JPH0740767U - Electroless tin plating equipment - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an electroless tin plating device for a TAB tape, which can prevent the generation of whiskers and eliminate the cause of a short circuit between leads of a fine wiring pattern of the TAB tape. The electroless tin plating apparatus used in the method for producing a tape for TAB is characterized in that an ultrasonic wave generator 12 is provided in the tin plating tank in order to apply high frequency vibration to the tin plating layer.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electroless tin plating apparatus used in a tape manufacturing method for Tape Automated Bonding (abbreviated as TAB), which is equipped with a high-frequency vibrating means in a tin plating tank and is used for a TAB tape for a liquid crystal driver. The present invention relates to an electroless tin plating apparatus suitable for manufacturing.

[0002]

[Prior art]

 In the conventional TAB tape manufacturing method, a resin tape, for example, a polyimide tape is punched to form an opening such as a device hole, and a copper foil is laminated on this. Next, the copper foil is subjected to resist coating, exposure and development for forming patterns and leads. Next, a backing resist is applied to protect the backside of the copper foil in the device holes and the like from etching.

After that, the copper foil is subjected to an etching process to form patterns and leads, and the pattern resist and backing resist that are no longer needed after etching are dissolved and removed with an alkaline solution.

Next, solder resist printing is performed to protect and insulate the copper wiring pattern other than the joint portion, and the copper wiring pattern is subjected to solder plating to improve the bondability.

In the above-mentioned solder plating method, so-called whiskers-free solder bonding with stable bondability must be applied. The plating methods include electrolytic plating and electroless plating.

In the former electrolytic plating, it is necessary to cut and process the power supply wiring after the formation and plating of the power supply wiring on the tape pattern. There are restrictions such as a decrease in design flexibility.

For this reason, the latter electroless tin plating, which does not have such a restriction, has come to be performed, but there are various defects in terms of quality and reliability due to tin plating.

The electroless tin plating apparatus used in the conventional TAB tape manufacturing method described above includes a material feeding section, a pretreatment section for degreasing and pickling, and a tin plating solution containing a temperature-controlled tin plating solution. It consists of a bath and a tin plating, plating solution recovery, water washing and product winding section.

In each of the above-mentioned parts, the tin plating tank is for passing the material to be plated through the tin plating solution for a predetermined time. During this passage, the tin of the tin plating solution was reduced by the oxidation-reduction reaction, and tin was deposited on the surface of the base material of the material to be plated, and plating was performed.

[0010]

[Problems to be solved by the device]

 In the above-mentioned conventional electroless tin plating apparatus, when tin is deposited and a crystal is oriented when forming a plating layer and a physical strain is generated in the crystal, a so-called whisker is generated, which is used for TAB. There is a problem that it causes a short circuit between leads of the fine wiring pattern of the tape.

In order to remove the physical strain in the crystal, there is a method in which after tin plating, heating is performed as soon as possible, but it cannot be completely removed.

As described above, there is a problem that the formation state of tin plating influences the characteristics of so-called Inner Lead Bonding (abbreviated as ILB), and the adverse influence on the performance of the TAB tape cannot be ignored. there were.

The present invention has been made in order to solve the above-mentioned problems of the prior art. For the TAB, the generation of whiskers is prevented and the cause of the short circuit between leads of the fine wiring pattern of the TAB tape is eliminated. It is an object of the present invention to provide an electroless tin plating device for tape.

[0014]

[Means for Solving the Problems]

 In order to achieve the above object, the configuration of the present invention relating to an electroless tin plating apparatus is such that in the electroless tin plating apparatus used in the TAB tape manufacturing method, the tin plating tank is provided with a high frequency vibrating means. Is characterized by.

Further, the high-frequency vibrating means is an ultrasonic wave generator.

[0016]

[Action]

 The functions of the above technical means are as follows.

According to the configuration of the present invention, since the ultrasonic generator is provided in the tin plating tank of the electroless tin plating apparatus, during the plating process, the tin plating crystal layer inside the tin plating crystal layer is generated due to the fine vibration from the ultrasonic generator. It is possible to remove the physical strain of (3), prevent the precipitation of directional tin-plated crystals, and prevent the formation of whiskers.

[0018]

【Example】

 An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic explanatory view of an electroless tin plating apparatus according to an embodiment of the present invention.

In FIG. 1, 1 is a material feeding section, 2 is a degreasing tank, 3 is a recovery tank, 4 is a water washing tank, 5 is an acid cleaning tank, 6 is a recovery tank, 7 is a water cleaning tank, 8 is a tin plating tank, Reference numeral 9 is a recovery tank, 10 is a water washing tank, 11 is a product winding section, and 12 is an ultrasonic wave generator. These constitute an electroless tin plating apparatus used for manufacturing TAB tapes.

In the above electroless tin plating apparatus, the material feeding section 1, the degreasing tank 2, the collecting tank 3, the washing tank 4, the pickling tank 5, the collecting tank 6, and the washing tank 7 are known. This is the same as the pre-treatment of the device of.

In the so-called reel-to-reel, the material feeding section 1 vertically feeds the TAB tape material into the plating apparatus. Of course, you can send it horizontally.

In the degreasing tank 2, the fed TAB tape material is cleaned of oil and fat adhering to the surface to be plated. The strength of the adhesion between the plating layer and the material is determined by the surface condition.

In the degreasing tank 2, first, immersion degreasing is performed. As the degreasing liquid, a known degreasing liquid such as sodium silicate liquid may be used.

Next, in the washing tank 4, the degreased liquid is rinsed with clean water and rinsed with the degreased liquid.

Next, in the pickling tank 5, pickling is performed in order to remove the oxide layer and the altered layer on the surface of the object to be plated of the TAB tape material.

Next, the pickling solution is recovered in the recovery tank 6 and washed in the water cleaning tank 7.

Since the tin plating tank 8 has a high hydrogen overvoltage, titanium trichloride is used as a reducing agent, and citric acid, EDTA, and nitrilotriacetic acid are used as complexing agents to improve the stability of the bath.

An example of the tin plating bath is as follows. Sodium citrate 0.34, ethylenediamine 0.05, sodium nitrilotriacetate 0.02, tin chloride 0. 05, titanium trichloride 0.03 and the like. All units are molar concentrations. The pH is 9 and the temperature is 70 to 80 ° C.

An ultrasonic wave generator 12 is attached to the tin plating bath 8. The output of the ultrasonic generator differs depending on the target object, but is approximately 1 MHz and tens to hundreds of watts, and the distance from the surface of the target object is approximately 20 cm and at most tens of cm.

With the ultrasonic generator 12 as described above, ultrasonic waves are continuously applied to the plating layer formed on the surface to be plated of the TAB tape raw material while passing through the tin plating bath.

In this way, it is possible to prevent the tin plating, which has directionality, from being deposited due to the fine vibration caused by ultrasonic waves, and to form a smooth plating layer without whiskers.

The TAB tape is completed by being processed in the known recovery tank 9 and water washing tank 10 and wound up on the product winding section 11.

[0034]

[Effect of device]

 As described above in detail, according to the present invention, it is possible to prevent whiskers from occurring and eliminate the cause of the short circuit between leads of the fine wiring pattern of the TAB tape. A plating apparatus can be provided.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an electroless tin plating apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1 Material feeding part 2 Degreasing tank 3 Recovery tank 4 Water washing tank 5 Pickling tank 6 Recovery tank 7 Water washing tank 8 Tin plating tank 9 Recovery tank 10 Water washing tank 11 Product winding section 12 Ultrasonic generator

Claims (2)

[Scope of utility model registration request] 1. An electroless tin plating apparatus used in a method for producing a TAB tape, characterized in that a tin plating tank is provided with a high-frequency vibrating means. 2. The electroless tin plating apparatus according to claim 1, wherein the high frequency vibrating means is an ultrasonic wave generator.