Deterioration detection printed circuit board
By designing through holes or cutouts and electrode pads on the printed board for deterioration detection, combined with solder resist, the cutting fluid corrosion wiring pattern is promoted, and the problem of disconnection of the main printed board in the cutting fluid environment is solved, and the deterioration detection is achieved Effectiveness and cost control.
Patent Information
- Application Number
- CN202180057461.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2020-08-03
- Filing Date
- 2021-07-28
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2041-07-28
AI Technical Summary
In the environment where the cutting fluid of the machine tool is scattered, the wiring pattern of the main printed substrate is prone to break due to corrosion. The existing printed substrate for deterioration detection is costly and the cutting fluid is difficult to adhere, resulting in poor deterioration detection effect.
Design a printing substrate for deterioration detection, whose insulator substrate forms through holes or cutouts on the back, and the wiring pattern is located on the back of the main printing substrate side. Electrode pads and solder resist are arranged around the wiring pattern and through holes to promote cutting liquid The wiring patterns are flowed and corroded, avoiding the formation of wiring patterns on the surface of the insulator substrate to reduce manufacturing costs.
Without increasing the manufacturing cost, the wiring disconnection of the wiring pattern is effectively promoted, the accuracy and efficiency of deterioration detection are ensured, and the formation of the wiring pattern on the surface of the insulator substrate is reduced, thereby suppressing the increase in manufacturing cost.
Smart Images
Figure CN116097907B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a printed circuit board for degradation detection which is mounted on a main printed circuit board to be detected for degradation. Background Art
[0002] The machine tool is used in an environment where cutting fluid containing foreign matter such as chlorides and sulfides is scattered. When the cutting fluid adheres to the main printed circuit board of the machine tool, the copper foil portion of the wiring pattern is corroded and disconnected. In order to predict the disconnection of the wiring pattern, a deterioration detection printed circuit board is installed on the main printed circuit board. The deterioration detection printed circuit board has a wiring pattern for deterioration detection that is easier to disconnect than the wiring pattern of the main printed circuit board.
[0003] For example, a deterioration detection printed circuit board includes an insulator substrate and wiring patterns formed on both surfaces of the insulator substrate. The wiring pattern is deteriorated by the adhesion of a mist-like cutting fluid that is scattered in the space. On the other hand, the wiring pattern is deteriorated by the adhesion of the cutting fluid that flows on the surface of the main printed circuit board or the cutting fluid that flows on the surface of the insulator substrate. However, when the wiring patterns are formed on both surfaces of the insulator substrate, the manufacturing cost of the deterioration detection printed circuit board increases.
[0004] Japanese Patent Publication No. 2018-41837 discloses a printed circuit board for degradation detection having a wiring pattern on the back of an insulating substrate. The wiring pattern is not formed on the surface of the insulating substrate. Therefore, according to Japanese Patent Publication No. 2018-41837, the manufacturing cost of the printed circuit board for degradation detection can be suppressed. Summary of the invention
[0005] A plurality of electrode pads connected to the wiring pattern of the main printed circuit board are provided on the back side of the insulator substrate. In order to ensure the bonding strength of the degradation detection printed circuit board with respect to the main printed circuit board, the plurality of electrode pads are provided at the edge of the back side. In addition, flux that scatters during soldering is attached around each electrode pad.
[0006] Recently, it is known that the flux attached to the electrode pads and their surroundings will block the cutting fluid from entering the gap between the main printed circuit board and the detection printed circuit board. In this case, the cutting fluid is difficult to adhere to the wiring pattern formed on the back side of the insulator substrate, and it is difficult to cause wire breakage.
[0007] Therefore, an object of the present invention is to provide a deterioration detection printed circuit board capable of promoting disconnection of a wiring pattern without increasing manufacturing cost.
[0008] The present invention is a printed circuit board for degradation detection which is mounted on a main printed circuit board that is an object of degradation detection. The printed circuit board for degradation detection has an insulating substrate and a wiring pattern for degradation detection formed on the outer surface of the insulating substrate. The wiring pattern is formed on the back side of the outer surface of the insulating substrate, which is located on the main printed circuit board side. The insulating substrate has a through portion that passes through from the back side to the surface located on the opposite side of the back side.
[0009] According to the present invention, disconnection of a wiring pattern can be promoted without increasing manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 is a schematic diagram of the main printed circuit board.
[0011] Figure 2 It is a perspective view of the deterioration detection printed circuit board according to the first embodiment.
[0012] Figure 3 It is a bottom view of the deterioration detection printed circuit board according to the first embodiment.
[0013] Figure 4 It is a perspective view of a deterioration detection printed circuit board according to a second embodiment.
[0014] Figure 5 It is a bottom view of the deterioration detection printed circuit board according to the second embodiment. DETAILED DESCRIPTION
[0015] The following are preferred embodiments, with reference to the attached drawings. Figure 1 The deterioration detecting printed circuit board of the present invention will be described in detail.
[0016] [1 Main printed circuit board 10]
[0017] Figure 1 1 is a schematic diagram of a main printed circuit board 10. The main printed circuit board 10 is used for a machine tool. A wiring pattern (not shown) of an electronic circuit is formed on at least one surface of the main printed circuit board 10, and a wiring pattern 12 of a degradation detection circuit is formed. In addition, a power terminal 14 and a ground terminal 16 are provided on the main printed circuit board 10. The power terminal 14 is connected to a power source. The ground terminal 16 is connected to the ground.
[0018] The wiring pattern 12 includes a first wiring 12a, a second wiring 12b, a third wiring 12c, a fourth wiring 12d, and a fifth wiring 12e. One end of the first wiring 12a, i.e., a first end portion, is connected to the power supply terminal 14. The other end of the first wiring 12a, i.e., a second end portion, is connected to a first electrode pad 40a of a deterioration detection printed circuit board 20 described later. One end of the second wiring 12b, i.e., a first end portion, is connected to a first electrode pad 40b of a deterioration detection printed circuit board 20. The other end of the second wiring 12b, i.e., a second end portion, is connected to a first electrode pad 40c of a deterioration detection printed circuit board 20. One end of the third wiring 12c, i.e., a first end portion, is connected to a first electrode pad 40d of a deterioration detection printed circuit board 20. The other end of the third wiring 12c, i.e., a second end portion, is connected to a ground terminal 16. The third wiring 12c is connected in series with a resistor R. Both ends of the resistor R are connected to a voltage sensor V for detecting a resistor voltage. One end, that is, a first end portion, of the fourth wiring 12d is connected to the second electrode pad 46a of the deterioration detection printed circuit board 20. The other end, that is, a second end portion, of the fourth wiring 12d is connected to the ground terminal 16. One end, that is, a first end portion, of the fifth wiring 12e is connected to the second electrode pad 46b of the deterioration detection printed circuit board 20. The other end, that is, a second end portion, of the fifth wiring 12e is connected to the ground terminal 16.
[0019] Figure 1 The wiring pattern 12 shown is an example. The shape of the wiring pattern 12 is not limited to Figure 1 Shape shown.
[0020] As described later, the wiring pattern 24 formed on the printed substrate 20 for degradation detection has a wiring 42a and a wiring 42b. The wiring 42a is connected to the first electrode pad 40a and the first electrode pad 40b. The wiring 42b is connected to the first electrode pad 40c and the first electrode pad 40d. The first wiring 12a, the wiring 42a, the second wiring 12b, the wiring 42b and the third wiring 12c are connected in series. The wiring 42a and the wiring 42b are thinner than the wiring (not shown) of the electronic circuit of the main printed substrate 10. Therefore, the wiring 42a and the wiring 42b are easily disconnected. When a predetermined voltage is applied to the power supply terminal 14 in a state where the wiring 42a and the wiring 42b (and the first wiring 12a to the third wiring 12c) are not disconnected, the voltage sensor V detects the resistance voltage. On the other hand, when a predetermined voltage is applied to the power supply terminal 14 in a state where the wiring 42a or the wiring 42b is disconnected, the voltage sensor V detects a voltage of zero. In this way, the detection value of the voltage sensor V becomes an index indicating the degree of degradation of the degradation detection printed circuit board 20. As a result, the detection value of the voltage sensor V becomes an index indicating the degree of degradation of the wiring pattern formed on the main printed circuit board 10.
[0021] [2 Deterioration detection printed circuit board 20]
[0022] Hereinafter, a first embodiment and a second embodiment will be described as specific examples of the deterioration detecting printed circuit board 20 .
[0023] [2-1 First Embodiment]
[0024] Figure 2 It is a perspective view of the deterioration detection printed circuit board 20 according to the first embodiment. Figure 3 FIG. 2 is a bottom view of a deterioration detection printed circuit board 20 according to the first embodiment. The deterioration detection printed circuit board 20 includes an insulator substrate 22, a wiring pattern 24, and a solder resist 26. Figure 3 In FIG. 1 , the solder resist 26 is indicated by dots. Figure 3 In FIG. 1 , the outer shape portion of the wiring pattern 24 covered with the solder resist 26 is indicated by a dotted line.
[0025] The insulator substrate 22 is a plate formed by an insulator component. In the first embodiment, the outer surface of the insulator substrate 22 facing the main printed circuit board 10 is set as the back surface 32, and the outer surface facing the direction opposite to the direction facing the back surface 32 is set as the surface 30. The insulator substrate 22 has a through hole (through portion) 34 that passes from the approximate center part of the back surface 32 to the approximate center part of the surface 30. A general through hole cannot allow liquid (cutting fluid) to flow. In contrast, the through hole 34 is large enough to allow liquid (cutting fluid) to flow from the surface 30 to the back surface 32. In the first embodiment, the shape of the through hole 34 when viewed from above is an oblong. However, the shape of the through hole 34 is not limited to this.
[0026] The wiring pattern 24 is made of a conductor such as copper and is printed on the back surface 32 of the insulating substrate 22. The wiring pattern 24 includes two sensor portions 36a and 36b that are easily disconnected and two disconnection promoting portions 38a and 38b that promote disconnection of the sensor portions 36a and 36b.
[0027] The sensor portion 36a includes the above-mentioned set of first electrode pads 40a, 40b and wiring 42a. The first electrode pads 40a and 40b are respectively arranged at two opposing edges of the plurality of edges of the back surface 32. The wiring 42a vertically penetrates the back surface 32 and passes around the through hole 34.
[0028] The sensor portion 36b includes the above-mentioned set of first electrode pads 40c and 40d and wiring 42b. The first electrode pads 40c and 40d are respectively arranged at two opposing edges of the plurality of edges of the back surface 32. The wiring 42b vertically penetrates the back surface 32 and passes around the through hole 34.
[0029] The wiring 42a is arranged on one side of the through hole 34 in the short side direction ( Figure 3The wiring 42b is arranged on the other side of the through hole 34 in the short side direction ( Figure 3 The wiring 42a and the wiring 42b are parallel to the longitudinal direction of the through hole 34.
[0030] As described above, the wirings 42a and 42b are relatively thin. In addition, as described later, at least a portion of the wiring 42a and at least a portion of the wiring 42b are exposed to the atmosphere near the through hole 34. Therefore, the wirings 42a and 42b are corroded by contact with the cutting fluid that flows from the surface 30 through the through hole 34 and is guided to the back surface 32. If the corrosion progresses, the wirings 42a and 42b are disconnected.
[0031] The disconnection promoting portion 38a is composed of one second electrode pad 46a and a ground portion 48a connected to the second electrode pad 46a. The second electrode pad 46a is arranged at the edge of the back surface 32. The ground portion 48a is adjacent to the wiring 42a at a predetermined interval.
[0032] The disconnection promoting portion 38b is composed of one second electrode pad 46b and a ground portion 48b connected to the second electrode pad 46b. The second electrode pad 46b is arranged at the edge of the back surface 32. The ground portion 48b is adjacent to the wiring 42b at a predetermined interval.
[0033] Figure 3 The shape of the wiring pattern 24 shown in the figure (the shape and arrangement of the sensor portions 36a, 36b and the disconnection promoting portions 38a, 38b) is an example. The shape of the wiring pattern 24 is not limited to Figure 3 Shape shown.
[0034] When the cutting fluid accumulates across the wiring 42a and the grounding portion 48a, and a potential difference is generated between the wiring 42a and the grounding portion 48a, copper ions move from the wiring 42a to the grounding portion 48a. Then, as the copper ions move, the wiring 42a is corroded and the wiring is broken. Similarly, when the cutting fluid accumulates across the wiring 42b and the grounding portion 48b, and a potential difference is generated between the wiring 42b and the grounding portion 48b, copper ions move from the wiring 42b to the grounding portion 48b. Then, as the copper ions move, the wiring 42b is corroded and the wiring is broken.
[0035] The solder resist 26 covers a portion of the back surface 32, the wirings 42a, 42b, and the grounding portions 48a, 48b. The solder resist 26 exposes a portion of the back surface 32, the wirings 42a, 42b, and the grounding portions 48a, 48b to the atmosphere. That is, a portion of the wirings 42a, 42b and the grounding portions 48a, 48b is covered by the solder resist 26. In addition, a portion of the wirings 42a, 42b and the grounding portions 48a, 48b is exposed to the atmosphere.
[0036] Around the through hole 34, the portion of the wiring 42a exposed to the atmosphere and the portion of the wiring 42a covered by the solder resist 26 are arranged alternately. In the outer direction of the wiring 42a, the portion of the disconnection promotion portion 38a exposed to the atmosphere and the portion of the disconnection promotion portion 38a covered by the solder resist 26 are arranged alternately. In addition, in the outer direction of the portion exposed by the wiring 42a, there is a portion of the back surface 32 exposed to the atmosphere. In the outer direction of the portion exposed by the back surface 32, there is a portion of the disconnection promotion portion 38a exposed to the atmosphere. In addition, in the outer direction of the portion covered by the solder resist 26 of the wiring 42a, there is a portion of the back surface 32 covered by the solder resist 26. In the outer direction of the portion covered by the solder resist 26 of the back surface 32, there is a portion of the disconnection promotion portion 38a covered by the solder resist 26. In addition, the wiring 42b, the disconnection promotion portion 38b, and the back surface 32 are also configured in the same manner as the wiring 42a, the disconnection promotion portion 38a, and the back surface 32.
[0037] The cutting fluid is likely to accumulate at the boundary between the wiring pattern 24 and the solder resist 26. The boundary between the wiring 42a and the solder resist 26 is arranged around the through hole 34. In addition, the boundary between the wiring 42b and the solder resist 26 is arranged around the through hole 34. According to such a structure, the cutting fluid that flows from the surface 30 through the through hole 34 and is guided to the back surface 32 is likely to accumulate at each boundary. Therefore, the wiring 42a is likely to be corroded and broken. In addition, the wiring 42b is likely to be corroded and broken.
[0038] In the first embodiment, the cutting fluid attached to the surface 30 of the insulator substrate 22 flows through the through hole 34 and is guided to the back surface 32, and accumulates in the gap between the main printed substrate 10 and the deterioration detection printed substrate 20. Therefore, the first embodiment can promote the disconnection of the wiring pattern 24 (wiring 42a, 42b) formed on the back surface 32 of the insulator substrate 22. According to the first embodiment, the through hole 34 guides the cutting fluid attached to the surface 30 to the back surface 32. Therefore, it is not necessary to form the wiring pattern 24 on the surface 30 of the insulator substrate 22. Therefore, the deterioration detection printed substrate 20 of the first embodiment can suppress the increase in manufacturing cost compared with the deterioration detection printed substrate in which the wiring pattern is formed on the surface and the back surface.
[0039] In addition, in the first embodiment, the wirings 42a and 42b are arranged around the through hole 34. Furthermore, the boundary between the wiring 42a and the solder resist 26 and the boundary between the wiring 42b and the solder resist 26 are arranged around the through hole 34. On the other hand, the first electrode pads 40a to 40d and the second electrode pads 46a and 46b are arranged at the edge of the back surface 32 of the insulator substrate 22, and are not arranged around the through hole 34. Therefore, the cutting fluid flowing to the back surface 32 is not blocked by the first electrode pads 40a to 40d and the second electrode pads 46a and 46b, but contacts the wirings 42a and 42b. Furthermore, the cutting fluid accumulates at the boundary between the wiring 42a and the solder resist 26. In addition, the cutting fluid accumulates at the boundary between the wiring 42b and the solder resist 26. The first embodiment can also promote the disconnection of the wiring pattern 24 (wiring 42a and 42b) in this regard.
[0040] [2-2 Second Embodiment]
[0041] Figure 4 It is a perspective view of a deterioration detection printed circuit board 20 according to the second embodiment. Figure 5 FIG. 2 is a bottom view of a deterioration detection printed circuit board 20 according to the second embodiment. Regarding the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Figure 5 In FIG. 1 , the outer shape portion of the wiring pattern 24 covered with the solder resist 26 is indicated by a dotted line.
[0042] The insulator substrate 22 of the second embodiment has a cutout portion (through portion) 50 instead of the through hole 34 of the first embodiment. The cutout portion 50 is a portion obtained by cutting a part of the insulator substrate 22 from the edge of the insulator substrate 22 .
[0043] On one side of the back side 32 ( Figure 5 A sensor portion 36a and a disconnection promotion portion 38a are provided on the other side ( Figure 5The sensor portion 36b and the wire breaking promotion portion 38b are provided on the left side of the insulator substrate 22. The first electrode pads 40a to 40d and the second electrode pads 46a and 46b are concentrated on one edge of the back side 32 of the insulator substrate 22. The second electrode pad 46a is provided between the first electrode pad 40a and the first electrode pad 40b. The second electrode pad 46b is provided between the first electrode pad 40c and the first electrode pad 40d. The wiring 42a is formed to pass through the two edges and the cutout portion 50. The grounding portion 48a is located on the inner side of the wiring 42a. The wiring 42b is formed to pass through the two edges and the cutout portion 50. The grounding portion 48b is located on the inner side of the wiring 42b. The shape of the wiring 42a and the shape of the wiring 42b are line symmetrical with the center line C of the back side 32 as the axis of symmetry. Similarly, the shape of the grounding portion 48a and the shape of the grounding portion 48b are line symmetrical with the center line C of the back side 32 as the axis of symmetry.
[0044] The second embodiment achieves the same effects as the first embodiment. In addition, in the second embodiment, the first electrode pads 40a to 40d and the second electrode pads 46a and 46b are concentrated on one edge of the back surface 32 of the insulator substrate 22. Therefore, the cutting fluid attached to the main printed substrate 10 can easily penetrate into the gap between the main printed substrate 10 and the deterioration detection printed substrate 20.
[0045] Figure 5 The shape of the wiring pattern 24 shown (the shape and arrangement of the sensor portions 36a and 36b, and the shape and arrangement of the disconnection promoting portions 38a and 38b) is an example. The shape of the wiring pattern 24 is not limited to Figure 5 Shape shown.
[0046] [3 Modifications]
[0047] In the first embodiment and the second embodiment, a solder resist 26 is provided. Alternatively, the entire wiring pattern 24 may be exposed to the atmosphere without being covered by the solder resist 26. Compared with the first embodiment and the second embodiment, this modification example has a lower probability of corrosion of the wiring pattern 24 (wiring 42a, 42b) and a lower probability of disconnection. However, as in the first embodiment and the second embodiment, this modification example also has a function of corroding the wiring pattern 24 (wiring 42a, 42b) and a function of disconnecting the wiring pattern 24 (wiring 42a, 42b).
[0048] The thickness of the wiring 42a and the thickness of the wiring 42b may be different. In this case, the resistor R connected to the wiring 42a and the resistor R connected to the wiring 42b may be different. In addition, the voltage sensor V connected to the wiring 42a and the voltage sensor V connected to the wiring 42b may be different. By such a modification, the degradation of the main printed circuit board 10 can be detected in two stages.
[0049] [4 Inventions according to embodiments]
[0050] The invention that can be grasped from the above-mentioned embodiment and modified examples will be described below.
[0051] The present invention provides a printed circuit board (20) for degradation detection which is mounted on a main printed circuit board (10) which is an object of degradation detection. The printed circuit board (20) for degradation detection has an insulating substrate (22) and a wiring pattern (24) for degradation detection formed on the outer surface of the insulating substrate, wherein the wiring pattern is formed on a back surface (32) located on the main printed circuit board side of the outer surface of the insulating substrate, and the insulating substrate has a through portion (34, 50) that passes through from the back surface to a surface (30) located on the opposite side of the back surface.
[0052] In an aspect of the present invention, the through portion may be a through hole (34) penetrating the insulator substrate from the back surface to the front surface.
[0053] In an aspect of the present invention, the through portion may be a cutout portion (50) formed by cutting out a portion of the insulator substrate from an edge portion of the insulator substrate.
[0054] In an aspect of the present invention, a solder resist (26) may be provided which covers the back surface and a part of the wiring pattern and exposes a part of the wiring pattern.
[0055] In the aspect of the present invention, a portion of the wiring pattern exposed by the solder resist may be provided around the through portion.
[0056] In addition, the deterioration detection printed circuit board of the present invention is not limited to the above-described embodiment and modified examples, and it is of course possible to adopt various configurations without departing from the gist of the present invention.
Claims
1. A degradation detection printed circuit board (20) mounted on a main printed circuit board (10) to be detected for degradation, the degradation detection printed circuit board (20) comprising an insulating substrate (22) and a wiring pattern (24) for degradation detection formed on an outer surface of the insulating substrate, It is characterized in that The wiring pattern is formed on a back surface (32) located on the main printed circuit board side of the outer surface of the insulator substrate. The insulator substrate has a through portion (34, 50) penetrating from the back surface to a surface (30) located on the opposite side of the back surface.
2. The deterioration detection printed circuit board according to claim 1, It is characterized in that The through-portion is a through-hole (34) that penetrates the insulator substrate from the back surface to the front surface.
3. The deterioration detection printed circuit board according to claim 1, It is characterized in that The through portion is a cutout portion (50) formed by cutting a portion of the insulating substrate from an edge portion of the insulating substrate.
4. The deterioration detection printed circuit board according to any one of claims 1 to 3, It is characterized in that The deterioration detection printed circuit board further includes a solder resist (26) that covers the back surface and a part of the wiring pattern and exposes a part of the wiring pattern.
5. The deterioration detection printed circuit board according to claim 4, It is characterized in that A portion of the wiring pattern exposed by the solder resist is provided around the through portion.