Overview

Short-run, high-mix microelectronics packaging presents a unique automation challenge. Manufacturers need the quality and repeatability benefits of automation, but frequent product changeovers can make conventional high-volume solutions impractical. A successful high-mix automation strategy begins with a standardized material-handling platform.Properly designed transport carriers and magazines allow multiple package types to move reliably between process work cells while minimizing equipment changeover. These systems can be integrated into a wide range of processes:​

• • • Die Attach​

    • Wire Bonding​
    • Inspection​​
    • Laser Marking​
    • Functional Testing​

    • Final Packaging​

By standardizing the method used to transport products throughout the manufacturing process, manufacturers can reduce operator intervention, improve process consistency, enhance product traceability, and create a scalable platform for future automation. Whether implemented within a standalone work cell or a fully integrated production line, transport carriers and magazines enable efficient product flow between manufacturing operations while supporting short-run, high-mix production requirements.​

This guide examines the first two foundational elements of that automation strategy: the package transport carrier and the carrier transport magazine.

​

Short-run, high-mix microelectronics packaging

Step 1: The Package Transport Carrier​

​
The package transport carrier is the foundation of any short-run, high-mix automated assembly process. By leveraging edge-belt conveyors, it efficiently moves packages through various process work cells, ensuring seamless and reliable automation.Selecting the right carrier is essential for maintaining precision, repeatability, and overall process efficiency. Factors such as size, material, and design should be carefully assessed to optimize workflow, enhance handling, and ensure long-term system performance.​

​

Sheetmetal Carrier

Carrier Design Considerations​

Carrier Size

To ensure consistency and efficiency, all products to be conveyed should be assessed, and a standardized carrier size should be selected to accommodate the full range of products. Standardizing the carrier width and length minimizes change over time between different product types, improving overall process efficiency. The size of the largest and smallest packages determines the required width of the carrier. Industry standard carrier length is 12 in. but shorter ones can be used if other circumstances require it. 

​

Parts per Carrier

Maximizing the number of parts per carrier seems like an efficient approach, but it comes with trade-offs. Here are some key considerations:
​

• • • Clamping Force Limitations
      Processes like heavy wire bonding require high clamping forces, which may be problematic if too many parts are loaded. ​
    • Work Order Size
      If the order size is small, it might not be efficient to use a high-capacity carrier if it results in partially filled loads. If the process relies on vacuum clamping, open or empty positions in the carrier can cause problems, potentially reducing stability and process reliability.​

Carrier Type​

Carriers are typically manufactured in two types:​

1. Sheet Metal Carriers​

Progressive dies are utilized to fabricate carriers from stainless steel sheet metal in an automated die process.​

• • • • • • Advantages
            Ideal for high-volume production, offering the lowest cost per unit.​
            ​
          • Disadvantages
             High non-recurring engineering (NRE) and tooling development​ costs make it less viable for low-quantity applications.​
            ​
          • Thermal Considerations
            When exposed to thermal cycling, they may​ warp over time, leading to feeding jams and requiring rework or replacement.
          • Accuracy
            These carriers use tabs for package positioning, which may not​ provide the precision required for certain assembly processes.

2. Machined Metal Carriers​

CNC milling equipment is utilized to manufacture carriers from various materials. ​For ESD safety, conductive materials and coatings should be used in most cases.​

• • • • • • Advantages
            Ideal for low-volume production, with lower NRE and tooling costs compared to sheet metal stamping.​
            ​
          • Disadvantages
            Higher per-unit cost due to increased manufacturing cost.​
            ​
          • Thermal Considerations
            Machined carriers resist warping even when subjected to thermal cycling. Typically, they will remain flat and precise for many years of use.​
            ​
          • Accuracy
            These carriers can be machined to tight tolerances, allowing for precise package positioning.
            They also enable the integration of locating and clamping features for enhanced stability.​

​Conclusion​

For most short-run, high-product-mix applications, machined carriers are preferred due to their lower upfront costs, extended lifespan and design options compared to sheet metal carriers.

Short-run, high-mix microelectronics packaging

Step 2: The Carrier Transport Magazine​

​
The carrier transport Magazine holds multiple carriers in slots, facilitating the automated loading and unloading of products into and out of assembly cells or an integrated line. ​

Unprocessed product on carriers are loaded into the magazine slots and placed into an upstream Magazine Unloader system that automates the feeding process. ​

Once processed, carriers are transferred into a downstream magazine via an automated Magazine Loader.
​

By integrating magazines with automated unloaders and loaders, manufacturers ​can streamline the feeding of carriers into individual work cells or along an automated production line, enhancing efficiency and reducing manual handling.​

Magazine Design Considerations​

​​

Magazine Size​

The magazine size is determined by the carrier dimensions. Standardizing carrier sizes allows Magazine Unloaders and Loaders to maintain a consistent configuration, eliminating the need for changeovers. The magazine's slot capacity depends on the height of the parts and the total weight of a fully loaded magazine. This should be carefully managed to prevent ergonomic issues of operators moving the magazines.​

​

Thermal Cycling​

Some users incorporate batch ovens for curing processes which must be considered when designing and manufacturing magazines. If using a convection type oven, then slots or holes to increase airflow is a crucial component.

Magazine Types​

​

1. Sheet Metal Magazine​

This type is manufactured using sheet metal fabrication methods, where parts are cut, formed, and assembled using welding or rivets.​

• • • • • • Advantages
            Ideal for high-volume production, offering the lowest cost per​
            unit. Lightweight and allows for easy integration of airflow features for​
            thermal cycling.​
            ​
          • Disadvantages
            Less rigid, leading to a shorter lifecycle and potential for​
            jamming
            .​
          • Thermal Considerations
            Deforms over time when exposed to thermal​ cycling, reducing lifespan​.

2. Extruded Magazine​

Constructed from extruded aluminum, these magazines are available in fixedsizes: 
3.1 x 12, 4.3 x 12, and 5.4 x 12.​
​

• • • • • • Advantages
            Cost-effective if the standard sizes meet requirements.
            ​​
          • Disadvantages
            Requires secondary operations for airflow slots or​ additional features. Includes stacking features but lacks interlocking,​ leading to movement when feeding carriers.​
            ​
          • Thermal Considerations
            Withstands thermal cycling, but adding​ airflow features significantly increases cost.

3. Machined Magazine​

Machined from solid material, offering maximum customization for size and features such as airflow slots and stacking capabilities.​

• • • • • • Advantages
            Best option for custom sizes and features. Cost-effective for​ smaller production quantities.​

             

          • Disadvantages
            Highest cost per unit.
            ​
            
          • Thermal Considerations
            Excellent resistance to thermal cycling.​
            ​

Short-run, high-mix microelectronics packaging

Magazine Conclusion​

​
For most short-run, high-product-mix applications extruded magazines are the best option if a standard size fits and thermal cycling is not required. ​

For custom sizes and thermal cycling needs, machined magazines are the preferred choice.​

​After finalizing your Transport Carrier and Magazine configurations, automated material handling is essential for efficiently moving products through the assembly process.​

At the upstream and downstream points of your assembly cell or integrated line, Magazine Unloaders (upstream) and Magazine Loaders (downstream) play a crucial role in automation.​

​By incorporating the appropriate magazine handling system, you can streamline your process, improve efficiency, and reduce manual labor.​

Martek Automation's Magazine Handlers

We offer multiple models to fit varying capacity needs:

Single Capacity:​

SM500
Single Capacity Magazine Handlers

Designed for a single magazine

* Product page coming soon