CN112235941A - PCB key position structure and production method - Google Patents

Abstract

The invention provides a PCB (printed circuit board) key position structure and a production method thereof, wherein the PCB key position structure comprises a PCB substrate, a key position and a spring plate, wherein the key position is arranged on the PCB substrate, the spring plate covers the key position, the periphery of the spring plate hermetically covers the key position, the key position is concentric PAD and a ring, an annular isolation belt is arranged between the concentric PAD and the ring, and a conductive hole is arranged on the concentric PAD or the ring; an anti-oxidation film is coated on the key position, and the anti-oxidation film is an organic welding film OSP; on the premise of ensuring the quality, the invention greatly reduces the cost, greatly improves the production efficiency, improves the market competitiveness and meets the cost requirement of fast updating and upgrading of consumer electronics.

Description

PCB key position structure and production method

Technical Field

The invention relates to the production and manufacture of PCB key positions, in particular to a PCB key position structure and a production method.

Background

A PCB, i.e., a printed circuit board, also called a PCB, is a provider of electrical connection of electronic components. The circuit board has the main advantages of greatly reducing errors of wiring and assembly, and improving the automation level and the production labor rate. The key position can not be separated from the control of the circuit, in the existing key position control, the surface gold-deposition key position and the carbon film PCB key position are mainstream products, wherein, the key position structure with gold-deposition surface realizes the service life of the key position function by the characteristics of difficult oxidation of the gold surface and good conductivity, but has high cost and complex process. In the carbon film PCB key position, the carbon film adopts concentric inner circle and confined excircle ring, and the pad sets up in the below of inner circle, then main shortcoming has: the carbon film is easy to scratch after long use, so that the routing below the carbon film is exposed, and the key position is short-circuited; due to the limitation of the single-sided carbon film process, the concave-convex shape of the middle contact (i.e. the inner circle) causes that the key position is pressed lightly, the function cannot be realized, and the user experience effect is poor.

Disclosure of Invention

The invention provides a novel key position structure, which realizes the key position function, greatly saves the cost, enhances the competitiveness and solves the problems.

In order to solve the above problems, the technical scheme provided by the invention is as follows: a PCB board key position structure comprises a PCB substrate, a key position and a spring plate, wherein the key position is arranged on the PCB substrate, the spring plate covers the key position, the periphery of the spring plate is hermetically covered with the key position, the key position is concentric PAD and a ring, an annular isolation belt is arranged between the concentric PAD and the ring, and a conductive hole is arranged on the concentric PAD or the ring; and an anti-oxidation film is coated on the key position, and the anti-oxidation film is an organic welding film OSP.

In the preferable technical scheme, the distance of the annular isolation belt in the key position is 0.1-0.3 mm.

In a preferable technical scheme, the antioxidant film is purrocoline and the thickness is 0.1-0.4 UM.

According to the preferable technical scheme, the elastic sheet is in a pot cover shape with a convex middle part and a sealed periphery.

According to the preferred technical scheme, a sealing film is arranged on the periphery of the elastic piece, the sealing film and the key position are concentric and cover the elastic piece, and the diameter of the sealing film is at least 1mm larger than that of the elastic piece.

According to the preferable technical scheme, the concentric PAD is provided with an aligning body which is a base material position of a cross structure.

The preferable technical scheme is that the method comprises the steps of sequentially operating, key structure design, circuit etching, plate grinding, solder resisting, antioxidant film processing, spring plate mounting and sealing, wherein the antioxidant film processing further comprises → water washing → micro etching → water washing → acid washing → pure water washing → antioxidant film processing → pure water washing → drying.

According to the preferable technical scheme, the key structure design comprises the width and the distance arrangement of a concentric PAD, a circular ring and an annular isolation belt, the concentric PAD and the circular ring are compensated according to an etching factor, and the minimum distance of the annular isolation belt is the minimum distance of equipment etching.

According to the preferable technical scheme, the line is etched with concentric PAD and a circular ring, and the grinding plate is arranged before the anti-oxidation film is processed.

According to the preferable technical scheme, the middle part of the elastic piece is provided with a sunken or raised central datum point, the datum point of the elastic piece corresponds to the alignment body of the concentric PAD, the sealing membrane is in a ring structure or a circle, the contact part of the ring or the circle on the periphery of the elastic piece is elastic colloid, and the elastic colloid is annularly surrounded at the joint of the elastic piece and the PCB substrate.

Compared with the prior art, the invention has the advantages that by adopting the scheme, on the premise of ensuring the quality, the cost is greatly reduced, the production efficiency is greatly improved, the market competitiveness is improved, and the cost requirement of fast updating and upgrading of consumer electronics is met.

Drawings

For a clearer explanation of the embodiments or technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the invention, and it is obvious for a person skilled in the art that other drawings can be obtained from the drawings without creative efforts.

FIG. 1 is a schematic view of a key of the present invention;

FIG. 2 is a schematic diagram of the layered structure of the present invention.

Detailed Description

In order to facilitate an understanding of the invention, the invention is described in more detail below with reference to the accompanying drawings and specific examples. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

As shown in fig. 1 and 2, one embodiment of the present invention is: in order to solve the above problems, the technical scheme provided by the invention is as follows: the utility model provides a PCB board button position structure, PCB board button position structure includes PCB base plate 1, button position 2 and shell fragment 3, button position 2 is on PCB base plate 1, shell fragment 3 covers on button position 2, just the peripheral sealed cover of shell fragment 3 button position 2, button position 2 is concentric PAD4 and ring 5, there is annular median 6 between concentric PAD4 and the ring 5, according to the design, verifies the structural design that the button is in production, ensures the rationality of design between concentric PAD4 and the ring 5 on concentric PAD4 or ring 5, be equipped with the electrically conductive hole, the electrically conductive hole aperture is less, the consent is handled in the production process; the key position 2 is coated with an oxidation resistant film 7, the oxidation resistant film 7 is an organic welding film OSP, the oxidation resistant film 7 is purrocoline, the electrical performance of the oxidation resistant film 7 printed by the purrocoline is not influenced under the condition of controlling the thickness, the oxidation resistant film has a protective and oxidation resistant effect on the key position 2, and the thickness is 0.1-0.3 UM.

The elastic sheet 3 is made of stainless steel and is an important component of the switch, and the function of a high-quality switch is achieved between an operator and a product by means of the conductivity of the elastic sheet 3. Meanwhile, the stable resilience force (automatic return after being pressed) and the overlong service life of the elastic sheet 3 enable the elastic sheet 3 to become an important part in products such as a membrane switch, a micro switch, a PCB and the like, the important function of conducting a circuit is achieved, when the elastic sheet is pressed, the circuit is conducted, and when the elastic sheet is loosened, the circuit is automatically disconnected.

The elastic sheet 3 is in a pot cover shape with a convex middle part and a sealed periphery, a sealing film 8 is arranged on the periphery of the elastic sheet 3, the sealing film 8 and the key position 2 are concentric and cover the elastic sheet 3, and the diameter of the sealing film 8 is at least 1mm larger than that of the elastic sheet 3. The sealing film 8 isolates the key position 2 from air, so that the environment of the key position 2 is ensured to be dry, the oxidation of a copper surface under the condition that an OSP film is damaged is avoided, and the stability of the electrical performance is further determined. Elastic colloid has realized gaseous space transfer when shell fragment pressurized and release, and the gaseous entering or revealing in the sealing film of limited avoidance has realized the protection of antagonism oxide film, and simultaneously in practical process, perhaps the shell fragment practical process of long-time high frequency, the anti-oxidant film is damaged, and under the damaged condition of anti-oxidant film, the gas in the sealing film is not oxidizing the copper face, realizes the extension by a wide margin of button life-span.

The distance between the annular isolation belts 6 in the key position 2 is 0.05-0.3mm, the distance between the concentric PAD4 and the circular ring 5 is ensured, and the problem of electrical short circuit caused by the distance problem is avoided.

The concentric PAD4 is provided with an aligning body which is a base material position of a cross structure. The aligning body can also be of other structures, so that the elastic sheet 3 and the key position 2 can be conveniently aligned and installed.

The oxidation resistant film 7 only floats on the clean bare copper surface, a layer of organic film is chemically grown, the oxidation resistant film 7 has oxidation resistance, thermal shock resistance and moisture resistance, is used for protecting the copper surface of the circuit board from being oxidized or vulcanized in a normal environment and the like so as to ensure the stable performance of the oxidation resistant film 7, in order to ensure the cleanness of the copper surface, firstly, oil removal is needed in the process of oxidation resistant treatment, the oil removal comprises acid washing or alkali washing in the process of plate grinding, water washing is carried out after each acid washing or alkali washing in order to clean acid or alkali of a key position, in order to increase the roughness of the copper surface, micro etching is carried out after the water washing, the micro etching increases the roughness of the copper surface, so that the oxidation resistant film 7 is firmly combined on the copper surface, in the micro etching process, an etching solution is acidic or alkaline, and is also subjected to water washing after the micro etching, meanwhile, the cleaning of the copper surface is ensured by pure water washing, so the conventional OSP process also comprises the following procedures of degreasing → water washing → micro etching → water washing → acid washing → pure water washing → OSP → pure water washing → drying.

The technical features mentioned above are combined with each other to form various embodiments which are not listed above, and all of them are regarded as the scope of the present invention described in the specification; also, modifications and variations may be suggested to those skilled in the art in light of the above teachings, and it is intended to cover all such modifications and variations as fall within the true spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A PCB key position structure is characterized by comprising a PCB substrate, a key position and a spring plate, wherein the key position is arranged on the PCB substrate, the spring plate covers the key position, the periphery of the spring plate hermetically covers the key position, the key position is concentric PAD and a ring, an annular isolation belt is arranged between the concentric PAD and the ring, and a conductive hole is arranged on the concentric PAD or the ring; and an anti-oxidation film is coated on the key position, and the anti-oxidation film is an organic welding film OSP.

2. The PCB board key position structure of claim 1, wherein the distance between the annular isolation strips in the key position is 0.1-0.3 mm.

3. The PCB of claim 2, wherein the oxidation-resistant film is purrocoline and the thickness is 0.1-0.4 UM.

4. The PCB board key position structure of claim 1, wherein the spring plate is a pot cover shape with a convex middle part and a sealed periphery.

5. The PCB of claim 4, wherein a sealing membrane is disposed around the spring, the sealing membrane and the key are concentric and cover the spring, and a diameter of the sealing membrane is at least 1mm larger than a diameter of the spring.

6. The PCB board key position structure of any one of claims 1-4, wherein the concentric PAD is provided with a counter, and the counter is a base material position of a cross structure.

7. The method for manufacturing a key position structure of a PCB according to claims 1-5, wherein the key structure design, the circuit etching, the board grinding, the solder resist, the anti-oxidation film treatment, the spring sheet installation and the sealing arrangement are sequentially operated, wherein the anti-oxidation film treatment further comprises → water washing → micro-etching → water washing → acid washing → pure water washing → anti-oxidation film treatment → pure water washing → drying.

8. The method as claimed in claim 7, wherein the key structure design includes width and pitch arrangements of concentric PAD, circular ring and annular isolation strip, the concentric PAD and circular ring are compensated according to etching factor, and the minimum pitch of annular isolation strip is the minimum pitch of equipment etching.

9. The method as claimed in claim 7, wherein the lines are etched with concentric PADs and rings, and the grinding plate is disposed before the anti-oxidation film.

10. The method for manufacturing a key position structure of a PCB of claim 7, wherein the middle part of the spring plate is provided with a center reference point which is concave or convex, the reference point of the spring plate corresponds to the alignment body of the concentric PAD, the sealing film is in a ring structure or a circle, the contact part of the ring or the circle on the periphery of the spring plate is elastic colloid, and the elastic colloid is in a ring shape and surrounds the joint of the spring plate and the PCB substrate.

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