Audio design-box waterproof design
Foreword
In this era of smart phones, smart phones have become an essential tool for each of us, not only as a communication tool, but also as a digital camera, game console, e-mail and even a wallet. It can bring us convenience, joy, and touch. But one thing that makes us sad is that "mobile phones are flooded, so mobile phone waterproofing is being added to the new mobile phones as one of the selling points of many brand mobile phones following the industry trend. The waterproof technology is expected to replicate the popularity of fingerprint recognition technology, from Apple Samsung, etc. The flagship flagship mobile phones are popularized to other mid-to-high-ends. The waterproofing of mobile phones is expected to spread rapidly to increase the penetration rate. As an acoustic supplier, the demand for the waterproof function of acoustic products has greatly increased. Today, we discuss the design of the acoustic box waterproof solution.
Waterproof structural parts and related process requirements
Waterproof SPK structure-front and back cavity isolation-design four sides steps
The waterproof box needs to be designed with four-sided steps as shown in Figure 3, and the ordinary box is designed with three-sided steps as shown in Figure 1. The air pressure will separate the single sound film and the basin frame, causing the front and rear chambers to collude and lead to waterproof failure; Yellow area.
Waterproof SPK structure-the front cavity is isolated from the outside-design four-sided steps
1. The step on the fourth side will occupy the space of the sound channel. In order to ensure the acoustic performance, a boss should be designed under the fourth side, such as a yellow transparent area.
2. The step width needs 0.55mm.
Waterproof SPK structure-front and back cavity isolation-double-sided adhesive steel sheet
Waterproof SPK structure-front and back cavity isolation-double-sided adhesive steel sheet
The steel sheet has higher requirements on the height space, while affecting the minimum sound channel;
Taking 0916 monomer as an example, the distance from the dome of the non-waterproof project to the surface of the box requires 0.65 vibration space + 0.2 steel sheet = 0.85mm; the waterproof project requires 0.65 vibration space + 0.5 plastic + 0.2 double-sided adhesive + 0.2 steel sheet = 1.55mm .
Waterproof SPK structure-front and rear cavity isolation-steel sheet injection + glue
The injection-molded steel sheet is designed with a glue storage groove, and the edge and the glue storage groove form a continuous circle of glue to ensure its waterproof performance. The edge area needs to be glued to prevent collusion between the front and back chambers. It is not recommended to use this scheme, because there are many glue application areas, the process is cumbersome, and the risk of airtight NG is slightly higher;
The steel sheet is designed with a convex hull to glue the sink area;
Space requirements: convex hull drop 0.2mm; glue width 0.6mm;
Waterproof SPK structure-sound hole and machine seal-two-color injection
Two-shot injection molding soft rubber, by extruding the soft rubber with the inclined surface of the whole machine to achieve waterproof requirements;
Two-color injection molding is easy to produce soft rubber burrs, overflows, welded lines, trapped air, shrinkage. The height of the soft rubber is sensitive to the injection molding process.
Waterproof SPK structure-sound hole and whole machine seal-polishing of sound hole
The red surface is polished, and the silicone mat and other parts are attached to the whole machine to form an extrusion with the box to waterproof it.
The pin refers to the connection between the internal circuit of the integrated circuit (chip) and the peripheral circuit, and the pin constitutes the interface of the chip. According to the function, the pins of AT89S52 can be divided into four categories: main power supply, external crystal oscillator or oscillator, multi-function I/O port, and control, strobe and reset.
Terminal Pins,Terminal Hardware Pin,High Precision Terminal Pins,Terminal Pins For Pcb
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