Introduction of surface treatment of aluminum heat sink

Because of the particularity of the customer's products, sometimes the customer has some special requirements on the surface of the aluminum heat sink. For example, extruded aluminum heat sink, its surface corrosion resistance is not very strong, so sometimes the need for anodizing (blackening) for surface treatment to increase the corrosion resistance, wear resistance and appearance of the beauty of the aluminum.

The main process of anodized aluminum heat sink anodized process is as follows:

Surface pretreatment: clean the profile surface with chemical or physical methods, exposing the pure matrix, in order to obtain a complete, dense artificial oxide film. A mirror or matte surface can also be obtained mechanically.

Anodizing: for the profile pretreated on the surface, under certain technological conditions, anodizing occurs on the surface of the matrix, resulting in a dense, porous and adsorptive layer of AL203.

Seal the pores: seal the pores of the porous oxide film after anodizing , so that the anti-pollution, anti-corrosion and anti-wear properties of the oxide film are enhanced.Oxidation film is colorless transparent, the use of the strong adsorbability of the oxidation film before sealing the hole, adsorption deposit some metal salt in the film hole, can make the aluminum profile appearance appears ecru (silver-white) many other colors, such as: black, bronze, gold and stainless steel color.

The production and processing of bonded fin heat sink

Bonded fin heat sink is a kind of high power electronic heat sink made of base and finr through mechanical processing. Can be customized according to user requirements, to meet a variety of different cooling needs.

1. Bonded fin heat sink before the mold test, should first adjust the extrusion center, extrusion shaft, spindle and mold seat outlet in a Central Line.

2. During the mold test and normal production process, the heating temperature of aluminum rod should be between 480-520℃.

3. Bonded fin heat sink mold in the mold test or production process, if found blocking, tooth deviation, fast and slow deviation is too big phenomenon to stop immediately, and in the way of point back, try to avoid the scrap of the mold, reduce the loss.

4. In the straightening process, to carefully detect before and after the change of bonded fin heat sink, operating specifications, moderate force, strict guarantee product quality.

5. The operator shall set the scale reasonably according to the requirements of the production plan. When sawing, the feeding speed of sawtooth shall not be too fast to avoid damaging the end.

6. Finished products in the basket to be standardized, including the pad to be placed reasonably, to avoid damage to the profile.

https://www.lorithermal.com/electronic-heat-sink

Why do copper heat sinks dissipate more slowly than aluminum heat sinks

Copper absorbs heat faster than aluminum, and copper loses heat faster than aluminum. So the copper heat sink base is equipped with the fan of high rotating speed, big air volume commonly, increase the heat dissipation capacity of copper base. The heat sink manufacturer also borrowed this idea to launch plug copper, set copper heat sink, reason is to use copper to take away heat quickly, send out quickly through aluminous qualitative fin next

 After all, what is the scientific basis for the statement that copper absorbs heat faster than aluminum, and copper loses heat faster than aluminum? Perhaps you can clearly say a few, today small make up to tell you the basic principle of this phenomenon.

Thermal conductivity K (W/m2K)

Silver 429

Copper 401

Gold 317

Aluminum 237

The popular definition of heat transfer coefficient is "heat per unit area per unit time at unit temperature difference", the unit is J/m2ks, or W/m2k, where J is the unit joule of heat, m2 is the unit square meter of area, K is the unit kelvin of temperature, can also be replaced by C on the Celsius scale, s is the unit second of time. From above the heat conduction coefficient of copper is about 1.69 times that of aluminium, because this uses copper and aluminium to make the heat sink of same sectional area, inside unit time pure copper can take away more heat than pure aluminium, "copper absorbs heat faster than aluminium", the preceding half sentence has been proved.

Material specific heat capacity J/kgK

Aluminum 0.9

Silver 0.24

Copper 0.39

Copper loses heat as fast as aluminum, which is true. Proving this leads to another important thermodynamic parameter: specific heat. Anyone who has studied high school physics knows that specific heat is defined as "the amount of heat required to raise the temperature of a substance by one degree per unit mass," in units of J/kgK. You can also see from the table above that the specific heat capacity of copper is smaller than that of aluminum. Copper should lose less heat than aluminum if it loses 1 degree of temperature. In this way, copper should lose heat faster than aluminum. However, you may not have noticed that the density of copper is 8.9kg/m3, while that of aluminum is only 2.7kg/m3, which is nearly 3.3 times that of aluminum. Therefore, if you make a heat sink of the same volume, the mass of copper is nearly 3.3 times larger than that of aluminum, and the heat capacity of pure copper is still nearly half that of pure aluminum.The larger the heat capacity, the slower the heat dissipation.Through the explanation of the above theory, we have also found out the reason why "copper loses heat faster than aluminum".　　

We fundamentally understand that "copper absorbs heat faster than aluminum, copper does not dissipate heat as fast as aluminum". When choosing heat sink later, can apply this theory, if choose pure copper heatsink, should choose to equip with rotating speed taller, the fan product with larger air volume, avoid copper heat to send out not, generation dissipates heat bottleneck.

Bonded fin heat sink

Bonded fin heat sink production is not complicated, it is a kind of structure is simpler product, but its power is very high, specification is a lot of, The process is also relatively simple, Therefore, a lot of customers who do not have high requirements for the process will choose to bonded fin heat sink for heat dissipation.

As shown in the picture above, this is a bonded fin heat sink customization project recently received by lORI. After our preliminary design and production, this batch of bonded fin heat sink has been basically completed, will enter the final process, can be delivered soon.

Though the main direction of the Lori positioning for extruded heat sink , heat pipe heat sink , water cooling plate technology better and more efficient products, but we still retains its bonded fin heat sink r &d and production team, is still a professional bonded fin heat sink manufacturers, for the majority of industry users to provide long-term high-quality bonded fin heat sink and cooling solution.

If users have higher requirements for heat dissipation, they can also use a single side combined heat sink solution, which is a product newly developed by LORI this year and can perfectly replace bonded fin and skived fin.

Aluminum heat sink production and processing requirements

The material that produces aluminum heatsink heat conduction property is good, at present the majority uses 6063 aluminium alloy, its have the characteristic such as easy processing, heat dissipation performance is good, mechanical property is good. Additional need from ingot, mold, extrude craft a few respects to cooperate, ability produces heat sink profile smoothly.

Because the mold of aluminum extrusion heat sink profiles are a lot of long and thin fin, want to bear very big extrusion pressure, every heat sink fins should have very high strength and toughness, if the performance between each other has very big difference, easy to make the strength or toughness of those teeth produced fracture.

Can smooth extrusion success, the key is the design of the mold to reasonable, manufacturing to accurate, this aluminum heat sink manufacturers of higher technical requirements, only strong manufacturers can complete from mold design extrusion to the finished product of the whole process.

How to choose the photovoltaic inverter heat sink ?

Industry users are paying attention to the overall performance of the photovoltaic inverter, not just focus on their conversion efficiency, the largest dc voltage, ac output power, protection grade, such as heat dissipation problem of photovoltaic inverter also need us to pay special attention to, choose a high performance inverter heat sink is very necessary, because it will directly affect the inverter heat dissipation performance indicators.

Various components in the photovoltaic inverter have rated operating temperature. If the photovoltaic inverter  heat sink selected by the inverter has poor heat dissipation performance, when the inverter continues to work, the heat generated by the components inside has been collecting in the cavity, and its temperature will become higher and higher. High temperature will reduce the performance and life of components, the machine is prone to failure.

When the inverter works, it generates heat, and the power loss is inevitable. For example, for an inverter of 5kW, the system heat loss is about 75-125w, which affects the power generation. To solve the heat dissipation problem of inverter, it is best to cooperate with heat sink manufacturers to customize the inverter heat sink. After the heat sink manufacturers optimize, the heat dissipation loss can be reduced.

The heat dissipation mode of the photovoltaic inverter heat sink

At present, the heat dissipation technology used in photovoltaic inverter heat sink mainly includes natural cooling, liquid cooling, forced air cooling heat sink, etc., and its main application forms are natural cooling and forced air cooling.

The natural cooling of inverter heat sink

Natural cooling means that no external auxiliary energy is used to let the local heating device dissipate heat to the surrounding environment, so as to achieve temperature control. Natural cooling is suitable for low power devices with low requirements for temperature control.

Forced air cooling of inverter heat sink

In general, the cooling method of forced cooling is mainly by means of fans and so on, thus taking away the heat emitted by the device. At present, the material of this kind of high power heat sink basically is to wait with aluminous, or cupreous aluminous compound.

Lori has cooperated with many enterprises in the photovoltaic industry, and has provided them with efficient inverter cooling solutions for a long time. Whether it is natural cooling or forced air cooling, we have successful application cases. We can provide various types of heat sink products, such as skived heat sink, water cooled heat sink, heat pipe heat sink and so on. For further information, please contact us.