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- 9月
PCB高频板分类
高频板是指专用电磁频率电路板，用于高频（频率大于300MHZ或波长小于1米）和微波（频率大于3GHZ或波长小于0.1米）领域PCB，是在微波基覆铜上采用普通刚性电路板制造方法的一部分工艺或采用特殊加工方法而生产的电路板。 一般来说，高频板可以定义为频率在1GHz以上的电路板。
With the rapid development of science and technology, more and more equipment design is in the microwave band (> 1GHZ) and even with the millimeter wave field (30GHZ) above the application, which also means that the frequency is higher and higher, the substrate of the circuit board requirements are also higher and higher. 例如，基板材料需要具有优良的电性能、良好的化学稳定性，随着功率信号频率的增加，基板损耗要求非常小，因此高频板的重要性就凸显出来。
Classification of PCB high frequency plate
1, at the end of the ceramic filled thermosetting material
处理方法：
And epoxy resin/glass woven cloth (FR4) similar processing process, but the plate is more brittle, easy to break, drilling and gong plate drill nozzle and gong knife life is reduced by 20%.
2. PTFE（聚四氟乙烯）材料
处理方法：
1.开料：必须保留保护膜，防止划伤和压痕
2. 演练：
2.1 use a new drill (standard 130), one piece stacked is the best, the presser foot pressure is 40psi
2.2 铝板做盖板，再用1mm密胺板，拧紧聚四氟乙烯板
2.3 钻孔后用气枪将孔内灰尘吹出
2.4 用最稳定的钻机，钻孔参数（基本上孔越小，钻孔速度越快，排屑量越小，回程率越小）
3.孔加工
等离子处理或钠-萘活化处理有利于孔隙金属化
4. PTH沉铜
4.1 微蚀后（微蚀速率已控制在20微英寸），板从PTH拉出的除油缸进料
4.2 If necessary, go through the second PTH, just from the forecast? The cylinder began to enter the plate
5. The resistance welding
5.1 Pre-treatment: use acid washing plate instead of mechanical grinding plate
5.2 After pre-treatment, bake plate (90℃, 30min), brush green oil and cure
5.3 Three baking plates: one is 80℃, 100℃ and 150℃ for 30min each (if oil is found on the substrate surface, it can be reworked: wash off the green oil and reactivate it)
6. Gong board
Lay the white paper on the PTFE board circuit surface, and clamp it with fr-4 base plate or phenolic base plate with a thickness of 1.0mm and copper removal: As shown in the figure:
PCB高频板有哪些？ PCB高频板分类
高频高速片材
在为高频电路选择PCB基板时，应特别考虑材料DK在不同频率下的变化特性。 For the requirements of signal high-speed transmission or characteristic impedance control, DF and its performance under the conditions of frequency, temperature and humidity are mainly investigated.
Under the condition of frequency variation, the DK and DF values of general substrate materials change greatly. 特别是在 L MHz 到 L GHz 的频率范围内，它们的 DK 和 DF 值变化更加明显。 For example, the GENERAL epoxy – glass fiber substrate material (general FR-4) has a DK value of 4.7 at lMHz and a DK value of 4.19 at lGHz. 在lGHz以上，其DK值变化平缓。 For example, under l0GHz, the DK value of FR-4 is 4.15. For substrate materials with high speed and high frequency characteristics, the DK value changes slightly. From lMHz to lGHz, the DK value mostly stays within 0.02 range. The DK value tends to decrease slightly at different frequencies from low to high.
The dielectric loss factor (DF) of the general substrate material is larger than that of DK due to the influence of frequency variation (especially in the high frequency range). 因此，在评估基板材料的高频特性时，应重点关注其DF值的变化。 The substrate materials with high speed and high frequency characteristics are obviously different from the general substrate materials in terms of the variation characteristics at high frequency. One is that with the change of frequency, its (DF) value changes very little. 另一种在变化范围上与一般基板材料相似，但其自身（DF）值较低。
How to choose high frequency high speed plate
PCB板的选择必须满足设计要求、量产与成本之间的平衡。 In short, the design requirements consist of two components: electrical and structural reliability. This is usually important when designing very high speed PCB boards (frequencies greater than GHz). For example, the fr-4 material commonly used today may not be applicable due to its large Df (Dielectricloss) at several GHz frequencies.
PCB高频板有哪些？ PCB高频板分类
For example, a 10Gb/S high-speed digital signal is a square wave, which can be regarded as a superposition of sinusoidal signals of different frequencies. Therefore, 10Gb/S contains many different frequency signals: 5Ghz fundamental signal, 3 order 15GHz, 5 order 25GHz, 7 order 35GHz signal, etc. The integrity of the digital signal and the steepness of the upper and lower edges are the same as the low loss and low distortion transmission of rf microwave (the high frequency harmonic part of the digital signal reaches the microwave band). Therefore, in many respects, the PCB material selection of high-speed digital circuits is similar to the requirements of RF microwave circuits.
PCB高频板有哪些？ PCB高频板分类
In practical engineering operations, the selection of high-frequency plates seems simple, but there are still many factors to be considered. Through the introduction of this paper, AS a PCB design engineer or a high-speed project leader, I have a certain understanding of the characteristics and selection of plates. 了解电性能、热性能、可靠性等。 And rational use of stacking, design a piece of high reliability, good processing products, various factors to consider the best.
下面将介绍选择合适板材时要考虑的主要因素：
1、可制造性：
如多重压制性能、温度性能、CAF/耐热性和机械韧性（粘度）（可靠性好）、防火等级；
2, with the product matching performance (electrical, performance stability, etc.) :
损耗低，Dk/Df参数稳定，色散小，随频率和环境变化系数小，材料厚度和橡胶含量公差小（阻抗控制好），如果线长，考虑低粗糙度铜箔。 In addition, simulation is needed in the early stage of high-speed circuit design, and simulation results are the reference standard for design. “兴森科技-安捷伦（高速/射频）联合实验室”解决了仿真结果与测试不一致的性能问题，并做了大量仿真与实际测试闭环验证，通过独特的方法实现了仿真结果的一致性模拟和测量。
PCB高频板有哪些？ PCB高频板分类
3. 材料及时供应：
Many high-frequency plate procurement cycle is very long, even 2-3 months; In addition to the conventional high frequency plate RO4350 has inventory, many high frequency plates need to be provided by customers. Therefore, high frequency plate and manufacturers need to communicate well in advance, as soon as possible;
4、成本因素：
Depending on the price sensitivity of the product, whether it is a consumer product, or a telecommunications, medical, industrial, military application;
5. Applicability of laws and regulations, etc.
兼容不同国家的环保法规，满足RoHS和无卤要求。
Among the above factors, the running speed of high-speed digital circuit is the main factor to consider in PCB selection. The higher the circuit speed, the smaller the selected PCBDf value should be. 中低损耗电路板适用于10Gb/S数字电路； The plate with lower loss is suitable for 25Gb/s digital circuit; 具有超低损耗的面板将适应速度为 50Gb/s 或更高的更快、高速数字电路。
From the material Df:
df在0.01~0.005之间的电路板，适用于10Gb/S数字电路的上限；
df在0.005~0.003之间的电路板，适用于25Gb/S数字电路的上限；
Circuit boards with Df not more than 0.0015 are suitable for 50Gb/S or higher speed digital circuits.
Commonly used high-speed plates are:
1), Rogers: RO4003, RO3003, RO4350, RO5880, etc
2), Taiyao TUC:Tuc862, 872SLK, 883, 933, etc
3), Panasonic: Megtron4, Megtron6, etc
4）、Isola：FR408HR、IS620、IS680等
5) Nelco: N4000-13, N4000-13EPSI, etc
6）、东莞盛益、台州旺菱、泰兴微波等