CN101202422A - Chip type air discharge protection assembly and preparation method thereof - Google Patents

Abstract

A method for preparing a chip type air discharge protection component comprises a copper electrode pair preparation step and a hollow air chamber preparation step; the copper electrode couple preparation step is to manufacture the copper electrode couple with the relative spacing of several microns by using the yellow light lithography process. A chip-type air discharge protection assembly manufactured by the above method, comprising: a substrate; a seed layer formed over the substrate; the pair of convex electrode couples are formed above the seed layer, and the discharge ends of the two convex electrode couples are mutually isolated and have a gap; a bridging layer which is attached to the upper parts of the two electrode couples; a polymer dry film passivation layer formed on the bridging layer; an outer passivation layer formed on the polymer dry film passivation layer; a pair of back electrodes; a pair of terminal electrodes; and a pair of solder interface layers. The gap between the two metal electrode pairs can be controlled to be 0.5-10 μm, and the arc-shaped opposite end faces can prevent the discharge tip from being damaged easily due to the tip discharge.

Description

Chip type air discharge protection component and preparation method thereof

technical field

The invention relates to a discharge protection component and a preparation method thereof, in particular to a metal electrode couple obtained through a yellow light lithography process and a metal electrode electroforming process, so that the two metal electrode couples face each other in an arc shape, and the gap between the two metal electrode couples is The gap can be controlled between 0.5-10 μm, and through a bridging process that does not need to fill the gap with additional gas, to complete a chip-type air discharge protection component and its preparation method.

Background technique

Overvoltage protection or discharge protection components are widely used in various electronic system products such as telephones, fax machines, and modems, especially electronic communication equipment. How to avoid abnormal voltage or electrostatic discharge (Electro-Static Discharge, ESD) It is especially important to cause damage to electronic equipment.

At present, there are many ways to protect the design of electrostatic discharge, such as: shielding (Shielding) protection, gap discharge (Gap Discharge), capacitor (Capacitor), multilayer MLV, semiconductor components, etc.

Among them, the principle of using gap discharge as overvoltage protection is widely used, but what is critical to the effectiveness of overvoltage protection, in addition to the shape of the electrodes, the biggest factor affecting the operation of gap discharge is the dielectric material between the two electrodes. One of the most ideal materials is gas as the medium.

Taking two copper electrodes filled with air (that is, the principle of gap discharge when the medium is air) as an example, the relationship between the electrode spacing and the trigger voltage of the component when the component is impacted by ESD is shown in Figure 4.

However, for air discharge components that are commonly used at present, the gap between the discharge electrodes is relatively high (approximately 10-30 μm) because the gap is mainly formed by diamond blade cutting or laser cutting. In this way, the energy triggered by the components is also quite high, which is only suitable for the protection of lightning strikes or high-energy surges, and it is still insufficient for the electrostatic protection of electronic communication equipment.

Contents of the invention

The object of the present invention is to produce a metal electrode pair with a gap of only 0.5-10 μm between them by providing a chip-type air discharge protection component and its preparation method by using yellow light lithography process and metal electrode electroforming process.

According to the chip-type air discharge protection component and its preparation method of the present invention, the opposite end of the metal electrode couple obtained through the yellow light lithography process and the metal electrode electroforming process is arc-shaped, which can avoid the damage of the discharge tip caused by tip discharge. Deletion is the second object of the present invention.

According to the chip-type air discharge protection component and its preparation method of the present invention, because the discharge gap between the metal electrode pairs can be controlled below 10 μm, the breakdown voltage is reduced, and it can be more widely used in various electronic circuits. Another object of the present invention.

The present invention is realized by adopting the following technical means:

A method for preparing a chip-type air discharge protection component, including a preparation step of a copper electrode pair and a preparation step of a hollow air chamber; the preparation step of the copper electrode pair is to manufacture a copper electrode pair with a relative spacing of several microns by using a yellow light lithography process .

The aforementioned hollow air chamber preparation step is to use a polymer material as a bridging layer, which is pasted on the top of the two copper electrode pairs, and the bridging layer is located on the gap between the two copper electrode pairs with micropores, and then the polymer material Dry film is applied as a protective layer.

Aforesaid copper electrode pair preparation step, comprises the following steps:

Prepare the substrate material; coat the seed layer on the substrate material; coat the photoresist on the seed layer; remove part of the photoresist after exposure and development; plate the copper electrode on the bare part of the seed layer not covered by the photoresist to form A pair of copper electrodes a few microns apart with facing tips; remove the remaining photoresist layer; remove the seed layer.

The aforementioned hollow chamber preparation steps include the following steps:

On the top of the two copper electrode pairs with a distance of only a few microns, a polymer material is used as a bridging layer, and the bridging layer forms micropores at the position of the gap; the polymer dry film is pasted on the bridging layer for protection; The second protective layer coating is carried out on the molecular dry film; the back electrode is coated; the soldering interface layer is coated; the terminal electrode is coated.

The aforementioned seed layer is a titanium tungsten/copper (TiW/Cu) thin film.

The present invention can also adopt following technical means to realize:

A chip-type air discharge protection component, comprising: a substrate; a seed layer formed above the substrate; a pair of convex electrode pairs formed above the seed layer, the discharge ends of the two convex electrode pairs are isolated from each other with a gap; The bridging layer is pasted on the top of the two electrode couples; a polymer dry film protective layer is formed on the bridging layer; an outer protective layer is formed on the polymer dry film protective layer; a pair of back electrodes; a counter electrode; and a pair of solder interface layers.

The aforementioned electrode material and seed layer material can be copper, copper alloy, silver, silver alloy, titanium, titanium alloy, nickel, nickel alloy, gold, gold alloy, platinum, platinum alloy, aluminum or aluminum alloy.

The aforementioned polymer material can be epoxy resin (Epoxy), polyimide (Polyimide), acrylic (Acrylic) or silicone (Silicon).

Compared with the prior art, the present invention has the following obvious advantages and beneficial effects:

According to the chip-type air discharge protection component and its preparation method of the present invention, when the gap between the metal electrode pair drops below 10 μm, if static electricity (ESD) passes through the component, it can be triggered and driven below 500 mV, achieving a real overshoot. Voltage protection function.

Description of drawings

Fig. 1a to Fig. 1g are the upper view and the sectional view of the preparation process of the copper electrode pair of the present invention;

Figure 2a to Figure 2f are the top view and cross-sectional view of the preparation process of the hollow chamber of the present invention;

Fig. 3 is the sectional view of the chip type air discharge protection assembly of the present invention;

Fig. 4 is a graph showing the relationship between the electrode spacing and the trigger voltage when the component is impacted by ESD.

Detailed ways

Specific embodiments of the present invention are described below in conjunction with accompanying drawing:

Chip type air discharge protection component of the present invention, its preparation step comprises:

Please refer to FIG. 1a to prepare an alumina substrate 11;

Please refer to FIG. 1b, a titanium tungsten/copper (TiW/Cu) film is coated on a cleaned alumina substrate 11 as a seed layer 12;

Please refer to FIG. 1c, a layer of photoresist 13 is coated on the surface of the seed layer 12;

Please refer to FIG. 1d, expose and develop, and remove the photoresists of the preliminary patterns 141 and 142 for subsequent electroforming processes;

Referring to Fig. 1e, the metal electrodes are plated on the preliminary patterns 141, 142 to form a pair of metal electrodes 151, 152 that are several microns apart and opposite;

Please refer to FIG. 1f, the photoresist layers 161, 162 other than the metal electrode pairs 151, 152 are removed;

removing the seed layers 171, 172 other than the metal electrode pairs 151, 152 by etching;

Please refer to FIG. 1g to complete the preparation of a metal electrode pair 151, 152 with a gap of several microns on the alumina substrate 11;

Please refer to shown in Figure 2a, above the gap between the metal electrode pair 151, 152 (hereinafter referred to as the hollow air chamber), a layer of polymer dry film material is pasted as the bridging layer 21, and the size of the bridging layer 21 is suitable for covering Hollow air chamber 22, the bridging layer 21 leaves a micropore 23 relative to the position of the hollow air chamber 22, the setting of the bridging layer 21 is to increase the thickness of the hollow air chamber, so as to avoid the photoresist when the subsequent photoresist is pasted. Sticking to the substrate and destroying the hollow structure;

Please refer to Fig. 2b, a polymer dry film is pasted on the outside of the bridging layer 21 as the first protective layer 24 to form a completely sealed hollow air chamber 22;

Referring to FIG. 2c, the second protective layer 25 is printed and covered to cover all air gaps and protect the circuit;

Please refer to FIG. 2d, implement material coating of back electrodes 261, 262;

Please refer to FIG. 2e, using nickel-chromium/nickel-copper alloy (Ni-Cr/Ni-Cu alloy) as the terminal electrode material to cover the terminal electrodes 271 and 272;

Please refer to FIG. 2f, nickel/tin (Ni/Sn) is used as the solder interface layer 281, 282.

The chip-type air discharge protection component of the present invention is completed.

The above metal electrode material or seed layer material can be copper, copper alloy, silver, silver alloy, titanium, titanium alloy, nickel, nickel alloy, gold, gold alloy, platinum, platinum alloy, aluminum or aluminum alloy.

The above polymer material or photoresist can be epoxy, polyimide, acrylic or silicon.

The chip-type air discharge protection component 3 obtained by the above process, as shown in Figure 3, the chip-type air discharge protection component 3 includes:

An alumina substrate 31; a seed layer 32 formed on the alumina substrate 31;

A pair of convex electrode pairs 331, 332 are formed above the seed layer 32. The discharge ends 331A, 332A of the two convex electrode pairs 331, 332 are separated from each other with a gap 333, and the front of the discharge ends 331A, 332A is in a convex arc shape. ;

A bridging layer 34 is attached above the discharge terminals 331A, 332A of the two electrode pairs 331, 332. A micropore 341 is formed in the center of the bridging layer 34, and the micropore 341 is located at the gap 333 between the two electrode pairs. at the top;

A polymer dry film protection layer 35 is formed on the top of the bridging layer 34, and its covering range reaches part of the electrode pair and part of the seed layer;

An outer protection layer 36 is formed on the top of the polymer dry film protection layer, and its covering range is part of the electrode pair and part of the seed layer;

A pair of back electrodes 371 , 372 ; a pair of end electrodes 381 , 382 ; and a pair of solder interface layers 391 , 392 .

The chip-type air discharge protection component of the present invention obtained by the above process, because its discharge gap can be effectively controlled to only about a few μm, therefore, when there is an appropriate potential difference, the gas existing between the electrode pair can be dissociated and suppresses the ESD voltage across the component.

Finally, it should be noted that: the above embodiments are only used to illustrate the present invention rather than limit the technical solutions described in the present invention; Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced; and all technical solutions and improvements that do not depart from the spirit and scope of the invention should be covered by the claims of the present invention.

Claims (8)

1. the preparation method of a chip-type air discharging protection component includes copper electrode idol preparation process and hollow gas chamber preparation process; It is characterized in that: described copper electrode idol preparation process, even for utilizing the gold-tinted micro-photographing process to produce relative spacing for several microns copper electrode.

2. according to the preparation method of claims 1 described chip-type air discharging protection component; it is characterized in that: described hollow gas chamber preparation process; for using macromolecular material as the layer of building bridge; be covered on the top of two copper electrode idols; and this bridge formation layer is positioned on the gap of two copper electrode idols and offers micropore, pastes with the macromolecule dry film and makes protective layer.

3. according to the preparation method of claims 1 described chip-type air discharging protection component, it is characterized in that: described copper electrode idol preparation process may further comprise the steps:

The preparation baseplate material;

Seed Layer is covered on baseplate material;

Photoresistance is covered on Seed Layer;

After exposure, development, the part photoresistance is removed;

Copper electrode is plated in the Seed Layer exposed section that is not covered by photoresistance, to form one at a distance of several microns and most advanced and sophisticated relative copper electrode idol;

Remaining photoresist layer is removed;

Seed Layer is removed.

4. according to the preparation method of claims 1 or 3 described chip-type air discharging protection components, it is characterized in that: described hollow gas chamber preparation process may further comprise the steps:

Above the two copper electrodes idol of spacing number micron, use macromolecular material as the layer of building bridge, this layer of building bridge forms micropore in the position in gap;

Being covered on the layer top of building bridge with the macromolecule dry film protects;

Carry out the protective layer lining second time in macromolecule dry film top;

The lining of enforcement back electrode;

Lining soldering boundary layer;

The termination electrode lining.

5. according to the preparation method of claims 3 described chip-type air discharging protection components, it is characterized in that: described Seed Layer is tungsten titanium/copper (TiW/Cu) film.

6. chip-type air discharging protection component is characterized in that comprising:

One substrate;

One Seed Layer is formed at the substrate top;

A pair of convex-end electrode idol is formed at the Seed Layer top, and the discharge end of two convex-end electrode idols is isolated mutually and had the gap;

One bridge formation layer is covered on two electrodes idol top;

One macromolecule dry film protective layer is formed at the layer top of building bridge;

One external protection is formed at macromolecule dry film protective layer top;

A pair of back electrode;

The pair of end electrode; And

A pair of soldering boundary layer.

7. according to claims 6 described chip-type air discharging protection components, it is characterized in that: described electrode material and seed layer materials are copper, copper alloy, silver, silver alloy, titanium, titanium alloy, nickel, nickel alloy, gold, billon, platinum, platinum alloy, aluminum or aluminum alloy.

8. according to claims 6 described chip-type air discharging protection components, it is characterized in that: described macromolecular material is epoxy resin (Epoxy), poly-imines (Polyimide), acryl (Acrylic) or silica gel (Silicon).

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