阅读说明：本技术 一种均温板制作方法及均温板 (Temperature-equalizing plate manufacturing method and temperature-equalizing plate ) 是由 陈晓杰 徐莎莎 石一卉 于 2020-12-25 设计创作，主要内容包括：本发明提供一种均温板制作方法及均温板,该均温板制作方法由盖板获取步骤、盖板钝化步骤、毛细结构获取步骤和盖板固定步骤组合而成,在以钢片为原材料制作的第一盖板和第二盖板的表面形成一层致密的钝化膜,而后在钝化膜表面设置毛细结构,最后盖合第一盖板和第二盖板形成封闭内腔,密闭内腔内填充冷却介质,毛细结构收容于密闭内腔；由该方法制作的均温板由于在均温板的表面钝化形成有一层致密的钝化膜,在均温板应用过程中可以降低钢材与水的反应,延长其使用寿命。(The invention provides a temperature-uniforming plate manufacturing method and a temperature-uniforming plate, wherein the temperature-uniforming plate manufacturing method is formed by combining a cover plate obtaining step, a cover plate passivating step, a capillary structure obtaining step and a cover plate fixing step, wherein a layer of compact passive film is formed on the surfaces of a first cover plate and a second cover plate which are manufactured by taking a steel sheet as a raw material, then a capillary structure is arranged on the surface of the passive film, finally the first cover plate and the second cover plate are covered to form a closed inner cavity, a cooling medium is filled in the closed inner cavity, and the capillary structure is accommodated in the closed inner cavity; the temperature-equalizing plate manufactured by the method can reduce the reaction of steel and water in the application process of the temperature-equalizing plate and prolong the service life of the temperature-equalizing plate because a layer of compact passive film is formed on the surface of the temperature-equalizing plate in a passive mode.)

1. A manufacturing method of a vapor chamber is characterized by comprising the following steps:

a cover plate obtaining step: obtaining a first cover plate and a second cover plate which are made of steel sheets;

a cover plate passivation step: placing the first cover plate and/or the second cover plate in a passivation solution for passivation treatment to obtain the first cover plate and/or the second cover plate with a passivation film structure attached to the surface, wherein the passivation solution comprises a transition metal compound with the concentration of 3-15 g/L, phosphoric acid/sodium phosphate with the concentration of 0-20 g/L, nitric acid with the concentration of 0-10 ml/L, phytic acid/sodium phytate with the concentration of 0-8 g/L, tartaric acid/potassium sodium tartrate with the concentration of 0-7 g/L, citric acid/sodium citrate with the concentration of 0-5 g/L and a surfactant with the concentration of 0.5-5 g/L;

a capillary structure obtaining step: arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate;

a cover plate fixing step: and combining and fixedly connecting the first cover plate and the second cover plate to form a closed inner cavity, wherein the capillary structure is contained in the closed inner cavity, and a cooling medium is filled in the closed inner cavity.

2. The method for manufacturing a vapor chamber according to claim 1, wherein the first cover plate and the second cover plate are made of steel sheets having a thickness of 0.05-0.4 mm.

3. The method of claim 1, wherein the transition metal compound comprises at least one of zinc sulfate, sodium molybdate, and sodium tungstate.

4. The method for manufacturing the temperature-uniforming plate according to claim 1, wherein the surfactant is a nonionic surfactant and comprises at least one of polyvinyl alcohol, alkylphenol ethoxylates, fatty alcohol-polyoxyethylene ethers, fatty acid methyl ester ethoxylates and polyethylene glycol 400-2000.

5. The method for manufacturing the vapor chamber plate as claimed in claim 1, wherein the passivation solution further comprises 0.01-5 g/L of a rare earth compound, and the rare earth compound is at least one of cerium salt, lanthanum salt, praseodymium salt and neodymium salt.

6. The method for manufacturing the vapor chamber according to claim 1, wherein the solution temperature of the passivation solution in the cover plate passivation step is 40-60 ℃, and the passivation time is 5-30 min.

7. The method of claim 1, wherein the step of passivating the cover plate further comprises: and drying the passivated first cover plate and/or second cover plate at the temperature of 80-100 ℃ for 5-15 min.

8. The method of claim 1, wherein the step of passivating the cover plate further comprises:

and performing one or more of degreasing treatment, pickling treatment and activation treatment on the first cover plate and/or the second cover plate.

9. The method for manufacturing the vapor chamber according to claim 8, wherein the degreasing treatment specifically comprises:

and (2) soaking the first cover plate and/or the second cover plate in an oil removing solution at the temperature of 70-80 ℃ for 20-30min, wherein the oil removing solution comprises 10-50 g/L sodium hydroxide, 10-50 g/L sodium carbonate and 1-5 ml/L OP emulsifier, and then cleaning with pure water.

10. The method for manufacturing a vapor chamber according to claim 8, wherein the pickling process specifically comprises:

and (2) soaking the first cover plate and/or the second cover plate in an acid washing solution at the temperature of 20-40 ℃ for 1-2 min, wherein the acid washing solution comprises hydrochloric acid with the volume fraction of 20-30% and corydalis tuber with the concentration of 3-5 g/L, and then cleaning the cover plates by using pure water.

11. The method for manufacturing a vapor chamber according to claim 8, wherein the activating treatment specifically comprises:

and (2) soaking the first cover plate and/or the second cover plate in an activating solution at the temperature of 15-30 ℃ for 0.5-1 min, wherein the activating solution comprises hydrochloric acid with the volume fraction of 10-20% and acetic acid with the concentration of 5-10 g/L, and washing with pure water after being taken out.

12. A vapor-chamber, characterized in that it is made by the method of any one of claims 1-11.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of heat conduction, and relates to a temperature-uniforming plate and a manufacturing method thereof.

[ background of the invention ]

With the development of technology and the increasingly thinner electronic products, many types of temperature equalization plates have been developed to conduct and dissipate heat of electronic heating elements.

At present, most of the materials of the temperature-uniforming plate are copper and copper alloy, the strength and the supporting effect of the materials are poor, ultra-thinning is difficult to realize, steel is used as a high-strength supporting material for the temperature-uniforming plate, non-condensable gas can be generated in the using process of the temperature-uniforming plate, the steel cannot be directly used, chemical or physical treatment must be carried out on the inner side of the cover plate, although the problem is improved by covering a copper layer on the surface in the prior art, a primary battery can be formed between the copper and the steel so as to accelerate the reaction between the steel and water, a layer of non-porous thick copper needs to be plated to effectively prevent, and the production cost of the temperature-uniforming.

At present, no better solution scheme is provided for adopting steel as the material of the temperature-equalizing plate

[ summary of the invention ]

The technical problem to be solved by the invention is as follows: the invention provides a manufacturing method of a temperature-uniforming plate and the temperature-uniforming plate, wherein a passivation film of a transition metal compound is arranged on the surface of a first cover plate and/or a second cover plate of the temperature-uniforming plate so as to make up for the application defect of steel temperature-uniforming plates, and a simple and feasible scheme is provided for the ultra-thinning of the temperature-uniforming plate.

In order to solve the technical problems, the invention adopts the technical scheme that:

the invention provides a manufacturing method of a vapor chamber, which comprises the following steps:

a cover plate obtaining step: obtaining a first cover plate and a second cover plate which are made of steel sheets;

a cover plate passivation step: placing the first cover plate and/or the second cover plate in a passivation solution for passivation treatment to obtain the first cover plate and/or the second cover plate with a passivation film structure attached to the surface, wherein the passivation solution comprises a transition metal compound with the concentration of 3-15 g/L, phosphoric acid/sodium phosphate with the concentration of 0-20 g/L, nitric acid with the concentration of 0-10 ml/L, phytic acid/sodium phytate with the concentration of 0-8 g/L, tartaric acid/potassium sodium tartrate with the concentration of 0-7 g/L, citric acid/sodium citrate with the concentration of 0-5 g/L and a surfactant with the concentration of 0.5-5 g/L;

a capillary structure obtaining step: arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate;

a cover plate fixing step: and combining and fixedly connecting the first cover plate and the second cover plate to form a closed inner cavity, wherein the capillary structure is contained in the closed inner cavity, and a cooling medium is filled in the closed inner cavity.

Preferably, the first cover plate and the second cover plate are made of steel sheets with the thickness of 0.05-0.4 mm.

Preferably, the transition metal compound includes at least one of zinc sulfate, sodium molybdate, and sodium tungstate.

Preferably, the surfactant is a nonionic surfactant and comprises at least one of polyvinyl alcohol, alkylphenol ethoxylates, fatty alcohol-polyoxyethylene ether, fatty acid methyl ester ethoxylates and polyethylene glycol 400-2000.

Preferably, the passivation solution further comprises 0.01-5 g/L of rare earth compound, and the rare earth compound is at least one of cerium salt, lanthanum salt, praseodymium salt and neodymium salt.

Preferably, the solution temperature of the passivation solution in the cover plate passivation step is 40-60 ℃, and the passivation treatment time is 5-30 min.

Preferably, the cover plate passivation step further comprises the following steps: and drying the passivated first cover plate and/or second cover plate at the temperature of 80-100 ℃ for 5-15 min.

Preferably, the cover plate passivation step further comprises, before the step of:

and performing one or more of degreasing treatment, pickling treatment and activation treatment on the first cover plate and/or the second cover plate.

Preferably, the oil removal treatment specifically includes:

and (2) soaking the first cover plate and/or the second cover plate in an oil removing solution at the temperature of 70-80 ℃ for 20-30min, wherein the oil removing solution comprises 10-50 g/L sodium hydroxide, 10-50 g/L sodium carbonate and 1-5 ml/L OP emulsifier, and then cleaning with pure water.

Preferably, the acid washing treatment specifically includes:

and (2) soaking the first cover plate and/or the second cover plate in an acid washing solution at the temperature of 20-40 ℃ for 1-2 min, wherein the acid washing solution comprises hydrochloric acid with the volume fraction of 20-30% and corydalis tuber with the concentration of 3-5 g/L, and then cleaning the cover plates by using pure water.

Preferably, the activation treatment specifically includes:

and (2) soaking the first cover plate and/or the second cover plate in an activating solution at the temperature of 15-30 ℃ for 0.5-1 min, wherein the activating solution comprises hydrochloric acid with the volume fraction of 10-20% and acetic acid with the concentration of 5-10 g/L, and washing with pure water after being taken out.

The invention provides a temperature-uniforming plate which is manufactured by the temperature-uniforming plate manufacturing method.

The invention has the beneficial effects that: according to the invention, steel is adopted as the cover plate of the temperature-equalizing plate, so that the material strength and the supporting effect of the cover plate of the temperature-equalizing plate can be effectively improved; after the passivation treatment is carried out on the first cover plate and/or the second cover plate of the uniform temperature plate, a layer of compact transition metal compound passivation film with good bonding force is formed on the surface of the first cover plate and/or the second cover plate, the reaction of steel and water can be reduced in the application process of the uniform temperature plate, and the service life of the uniform temperature plate is prolonged.

[ description of the drawings ]

FIG. 1 is a flow chart of a method for fabricating a vapor chamber according to the present invention;

FIG. 2 is an overall structure diagram of the vapor chamber of the present invention;

FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2;

FIG. 4 is an exploded view of the vapor plate of the present invention;

wherein: 100-temperature-equalizing plate; 10-a lower cover plate; 101-a support column; 20-an upper cover plate; 30-a capillary structure; 40-passivation film.

[ detailed description ] embodiments

The invention is further described with reference to the following figures and embodiments.

The invention provides a manufacturing method of a vapor chamber, aiming at preventing the erosion of water vapor by generating a layer of compact passivation film on the surface of the vapor chamber, and referring to a flow chart of the manufacturing method of the vapor chamber shown in figure 1, the manufacturing method comprises the following steps:

a cover plate acquisition step 101: a first cover plate and a second cover plate made of steel sheets are obtained.

Specifically, two steel sheets with the thickness of 0.05-0.4 mm are provided, the two steel sheets are etched or punched to obtain a first cover plate and a second cover plate of the temperature-uniforming plate, the size of the temperature-uniforming plate is reduced by the cover plate with the ultrathin thickness, and meanwhile the material supporting strength of the temperature-uniforming plate is met.

Cover plate passivation step 102: and placing the first cover plate and/or the second cover plate in a passivation solution for passivation treatment to obtain the first cover plate and/or the second cover plate with the surface attached with a passivation film structure.

Specifically, the first cover plate and/or the second cover plate are/is placed in a passivation solution with the solution temperature of 40-60 ℃ for passivation treatment for 5-30 min. The passivation solution comprises a transition metal compound with the concentration of 3-15 g/L, phosphoric acid/sodium phosphate with the concentration of 0-20 g/L, nitric acid with the concentration of 0-10 ml/L, phytic acid/sodium phytate with the concentration of 0-8 g/L, tartaric acid/potassium sodium tartrate with the concentration of 0-7 g/L, citric acid/sodium citrate with the concentration of 0-5 g/L and a surfactant with the concentration of 0.5-5 g/L; the transition metal compound comprises at least one of zinc sulfate, sodium molybdate and sodium tungstate, molybdenum, tungsten and chromium are in the same family, and chromate-like passivation reaction can be carried out on the surface of the matrix to form a reticular mixed oxide film or complex film to play a role in protection; the zinc ion outer layer also has a plurality of empty tracks, and is easy to form an oxide or complex film attachment surface with negative-charged substances; the phosphate and the nitrate also have auxiliary functions, the addition of the organic carboxylic acid and the organic phosphoric acid has a synergistic effect, the generation of a poly-complex can be promoted, and the quality of a passivation film can be improved by adding a small amount of the organic carboxylic acid and the organic phosphoric acid; the surfactant plays a role in wetting the surface, dispersing the organic additive and improving the solubility, enhances the efficacy of the organic additive, promotes the coordination of transition metal ions and organic matters, and improves the adsorbability and the integrity of the film layer, preferably, the surfactant is a nonionic surfactant and comprises at least one of polyvinyl alcohol, alkylphenol ethoxylates, fatty alcohol-polyoxyethylene ether, fatty acid methyl ester ethoxylate and polyethylene glycol 400-2000.

The passivation solution can be added with 0.01-5 g/L of rare earth compound, and the rare earth compound is at least one of cerium salt, lanthanum salt, praseodymium salt and neodymium salt, so that the combined passivation film forming effect is better than the single transition metal passivation effect.

The cover plate passivating step 102 may further include one or more of degreasing, pickling, and activating the first cover plate and/or the second cover plate.

Wherein, carry out deoiling to first apron and/or second apron and handle specifically including: and (2) soaking the first cover plate and/or the second cover plate in an oil removing solution at the temperature of 70-80 ℃ for 20-30min, wherein the oil removing solution comprises 10-50 g/L of sodium hydroxide, 10-50 g/L of sodium carbonate and 1-5 ml/L of OP emulsifier, and then immediately cleaning the first cover plate and/or the second cover plate by pure water. The step is to remove oil stains on the surface of the first cover plate and/or the second cover plate, and to make the surface completely hydrophilic. The degreasing force is insufficient when the concentration of sodium hydroxide and sodium carbonate in the components is too low, oil stains are difficult to completely remove, the uniformity and the bonding force of later-stage electroplating are affected, the defects of surface flowering, poor welding and the like are caused, and the wettability is poor when the concentration is too high, and the cover plate can be damaged; the OP emulsifier is used as a surfactant, improves the dispersibility and wettability, is beneficial to enhancing the degreasing capability, has poor effect when being too low, and is easy to remain on the surface and difficult to clean when being too high.

The pickling treatment of the first cover plate and/or the second cover plate specifically comprises: and (2) soaking the first cover plate and/or the second cover plate in an acid washing solution at the temperature of 20-40 ℃ for 1-2 min, wherein the acid washing solution comprises hydrochloric acid with the volume fraction of 20-30% and formosan with the concentration of 3-5 g/L, and then immediately cleaning the first cover plate and/or the second cover plate with pure water. This step is to remove the scale from the surface of the first cover plate and/or the second cover plate. The hydrochloric acid has strong capacity of removing the oxide skin of the stainless steel, the time required by the hydrochloric acid is long when the hydrochloric acid is too low, the efficiency is low, the surface is over-corroded when the hydrochloric acid is too high, and the corrosion is accelerated when the hydrochloric acid is too high, so that the hydrochloric acid is not suitable for being higher than 40 ℃; in order to avoid over-corrosion and inhibit acid mist, a proper amount of corrosion inhibitor such as chlorhydrine and the like can be added, and the pickling efficiency is influenced when the content of the corrosion inhibitor is too low or too high.

The activating treatment of the cover plate specifically includes: and (3) soaking the first cover plate and/or the second cover plate in an activating solution at the temperature of 15-30 ℃ for 0.5-1 min, wherein the activating solution comprises hydrochloric acid with the volume fraction of 10-20% and acetic acid with the concentration of 5-10 g/L, and washing the first cover plate and/or the second cover plate with pure water after being taken out. The step is to improve the surface activity and ensure the bonding force between the passivation layer and the cover plate. The acidity of the activating solution is not too high and not too long, because after pickling the oxide layer is not yet or very thin, and too high acidity or too long time can cause over-corrosion, which affects the performance of the cover plate, and it is better to keep the concentration at a low level (< 20%) and add certain acetic acid to reduce the corrosion of chloride ions, but it is not too low to ensure the effective concentration (< 10%), especially when the residence time between pickling and passivation is long. Preferably, in order to obtain a better passivation treatment effect, the first cover plate and/or the second cover plate may be subjected to a degreasing treatment, an acid washing treatment, and an activation treatment in this order.

After the cover plate passivation step 102, the first cover plate and/or the second cover plate after passivation treatment is/are dried for 5min-15min at the temperature of 80-100 ℃, and the bonding force between the passivation film and the cover plate is further improved.

Capillary structure obtaining step 103: arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate; the capillary structure is a porous or reticular structure formed by weaving metal wires or sintering metal powder or performing electrochemical deposition on the surface, and is one of copper and copper alloy.

Cover plate fixing step 104: and combining and fixedly connecting the first cover plate and the second cover plate to form a closed inner cavity, accommodating the capillary structure in the closed inner cavity, and filling a cooling medium in the closed inner cavity.

Through the manufacturing method, the transition metal compound passive film with the thickness of 10nm-100nm is prepared on the first cover plate and/or the second cover plate made of the steel sheet, so that the corrosion resistance of the steel sheet is greatly improved, the iron element which is easy to be corroded by water vapor is completely covered, the suppression of the iron-water reaction and the galvanic cell reaction caused between iron and copper is facilitated, and the service life of the uniform temperature plate is prolonged by about 3-10 times.

The following are the implementation steps of the specific embodiment of the invention:

example 1

Providing two steel sheets with the thickness of 0.2mm, and etching the two steel sheets to obtain a first cover plate and a second cover plate of the uniform temperature plate.

And (3) soaking the first cover plate and/or the second cover plate in an oil removing solution at the temperature of 80 ℃ for 30min, wherein the oil removing solution comprises 15g/L sodium hydroxide, 30g/L sodium carbonate and 5ml/L OP emulsifier, and then immediately cleaning the first cover plate and/or the second cover plate by pure water.

And (3) soaking the first cover plate and/or the second cover plate which is completely degreased in an acid washing solution at the temperature of 25 ℃ for 2min, wherein the acid washing solution comprises hydrochloric acid with the volume fraction of 20% and floxun with the concentration of 5g/L, and immediately cleaning the first cover plate and/or the second cover plate by pure water.

And (3) soaking the acid-washed first cover plate and/or second cover plate in an activating solution at the temperature of 25 ℃ for 30s, wherein the activating solution comprises hydrochloric acid with the volume fraction of 15% and acetic acid with the concentration of 5g/L, and washing the acid-washed first cover plate and/or second cover plate with pure water after being taken out.

Soaking the activated first cover plate and/or second cover plate in a passivation solution at the solution temperature of 45 ℃ for 5min, wherein the passivation solution comprises zinc sulfate with the concentration of 5g/L, nitric acid with the concentration of 10ml/L, phytic acid with the concentration of 2g/L, tartaric acid with the concentration of 5g/L and polyvinyl alcohol with the concentration of 1 g/L; taking out, washing the redundant solution with pure water, and then putting the solution into a drying oven at 90 ℃ for drying for 12min to obtain the cover plate with the surface attached with the passivation film structure.

And arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate. And combining and welding the first cover plate and the second cover plate to form a closed inner cavity, accommodating the capillary structure in the closed inner cavity, and filling a cooling medium in the closed inner cavity.

Example 2

The cover plate obtaining step, the degreasing treatment, the pickling treatment, and the activation treatment in example 2 are the same as those in example 1, and are not described again here.

Placing the first cover plate and/or the second cover plate after activation treatment in a passivation solution with the solution temperature of 60 ℃ for soaking for 20min, wherein the pH value of the passivation solution is 5.5, and the passivation solution comprises 8g/L of sodium molybdate, 16g/L of sodium phosphate, 5g/L of sodium citrate and 2g/L of polyvinyl alcohol; taking out, washing the redundant solution with pure water, and then putting the solution into a drying oven at 80 ℃ for drying for 15min to obtain the cover plate with the surface attached with the passivation film structure.

And arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate.

And combining and welding the first cover plate and the second cover plate to form a closed inner cavity, accommodating the capillary structure in the closed inner cavity, and filling a cooling medium in the closed inner cavity.

Example 3

The cover plate obtaining step, the degreasing treatment, the pickling treatment, and the activation treatment in example 3 are the same as those in example 1, and are not described again.

Placing the activated first cover plate and/or second cover plate in a passivation solution with the solution temperature of 40 ℃ for soaking for 30min, wherein the pH value of the passivation solution is 9, and the passivation solution comprises sodium tungstate with the concentration of 10g/L, sodium phytate with the concentration of 8g/L, sodium citrate with the concentration of 5g/L and polyvinyl alcohol with the concentration of 0.5 g/L; taking out, washing the redundant solution with pure water, and then putting the solution into a drying oven at 80 ℃ for drying for 15min to obtain a first cover plate and/or a second cover plate with a passivation film structure attached to the surface.

And arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate.

And combining and welding the first cover plate and the second cover plate to form a closed inner cavity, accommodating the capillary structure in the closed inner cavity, and filling a cooling medium in the closed inner cavity.

Example 4

The cover plate obtaining step, the degreasing treatment, the pickling treatment, and the activation treatment in example 4 are the same as those in example 1, and are not described again here.

Placing the first cover plate and/or the second cover plate after activation treatment in a passivation solution with the solution temperature of 25 ℃ for soaking for 15min, wherein the pH value of the passivation solution is 3.8, and the passivation solution comprises zinc sulfate with the concentration of 15g/L, nitric acid with the concentration of 8ml/L, phosphoric acid with the concentration of 7g/L, polyvinyl alcohol with the concentration of 1.3g/L and lanthanum sulfate with the concentration of 0.5 g/L; taking out, washing the redundant solution with pure water, and then putting the solution into a drying oven at 80 ℃ for drying for 15min to obtain a first cover plate and/or a second cover plate with a passivation film structure attached to the surface.

And arranging a capillary structure on the surface of the passivation film of the first cover plate or the surface of the passivation film of the second cover plate.

And combining and welding the first cover plate and the second cover plate to form a closed inner cavity, accommodating the capillary structure in the closed inner cavity, and filling a cooling medium in the closed inner cavity.

Table 1 compares the main properties of examples 1-4.

TABLE 1

Examples	Thickness of passivation film	Binding force	Pitting corrosion resistance
				1	40-50nm	Qualified	3.5-4h
2	55-65nm	Qualified	5-6h
				3	80-90nm	Qualified	6-7h
4	50-60nm	Qualified	7.5-8h
				Blank (untreated)	/	/	1h

In the invention, the binding force between the passive film and the steel sheet is evaluated by combining a cathode test and a corrosion resistance test, the passivated steel sheet is placed in a 5% sodium hydroxide solution as a cathode, stainless steel is used as an anode, the operation temperature is 90 ℃, the electrolysis treatment is carried out for 15min by using a current of 10A/dm2, and the passivated film with poor binding force can be peeled and fallen off from the steel sheet after the treatment, so that a blue spot (generally within 5 min) rapidly appears in the subsequent pitting corrosion resistance test. The passive film obtained by the invention does not fall off after the electrolytic treatment, and the pitting corrosion resistance test shows that the passive film is tightly combined with the steel sheet.

The pitting resistance test adopts a mixed solution of potassium ferricyanide (10g/L) and sodium chloride (20g/L), a dropper is used for dropping the solution on the surface of a sample to be tested, and the time for the color to be completely transparent is collected as one representation of the pitting resistance.

Therefore, the passive film greatly improves the corrosion resistance of the steel sheet, completely covers the iron element which is easy to be corroded by water vapor, and is beneficial to inhibiting the iron-water reaction and the galvanic cell reaction caused between iron and copper, thereby prolonging the service life of the uniform temperature plate.

In another aspect of the present invention, a vapor chamber 100 is provided, which is manufactured by the above-mentioned vapor chamber manufacturing method, as shown in fig. 2-4, the vapor chamber includes a first cover plate 10 and a second cover plate 20 disposed opposite to the first cover plate 10 and covering the first cover plate 10, a capillary structure 30 is disposed on a surface of the second cover plate 20, a supporting pillar 101 abutting against the capillary structure 30 is disposed on the first cover plate, and a passivation film 40 is attached to surfaces of the first cover plate 10 and the second cover plate 20.

In summary, after the first cover plate and/or the second cover plate of the uniform temperature plate is passivated, a layer of dense transition metal compound passivation film with good bonding force is formed on the surface of the first cover plate and/or the second cover plate, and the reaction between steel and water can be reduced and the service life of the uniform temperature plate can be prolonged in the application process of the uniform temperature plate.

While the foregoing is directed to embodiments of the present invention, it will be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention.