Depaneling

This article is not adequately provided with supporting documents (for example individual proofs ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

A depaneling machine or depaneling machine is a device for separating printed circuit boards . A depaneling machine is selected depending on the circuit board design (contour, structure, etc.), the specified accuracy for the separation, the permissible mechanical stress during separation, cycle time, quality specifications and costs.

In the packaging industry, a depaneling or depaneling tool is a tool with which individual copies (blanks) are separated from one another and stacked after being punched out of the cardboard sheet.

A quadruple use of a PCB before separation

Depaneling classification

The depaneling systems are basically classified according to the separation process and as a subgroup according to their integration into the production process:

Classification according to separation method

1. Dividing, non-cutting (= cutting, shearing, punching, ...) depaneling
2. Cutting depaneling machines, based on saws or milling machines (colloquially often referred to as "utility saw" or "utility milling machine")
3. Laser depaneling

Cutting depaneling machines and laser depaneling machines are often referred to as “automatic depanelling machines”, although this is not entirely correct - also dividing depaneling machines can be automated - albeit less frequently.

Classification according to integration in the production process

1. Offline depaneling

   In contrast to the inline depaneling machine, offline depaneling machines are not integrated into a production line and are not loaded and unloaded automatically, but manually (by an operator).

2. Inline depaneling

   Inline depaneling machines are integrated in an automatic production line and are automatically loaded or unloaded. Often the panels are fed to the machine via a conveyor belt (with / without goods carrier) or automatic handling. The separated circuit boards are unloaded, for example, via a conveyor belt.

Depaneling types

Dividing, non-cutting depaneling machines

Depaneling machine with roller knife

Here a panel (usually with a pre-scored groove) is inserted into the cutting device and cut using one or two roller knives. The pre-scored groove in which the roller knife plunges serves as a guide, alignment and reduction of the cutting depth. Typical separation thickness of the circuit board (remaining thickness in the pre-scored groove): min. 0.3 mm - max. 0.8 mm.

Often implemented design variants:

• Two roller knives opposite one another, the panel is dipped into the upper roller knife with the pre-scored groove on top and pushed manually through the two roller knives.

• An overhead roller knife that is attached to a linear guide and an opposing, rigid abutment. After inserting the panel, the roller knife is moved linearly over the fixed panel.

The depaneling machines with roller knives are also available with electr. Drive available. Most of these are implemented as offline systems.

The process is colloquially (analogous to pizza cutting with a slitter) often referred to as "pizza cut".

Advantages :

• low investment costs
• lower qualification of operator and Maintenance personnel required
• easy construction

Cons :

• higher stress for the circuit boards than with various other separation processes
• Risk of fraying (fibers can limit the function of mechanical assemblies or penetrate the skin)
• lower cutting accuracy than with various other cutting processes
• higher personnel costs than with inline systems
• low flexibility with regard to the variety of circuit boards (only linear sections)
• pre-scored circuit boards required
• higher risk of operator errors

Depaneling machine with punching device

The panels are placed in the cutting device and separated using a punch. Often implemented design variants:

1. Complete punch:

   The panel is inserted into the device with a pre-scored groove over the die, the punching tool is located above the groove. The punch is often operated pneumatically (costs!); Furthermore, hydraulic drives are less desirable in the electronics sector because of the risk of contamination. The entire panel is punched out.

1. Bar separator:

   In the case of the bar separator, the circuit board is milled free all the way down to the bars. Here only the webs are punched out (analogous to the complete punch).

The process is often referred to colloquially as a "utility punch" and is mainly used as an offline system.

Advantages :

• low investment costs
• lower qualification of operator and Maintenance personnel required
• easy construction

Cons :

• higher stress for the circuit boards than with various other separation processes
• Risk of fraying (fibers can limit the function of mechanical assemblies or penetrate the skin)
• lower cutting accuracy than with various other cutting processes
• higher personnel costs than with inline systems
• low flexibility with regard to the variety of printed circuit boards (→ new tools)
• Changes in contour can mean tool changes
• pre-scored circuit boards required

Bite cutting process

In the bite cutting process, the circuit board is milled free all the way down to the webs, as is the case with the bar cutter. Here the dividers are cut off with knives (similar to a complete punch).

Despite the cutting process using knives, the process is colloquially referred to as a "blank punch".

Advantages :

• low investment costs
• lower qualification of operator and Maintenance personnel required
• easy construction
• With correct panel design, low stress can be expected (approx. 200 μm / m)
• high separation accuracy (accuracy depends on the tolerances in the production of circuit boards)
• Can be used as an offline or inline system

Cons :

• low flexibility with regard to the variety of printed circuit boards (→ new tools)
• not economical for small quantities
• Can only be used to a limited extent with aluminum and copper core circuit boards

Depaneling with wedge knife

Here a panel (usually with a pre-scored groove) is inserted into the separating device, which consists of two wedge-shaped knives (one knife above, one knife below the panel). For separation, the upper knife is usually lowered (using a hand lever, pneumatically or electromechanically) and the lower knife is stationary. The pre-scored groove in which the wedge knife plunges serves as a guide, alignment and reduction of the cutting depth.

Advantages :

• Low stress on printed circuit boards (approx. 100 m / m)
• low investment costs
• lower qualifications of operating and maintenance personnel required
• easy construction

Cons :

• Risk of fraying (fibers can limit the function of mechanical assemblies or penetrate the skin)
• lower cutting accuracy than with various other cutting processes
• higher personnel costs than with inline systems
• low flexibility with regard to PCB variety (only linear sections)
• pre-scored circuit boards required
• higher risk of operator errors

Depaneling with saw / milling machine

introduction

Cutting depaneling machines with saws and / or milling machines are often used where high quality requirements are placed on the cutting (especially with regard to precision and circuit board stress) or high demands on flexibility and performance.

PCB separator (type: IPTE TOF router); Combination of saw module and milling module to separate the benefits from above; left in the picture: hose for dust extraction

In comparison to the dividing, non-cutting depaneling machines, there are the following advantages / disadvantages:

Advantages :

• Minimal mechanical stress on the circuit boards (with the result of component, conductor track or solder joint damage)
• no risk of fraying - only a very low level of dust
• higher separation accuracy - especially with camera-assisted position correction
• greater flexibility with regard to the variety of circuit board types (software adjustments)
• no shifting of the circuit board by the operator during the cutting process

Cons :

• higher investment costs
• higher qualification of operator and Maintenance personnel required
• more complex structure

Separation process

The cutting depaneling machines use saws and / or milling cutters for cutting. For this purpose, the panel is fixed (in a fixture or in a gripper) and the cutting device (saw / milling machine) moves relative to the panel.

This results in the following systems:

1. The cutting device is moved - the panel is fixed.
2. The panel is moved - the separating device is fixed.

Typical milling cutter data (orders of magnitude!):

• Speed: 27,000 - 45,000 rpm
• Diameter: 1.2 - 3.0 mm
• Feed: 2 - 3 m / min

Typical saw blade data (order of magnitude!):

• Speed: 6,000 - 12,000 / min
• Diameter: 75/100/125 mm
• Thickness: Carbide saw blade: 0.3-0.5mm; Diamond-coated saw blade: 0.4 - 1.2 mm
• Feed: 10 m / min

The separating devices can be located above or below the panel and are positioned via axis systems (often NC- programmable). The sawing / milling dust that occurs is extracted during the cutting process.

Advantages of sawing :

• Saw blades usually have a longer service life than milling cutters
• The feed rate is higher than for milling.

Advantages of milling :

• higher contour flexibility (non-linear contours / curves, short separation lengths are possible)
• less "immersion space" in front of and behind the web to be cut in the circuit board is necessary than with the saw blade
• automatic tool change (= cutter change) possible

Offline saw / mill depaneling machine

Systems with turntables and shuttles (linearly movable holders) that are manually loaded and unloaded (offline operation) are used as the machine base. These are usually designed in such a way that, in parallel to processing the panel, the separated circuit boards can be unloaded and new panels can be loaded.

With turntable systems, one holder is in the machining position for sawing / milling, the other holder, offset by 180 degrees, in the loading and unloading area.

With shuttle systems, one or two shuttle (s) are used that drive (alternately) into the machine.

The panels are inserted manually into a recording ("fixture"). This recording has 2 functions:

1. Ensuring the positioning accuracy of the panel during the cutting process
2. Fixation of the individual circuit boards and residual circuit board strips after separation

The type-specific separation program is often loaded automatically by coding the recording.

Typical sequence using the example of a turntable system:

1. The operator removes the separated circuit boards from the holder and inserts a new panel into the holder
2. Operator triggers a 180 degree rotation of the turntable

   The pickup with the new panel is brought into the cutting area (saw / milling machine) of the machine, the 2nd pickup with the separated panel is simultaneously brought from the cutting area into the loading / unloading area.

3. While the new separation process is being carried out, the operator unloads the holder with the separated circuit boards and inserts a new panel.

In the case of offline depaneling machines, the separating device is usually moved while the circuit board is in the holder. The milling dust is extracted above or below the circuit board.

Inline saw / mill depaneling machine

Systems with panel feed via Edgebelt Conveyor (belt transports in which the panel rests on the left and right of the edge on the belt) are mostly used as the machine base, but other feeds (e.g. panel feed in the workpiece carrier) are also used.

These depanels are loaded and unloaded automatically and are therefore integrated in a production line (inline).

Often, quality information on the individual circuit board from the preprocess (e.g. assembly, test) is used for further processing (e.g. database query via a data matrix or barcode on the circuit board), in order to then obtain a good after the circuit board has been separated. / Bad sorting of the individual circuit boards. The remaining strips (which have connected the printed circuit boards in the panel and are no longer needed after separation) are taken to a waste container.

The removal of the separate circuit boards is varied (and closely related to the subsequent production steps). B. about:

• Workpiece carrier
• Turntable
• Belt transport (flat belt or double belt belt / edge belt)
• Tray

The following machine variants are often used for inline depaneling:

Speed ​​routing

With "speed routing", once the panel has been received, it is completely picked up with a gripper and guided over the fixed cutting device (milling machine and / or saw). After the complete separation process, the separated circuit boards (waste strips, good circuit boards, bad circuit boards) are deposited.

Due to the one-time inclusion of the entire panel in the gripper, this process is the machine type with the highest performance in the cutting inline depaneling machines - hence the name "speed routing".

The relatively complex, circuit board-specific grippers are disadvantageous here. This system is therefore particularly found in production lines where high numbers of printed circuit boards have to be separated with a small variety of types.

Flex routing

With "flexrouting", the panel is fixed after it has entered and then each individual circuit board is separated. During the cutting process (with milling machine), the respective circuit board is held from above with a gripper, while the cutting tool processes the circuit board from below.

If a single circuit board is separated, it is deposited with the gripper in the storage (belt, tray, workpiece carrier, bad storage, ...).

Then the gripper moves to the next printed circuit board to be cut and the cutting process continues.

If the complete panel is separated, the waste strips are removed and a new panel is received.

The gripper is often designed as a servo gripper - this allows different gripping distances to be set automatically and thus different types of panels to be processed without changing the gripper (→ lower tool costs than with speed routing). With the multi-gripper, several circuit boards can be gripped at the same time, thus reducing the influence of circuit board handling time - this is often at the expense of flexibility, as these are designed in accordance with the circuit board.

When designing the circuit board, make sure that the panel still has sufficient stability while the individual circuit boards are being separated and removed.

The performance of the machine is lower than with speed routing, since several gripping cycles are necessary due to the individual handling of the printed circuit boards and longer travels result.

This system is therefore particularly found in production lines where a large variety of circuit board types are manufactured in small numbers.

1D routing

With 1D routing, the benefit is clamped after conveyance. Thereafter, the cutting device (saw or milling machine) is usually fed in from above and the panels are separated transversely to the transport direction (hence the name part 1D for one-dimensional milling contour). After the complete separation process, it is transported to a separation device. Here the separated circuit boards (which are only slightly spaced from one another) are conveyed individually out of the machine via suitable clamping / stop devices on the transport devices.

However, this very inexpensive variant of an inline system can only be used for uses whose design allows this separation process.

Laser depaneling

Laser panel cutting is the latest among the cutting processes mentioned. The circuit board is positioned under a laser source and separated with the positionable laser beam. The resulting smoke is sucked off.

Advantages of the procedure:

• no stress on the circuit board
• no vibrations / oscillation as in the machining process
• high precision
• small separation width

Disadvantages of the procedure:

• "Carbonization" (carbon deposits) especially on interfaces
• Risk of smoke deposits on the circuit board
• High investment costs

In particular, due to the risks from carbonization and smoke deposits, the laser backing separators are only accepted to a limited extent.