Would this portable LED light array which has 30 LEDs spread over an area of around 6 inches by 1 inch be suitable for bedikat chametz? If not, why would a traditional beeswax candle be better? The LED array would be far more effective.
Rav Moshe Mintz, a posek in Ner Israel, told me that you can ideally use any light that can be focused in one area (as opposed to the sunlight or the main light in a room, which lights up the entire room), as the purpose of the candle at night is to contrast with the dark in the rest of the room.
Rav Moshe Heinemann writes in Hilchos Pesach (1:2):
The Gemara says we use a נר for חיפוש, searching for חמץ (Pesachim 7b). In order to be considered a נר, you need to have fuel, a כלי to hold the fuel, and a wick which draws the fuel from the כלי to produce a flame. Even if you have a fluorescent light which has fuel in the electricity and the bulb acting as the כלי, you still lack the wick. Therefore, you cannot use fluorescent light bulbs for נרות שבת. Frosted bulbs versus unfrosted bulbs doesn’t make a difference except by הבדלה where we say בורא מאורי האש to see the different colors of the fire. When the bulb is frosted, then you cannot see the different colors. However, you can see the different colors of the tungsten filament in an unfrosted incandescent bulb. An LED light seems to be a מחלוקת whether it has a filament or not. I don’t know how that can be a מחלוקת, but if an LED bulb has a filament then you may use it for בדיקת חמץ, and if it doesn’t then you should not use it. בדיעבד make the ברכה on a candle, search for חמץ with it a little bit, then use an LED or fluorescent bulb.
The LED light array may be fine, but Rav Heinemann explains why using a candle may be better since it contains all three aspects of a "ner": fuel, utensil to hold the fuel, and a wick to draw the fuel from the utensil.