Datasheet Protective Cover Option For SHT3x Humidity and Temperature Sensors Protects the sensor against pollution during assembly processes Enables cost-effective brush-over and spray-over conformal coating procedures Withstands multiple standard reflow cycles Removable with tweezers at end-of-line Delivered in T&R packaging Product Summary The SHT3x protective cover is a polyimide foil, dedicated application procedures of conformal coating material. to protect the sensor opening from pollution. The sensor The protective cover can be easily removed with is delivered with the protective cover attached such that tweezers at the end of the assembly process to allow for the sensor opening is completely covered and sealed. proper sensor operation. This enables cost-effective brush-over and spray-over Datasheet: Intention of Use This datasheet is meant to provide all relevant in Table 1, together with their respective order number. specifications for the additional protective cover option of Any further information about sensor performance, the RH&T-sensors of type SHT3x. All SHT3x products communication protocols etc. are to be found in the coming with the protective cover option are listed respective main datasheets, only. and other possible pollutants during production process. 1 General information However, the cover does not protect sensor contamination by volatile chemicals resulting from The SHT3x protective cover is an optional polyimide foil, outgassing or curing of the conformal coating. Sensirion directly attached to the top surface of the sensor. It recommends to cure conformal coatings according to covers the complete sensing area of the SHT3x and thus supplier specifications (temperature und timing) and to acts as a reliable shield against pollution during SMT provide for increased ventilation. Further extended assembly of the sensor and subsequent processes such curing times will additionally reduce the risk of as conformal coating or potting. The protective cover is contamination. More details on contamination and a list designed to withstand multiple reflow cycles. After of suitable conformal coatings can be found in the assembly and for proper operation of the sensor the document SHTxx Handling Instructions, downloadable cover tape must be removed. from our website. The cover features a flap that extends over the outside As the cover flap extends over one side of the sensor, dimension of the sensor package on one side. This flap please keep in mind that the underneath area of the PCB is designed to allow the cover to be peeled off easily by will not be coated. The relevant dimensions are sketched using tweezers. After peel-off the sensor will operate in Figure 1 which will help proper PCB design. The two regularly as specified in the respective datasheet. metallic contacts which are in the side wall of the sensor All typical application procedures such as brushing, and lay under the protective cover do not need conformal spraying or potting can be used as long as the protective coating, as they are electrically grounded. cover is attached. The cover will effectively protect the sensor opening from direct exposure to these coatings www.sensirion.com May 2019 - Version 3 1/4 Datasheet Protective Cover Option Handling and storage recommendations in the SHTxx 3 Technical Drawing handling instructions document also apply to sensors with the protective cover option. After reflow soldering the sensor will need a reconditioning procedure if immediate functional testing is desired. Details on the reconditioning steps are listed in SHTxx handling instructions. 2 Ordering Information The SHT3x protective cover can be ordered in tape and reel packaging in different reel sizes given in Table 1. The reels are delivered in sealed ESD bags. Name Quantity Order Number Figure 1 Dimensional drawing of SHT3x protective cover SHT30-DIS-P2.5kS 2500 1-101461-01 sensor package. Pin 1 is indicated through the cut corner SHT30-DIS-P10kS 10000 1-101326-01 of the flap. SHT31-DIS-P2.5kS 2500 1-101458-01 SHT31-DIS-P10kS 10000 1-101472-01 SHT30-LSS-P2.5kS 2500 1-101468-01 SHT30-LSS-P10kS 10000 1-101342-01 Table 1 SHT3x protective cover ordering options. 4 Land Pattern For recommended metal land pattern please refer to the respective SHT3x data sheet. In case conformal coating is used, it is not recommended to place components or open metal surfaces on the PCB underneath the extension flap of the protective cover because this area will not be coated properly. www.sensirion.com May 2019 - Version 3 2/4