In examples, a method of forming a semiconductor package comprises forming a conversion coating solution comprising a salt of a vanadate, a salt of a zirconate, or both with a complexing agent; cleaning a copper lead frame, wherein the cleaned copper lead frame comprises copper oxide on an outer surface thereof; immersing the cleaned copper lead frame in the conversion coating solution; rinsing the copper lead frame; and forming an assembly by coupling a semiconductor die to the copper lead frame, coupling the semiconductor die to a lead of the copper lead frame, applying a mold compound onto at least a portion of the outer surface of the copper lead frame, and curing the mold compound. An adhesion strength at an interface between the mold compound and the at least the portion of the outer surface of the copper lead frame is increased relative to a same assembly formed without immersing the copper lead frame in the conversion coating solution.

In examples, a method of forming a semiconductor package comprises forming a conversion coating solution comprising a salt of a vanadate, a salt of a zirconate, or both with a complexing agent; cleaning a copper lead frame, wherein the cleaned copper lead frame comprises copper oxide on an outer surface thereof; immersing the cleaned copper lead frame in the conversion coating solution; rinsing the copper lead frame; and forming an assembly by coupling a semiconductor die to the copper lead frame, coupling the semiconductor die to a lead of the copper lead frame, applying a mold compound onto at least a portion of the outer surface of the copper lead frame, and curing the mold compound. An adhesion strength at an interface between the mold compound and the at least the portion of the outer surface of the copper lead frame is increased relative to a same assembly formed without immersing the copper lead frame in the conversion coating solution.

A pH-sensitive release system comprising a capsule capable of releasing an agent in both low pH environments and high pH environments. The capsule encapsulates an agent and comprises at least two weak polyelectrolytes (e.g., PEI and PAA). The capsule responds to both low and high pH changes in the local environment by releasing the agent. The agent may include a corrosion inhibitor and may help prevent or ameliorate the effects of corrosion.

A pH-sensitive release system comprising a capsule capable of releasing an agent in both low pH environments and high pH environments. The capsule encapsulates an agent and comprises at least two weak polyelectrolytes (e.g., PEI and PAA). The capsule responds to both low and high pH changes in the local environment by releasing the agent. The agent may include a corrosion inhibitor and may help prevent or ameliorate the effects of corrosion.

Disclosed is a surface anti-corrosion treatment method for stainless steel. The method comprises the following steps: (1) performing chemical de-oiling and alkaline corrosion treatments on the surface of stainless steel by using a sodium hydroxide solution and a solution containing an alkaline corrosion active agent, and then washing with water; (2) performing, by using an oxidation solution, an oxidation treatment on the surface of the stainless steel treated in step (1), and then washing with water; (3) using the surface of the stainless steel treated in step (2) as a cathode and soaking same in an electrolyte for electrolysis, and then washing with water; and (4) placing the surface of the stainless steel treated in step (3) at a temperature of 50° C.-60° C. under a humidity of 60%-70%, and performing a hardening treatment. Also disclosed are the use of the treatment method in the treatment of a stainless steel part and a stainless steel part obtained after the treatment by means of the treatment method.

Disclosed is a surface anti-corrosion treatment method for stainless steel. The method comprises the following steps: (1) performing chemical de-oiling and alkaline corrosion treatments on the surface of stainless steel by using a sodium hydroxide solution and a solution containing an alkaline corrosion active agent, and then washing with water; (2) performing, by using an oxidation solution, an oxidation treatment on the surface of the stainless steel treated in step (1), and then washing with water; (3) using the surface of the stainless steel treated in step (2) as a cathode and soaking same in an electrolyte for electrolysis, and then washing with water; and (4) placing the surface of the stainless steel treated in step (3) at a temperature of 50° C.-60° C. under a humidity of 60%-70%, and performing a hardening treatment. Also disclosed are the use of the treatment method in the treatment of a stainless steel part and a stainless steel part obtained after the treatment by means of the treatment method.

The invention relates to a method for producing a silane-modified silicate. In order to obtain optimal corrosion protection properties, a silane compound according to the invention is at least partially hydrolyzed and/or condensed in the presence of a silicate compound at a pH value greater than or equal to 8 and then a pH value less than or equal to 7 is set by adding acid. The invention further relates to an aqueous acidic passivation composition for metal substrate coated with the passivation composition.

The invention relates to a method for producing a silane-modified silicate. In order to obtain optimal corrosion protection properties, a silane compound according to the invention is at least partially hydrolyzed and/or condensed in the presence of a silicate compound at a pH value greater than or equal to 8 and then a pH value less than or equal to 7 is set by adding acid. The invention further relates to an aqueous acidic passivation composition for metal substrate coated with the passivation composition.

A trivalent-chromium chemical conversion coating from which substantially no hexavalent chromium is released. The trivalent-chromium chemical conversion coating is one formed on the surface of a zinc or zinc-alloy deposit. In a brine spray test, the chemical conversion coating has unsusceptibility to corrosion (time required for white-rust formation) of 96 hours or longer. The chemical conversion coating has a hexavalent-chromium concentration less than 0.01 μg/cm.sup.2 in terms of metal atom amount. The amount of hexavalent chromium released after 30-day standing in a thermo-hygrostatic chamber at a temperature of 80° C. and a humidity of 95% (amount of hexavalent chromium released when the coating is immersed in 100° C. water for 10 minutes) is smaller than 0.05 μg/cm.sup.2.

A trivalent-chromium chemical conversion coating from which substantially no hexavalent chromium is released. The trivalent-chromium chemical conversion coating is one formed on the surface of a zinc or zinc-alloy deposit. In a brine spray test, the chemical conversion coating has unsusceptibility to corrosion (time required for white-rust formation) of 96 hours or longer. The chemical conversion coating has a hexavalent-chromium concentration less than 0.01 μg/cm.sup.2 in terms of metal atom amount. The amount of hexavalent chromium released after 30-day standing in a thermo-hygrostatic chamber at a temperature of 80° C. and a humidity of 95% (amount of hexavalent chromium released when the coating is immersed in 100° C. water for 10 minutes) is smaller than 0.05 μg/cm.sup.2.