Just entering the field of LED lamps, I have a lot of new knowledge and things to learn. There are many terms for LED lamp materials. I hope you can give me more guidance.

1. Please list more than 6 common mold types (5 points).

Stamping die, plastic die, die casting die, extrusion die (aluminum extrusion, plastic extrusion, copper extrusion), casting die, glass die (mouth blowing, machine pressing),

Rubber mold (glue pressing, glue injection and glue extrusion), ceramic mold, bakelite mold and knife mold.

2. Please list at least 10 common plastic materials (5 points).

ABS、PC、PA、PMMA、POM、PF、PS、PBT、PP、PVC、PPS、PET、PPO、TPR、TPU、TPE、BS、TPE、AS、PE、EVA

3. Please list at least 8 common hardware materials (5 points).

Gold, silver, copper, iron, tin, aluminum alloy, steel, stainless steel, aluminum and zinc alloy.

4. Can plastic materials turn white by spraying ash oil? Why? (5 points)

No, what color is usually sprayed? The background color of the beer block should be similar to it, otherwise it will easily transmit light and change color.

5. List more than 6 common surface treatment methods for metal parts. (5 points)

Oxidation, electroplating, baking paint, powder spraying, polishing, wire drawing, shot blasting, sand blasting and vibration grinding.

6. How to judge whether the structural design of a product is reasonable? (5 points)

Structure: meet the assembly requirements when designing, with simple processing and low cost; Appearance: meet customer requirements, market innovation.

7. What safety tests should lamps sold in Germany and the United States pass? (5 points)

European lamps are generally certified by CE safety regulations, while American lamps are certified by UL/CUL or ETL safety regulations.

8. What are the representative symbols and units of luminous flux, light intensity, illuminance and color temperature of 8.LED? (5 points)

Luminous flux: ∮-Lm light intensity: I-cd illumination: E-Lux color temperature: K-K.

9. Can aluminum alloy die-casting shell be anodized? Why? (5 points)

No, the die-cast aluminum material is very miscellaneous, and it is difficult to control the color blackening of the anode, with a high reject rate. Electroplating is the same problem, and the cost is high, so the general surface treatment is baking paint.

What are the highest IP protection levels of 10, dustproof and waterproof respectively? What is meaning (5 points)

Dust-proof: IP60 lamp can completely prevent dust from entering waterproof; IP68 lamp can work normally when immersed in water.

1 1. What are the key points of mold design when designing plastic shell? (5 points)

The wall thickness is even, and the back buckle is avoided. When the screw column is high or far away from the outer wall, it is necessary to adopt reinforcement method to increase the rigidity of the product, and the thickness of reinforcement is 0.4 or 0.6 times of the wall thickness.

12. Please state the types of finished lamps above 15 (5 points).

Ceiling lamp, floor lamp, wall lamp, display lamp, table lamp, ceiling lamp, flat lamp, track lamp, street lamp, chandelier, cabinet lamp, underground lamp, trail lamp, courtyard lamp,

T-tube, hard light bar, corner lamp, LED finished light source, projection lamp, wall washing lamp, etc.

13. What is the material of LED lamp shell? And tell the characteristics, surface treatment and what problems should be paid attention to in design. (10)

Generally, the die-casting material is ADC 12/ADC 10, and the better material is A356/A360/A380. The materials of aluminum profiles are 6063 and 6061;

Die-casting die has high cost, low unit price and poor heat dissipation; Aluminum extrusion die has low cost, high unit price and good heat dissipation;

Surface treatment of die casting: polishing, baking paint, powder spraying, etc. Surface treatment of aluminum profile: polishing, baking, powder spraying, sand blasting, oxidation, etc.

The design needs to consider the maximum contact area and heat dissipation area between the radiator and the heating element, the simplicity and cost of production and processing.

14. How to deal with the structural problems in product production? (10)

Analyze the reasons according to the actual production situation, provide temporary solutions for production, follow up in time to ensure delivery, propose fundamental solutions, and report relevant reports to the heads of various departments;

If you need to modify the mold, you should consider the handling method of the core before modifying the mold, and whether you can modify the mold immediately. After the mold modification is confirmed, do relevant tests, assembly verification, re-identify materials, and notify relevant departments of new ones.

The distinction between old parts and the treatment methods of old parts to avoid mixed materials in the future.

15, product development process (15)

Project initiation-preliminary review -3D design-review-design modification -2D drawings-cost quotation-mold delivery-sample making-sample testing-product specifications-new product release-

After BOM establishment-drawing release-work instruction-production fixture-assembly briefing-small batch trial production-mass production-the engineering department is fully responsible for all actions, and the R&D department assists.

16, which professional LED industry websites or forums do you know (5 points)

Remarks: 60~69 points -3.5k70 ~ 79 points -4.5k80 ~ 89 points -5.5k90 ~ 95 points -6.5k96 ~ 100 points -8k or above (supply only).