Detonator PCB Positioning Using Fluent Explosive Embedding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic detonator manufacturing techniques face issues with inconsistent explosive composition loading, potential damage to electronic components, and improper positioning of the printed circuit board, leading to unreliable operation and potential malfunctions.
Innovation Solution
A detonator assembly featuring a cup-shaped moulded body with complementary formations to precisely position the printed circuit board and ignition element, using a fluent explosive composition that sets in situ to embed the components, and a binder to maintain suspension and prevent segregation, ensuring intimate contact and accurate dosing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the printed circuit board is sealed to the tube using potting compound, then the sealing function is achieved, but the electronic components on the printed circuit board can be damaged
Solution Approach 1:
The invention extracts the sealing function from the potting compound and assigns it to a dedicated seal member (O-ring or grommet) that is inserted into a groove on the printed circuit board. This separates the sealing function from the structural support function, allowing the seal to protect electronic components while maintaining reliable sealing without the harmful effects of potting compound.
Solution Approach 2:
The seal member acts as an intermediary element between the printed circuit board and the explosive composition. It provides the sealing function while physically isolating the electronic components from direct contact with the explosive material, thus preventing damage while maintaining sealing reliability.
2Reliability
If the printed circuit board is sealed to the tube using potting compound, then the sealing function is achieved, but the sealing process can be problematic and lead to malfunction
Solution Approach 1:
The sealing function is extracted from the complex potting compound application process and assigned to a pre-formed seal member. This simplifies the manufacturing process by eliminating the need for skilled potting operations while ensuring consistent sealing quality through the standardized seal member installation.
Solution Approach 2:
The invention changes the physical state and form of the sealing solution from a viscous potting compound requiring application skills to a pre-formed elastomeric seal member that can be easily installed. This parameter change transforms a complex manufacturing step into a simple insertion operation.
3Quantity of substance
If the explosive composition is placed in particulate form into the tube, then the explosive loading is achieved, but the quantity may vary from detonator to detonator producing inconsistent outcomes
Solution Approach 1:
The invention changes the physical state of the explosive composition from particulate solid to fluent form (paste or slurry). This allows the explosive to be delivered in a controlled, consistent quantity through volumetric dosing mechanisms, eliminating the variability inherent in particulate filling and tamping processes.
Solution Approach 2:
The invention replaces the mechanical tamping process with a chemical setting process. The fluent explosive composition is placed in the cavity and then allowed to set or cure in situ, forming a solid component that firmly embeds the ignition element without requiring mechanical compression. This substitution eliminates the inconsistency caused by variable tamping forces.
4Reliability
If the explosive composition is tamped around the ignition element, then the intimate contact is achieved, but physical damage can occur to the ignition element
Solution Approach 1:
The invention changes the explosive composition from particulate form requiring mechanical tamping to fluent form that can be placed without compression. The fluent explosive is then allowed to set and firmly embed the ignition element, achieving intimate contact without the harmful mechanical forces of tamping.
Solution Approach 2:
The invention provides beforehand cushioning by using the fluent explosive composition as a cushioning medium during the embedding process. As the explosive sets, it gradually forms a firm bond around the ignition element without sudden mechanical impacts, protecting the element from physical damage while ensuring intimate contact.
5Ease of manufacture
If the printed circuit board protrudes from the tube, then the assembly is accessible for manufacturing, but the sealing of the board to the tube becomes problematic
Solution Approach 1:
The invention extracts the sealing function from the interface between the protruding printed circuit board and the tube, and assigns it to a dedicated seal member mounted on the board. This allows the board to remain accessible for manufacturing while the seal member provides reliable sealing at the interface with the explosive composition.
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
This solution ensures reliable operation by eliminating sealing and tamping-related issues, preventing physical damage to components, and achieving consistent explosive composition distribution, thereby enhancing the reliability and consistency of detonator performance.
Implementation Method 1
The binder should have the capability of keeping the explosive material in suspension with limited segregation over time
Implementation Method 2
The binder may be carried in a solvent which may be volatilised at a relatively low temperature e.g. of the order of 60°C to 80°C
Implementation Method 3
an explosive composition which, in fluent form, in the interior of the cup-shaped body covers at least the ignition element and the mounting location, and which is then allowed to set, in situ, to form a solid component
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A detonator which includes a tubular body within which is located a detonator assembly which comprise a container (20) which houses a set explosive composition element in which is embedded part of a PCB (72, 76) which carries an ignition element (66).