Gas Sensor Package with Segmented Molding and Isolated Heater
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas sensor packages face challenges in minimizing dead volume and outgassing effects, which can impact measurement accuracy, especially when integrated into portable electronic devices, and require a design that ensures stable power supply and thermal insulation for sensitive layers.
Innovation Solution
A gas sensor package with a semiconductor chip featuring a sensitive layer, a heater, and a molding compound that encapsulates the chip while maintaining access to the sensitive layer, reducing dead volume and outgassing impact, and includes a die pad for thermal management and separate power supply for the heater to ensure reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas sensor chip is fully encapsulated in molding compound, then protection and structural integrity are improved, but dead volume increases and outgassing effects worsen
Solution Approach 1:
The patent extracts the sensitive layer from the bulk molding compound by creating a cavity that exposes it to the external environment. This allows the sensitive layer to be isolated from the harmful outgassing effects of the molding compound while maintaining the protective encapsulation for the rest of the sensor chip.
Solution Approach 2:
The molding compound is segmented into two distinct regions: an encapsulating region that protects the sensor chip components, and an exposed region that provides direct access to the sensitive layer. This segmentation enables differential treatment of different sensor components, protecting those that need protection while exposing those that need environmental access.
2Device complexity
If the heater and sensor share the same power supply, then device complexity is reduced, but power supply stability and thermal insulation deteriorate
Solution Approach 1:
The power supply system is segmented into two independent channels: one dedicated to the heater and another to the sensor. This segmentation ensures that the high current demands of the heater do not interfere with the stable voltage supply required by the sensitive sensor measurements, thereby improving overall system reliability.
Solution Approach 2:
The patent introduces separate power supply traces and connection points as intermediaries between the external power source and the internal heater/sensor components. These intermediary structures provide electrical isolation and independent control, preventing cross-interference between the heater and sensor power requirements.
3Measurement precision
If the sensitive layer is fully exposed for gas access, then measurement precision is improved, but thermal insulation deteriorates
Solution Approach 1:
The molding compound is applied with local quality differentiation: it fully encapsulates the sensor chip substrate and heater regions for thermal protection, while deliberately leaving the sensitive layer region exposed for gas access. This localized approach provides thermal insulation exactly where needed without compromising measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves a compact, reliable gas sensor package with reduced outgassing effects, stable power supply, and effective thermal insulation, enabling accurate gas analysis in portable devices.
Implementation Method 1
a heater (34) arranged in or under the membrane (33) for heating the sensitive layer (31)
Implementation Method 2
A gas sensor package with a semiconductor chip featuring a sensitive layer, a heater, and a molding compound that encapsulates the chip while maintaining access to the sensitive layer, reducing dead volume and outgassing impact
Implementation Method 3
includes a die pad for thermal management
Data Source
Figure 1~2
Figure 3~4
AI summary
A gas sensor package comprises a gas sensor chip (3) with a layer (31) sensitive to a gas, and with a heater (34) for heating the sensitive layer (31). Contact pads (22-27) are provided for electrically contacting the gas sensor package and a die pad (21) is provided for mounting the gas sensor chip (3) to. Electrical connections connect the gas sensor chip (3) and the contact pads (22-27). A molding compound (1) at least partially encloses the gas sensor chip (3). An opening (11) in the molding compound (1) provides access to the sensitive layer (31) of the gas sensor chip (3). One of the contact pads (26) serves as a pin for supplying electrical current to the heater (34) of the gas sensor chip (3).