A gold-plated pad protection structure for line etching

Abstract

This utility model relates to a gold-plated PAD protection structure for circuit etching, including a gold-plated PAD, a dry film protection section, and a dry film protection ring. The dry film protection section covers the surface of the gold-plated PAD and has a preset compensation width on one side relative to the edge of the gold-plated PAD. The dry film protection ring is located outside the dry film protection section and has at least three supporting ribs between it and the dry film protection section. An etching gap is provided between the dry film protection ring and the dry film protection section to allow etching solution to enter. By adding a dry film protection section with a preset compensation width on one side relative to the edge of the gold-plated PAD, this utility model can accurately match the lateral etching requirements of the copper layer during the etching process, avoid damage to the edge of the gold-plated PAD due to over-etching, reduce excessive hollowing of the copper layer under the gold-plated PAD, thereby significantly reducing the gold suspension length and the risk of electrical performance failure.

Description

Technical Field

[0001] This utility model relates to the field of circuit board processing technology, specifically to a gold-plated PAD protection structure for circuit etching. Background Technology

[0002] In the field of high-end precision PCB pattern etching technology, as electronic devices develop towards higher integration and higher performance, increasingly higher requirements are placed on the manufacturing precision and reliability of PCB circuit boards. In particular, the etching quality of gold-plated PADs directly affects the electrical performance and service life of the products.

[0003] In existing technologies, gold-plated PAD pattern etching mainly employs two methods: one is the gold-plated lead process, which requires two pattern processing steps, making the process cumbersome and prone to leaving residues after etching, interfering with signal transmission and affecting line spacing. The other is the gold layer resist process, which overcomes the shortcomings of the former. It mainly utilizes the alkali-resistant properties of gold to directly etch after gold plating. However, in the existing gold layer resist process, as the copper layer thickness increases, gold overhang is prone to occur, and the length of the overhang increases accordingly. The overhang may fall off in subsequent processes, leading to short circuits in the product and posing serious reliability risks such as terminal conductive anode wire failure (CAF failure) and electrical performance failure.

[0004] Therefore, how to optimize the existing gold layer etching process to reduce the gold suspension length and increase the etching factor, thereby improving the accuracy of gold-plated PAD etching and the reliability of the product, has become an urgent technical problem to be solved in the current PCB manufacturing. Utility Model Content

[0005] To address the issue of gold layer corrosion protection in existing gold-plated PAD pattern etching processes, which can easily lead to gold overhang, this invention provides a gold-plated PAD protection structure for circuit etching.

[0006] The technical solution of this utility model is as follows:

[0007] A gold-plated PAD protection structure for circuit etching includes a gold-plated PAD, a dry film protection section, and a dry film protection ring.

[0008] The dry film protective portion covers the surface of the gold-plated PAD and has a single-sided preset compensation width relative to the edge of the gold-plated PAD;

[0009] The dry film protection ring is located outside the dry film protection part, and at least three support ribs are provided between it and the dry film protection part. The support ribs are used to connect the dry film protection part and the dry film protection ring.

[0010] An etching gap is provided between the dry film protection ring and the dry film protection part, and the etching gap is used to allow the etching solution to enter.

[0011] As a preferred technical solution of this utility model, the single-sided preset compensation width is 1.0mil to 2.0mil.

[0012] Preferably, the preset compensation width on one side is 1.5 mil.

[0013] As a preferred embodiment of this invention, the etching spacing is 2.0 mil to 3.5 mil.

[0014] Preferably, the etching spacing is 3.0 mil.

[0015] As a preferred embodiment of this invention, the width of the dry film protective ring is 1.5 mil to 2.5 mil.

[0016] Preferably, the width of the dry film protective ring is 2.0 mil.

[0017] As a preferred embodiment of this utility model, the width of the support rib is 1.0 mil to 2.0 mil.

[0018] Preferably, the width of the support rib is 1.5 mil.

[0019] As a preferred embodiment of this utility model, a plurality of the supporting ribs are arranged at intervals, with one supporting rib arranged at every 5mm interval.

[0020] The advantages of this utility model based on the above solution are as follows:

[0021] This invention adds a dry film protection section to the gold-plated PAD, and the dry film protection section has a preset compensation width on one side relative to the edge of the gold-plated PAD. This can accurately match the side etching requirements of the copper layer during the etching process and avoid damage to the edge of the gold-plated PAD due to excessive etching. The dry film protection ring is located outside the dry film protection section. With the stable connection of the support rib, it can limit the etching range and rate of the etching solution within the etching interval, reduce excessive hollowing of the copper layer under the gold-plated PAD, thereby significantly reducing the length of the suspended gold and reducing the risk of electrical performance failure.

[0022] Meanwhile, by precisely controlling the etching process, this invention effectively improves the etching factor while ensuring the integrity of other patterns, thereby enhancing the precision and reliability of PCB manufacturing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] Figure 2 This is a top view of the present invention;

[0025] Figure 3 This is a schematic diagram showing the etching process completed and the film removed.

[0026] Figure 4 This is a microscopic image of the present invention.

[0027] Figure 5 This is a schematic diagram of the existing technology;

[0028] Figure 6 This is a schematic diagram of the existing technology after etching is completed and the film has been removed;

[0029] Figure 7 This is a microscopic image of the effect of existing technology.

[0030] In the diagram,

[0031] 1. Gold-plated PAD; 2. Dry film protection layer; 3. Dry film protection ring; 4. Etching spacing; 5. Support ribs; 6. Copper layer. Detailed Implementation

[0032] To better understand the purpose, technical solution, and technical effects of this utility model, the following description, in conjunction with the accompanying drawings and embodiments, will provide further explanation. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need further definition and explanation in subsequent drawings. It is also stated that the embodiments described below are only for explaining this utility model and are not intended to limit it.

[0033] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there may be an intermediate component.

[0034] The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art, and is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. The term "several" means two or more, unless otherwise expressly and specifically defined.

[0035] like Figures 5 to 7As shown, in existing gold-plated resist etching processes, as the thickness of the copper layer 6 increases, gold overhang is easily observed, and the length of the overhang increases accordingly. To address the problem of gold overhang in existing gold-plated PAD pattern etching processes, this invention provides a gold-plated PAD protection structure for circuit etching.

[0036] like Figure 1 and Figure 2 As shown, a gold-plated PAD protection structure for circuit etching includes a gold-plated PAD 1, a dry film protection section 2, and a dry film protection ring 3. The dry film protection section 2 covers the surface of the gold-plated PAD 1 and has a single-sided preset compensation width relative to the edge of the gold-plated PAD 1. The dry film protection ring 3 is located outside the dry film protection section 2 and has at least three supporting ribs 5 between it and the dry film protection section 2. The supporting ribs 5 are used to connect the dry film protection section 2 and the dry film protection ring 3. An etching gap 4 is provided between the dry film protection ring 3 and the dry film protection section 2, and the etching gap 4 is used to allow etching solution to enter.

[0037] The principle of this invention is based on precise control of the etching path of the etching solution, combined with the physical protection of the copper layer 6 by the dry film to improve etching accuracy. Specifically, the dry film protection part 2 covers the surface of the gold-plated PAD1 and is set with a preset compensation width on one side. This compensation amount can match the side etching requirements of the copper layer during etching, forming the first layer of protection, directly resisting the unlimited etching of the copper layer at the edge of the gold-plated PAD by the etching solution; the dry film protection ring is located outside the dry film protection part, and the etching gap between it and the dry film protection part provides an entry channel for the etching solution, ensuring that the copper layer to be etched can be effectively etched. At the same time, the protection ring prevents excessive diffusion of the etching solution through its own structure, reducing the "hollowing out" effect on the copper layer below the gold-plated PAD; the support ribs firmly connect the dry film protection part and the protection ring, preventing the protection ring from falling off due to its small width, and ensuring the stability of the overall protection structure during the etching process.

[0038] like Figure 3 and Figure 4 As shown, by adopting the above technical solution, the etching solution can only etch the copper layer 6 within a controlled range at the etching interval 4. The compensation design of the dry film protection part 2 offsets the influence of side etching, and the protection ring 3 limits the penetration depth of the etching solution, ultimately achieving effective control over the length of the suspended gold, which can be controlled within 35μm. At the same time, the etching factor is improved, solving the problem of short circuits and terminal failures caused by suspended gold falling off in traditional processes. Here, the etching factor is the ratio of etching depth to side etching amount.

[0039] In actual processing, the thickness difference of copper layer 6 will lead to different lateral etching amounts. For thinner copper layers, a compensation width of about 1.0 mil can be used to avoid excessive compensation affecting the etching of surrounding patterns; for thicker copper layers, a compensation width of about 2.0 mil can be used to more effectively resist lateral etching and prevent excessive etching of the copper layer at the edge of the gold-plated PAD. In a specific embodiment, the preset compensation width on one side is 1.5 mil, which matches the copper layer thickness parameter design. This value just matches the lateral etching requirements under the conventional copper layer thickness, and can protect the edge of the gold-plated PAD1 while reserving a reasonable working space for the etching solution.

[0040] The etching spacing 4 can be 2.0mil, 2.2mil, 2.4mil, 2.6mil, 2.8mil, 3.0mil, 3.2mil, or 3.5mil. The spacing can be selected based on the etching power of the etching solution: when the etching solution has a strong etching power (e.g., high concentration) or the copper layer is thin, a smaller etching spacing should be chosen to reduce the contact time and area of ​​the solution in that region, avoiding over-etching of the copper layer beneath the gold-plated PAD; when the etching solution has a weak etching power or the copper layer is thick, a larger etching spacing should be chosen to ensure that the copper layer to be etched is fully etched, guaranteeing etching integrity.

[0041] In this invention, the width of the dry film protection ring 3 is 1.5 mil to 2.5 mil. The width of the support rib 5 is 1.0 mil to 2.0 mil. In a preferred embodiment, the width of the dry film protection ring 3 is 2.0 mil. The width of the support rib 5 is 1.5 mil. This width of the dry film protection ring 3 ensures effective blocking of the etching solution and also provides suitable structural strength. Combined with the 1.5 mil wide support rib 5, it can stably connect the dry film protection ring 3 and the dry film protection part 2, preventing the dry film protection ring 3 from falling off during the etching process.

[0042] In this invention, several support ribs 5 are spaced apart, with one support rib 5 every 5 mm. This arrangement provides uniform and stable support based on the actual length of the dry film protection ring 3. By distributing the support ribs 5 at fixed intervals, it is possible to avoid the dry film protection ring 3 from falling off due to excessive local stress caused by uneven distribution of support points, thus ensuring that the dry film protection ring 3 maintains stable connection with the dry film protection part 2 throughout the etching process.

[0043] In summary, this invention, by adding a dry film protection section 2 to the gold-plated PAD1, and with the dry film protection section 2 having a pre-set compensation width on one side relative to the edge of the gold-plated PAD1, can precisely match the lateral etching requirements of the copper layer 6 during the etching process, preventing damage to the edge of the gold-plated PAD1 due to excessive etching. The dry film protection ring 3, located outside the dry film protection section 2, combined with the stable connection of the support rib 5, can limit the etching range and rate of the etching solution within the etching gap 4, reducing excessive hollowing of the copper layer 6 below the gold-plated PAD, thereby significantly reducing the length of the suspended gold and controlling it within 35μm. This reduces the risk of the suspended gold falling off in subsequent processes, leading to product short circuits, terminal CAF failure, and electrical performance failure. At the same time, this invention, through precise control of the etching process, effectively improves the etching factor while ensuring the integrity of other pattern etching, thus improving the accuracy and reliability of PCB circuit board manufacturing.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A gold-plated PAD protective structure for circuit etching, characterized in that, Includes gold-plated PADs, dry film protection components, and dry film protection rings; The dry film protective portion covers the surface of the gold-plated PAD and has a single-sided preset compensation width relative to the edge of the gold-plated PAD; The dry film protection ring is located outside the dry film protection part, and at least three support ribs are provided between it and the dry film protection part. The support ribs are used to connect the dry film protection part and the dry film protection ring. An etching gap is provided between the dry film protection ring and the dry film protection part, and the etching gap is used to allow the etching solution to enter.

2. The gold-plated PAD protection structure for circuit etching according to claim 1, characterized in that, The preset compensation width on one side is 1.0mil to 2.0mil.

3. The gold-plated PAD protection structure for circuit etching according to claim 2, characterized in that, The preset compensation width on one side is 1.5mil.

4. The gold-plated PAD protection structure for circuit etching according to claim 1, characterized in that, The etching spacing is 2.0 mil to 3.5 mil.

5. The gold-plated PAD protection structure for circuit etching according to claim 4, characterized in that, The etching spacing is 3.0 mil.

6. The gold-plated PAD protection structure for circuit etching according to claim 1, characterized in that, The width of the dry film protective ring is 1.5 mil to 2.5 mil.

7. The gold-plated PAD protection structure for circuit etching according to claim 6, characterized in that, The width of the dry film protective ring is 2.0 mil.

8. The gold-plated PAD protection structure for circuit etching according to claim 1, characterized in that, The width of the support rib is 1.0 mil to 2.0 mil.

9. The gold-plated PAD protection structure for circuit etching according to claim 1, characterized in that, The width of the supporting rib is 1.5 mil.

10. A gold-plated PAD protection structure for circuit etching according to claim 1, characterized in that, The supporting ribs are spaced apart, with one supporting rib spaced 5mm apart.

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