Technology’s improvements everyday has made a lot of things possible through updates on what we currently have, affecting everything from the biggest machines we use to the smallest ones that make up the gadgets we use daily. The process of PCB fabrication has also been subject to many changes that have positively affected its development, essentially allowing people to make smaller and smaller versions of these, and in consequence allowing for the development of smaller, sleeker, and more advanced gadgets.
One of the most important parts of PCB fabrication is the putting of copper finishing on the surface of each board made. Copper finishing is known in the PCB fabrication industry as being as essential to the process as is breathing to us humans. Copper finishing is the main reason why PCBs are not susceptible to deterioration, as it prevents the corrosion of the board regardless of the climate you put it in. In its essence, the finish is used as a protection for the circuitry placed on the bard, and as a way to provide a surface for the soldering process.
In the past, the most used method of soldering used was the HASL, or the Hot Air Solder Leveling. However, as circuitries in each printed circuit board becoming more and more complex, and with each circuit board being required to take up less and less space, the use of this method has been deemed as being too impractical and difficult to maintain. The limitations that this process has given to PCB development has led experts to think of better solutions to solder materials in boards. Alternatives have been introduced recently in order to prevent encountering the problems with HASL.
Let us talk a bit more about HASL for a bit. This method has been the most used one in the industry for a very long time. The HASL process involves the immersion of circuit boards into molten tin or lead, and then removing the excess with the use of an air knife. This air knife will blow the board’s surface and will remove any excess molten tin that may have gotten on the board. The obvious benefit of this process is that since this PCB fabrication process would involve subjecting the boards to temperatures as high as 265 degrees Celsius, it would mean that future issues with delamination will easily be seen before any components that might cost a lot are attached to them.
Just some of the benefits of HASL include low costs given that this PCB fabrication process is both old and common, it is also easily available, can be worked on multiple times, and the process has a very long life span. However, the downsides to this process would include the quality being not so good since the surfaces might come off as uneven, and there will be lead content in the boards since this is the main ingredient in HASL. PTHs or Plated Through Holes are also reduced.
• Immersion Tin.
The benefits of this process includes not having to deal with bumps on the surface given that it results in flat surfaces, as well as being easy to rework with and not having and Pb of any kind. In addition, this has also been considered as the best choice for a Press Fit Pin Insertion.
On the other hand, this Immersion tin can easily cause handling damage, and the process uses thiourea, which is known as a cancer-causing material. The exposed tin during the last stage of the process is also susceptible to corrosion, and the process itself is not reliable when it comes to assembly or multiple reflow.
• OSP or Entek.
This preserves the surface copper and prevents oxidation from touching it with the use of a protective material over the exposed copper. The compound used is water based, and so it is considered as being environmentally friendly.
Just like the immersion tin, it is also re-workable and produces flat surfaces, although this actually costs less to do unlike the other two methods mentioned. On the other hand, the disadvantages include the fact that thickness cannot be exactly measured with this process, and the shelf life tends to be short. It is also not good for plated through holes (PTH), and the products can be difficult to handle due to their sensitivity. Not only that, there are times when PCB produced with this method can actually experience problems with ICT, though this is rare.
PCB fabrication is a multi-step handle that is for the most part conveyed by machines. The printed circuit board are a standout amongst the most vital segments in the realm of hardware today.
When people talk about golf, they often associate it with clubs, tees, balls, and bags. While all these equipment are essential, they are not the only things that matter in this sport. If you are a serious golfer, you know that your golf apparel can have a huge impact on your game play. What you wear can actually affect how you play.
For instance, you should go for waterproof golf apparel. Rockbottomgolf.com you can choose the different Golf Apparel. Choose fabrics or garments that are especially treated by laminate or coating to prevent water from seeping through. Check the backside of the fabric to see if it is laminated or coated. If you want the best waterproof garments, you should look for seam-sealed. These garments are highly recommended if you play golf for long hours.
Seam-sealed garments are sealed using a special tape to make them completely waterproof. They may also be rolled for a certain amount of time. Such rolling process can take a lot of time and require much attention to detail. Seam-sealed garments can be quite expensive because they are usually seam-taped by hand. You can opt for full seam-sealed garments if you want every stitching to be covered by tape.
Then again, if you are on a budget, you can choose critical seam-sealed golf apparel. They are generally less expensive. Critical seam-sealed garments only have certain areas, such as front seams and shoulders, sealed. Areas that are not susceptible to water are not taped. This makes them an excellent alternative to full seam-sealed garments. They can still protect you against the elements without being too heavy on your pocket.
You can also opt for water-resistant garments. They are not as sturdy as waterproof garments and they can only keep water out for a limited period of time. So if you get caught in a rainstorm, you will be wet after just a few minutes. Also, these garments are usually just treated on the top layer. After several washing, their top coating will start to wear off and they will just be regular golf apparel that cannot protect you against water.
Water-resistant garments are typically sprayed or coated with DWR coatings. Such coatings are applied to the top part of the fabric to shed water. Over time, they can break down, but you may still rejuvenate them using wash-in DWR. It is not possible to apply a waterproof coating on the top part of a fabric because of its rubber-like texture.
Also make sure that your get wind-proof apparel to keep the wind out. You can find out whether a garment is wind-proof or not by blowing through its fabric. If you are able to blow through it, it is not wind-proof. If you wear something that is not wind-proof, you can easily get cold, especially during the winter season. Keep in mind that an insulated jacket can still lose its warmth if the wind blows it away.
Of course, you need to choose breathable clothing to keep you comfortable and dry all day. Non-breathable clothes are very uncomfortable and do not hold up well against moisture. Most waterproof garments are not breathable, which is why you need to stay away from them. Waterproof and breathable golf garments are available but can be quite expensive. Do not hesitate to pay a high price for them because they are good investments.
Furthermore, you should consider insulation. You should go for well-insulated golf apparel that are also breathable and waterproof. Nonetheless, you can wear a shell or a non-insulated garment during the summer, spring, or fall.
Pregnancy is a very challenging period in a woman’s life. The body undergoes numerous changes and adjustments that are geared towards making sure that everything that happens in the woman’s body essentially protects the budding life inside the womb. All these changes are inevitable, and the only thing that can be done to prepare for the unfolding of this miracle is to have a better grasp of the specific changes that are happening, especially in the reproductive system and to the menstrual cycle.
The Purpose of the Menstrual Cycle
Menstruation commences for one sole purpose: to stimulate the ovaries to produce viable eggs that can be fertilized and can grow and develop to become a fetus. The survival of every living organism is dependent on two things: the ability to adapt to outside changes and the ability to reproduce. The responsibility of bearing and rearing the offspring before it is ready for birth has been given to the female species.
Since the menstrual cycle starts early, probably years or decades before a woman decides to marry and try to have a baby, it is easy to forget that menstruation is just a means to an end. The moment that a fertilized egg is formed, menstruation will cease because the goal has been achieved. It will only commence once the mother gives birth and the body is ready to undergo the entire process again.
Interrupted Menstrual Processes
The most affected portion of the menstrual cycle when pregnancy ensues is the corpus luteum. To backtrack, the corpus luteum is the residue of the follicle that originally contained the egg cell that was released during the ovulation phase. If no fertilization occurs, the corpus luteum loses its purpose and atrophies; this forms the menstrual fluid that is secreted once the menstrual cycle resets. When fertilization occurs, however, a hormone known as Human Chorionic Gonadotropin (HCG) is released from the fertilized egg. It preserves the corpus luteum, and this informs the corresponding glands in the body that pregnancy will commence.
Link between the Luteinizing Hormone and HCG
Further analysis of the menstrual cycle points to the role of the luteinizing hormone in the transformation that the dominant follicle undergoes to become the corpus luteum. This change occurs in anticipation of the possible union that will occur between an egg cell and a sperm cell. Once fertilization is successful, HCG takes over the role of the luteinizing hormone in preserving the corpus luteum and maintaining the consistent production of progesterone and estrogen. These hormones, in turn, play a major role in ensuring that the body undergoes all the necessary changes, making way for the implantation of the fetus in the uterine wall and its gradual development and growth.
Preparing for Other Major Changes
Amenorrhea, or the ceasing of the menstrual cycle, is just the start. In addition, this could be the easiest change that a pregnant woman would undergo. As hormone levels increase and peak, especially during the third month of pregnancy, a pregnant woman must be ready to deal with morning sickness, the gradual expansion of the abdomen and pelvic area, and the inevitable process of giving birth.
Menstruation and pregnancy are interrelated processes. HCG is the primary hormone that ensures a smooth transition from having monthly menstrual cycles to preparing the body for the changes that will unfold in the months to come. Within the first three months, this hormone plays a crucial role in adjusting the processes that a woman’s body has been accustomed to, in order to ensure that the fetus is protected and will be able to grow and develop normally.