1. PCB Surface Treatment: Options include anti-oxidation, tin spray, lead-free tin spray, immersion gold, immersion tin, immersion silver, hard gold plating, full board gold plating, gold fingers, and nickel-palladium-gold. OSP offers lower costs, good solderability, environmental friendliness, and effective welding under harsh storage conditions, albeit with a shorter lifespan.
Tin spraying is typically employed in multilayer (4-46 layers) high-precision PCB models and is widely used by major domestic companies in communication, computing, medical devices, and aerospace sectors. The “golden finger” serves as the connection between memory modules and slots, allowing signal transmission through its gold contacts.
Why Use “Gold Paste” on PCB Circuit Boards:
Gold fingers consist of numerous gold-plated conductive contacts arranged like fingers. This gold coating on the copper-clad board is achieved through a specialized process, thanks to gold’s excellent oxidation resistance and conductivity. However, due to gold’s high cost, many manufacturers have shifted to tin plating. Since the 1990s, tin has become the standard material, with most motherboard, memory, and graphics card connections now using it. Only certain contact points on high-performance servers and workstations continue to utilize gold plating, which naturally incurs a higher expense.
2. Advantages of Gold-Plated Boards:
As IC integration levels rise, pin density increases, making it difficult for the vertical spray tin process to maintain flat pads. This poses challenges for SMT placement, and the shelf life of spray tin boards is quite limited. Gold-plated boards effectively address these issues:
1. For surface mount processes, especially with ultra-small components like 0603 and 0402, pad flatness is critical for the quality of solder paste printing, directly impacting reflow soldering quality. Consequently, full board gold plating is common in high-density and ultra-small surface mount applications.
2. During trial production, factors like component procurement often delay immediate soldering, leading to boards sitting unused for weeks or even months. Gold-plated boards have a significantly longer shelf life compared to lead-tin alloys, making them more desirable. Moreover, the costs for gold-plated PCBs during the sample phase are nearly equivalent to those of lead-tin alloy boards.
However, as routing becomes denser, line widths and spacing have reached 3-4 mils, leading to potential issues with gold wire short circuits. As signal frequencies increase, the skin effect in multilayer transmission can more significantly affect signal quality.
1. The skin effect refers to the phenomenon where high-frequency alternating current tends to concentrate near the surface of a conductor. Calculations show that the skin depth is frequency-dependent.
2. **Why Use Immersion Gold Boards?**
Why apply “immersion gold” on PCB circuit boards?
To address the issues associated with gold-plated boards, PCBs that utilize immersion gold offer the following advantages:
3. Due to differences in crystal structures formed by immersion gold and gold plating, immersion gold appears more golden yellow, leading to higher customer satisfaction.
4. Immersion gold is easier to solder than gold plating, reducing the risk of poor soldering and subsequent customer complaints.
5. Since the immersion gold board features only nickel and gold on the pads, the signal transmission affected by the skin effect does not interfere with the signal on the copper layer.
6. The denser crystal structure of immersion gold compared to gold plating makes it less susceptible to oxidation.
7. With only nickel and gold on the pads, immersion gold boards are less likely to produce gold wires that could lead to slight short circuits.
8. The absence of materials other than nickel and gold on the pads results in a stronger bond between the solder mask on the circuit and the copper layer.
9. Project adjustments will not affect the spacing during compensation processes.
10. Due to the differing crystal structures, the stress in immersion gold plates is more controllable, making it more suitable for products that require bonding. Additionally, immersion gold is softer than gilding, which means immersion gold plates are not as wear-resistant as gold fingers.
11. The flatness and longevity of immersion gold boards are comparable to those of gold-plated boards.
12. **Immersion Gold Boards vs. Gold-Plated Boards**
In fact, the gold plating process can be categorized into two types: electroplating and immersion gold.
13. The effects of tinning in the gilding process are significantly reduced, while immersion gold offers better tinning results; unless binding is specifically required by the manufacturer, most prefer the immersion gold process. Typically, PCB surface treatments include gold plating (both electroplated and immersion), silver plating, OSP, and tin spraying (both lead and lead-free). These methods are primarily used for FR-4 or CEM-3 boards, with paper substrates also utilizing rosin coatings.
14. The issue of poor tin application (poor tinning) is considered only after excluding production and material process factors from the chip manufacturer, such as solder paste.
15. Focusing on PCB concerns, there are several considerations:
16. During PCB printing, the presence of oil-permeable film on the pad area can hinder tinning; this can be confirmed through a tin bleaching test.
17. The lubrication position of the pad must meet design specifications to ensure proper support functionality.
18. Pad contamination can be assessed through ion contamination testing; these three factors are critical for PCB manufacturers.
19. Each surface treatment method has its pros and cons!
20. Gold plating can prolong PCB shelf life and is less sensitive to fluctuations in temperature and humidity compared to other treatments, typically allowing for around one year of storage. In contrast, the surface treatments of tin spraying and OSP require close attention to storage conditions.
21. Generally, immersion silver treatment differs slightly in that it is more expensive and has stricter storage requirements, necessitating packaging in sulfur-free paper, with a shelf life of about three months. When it comes to tinning effectiveness, immersion gold, OSP, and tin spraying yield similar results, with manufacturers primarily weighing cost-effectiveness.
If you have any PCB manufacturing needs, please do not hesitate to contact me.Contact me
Tin spraying is typically employed in multilayer (4-46 layers) high-precision PCB models and is widely used by major domestic companies in communication, computing, medical devices, and aerospace sectors. The “golden finger” serves as the connection between memory modules and slots, allowing signal transmission through its gold contacts.
Why Use “Gold Paste” on PCB Circuit Boards:
Gold fingers consist of numerous gold-plated conductive contacts arranged like fingers. This gold coating on the copper-clad board is achieved through a specialized process, thanks to gold’s excellent oxidation resistance and conductivity. However, due to gold’s high cost, many manufacturers have shifted to tin plating. Since the 1990s, tin has become the standard material, with most motherboard, memory, and graphics card connections now using it. Only certain contact points on high-performance servers and workstations continue to utilize gold plating, which naturally incurs a higher expense.
2. Advantages of Gold-Plated Boards:
As IC integration levels rise, pin density increases, making it difficult for the vertical spray tin process to maintain flat pads. This poses challenges for SMT placement, and the shelf life of spray tin boards is quite limited. Gold-plated boards effectively address these issues:
1. For surface mount processes, especially with ultra-small components like 0603 and 0402, pad flatness is critical for the quality of solder paste printing, directly impacting reflow soldering quality. Consequently, full board gold plating is common in high-density and ultra-small surface mount applications.
2. During trial production, factors like component procurement often delay immediate soldering, leading to boards sitting unused for weeks or even months. Gold-plated boards have a significantly longer shelf life compared to lead-tin alloys, making them more desirable. Moreover, the costs for gold-plated PCBs during the sample phase are nearly equivalent to those of lead-tin alloy boards.
However, as routing becomes denser, line widths and spacing have reached 3-4 mils, leading to potential issues with gold wire short circuits. As signal frequencies increase, the skin effect in multilayer transmission can more significantly affect signal quality.
1. The skin effect refers to the phenomenon where high-frequency alternating current tends to concentrate near the surface of a conductor. Calculations show that the skin depth is frequency-dependent.
2. **Why Use Immersion Gold Boards?**
Why apply “immersion gold” on PCB circuit boards?
To address the issues associated with gold-plated boards, PCBs that utilize immersion gold offer the following advantages:
3. Due to differences in crystal structures formed by immersion gold and gold plating, immersion gold appears more golden yellow, leading to higher customer satisfaction.
4. Immersion gold is easier to solder than gold plating, reducing the risk of poor soldering and subsequent customer complaints.
5. Since the immersion gold board features only nickel and gold on the pads, the signal transmission affected by the skin effect does not interfere with the signal on the copper layer.
6. The denser crystal structure of immersion gold compared to gold plating makes it less susceptible to oxidation.
7. With only nickel and gold on the pads, immersion gold boards are less likely to produce gold wires that could lead to slight short circuits.
8. The absence of materials other than nickel and gold on the pads results in a stronger bond between the solder mask on the circuit and the copper layer.
9. Project adjustments will not affect the spacing during compensation processes.
10. Due to the differing crystal structures, the stress in immersion gold plates is more controllable, making it more suitable for products that require bonding. Additionally, immersion gold is softer than gilding, which means immersion gold plates are not as wear-resistant as gold fingers.
11. The flatness and longevity of immersion gold boards are comparable to those of gold-plated boards.
12. **Immersion Gold Boards vs. Gold-Plated Boards**
In fact, the gold plating process can be categorized into two types: electroplating and immersion gold.
13. The effects of tinning in the gilding process are significantly reduced, while immersion gold offers better tinning results; unless binding is specifically required by the manufacturer, most prefer the immersion gold process. Typically, PCB surface treatments include gold plating (both electroplated and immersion), silver plating, OSP, and tin spraying (both lead and lead-free). These methods are primarily used for FR-4 or CEM-3 boards, with paper substrates also utilizing rosin coatings.
14. The issue of poor tin application (poor tinning) is considered only after excluding production and material process factors from the chip manufacturer, such as solder paste.
15. Focusing on PCB concerns, there are several considerations:
16. During PCB printing, the presence of oil-permeable film on the pad area can hinder tinning; this can be confirmed through a tin bleaching test.
17. The lubrication position of the pad must meet design specifications to ensure proper support functionality.
18. Pad contamination can be assessed through ion contamination testing; these three factors are critical for PCB manufacturers.
19. Each surface treatment method has its pros and cons!
20. Gold plating can prolong PCB shelf life and is less sensitive to fluctuations in temperature and humidity compared to other treatments, typically allowing for around one year of storage. In contrast, the surface treatments of tin spraying and OSP require close attention to storage conditions.
21. Generally, immersion silver treatment differs slightly in that it is more expensive and has stricter storage requirements, necessitating packaging in sulfur-free paper, with a shelf life of about three months. When it comes to tinning effectiveness, immersion gold, OSP, and tin spraying yield similar results, with manufacturers primarily weighing cost-effectiveness.
If you have any PCB manufacturing needs, please do not hesitate to contact me.Contact me
