PCB Carrier Flattening for Precise Pick-and-Place Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the semiconductor industry, positioning printed circuit boards (PCBs) with electrical components requires precise alignment within a specific depth of field for accurate inspection, but existing technologies struggle to maintain this precision due to PCB bow and twist tolerances exceeding the camera's depth of field, leading to variability in component placement accuracy.
Innovation Solution
A carrier positioning device with a flattening unit and actuator system that flattens the PCB to remove bow and twist, ensuring the component surface is pressed against a stationary abutment member, maintaining the necessary alignment for inspection cameras, and allowing for the placement of electrical components on a clamped PCB.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PCBs are manufactured following standard tolerances (IPC-A-600), then manufacturing cost and ease of manufacture are improved, but positioning precision and manufacturing precision deteriorate because bow and twist exceed camera depth of field
Solution Approach 1:
The flattening unit performs preliminary flattening of the PCB before the die attach process. The flattening member with vacuum openings is positioned against the PCB surface, and vacuum is applied to pull the PCB surface into contact with the flattening member, removing bow and twist in advance so that subsequent positioning and inspection can proceed within the camera's depth of field
Solution Approach 2:
The flattening member acts as an intermediary between the PCB and the positioning/inspection system. By introducing this intermediate flattening mechanism, the PCB can be temporarily deformed to meet positioning requirements without permanently altering the PCB design or manufacturing standards
2Measurement precision
If the depth of field of inspection cameras is limited to +/â60 micrometer, then measurement precision is improved for component inspection, but positioning precision deteriorates because PCB thickness variation and bow exceed this range
Solution Approach 1:
The system performs preliminary flattening of the PCB surface using vacuum suction before inspection. The flattening member is positioned against the PCB, vacuum is applied through the vacuum openings to remove bow and twist, ensuring the PCB surface is within the camera's depth of field before component placement and inspection occur
Solution Approach 2:
The flattening system is dynamically activated only when needed. The flattening member can be positioned and vacuum applied temporarily during the die attach process, then removed or deactivated, allowing the system to adapt to different PCB states without permanent modification
3Manufacturing precision
If flattening unit and actuator system are added to the carrier positioning device, then positioning precision and manufacturing precision are improved, but device complexity increases
Solution Approach 1:
The flattening member serves multiple functions: it flattens the PCB surface using vacuum suction, provides a reference surface for positioning, and can potentially serve as a support during inspection. This multi-functionality reduces the need for separate dedicated components for each function
Solution Approach 2:
The flattening member with vacuum openings is integrated into the existing carrier positioning device structure. The vacuum openings are incorporated into the flattening member itself, and the actuator system is integrated with the positioning mechanism, creating a compact nested arrangement rather than separate external systems
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 solution effectively maintains the PCB surface within the camera's depth of field, ensuring accurate placement and inspection of electrical components, addressing the variability caused by PCB tolerances and improving the precision of the die attach process.
Implementation Method 1
a vacuum unit configured for exerting a suction force through the one or more vacuum openings of the flattening side to flatten the carrier
Data Source
AI summary
A carrier positioning device for positioning a carrier, and a pick-and-place device including the same is provided. The disclosure relates to a method for positioning a carrier, and to a method for arranging an electrical component on a carrier. The carrier includes a first and a second surface, the first surface includes a first central region on which electrical components are arranged, and a first edge region adjacent to the first central region. According to an aspect of the present disclosure, the carrier is flattened on a flattening side of a flattening member. The flattening member with the carrier on the flattening side is moved so that the carrier is pressed with its first surface against a flat abutment side of an abutment member. The abutment member is configured to leave an opening exposing the first central region when the carrier is in abutment with the flat abutment side.