, the upper line layer comprises an upper PET layer and upper lines printed on the lower side of the upper PET layer, the lower line layer comprises a lower PET layer and lower lines printed on the lower side of the lower PET layer, the upper layer metal contact point is a silver paste coating contact point arranged on the upper lines, and the lower upper layer metal contact point is a silver paste coating contact point arranged on the lower lines.

[0013] The present application has the beneficial technical effects that: the anti-sulfuration coating is sealed and covered on the surface of the upper lines of the upper line layer of the film circuit board, and the lower anti-sulfuration coating is sealed and covered on the surface of the lower lines of the lower line layer, so that the film circuit board is not easily covered by sulfuration when used in various environments, the influence of sulfuration on the metal circuit and electronic components on the film circuit board is prevented, the operation stability of the film circuit board is effectively improved, and the service life of the film circuit board is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a front view of a traditional film circuit board;

[0015] Figure 2 It is a front view of a traditional film circuit board; Figure 1 It is an enlarged view of A part in the middle;

[0016] Figure 3 It is a front view of a traditional film circuit board;

[0017] Figure 4 It is a front view of a traditional film circuit board; Figure 3 It is an enlarged view of B part in the middle;

[0018] Figure 5 It is a front view of a traditional film circuit board;

[0019] Figure 6 It is a front view of a traditional film circuit board; Figure 5 It is an enlarged view of C part in the middle;

[0020] Figure 7 It is a front view of a traditional film circuit board;

[0021] Figure 8 It is a front view of a traditional film circuit board; Figure 7 It is an enlarged view of D part in the middle;

[0022] Figure 9 It is a schematic view of the upper anti-sulfuration coating covering the upper lines of the present application;

[0023] Figure 10 It is a schematic view of the interlayer structure of the present application. DETAILED DESCRIPTION

[0024] Embodiment: a thin film circuit board with anti-sulfuration function, comprising upper circuit layer 11 layer 1, lower circuit layer 21 layer 2, middle separation layer 3, upper anti-sulfuration coating 4 and lower anti-sulfuration coating 5, the upper anti-sulfuration coating 4 made of anti-sulfuration material is arranged on the lower side surface of the upper circuit layer 11 layer 1, the upper anti-sulfuration coating 4 can seal and cover the upper circuit 11 on the lower side of the upper circuit layer 11 layer 1, the lower anti-sulfuration coating 5 made of anti-sulfuration material is arranged on the upper side surface of the lower circuit layer 21 layer 2, the lower anti-sulfuration coating 5 can seal and cover the lower circuit 21 on the upper side of the lower circuit layer 21 layer 2, and the upper anti-sulfuration coating 4 is formed with upper break 41 for exposing upper layer metal contact point 12 on the lower side surface of the upper circuit layer 11 layer 1, the lower anti-sulfuration coating 5 is formed with lower break 51 for exposing lower layer metal contact point 22 on the upper side surface of the lower circuit layer 21 layer 2, the middle separation layer 3 is fixedly arranged between the upper circuit layer 11 layer 1 and the upper anti-sulfuration coating 4 thereon and the lower circuit layer 21 layer 2 and the lower anti-sulfuration coating 5 thereon, the middle separation layer 3 is formed with avoiding hollow hole position 31, the upper layer metal contact point 12 on the lower side surface of the upper circuit layer 11 layer 1 passes through the avoiding hollow hole position 31 to be opposite to the lower layer metal contact point 22, the position of the upper circuit layer 11 layer 1 opposite to the avoiding hollow hole position 31 can make the upper layer metal contact point 12 contact the lower layer metal contact point 22 downward after being pressed, and then a trigger signal is generated.

[0025] The upper anti-sulfuration coating 4 and the lower anti-sulfuration coating 5 are respectively formed on the lower side surface of the upper circuit layer 11 layer 1 and the upper side surface of the lower circuit layer 21 layer 2, and then the anti-sulfuration protection of the upper circuit layer 11 and the lower circuit layer 21 is realized, so that the metal circuit on the thin film circuit board is prevented from being corroded and damaged due to sulfuration during use, the circuit on the surface of the thin film circuit board is prevented from being damaged by sulfuration, the running stability of the thin film circuit board is effectively improved, and the service life of the thin film circuit board is prolonged.

[0026] The upper anti-sulfuration coating 4 is a thin film structure formed on the lower side surface of the upper circuit layer 11 layer 1 by printing or coating, the lower anti-sulfuration coating 5 is a thin film structure formed on the upper side surface of the lower circuit layer 21 layer 2 by printing or coating, the upper anti-sulfuration coating 4 and the lower anti-sulfuration coating 5 can prevent the formation of sulfides on the surface of the circuit on the upper circuit layer 11 layer 1 and the circuit on the lower circuit layer 21 layer 2. The anti-sulfuration coating is formed on the upper circuit layer 11 layer 1 and the lower circuit layer 21 layer 2 by printing, which is accurate in position and can ensure sufficient sealing and protection of the upper circuit layer 11 and the lower circuit layer 21 without increasing the occupied space and affecting the thickness of the thin film circuit board.

[0027] The upper anti-sulfurization coating 4 extends along the lower surface of the upper circuit 11 layer 1, completely covering the upper circuit 11 and the surface of the electronic components thereon; the lower anti-sulfurization coating 5 extends along the lower surface of the lower circuit 21 layer 2, completely covering the lower circuit 21 and the surface of the electronic components thereon. The anti-sulfurization coating is only distributed along the upper circuit 11 and the lower circuit 21, not fully covering the entire upper circuit 11 layer 1 and lower circuit 21 layer 2, saving material and having little impact on the thickness of the thin-film circuit board.

[0028] The width of the upper line 11 on the lower surface of the upper line 11 layer 1 and the lower line 21 on the lower surface of the lower line 21 layer 2 is 0.2mm. The widths of the upper anti-sulfurization coating 4 and the lower anti-sulfurization coating 5 are each 0.2mm wider on one side than the upper line 11 on the lower surface of the upper line 11 layer 1 and the lower line 21 on the lower surface of the lower line 21 layer 2. Traditionally, the width of silver lines on thin-film circuit boards is 0.3mm. This invention changes the width of the silver lines on the upper line 11 and the lower line 21 to 0.2mm, ensuring that the lines can pass smoothly.

[0029] The circuitry within the partition layer 3 exits only from the top and bottom directions, and the clearance hole 31 in the partition layer 3 is an irregularly shaped hole with a larger size in the middle and smaller sizes at both ends. In traditional designs, multiple circuits enter the partition layer 3 through the holes, making it easy for sulfur vapor to enter and corrode the silver wires. This invention changes the circuitry within the partition layer 3 so that it exits only from the top and bottom directions, and also changes the partition layer to an irregularly shaped hole. This ensures that the thickness of the anti-sulfurization coating does not affect the load-bearing capacity of the circuit board.

[0030] The upper side of the partition layer 3 is bonded and fixed to the lower side of the upper circuit layer 11 and its upper anti-sulfurization coating 4 via a hot melt adhesive layer 6. The lower side of the partition layer 3 is bonded and fixed to the upper side of the lower circuit layer 21 and its lower anti-sulfurization coating 5 via a waterproof adhesive layer 7. The hot melt adhesive layer 6 and the waterproof adhesive layer 7 are respectively provided with upper avoidance holes 61 and lower avoidance holes 71 corresponding to the avoidance cutout holes 31. The partition layer 3 is bonded together with the upper circuit layer 11 and the lower circuit layer 21 via the hot melt adhesive layer 6 and the waterproof adhesive layer 7, which is firmly welded and also provides a waterproof effect, preventing water from entering the thin film circuit board and causing short circuits in the lower circuit layers due to water immersion.

[0031] The clearance holes on the hot melt adhesive layer 6 are the same size as the clearance perforation holes and are aligned. The clearance holes on the waterproof adhesive layer 7 are larger than the clearance perforation holes. The center of the clearance holes on the waterproof adhesive layer 7 is directly opposite the center of the clearance perforation holes. The four sides of the clearance holes on the waterproof adhesive layer 7 and the four sides of the clearance perforation holes are symmetrically expanded outward.

[0032] The thickness of the upper circuit 11 layer 1 is 0.060±0.001mm, the thickness of the lower circuit 21 layer 2 is 0.075±0.001mm, the thickness of the upper and lower anti-vulcanization coatings 4 and 5 is 0.009±0.001mm, the thickness of the middle layer 3 is 0.038±0.001mm, the thickness of the hot melt adhesive layer 6 is 0.013±0.001mm, and the thickness of the waterproof adhesive layer 7 is 0.018±0.001mm.

[0033] The upper circuit 11 layer 1 comprises an upper PET layer and an upper circuit 11 printed on the lower side of the upper PET layer, the lower circuit 21 layer 2 comprises a lower PET layer and a lower circuit 21 printed on the lower side of the lower PET layer, and the upper metal contact point 12 is a silver paste coating contact point arranged on the upper circuit 11, and the lower upper metal contact point 12 is a silver paste coating contact point arranged on the lower circuit 21.

[0034] The anti-vulcanization coating experiment is performed on the conventional film circuit board and the film circuit board with anti-vulcanization function of the utility model, the experimental method and data are as follows:

[0035] 1. The conventional film circuit board is placed in a vulcanization testing machine for a 10-day anti-vulcanization test, and the silver wire is found to be obviously blackened, that is, the silver wire is deeply eroded by sulfur molecules. The resistance is greatly increased, and a part of the material appears an open circuit phenomenon. The experiment is determined as NG.

[0036] 2. The film circuit board with anti-vulcanization function of the utility model is placed in a vulcanization testing machine for a 10-day anti-vulcanization test, and the silver wire is not found to be obviously blackened, that is, the silver wire is not eroded by sulfur molecules. The resistance is not obviously increased. The experiment is determined as OK.

Claims

1. A thin film circuit board having a function of resisting vulcanization, characterized by: The upper anti-vulcanization coating made of anti-vulcanization material is arranged on the lower side surface of the upper line layer, and the upper anti-vulcanization coating can seal and cover the upper line (11) on the lower side of the upper line layer; the lower anti-vulcanization coating made of anti-vulcanization material is arranged on the upper side surface of the lower line layer, and the lower anti-vulcanization coating can seal and cover the lower line (21) on the upper side of the lower line layer; and the upper anti-vulcanization coating is formed with an upper break (41) for exposing the upper layer metal contact point on the lower side surface of the upper line layer, and the lower anti-vulcanization coating is formed with a lower break (51) for exposing the lower layer metal contact point on the upper side surface of the lower line layer; the middle separation layer is clamped between the upper line layer and the upper anti-vulcanization coating thereon and the lower line layer and the lower anti-vulcanization coating thereon, the middle separation layer is formed with an avoiding hollow hole (31), the upper layer metal contact point (12) on the lower side surface of the upper line layer passes through the avoiding hollow hole and is arranged opposite to the lower layer metal contact point (22), and the position of the upper line layer opposite to the avoiding hollow hole can make the upper layer metal contact point contact the lower layer metal contact point downward after being pressed, thereby generating a trigger signal.

2. The thin film circuit board having a sulfurization resistance function according to claim 1, characterized by: The upper anti-vulcanization coating is a film structure formed on the lower side surface of the upper line layer by printing or coating, and the lower anti-vulcanization coating is a film structure formed on the upper side surface of the lower line layer by printing or coating, and the upper anti-vulcanization coating and the lower anti-vulcanization coating can prevent the formation of vulcanates on the surfaces of the lines on the upper line layer and the lines on the lower line layer.

3. The thin film circuit board having a sulfurization-resistant function according to claim 1 or 2, characterized by: The upper anti-vulcanization coating extends along the upper line on the lower side surface of the upper line layer, and the upper anti-vulcanization coating completely covers the surface of the upper line and the electronic elements thereon; the lower anti-vulcanization coating extends along the lower line on the lower side surface of the lower line layer, and the lower anti-vulcanization coating completely covers the surface of the lower line and the electronic elements thereon.

4. The thin film circuit board having a sulfurization-resistant function according to claim 3, characterized by: The width of the upper line on the lower side surface of the upper line layer and the lower line on the lower side surface of the lower line layer is 0.2 mm, and the width of the upper anti-vulcanization coating and the lower anti-vulcanization coating is 0.2 mm wider than the width of the upper line on the lower side surface of the upper line layer and the lower line on the lower side surface of the lower line layer on one side.

5. The thin film circuit board having a sulfurization-resistant function according to claim 1, characterized by: The inner line of the middle separation layer only leads out from the upper and lower directions, and the avoiding hollow hole of the middle separation layer is a special-shaped hole with a large middle size and small end sizes.

6. The thin film circuit board having a sulfurization-resistant function according to claim 1, characterized by: The upper side surface of the middle separation layer is fixed and bonded to the lower side surface of the upper line layer and the upper anti-vulcanization coating thereon through a hot melt adhesive layer (6), and the lower side surface of the middle separation layer is fixed and bonded to the upper side surface of the lower line layer and the lower anti-vulcanization coating thereon through a waterproof adhesive layer (7), and the hot melt adhesive layer and the waterproof adhesive layer are respectively provided with an upper avoiding hole (61) and a lower avoiding hole (71) corresponding to the avoiding hollow hole.

7. The thin film circuit board having a sulfurization-resistant function according to claim 6, characterized by: The avoiding hole on the hot melt adhesive layer is consistent in size with the avoiding hollow hole, and is arranged in alignment, the size of the avoiding hole of the waterproof adhesive layer is larger than the size of the avoiding hollow hole, the center of the avoiding hole of the waterproof adhesive layer is opposite to the center of the avoiding hollow hole, and the four sides of the avoiding hole of the waterproof adhesive layer are arranged in a symmetrical and outwardly expanded state with the four sides of the avoiding hollow hole.

8. The thin film circuit board having a sulfurization resistant function according to claim 6, characterized by: The upper line layer has a thickness of 0.060±0.001 mm, the lower line layer has a thickness of 0.075±0.001 mm, the upper and lower anti-vulcanization coating layers each has a thickness of 0.009±0.001 mm, the middle separation layer has a thickness of 0.038±0.001 mm, the hot melt adhesive layer has a thickness of 0.013±0.001 mm, and the waterproof adhesive layer has a thickness of 0.018±0.001 mm.

9. The thin film circuit board having a sulfurization resistant function according to claim 1, characterized by: The upper line layer comprises an upper PET layer and upper lines printed on the lower side of the upper PET layer, the lower line layer comprises a lower PET layer and lower lines printed on the lower side of the lower PET layer, the upper layer metal contact point is a silver paste coating contact point arranged on the upper lines, and the lower upper layer metal contact point is a silver paste coating contact point arranged on the lower lines.

Images