Circuit Board Solder Pad Layout to Shield Vias From Solder
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ceramic circuit carriers with metallization layers at high-voltage potential face issues due to undefined solder outflow and air traps caused by via holes, which can lead to reduced service life and loss of electrical contact.
Innovation Solution
Applying solder resist on solder pads to shield vias from solder ingress, ensuring a defined solder layer and preventing air entrapment, thereby protecting the circuit board during the soldering process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vias are made substantial in length to extend through the semiconductor device thickness, then electrical contact from upper side to metallization layer is achieved, but solder outflow becomes undefined and service life is reduced
Solution Approach 1:
The solder resist is applied selectively only in the via regions of the solder pad, creating local differentiation where the via areas are protected from solder while the surrounding pad areas remain solder-receptive. This local quality approach allows solder to form reliable connections in needed areas while preventing harmful solder ingress into vias.
Solution Approach 2:
Solder resist acts as an intermediary substance between the solder and the via holes. It provides a protective barrier that mediates the interaction between solder and via structures, preventing direct contact between solder and via interiors while still allowing the via to maintain its electrical function.
2Reliability
If vias extend through the semiconductor device, then electrical contact is established, but air traps are formed that lead to loss of electrical contact under temperature influence
Solution Approach 1:
The solder resist, which initially serves to prevent solder ingress, also inadvertently seals the via openings against air entrapment. By blocking the via entrances during soldering, it prevents air from being trapped inside, thereby converting the protective function against solder into a secondary protective function against air traps.
3Ease of manufacture
If solder is applied to the solder pad, then solder connection is formed, but solder ingress into via causes undefined outflow and potential circuit board damage
Solution Approach 1:
The solder pad surface is segmented into two functional zones: via regions covered with solder resist that repel solder, and open pad regions that accept solder. This segmentation allows the soldering process to proceed normally on the open areas while the via areas remain protected, eliminating the need for complex soldering control.
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 use of solder resist provides a secure and defined solder connection, reducing the risk of solder outflow and air entrapment, ensuring a stable electrical contact and extending the service life of the circuit board.
Implementation Method 1
A solder resist is partially arranged on the solder pad such that the via, which is applied to the solder pad, is shielded from the solder
Implementation Method 2
The electrical module includes a solder pad (also referred to as a solder contact) arranged on its upper side, which is in electrical contact via a solder layer with an associated solder pad of the circuit board
Data Source
AI summary
A circuit board arrangement includes a circuit board having an upper side and an underside, and an electrical module having an upper side and an underside. The upper side of the electrical module is arranged on the underside of the circuit board. The electrical module includes a solder pad that is in electrical contact via a solder layer with an associated solder pad of the circuit board. The electrical module includes a metallization layer located at a distance from the upper side, an electrical component that is arranged on the metallization layer and is electrically connected thereto, and at least one via extending from the solder pad on the upper side of the electrical module up to the metallization layer. A solder resist is partially arranged on the solder pad such that the at least one via, applied to the solder pad, is shielded from the solder.