Frankly speaking, your pay is stagnant (I may say so) is mainly due to the nature of your job and opportunities. Working as a lab analyst doesn't really contribute to the growth of the company that much, in fact, if you can afford to take a week's leave from your work and yet the company can still function as usual (without any temporary replacement or job assignments to others), then probably, you are not that critical to the company's major growth contribution.

Opportunities for such position is always, not as prosperous as key roles like sales, marketing, business development. As such key roles can "shine" you to the top if you put in more effort or if you are "lucky".

But then again, would you want to make sacrifice to your life to be part of the so called "elite" team of the company, traveling to countries you won't want to be, getting stress up when end of the month comes (with no sales), being blamed by customer when the products you sold to them is not reliable, being away from your family (if you happen to be married) during holidays in Singapore. Not being able to have dinner with your family for a week, and having dinner alone in the hotel. I am quite sure that you do not work overtime and be on time for dinner every day, with a mentality of a 5 working days job.

Sales (engineering or others) may look glamourous and paid well, but it is like any other jobs, there are price to pay. If you are willing to sacrifice, then I would advice you to switch to a more prominent roles in your company (job switch, check with your HR). I am sure they will cherish your 7 years of service with the company and willing to look for alternative jobs in your company.

Most important for you to consider, is that if you are happy with your present job and roles, why bother so much about not getting better pay. Do you desperately need them or you are just comparing with other peers. If you are happy with your present lifestyle, that means you do not need more $, sometimes, it maybe bad to have more $, then you will think of getting more $. I hope this wil help abit.