CN1306396C - Improved semi-automatic pick and place machine for assembly of components - Google Patents

Abstract

The present invention relates to an improved semi-automatic picking and placing (SAPP) machine for assembling small-spacing and standard surface mounting device (SMD) elements on a printed circuit board, which comprises a high-precision X and Y stage sub-element, a guide block sub-element, an X and Y braking element, a user interface software facing objects and a machine software for controlling the machine, wherein the user interface software is arranged in a computer system; the machine software is embedded into EPROM of a microcontroller sub-element.

Description

Improved semi-automatic pick and place machine for assembly components

technical field

The invention relates to an improved semi-automatic pick-and-place machine for Surface Mount Devices and small-pitch components.

Background technique

A pick-and-place machine for Surface Mount Devices (SMD) is an electromechanical system that is widely used in the PCB component assembly stage in the electronics industry. These computer-controlled machines not only help the operator to automatically pick up the correct SMD components, but also place these components very precisely on the Printed Circuit Boards (PCB). The application of these machines provides more economical PCB products.

The traditional lead-in electronic components are mounted and soldered on the back of the PCB through holes. Because the traditional lead-in components are installed through the holes of the PCB, they are called through-hole components. On the contrary, surface mount devices (SMD) are electronic integrated circuits and components that are installed and soldered on the surface of the printed circuit board without mounting holes.

A pick and place machine for surface mount equipment is an electromechanical system that is widely used in the electronics industry to mount SMD components on PCBs.

The following three categories of this machine are currently available in the international market:

i. Artificial

ii. Semi-automatic

iii. Fully automatic

Manual pick and place machine

The manual pick-and-place machine has a vacuum pick-up head, a PCB support frame and a bracket for accommodating the IC feeder. The vacuum is automatically activated and deactivated when the pick nozzle presses against the IC to be picked, or the PCB during placement. However, this type of machine is only used when few SMD components need to be placed on the PCB and the number of such PCBs is small.

Semi-automatic pick and place machine

Semi-automatic machines use computers to partially control the precise picking and placement of SMD components onto PCBs. A computer assists the operator in the assembly of the PCB. This type of machine, under the control of a computer, helps the operator to automatically pick up the correct SMD components and place them precisely on the PCB. This type of machine is useful in small to medium-sized productions where the total annual demand for one type of PCB assembly runs into the hundreds.

Automatic pick and place machine

Fully automatic pick and place machines for SMD are fully computer controlled and this type of machine is useful in large-scale assembly where the number of PCB assemblies reaches thousands. The throughput of such systems is much higher than that of semi-automatic machines.

Traditional semi-automatic pick and place machine sub-components

Figure 5 shows the block diagram of the semi-automatic pick and place machine. A traditional semi-automatic machine consists of the following subcomponents:

(i) Bracket and Feeder Parts

(ii) Turntable parts

(iii) X, Y components

(iv) X, Y air brake components and air compressor

(v) Pickup head assembly, vacuum on/off control and vacuum pump

(vi) Z and Θ components of the pickup head

(vii) Mounting frame for accommodating PCB

(viii) Movable armrest (Hand Rest)

(ix) Scope assembly with CCD camera and monitor (Periscopic Assembly)

(x) Microcontrollers and electromechanical hardware/software

(xi) Computer control

(xii) RS-232 interface

(xiii)PCBs

i) Bracket and Feeder Parts

The bracket part completes the function of accommodating up to 12 feeders. There are 15 of these interchangeable and coded brackets.

The feeder part houses the bar feeder used to supply SMD components in PCB assembly.

The microcontroller subassembly checks the rack code and identifies the feeder based on the lighting of the corresponding LED, helping the operator to pick components from the correct rack and feeder.

ii) Turntable parts

The turntable part completes the function of providing loose SMD components for PCB assembly. The carousel unit contains 40 trays to hold loose SMD components. The pallet is coded during the start-up operation of the machine. This part is mounted on the stepper motor. The microcontroller subassembly operates the stepper motors to position the correct tray to pick up the SMD components for assembly. The microcontroller subassembly assists the operator in picking components from the left or right carousel according to the corresponding lighting of the left/right LEDs.

iii) X, Y components

This part houses the pickup head part. The X, Y components in the semi-automatic machines available in the international market use a simple linear scale with 1.0mm resolution. This part provides the X,Y coordinates of the pick-up nozzle with 1.0mm resolution, which enables the X,Y coordinates of SMD components to be placed with ±1.0mm accuracy.

iv) Air compressor and X, Y air brake components

The air compressor supplies air to the X, Y air solenoid valves. The X, Y air brake mechanism contains an air solenoid valve that performs the function of braking the X, Y movement of the X, Y sliders.

v) Pickup head assembly, vacuum on/off control and vacuum pump

The vacuum pick-up head unit performs pick-and-place operations of SMD components with vacuum on/off control. The operator must manually move the pickup head assembly on the X, Y slides. Vacuum control realizes the function of turning the vacuum on and off through two proximity sensors installed on the pick-up head. The vacuum pump performs the function of generating the vacuum necessary to pick up the components.

vi) Z and Θ components of the pickup head

The Z action part completes the function of lowering the pick-up nozzle during the pick-and-place operation of SMD components. An electromagnetic solenoid relay is mounted on the pickup head assembly. This relay is automatically activated by the microcontroller subassembly when the operator attempts to drop the vacuum pick-up nozzle at the wrong pick-and-place coordinates. The theta action part of the pick head provides the function of rotation of the SMD component to enable it to be aligned during placement.

The operator manually controls the Z and θ motions.

vii) Mounting frame for accommodating the PCB

The mounting frame fulfills the function of housing the PCB to which the components are to be mounted. After completing the PCB assembly, the operator must manually remove the PCB.

viii) Movable armrests

Ergonomically movable armrests complete to provide firm support to the arm while moving the pickup head along the X, Y axis.

ix) Scope parts and CCD camera

The scope part completes the function of providing the zoomed-in overhead image to the video monitor through the CCD camera, and displays all four sides of the small-pitch SMD components simultaneously and without parallax.

x) Microcontrollers and electronic hardware and machine software

Semi-automatic machines available in the international market also have electronic hardware and microcontroller-based software to coordinate with computer-based user interface software to control the various functions of the machine.

The microcontroller and associated electronics perform the following functions in this machine:

(i) Identification of bracket components

(ii) Identification of the feeder

(iii) Rotation of the turntable member

(iv) Operation of X, Y air brakes with placement coordinate resolution of ±1.0mm

(v) Operation of the Z brake

(vi) Receive and send data to computer via RS-232

(vii) Send the X, Y coordinates of the pick-up mouth to the computer

(viii) Sending the assembly completion status of SMD components

The electronics hardware and machine software are developed around a microcontroller that controls the various functions of the machine. Microcontroller software is embedded in EPROM.

xi) Computer control:

The semi-automatic machines available in the international market use DOS as the operating environment and provide several menus for the operation of the machine to assist in the component assembly process as follows:

a) File menu: New, Open, Save as, Close, Exit

The File menu completes the operation of opening/closing or saving data files.

b) Edit menu: Table, Offline/Online

The Table submenu enables editing or entering data in a table such as X, Y coordinates of pick and place locations, etc.

The multiple options under the table menu are Insert, Paste, Delete, Mark, Teach, Sort, and ESC.

The Offline/Online submenu completes the operations of editing online or offline data in this form. The machine should remain on during online data editing.

c) Start (Start) menu: offset (type offset, tell offset) and assembly submenu

The Offset submenu option provides an offset value to the component's X, Y placement coordinates. This can be done by typing (Key in) or automatically telling (Teach) to the computer.

The Assembly submenu options provide the ability to assemble SMD components row by row according to the table defined in the table submenu.

The various options available to the user under the Assemble submenu are:

i. Start assembly from line number

ii. Start assembly from saved position

iii. Save the current assembly line number

iv. Switch to graphics screen

v. Display the current line number

vi. Display the X and Y coordinates of the vacuum pick-up nozzle

vii. Display the direction of the component

The assembly submenu stores the names of the components assembled by this machine in a file as well as in a dynamic array.

d) Print (Print) menu: All (All), Select range (Select range) Print menu completes the function of printing all or the selected range of the form.

e) Environment menu

The context menu contains the following submenus:

Port settings, assembly settings (PCB type number, PCB number and skip line number), maximum number of components.

The port setting submenu completes the operation of setting the communication port used by the computer to communicate with the machine.

The submenus of PCB type number and PCB number complete the operation of defining these parameters of the PCB.

The Skip Line Number submenu completion stores the line number to skip in the table during execution of the start menu's assemble submenu.

The Maximum Number of Components submenu completes the function of defining the maximum number of rows for tables in the Edit menu. The user can provide the individual parameters of the SMD components in this table. The assembly of SMD components in line with machines available on the international market can assemble up to 999 components by using the assembly submenu in the start menu.

f) Help menu

This menu provides online help to the user.

i) The RS-232 interface module provides the physical connection between the computer and the machine's microcontroller,

ii) PCB is the printed circuit board on which the SMD components will be assembled.

Prior Art Disclosure:

a).http://www.kmmnet.com/circuit.htnil

b).http://www.harotec.ch/haro_o.html

c).http://www.essemtec.com/english/products/pro_body_index.html

d).http://www.khbenz.co.uk.mansemi.htm

Contents of the invention

The main purpose of the present invention is to provide an improved semi-automatic pick-and-place machine for SMD and small-pitch components.

Another object of the present invention is to achieve a SMD component placement accuracy of ±0.1 mm for the manual motion of the pickup head over a length of 390 mm in the X,Y axes.

Yet another object of the present invention is to provide a new clamping device to prevent damage to the bearing surface.

Yet another object of the invention is to provide a software for controlling said machine using an object-oriented approach.

Yet another object of the present invention is to provide statistics menu options in the software so that the machine provides statistics of SMD components by PCB, and statistics about SMD components assembled on the PCB via the machine.

Another object of the present invention is to provide the conversion option of the environment menu software, which makes this machine compatible to directly link with the ORCAD PCB board definition (*.brd) file. The X, Y coordinates of component placement, component orientation, component name, and component position can be directly loaded from the ORCAD board definition (*.brd) file into the table of the machine's edit menu option.

Another object of the present invention is to provide a maximum number of components option for the environment menu software of this machine which enables this machine to assemble a maximum of 2000 SMD components per PCB.

Another object of the present invention is to provide a measurement option for the context menu software so that the machine can work compatibly in both meters and inches.

In order to achieve the above purpose, the present invention proposes an improved semi-automatic pick-and-place machine, which is used to assemble small-pitch and standard surface-mount equipment components on the printed circuit board without errors, and is characterized in that it includes: X, Y-level segment subcomponents, carrying Pickup head and vision guide device; guide block subassembly to guide said X, Y stage segment subassembly; linear encoder, coupled to said X, Y stage segment subassembly, to sense X and Y of pickup head movement Positional coordinates; Microcontroller subcomponents, communicating machine operating conditions with a computer system having an object-oriented user interface software component; wherein the machine software embedded in the erasable programmable read-only memory of the microcontroller subcomponents Monitor the position coordinates of the pick-up head obtained through the linear encoder; X, Y air brake components, actuated by machine software embedded in the erasable programmable read-only memory of the microcontroller sub-component, at ±0.1 Millimeter positional accuracy detents X, Y stage segment subassemblies at desired X, Y placement coordinates.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the X and Y sub-components provide the X and Y position coordinates of the pick-up motion sensed by the optical linear encoder with a resolution of 0.02 mm.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: through the X and Y sub-components, the manual action of the pick-up head on the X and Y axes with a length of 390 mm can achieve ±0.1 mm on the X and Y axes. X, Y placement accuracy.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the software embedded in the erasable programmable read-only memory is used to lock the X, Y movement of the pick-up head, and the surface-mounted device components with ±0.1mm Electronic hardware with coordinate precision placed in X, Y to stimulate air resistance braking.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the X and Y components in the machine include subcomponents including a bottom plate, an X slider, a Y slider, X and Y slide rails and a linear encoder scale.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the sub-component bottom plate completes the function of accommodating two X-axis slide rail rods and accommodating them with an accuracy of 10 microns.

According to the improved semi-automatic pick-and-place machine, it is characterized in that the X and Y sliders with only one degree of freedom slide effortlessly on the slide rail bar using a frictionless standard linear bearing.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: a high-precision linear encoder scale with a resolution of 0.1 mm is installed on the X and Y slide rails as a reference scale for measuring the X-Y conversion of the pick-up head.

According to said improved semi-automatic pick and place machine, it is characterized in that said machine provides a shock-free structure to place components by using finely adjustable air resistance brakes.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: when the vacuum pick-up nozzle reaches the range of ±0.1 mm of the X, Y placement coordinates of the surface mount equipment components, the X, Y air control with air solenoid valve The moving parts are automatically activated by the microcontroller.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the guide block subassembly includes a strip on the bottom side of the guide block, which provides protection to the supporting surface of the printed circuit board from being clamped Scratches and damage caused by screws or any other resulting damage.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the hardware equipment of the machine is controlled by software with object-oriented features.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the novel software provides statistical menu options to determine the statistics of components required in printed circuit board assembly through histogram display and table display, and in A statistic of how many components have been assembled by this machine on a printed circuit board.

According to said improved semi-automatic pick and place machine, characterized in that said software controlling the machine is capable of handling up to 2000 different printed circuit board components during assembly.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the software provides a conversion option in the environment menu to help the user avoid manually inputting or informing the X, Y placement coordinates of the components on the printed circuit board.

According to the improved semi-automatic pick-and-place machine, it is characterized in that the software controls the machine by providing the user with an option to enter/inform the X,Y coordinates in the table using millimeters or inches as the unit of measure.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the software prepares the form in advance by providing the direction, name, X, Y placement coordinates, and position of the component, so that these parameters can be directly obtained from the ORCAD board definition file loaded in the form.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the arrangement of the middle mirror in the scope part and the background light under the printed circuit board support frame illuminate the printed circuit board area, so as to relieve the operator's eyes fatigue and provides operators with a clearer pinout of surface mount equipment components.

According to the improved semi-automatic pick-and-place machine, it is characterized in that: the software controlling the machine also provides users with online help on hardware and software operations.

Description of drawings

Fig. 1, 2, 3, 4 are the block diagrams of the X, Y assembly arm of this machine;

Figure 5 is a block diagram of a semi-automatic pick-and-place machine for assembling SMD and small-pitch components on a PCB;

Figures 6 and 6(a) are flowcharts of the main user interface software;

Figure 7 shows the electronic hardware required to operate the machine;

8 and 8(a) are block diagrams of a mounting frame for accommodating a PCB.

Detailed ways

Summary of Inventions

The present invention provides an improved semi-automatic pick and place machine for SMD and fine pitch components by using a software using an object oriented approach to control the machine and making it more user friendly.

Detailed description of the invention

Accordingly, the present invention provides an improved semi-automatic pick and place (SAPP) machine for assembling small pitch and standard surface mount device (SMD) components on printed circuit boards, said machine comprising a high precision X, Y stage Segment sub-components, a guide block sub-component, X, Y brake components, an object-oriented user interface software component installed in a computer system, a microcontroller sub-component for controlling said machine, embedded in said machine Machine software in the component's EPROM.

The microcontroller software is embedded in EPROM in one embodiment of the invention, in this embodiment the electronic hardware and the machine software are developed around an Intel 8032 microcontroller for controlling the various functions of the machine.

The minimum hardware computer system in yet another embodiment of the present invention is Pentium-II.

In yet another embodiment of the present invention, there is a high precision X, Y class segment subassembly and vision guide for error-free assembly of fine pitch and standard surface mount devices (SMD) on printed circuit boards.

Additionally, in yet another embodiment of the present invention, the X, Y stage segment subassembly provides the X and Y positional coordinates of the pickup motion sensed by an optical linear encoder system having a resolution of 0.02mm.

In another embodiment of the present invention, the X, Y placement accuracy of ±0.1 mm is achieved for manual motion of the pickup head over a length of 390 mm in the X, Y axis through the X, Y sub-components.

In another embodiment of the invention, a software embedded in EPROM actuates the pneumatics through electronic hardware for locking the X, Y movement of the pickup head, X, Y placement coordinate accuracy of SMD components with ±0.1mm Air resistance braking.

Another embodiment of the present invention provides precise theta rotation of the pick-up head to enable the pick-up head along with the SMD components to be precisely rotated for alignment with the PCB pad during component placement on the PCB.

Furthermore, yet another embodiment of the present invention provides a novel clamping device that is used to provide adequate clamping of the bottom plate of the PCB holder and also protect the bearing surface between the plate and the base to Protects against scratches/damage from clamping screws.

Furthermore, yet another embodiment of the present invention provides an improved SAPP machine with a vibration-free structure to place components by using finely adjustable air resistance braking.

Additionally, yet another embodiment of the present invention provides an improved SAPP machine with X, Y pneumatic air brakes to automatically lock on the correct X, Y placement coordinates with +0.1mm accuracy Pickup head, to allow the pickup head to fly blindly to the correct position.

Furthermore, in yet another embodiment of the present invention, a simple electromagnetic solenoid is used to brake the Z movement.

In another embodiment of the invention, a Z detent is applied in the X and Y motions so that the user cannot pick/place components from the wrong position.

In yet another embodiment of the invention, the Z detent is released at the correct X, Y placement coordinates to allow the operator to place the component on the PCB.

Yet another embodiment of the present invention provides a pick head wherein the vacuum is automatically activated when the pick tip tip is pressed slightly on the component and the vacuum is deactivated when the component is pressed slightly on the PCB while placing.

Yet another embodiment of the present invention provides an ergonomically movable armrest that provides firm support for the arm while moving the X, Y coordinates of the pick-up head to provide firm support for the arm while placing components.

Another embodiment of the present invention provides a scope system incorporating a CCD camera and a color monitor for displaying enlarged upper layer images of all four sides of a small-pitch SMD simultaneously and without parallax.

In yet another embodiment of the present invention, the arrangement of the mirrors and the background lighting beneath the PCB holder illuminates the PCB area so as to reduce eye strain for the operator and allow direct viewing.

In addition, yet another embodiment of the present invention provides the latest Windows-based software using Visual Basic 6.0 as the base platform.

In yet another embodiment of the present invention, the hardware devices in the machine are controlled by software with object-oriented features.

Still another embodiment of the present invention provides software including a statistics menu that helps the user to know the statistics of the components needed in PCB assembly and the statistics of the components already assembled by the machine through the histogram display.

In addition, yet another embodiment of the present invention provides software that includes a context menu whereby the user can define the maximum number of rows in a table with values from 1 to 2000, so that the software can handle almost 2000 rows during assembly different PCB components.

Additionally, one embodiment of the invention relates to a software that controls the machine by providing the user with an option to enter/tell X,Y coordinates in a table using millimeters (mm) or inches as units of measurement.

Another embodiment of the present invention provides a Convert option in the context menu, wherein the user can avoid manually inputting or notifying the X, Y placement coordinates of the component on the PCB.

In another embodiment of the present invention, the X and Y placement coordinates of the components in the PCB, the direction of the components, the name of the components, and the position of the components can be directly loaded in the form from the ORCAD board definition file through this option.

In another embodiment of the present invention, the PCB component requirements form is prepared in advance and the time in the process of constructing the form is saved before the assembly process begins.

In another embodiment of the present invention, said software controls the machine and provides online help to the user regarding hardware and software operation.

The novel features of the present invention are further illustrated in the form of the following preferred embodiments.

In yet another embodiment of the present invention, the X, Y components of the machine comprise sub-components like a base plate, X slides, Y slides, X, Y slides and linear encoder scales.

The base plate fulfills the function of housing the two X-axis slideway rods, and housing them with 10 micron precision.

The X, Y sliders with only one degree of freedom slide effortlessly on the rail rods using frictionless standard linear bearings.

A high-precision linear encoder scale with a resolution of 0.02mm is installed on the X and Y slide rails as a reference scale for measuring the X-Y conversion of the pickup head.

In yet another embodiment of the invention, the microcontroller used is of the type Intel 8032 to implement X, Y air brakes with ±0.1mm placement coordinate resolution.

In yet another embodiment of the present invention, the graphical user interface provides the following Statistical Menu Options for an improved component assembly process.

In another embodiment of the present invention, the statistics menu provides the statistics of the components required for each PCB, the statistics of the components already assembled on the PCB, and the total number of PCB parts.

In yet another embodiment of the present invention, the Component Statistics submenu for each PCB performs the function of displaying a histogram of the statistics of the components required during the assembly of a PCB.

In addition, in another embodiment of the present invention, the statistics menu of PCB components completes the function of displaying the histogram of the statistics of the components assembled on the PCB, wherein the statistics are saved in a file or dynamic array during the assembly menu .

In another embodiment of the present invention, the total PCB submenu calculates and displays the total number of assembled PCBs.

Another embodiment of the present invention provides an Environment Menu with features similar to Port Settings, Assembly Settings (PCB Model, PCB Number, Skip Row Number).

In yet another embodiment of the present invention, the port setting submenu completes the operation of setting the communication port number through which the computer communicates with the machine.

In addition, in another embodiment of the present invention, the PCB model and PCB number submenus complete the operation of defining these parameters of the PCB.

In another embodiment of the present invention, the Skip Rows submenu completion stores the number of rows of the table to be skipped during the assembly submenu of the start menu.

In another embodiment of the present invention, the maximum number of components submenu completes the function of defining the maximum number of rows of the table in the edit menu, wherein the user can provide various parameters of SMD components in the table.

Another embodiment of the present invention provides an assembly sub-menu in the start menu, and using it to realize the assembly of SMD components can reach a maximum of 2000 components in a row.

Another embodiment of the present invention provides a measurement submenu with a utility function, whereby the user can work in millimeter or inch measurements.

In addition, another embodiment of the present invention provides a conversion submenu option with practical functions to directly load the ORCAD PCB board definition file in the table menu, which helps users avoid inputting X, Y placement coordinates, Component orientation, component name, component position.

The novel features of the graphical user interface in the present invention are further clarified in the form of the following preferred embodiments.

The user interface software is developed using Visual Basic 6.0 as the software language under the Window 95 environment. The flowchart of the user interface software developed for this machine is shown in Fig. 6.

The graphical user interface provided in this invention contains the following menus:

File Menu: The user chooses to assemble the PCB by opening a new file or using the OPEN option in the File menu if the file already exists. This file is used to store the contents of tables in the Edit menu, and to store statistics for elements in the Start menu.

Edit menu: Two submenus are available under this menu

i) Online/Offline

ii) Form

Online/Offline Submenu: Users can edit data online when the machine is available, or offline when the machine is not connected to a computer.

Form menu: The user can select the Form option in the Edit menu to enter the following data in the form:

(a) number of brackets,

(b) number of feeders or turntables,

(c) component name,

(d) X, Y coordinates of the pick-up position of the component,

(e) allowable error in X, Y pick-up coordinates,

(f) tools required for picking up components,

(g) the location of the component on the PCB,

(h) X, Y coordinates of the placement position of the SMD component,

(i) Allowable errors in the placement coordinates and directions of components on the PCB;

(j) error messages; and

(k) Orientation of components on the PCB

The options under the Form menu are:

Insert (Insert), Paste (Paste), Delete (Delete), Mark (Mark), Tell (Teach), Sort (Sort) and ESC.

Using the above options the operator can complete the form for the assembly process. In the sorting option, the entire table data can be sorted based on the number of brackets or the number of tools, so that the user does not have to change brackets and tools frequently during assembly.

Start menu: In our software, two options are provided in this menu, as follows:

1) Offset: The user can provide the offset value through the keyboard or inform the machine of the offset value by placing the pick-up head at the marked point of the PCB. The offset value is entered in millimeters (mm) if the METRIC flag=1 set in the environment's measurement options, and in inches if the METRIC flag=2.

2) Assembly: In the assembly option of the start menu, the various options that can be obtained by the user are as follows:

(i) Assemble from line number

(ii) Start assembly from the saved line number position

(iii) Save the current assembly line number

(iv) switch to graphics screen

(v) Display the current line number

(vi) Display the X, Y coordinates of the pickup head

(vii) Orientation of Display Components

In our machine, an assembly software subroutine performs the operation of sensing the completion of accurate placement of SMD components on the PCB.

Two inductive sensors are used on the vacuum pickup to sense the following states: vacuum off, pickup in home position, and current X,Y coordinates of the pickup matching the X,Y placement coordinates of the component defined in the table.

Once the machine checks these parameters, the machine software embedded in the EPROM notifies the computer of successful component placement.

The RUMGRAPHICS subroutine in the graphics screen option uses a square symbol to display the feeder position on the computer video monitor, and the left and right circles to display the turntable. The placement coordinates are shown by a square marked with cross-hatching, and the current head position is shown by a square marked with a cross. The graphic screen also displays the X, Y coordinates of the pick and place location, the current line number, the orientation of the component, the number of PCBs, and the type of PCB. This visual graphic aid to the user assists the operator in the assembly process of the SMD components through the computer.

The computer stores the names of the components assembled by the machine in a dynamic array and in a file.

Print Menu: The Print menu option helps the user to print selected rows of the table or the entire table.

Statistics menu:

Menu Statistics of Assembled SMD Components: This software menu is designed to count the number of components of each exact name assembled by using a file or by using a dynamic array created in the Assembly submenu.

Using Graph32.OCX's ActiveX control, draw the name and count of components through a histogram.

Use the ActiveX control of Grid32.OCX to display the name and count of components in table form.

Menu statistics for SMD components on each PCB

The names of the SMD components on each PCB are available in a table created during the table submenu, and these names are saved in an array variable. This software counts the number of SMD components of each distinct name based on the PCBs obtained from this array.

Total PCBs Assembled: This option displays the total number of PCBs that have been assembled.

Environment menu:

Under the Environment menu, the following features are available:

Communication port setting: This option sets the communication port for the computer to communicate with the machine.

Assembly Setup: The following three options are provided to setup the PCB:

Model number, PCB number and skip line number.

Convert:

Using this option, the user is able to import the PCB board definition file whose tables will be created. The included software then executes the MODLOC.EXE command on this board definition file. The MODLOC.EXE file in the ORCAD software generates a report of all component information in the board definition file, such as component reference designation, direction, X, Y coordinates, component name, etc. from the PCB board definition file. Thereafter, at the prompt received from the system, enter the X, Y reference coordinates of the PCB. Then, the system refers to this reference X, Y point to calculate the X, Y placement coordinates of other components. Next, the component X, Y placement coordinates, component orientation, component name, and component reference designation in the PCB are saved in one file.

measure:

By using this utility the software sets the METRIC flag to 1 for mm operation and 2 for inch operation. This utility is used to convert inches data to millimeters and vice versa if the METRIC flag is 2.

Enter X and Y coordinate data in inches or millimeters in the Table menu and in the Offset menu.

Maximum number of components:

As shown in the flowchart 6 (S1), the content of the form menu is assigned to the dynamic variable array with the maximum number of elements, which is assumed to be marked as ROWMAX.

The user enters the number of parts per PCB from 1 to 2000, assuming a range labeled ROWE. If ROWE is less than or equal to ROWMAX, the software reduces the number of rows in TABLE and assigns the contents of the array to the table.

If ROWE is greater than ROWMAX, increase the number of rows in the table and assign the contents of the array to the table.

In the table menu the user can provide the individual parameters of the PCB whose maximum number of rows is defined by this option. In the assembly menu, the computer passes this dynamic table line by line to the machine for assembling the components on the PCB.

Help menu: Provides online help about the hardware and software operations of the SAPP machine.

Detailed description of the attached drawings

Figures 1, 2, 3 and 4 are block diagrams of the X and Y assembly arms of the machine.

Figure 5 is a block diagram of a semi-automatic pick-and-place machine for assembling SMD and fine-pitch components on a PCB.

Figures 6 and 6(a) are flowcharts of the main user interface software.

Figure 7 shows the electronic hardware required to operate the machine.

8 and 8(a) are block diagrams of a mounting frame for accommodating a PCB.

The individual standard components and subassemblies included in Figure 1 are as follows:

Bar feeder part (101), bracket assembly (102), turntable part (103), PCB support part (104), main frame part (105), hand support part (106), Hall sensor part (107), pick up Head part (108), XY slide rail part (109), tape feeder part (110) and scope part (111).

Also included in Figure 1:

X slider (Fig. 2), Y slider (Fig. 3), base plate (Fig. 4), and standard components such as X, Y linear encoder scales, linear ball bearings, and guide rods.

The two X-guiding rods are accommodated parallel to each other with an accuracy of 5 microns, which is achieved in the X-slide by coordinate boring two holes with a center-to-center distance of 110 mm (±0.005 mm) as shown in FIG. 2 .

Similarly, the two Y guide rods also accommodate parallelism to an accuracy of .5 microns, which is achieved in the Y slider by having two holes with a 23mm (0.005mm) center-to-center spacing as shown in Figure 3 . These sliders are designed according to the principles of kinematic design.

The base plate (Fig. 4) performs the function of housing the two X-axis slider rods and their parallelism to 5 micron precision. The pair of holes for mounting the linear bearings, each in the base plate and X, Y sliders, are precisely positioned drilled to ensure parallelism between the hole axis and hole dimensional accuracy.

With only one degree of freedom, the X, Y slides (Figures 2, 3) slide effortlessly on the rail bars using standard frictionless linear bearings.

A high-precision standard linear encoder scale with a resolution of 0.02mm is installed on the X and Y slide rails as a reference scale for measuring the X-Y conversion of the pickup head.

A block diagram of the machine is depicted in FIG. 5 .

In Figure 5, block 501 is a rack and feeder component, block 502 is a turntable component, block 503 is an X, Y component, block 504 is an X, Y air brake mechanism and air compressor, and block 505 is a vacuum Pickup head, vacuum ON/OFF control and vacuum pump, block 506 is the Z and θ moving parts of the pickup head, block 507 is the mounting frame for accommodating the PCB, block 508 is the movable armrest, and block 509 is the scope observation system and CCD camera & monitor, block 510 is machine electronics hardware/software, block 511 is Pentium II computer with user interface software for monitoring, block 512 is RS-232 interface, block 513 is to be combined with SMD components PCB.

The rack and feeder part (501) and the carousel part provide SMD parts to the PCB (513) for assembly. The PCB (513) is securely housed by the mounting frame (507). These parts are picked up by the vacuum pick-up head (505) by manually switching the pick-up head on the X, Y parts (503). The Z and theta movement part (506) of the pick head allows the pick head part (505) to move in the +Z direction during pick and place operations. The pickup head (505) can be rotated 360 degrees by theta moving part (506). The X,Y air brake component (504) brakes the X,Y component (503) at the component's correct X,Y position coordinates. A movable armrest (508) provides firm support for the hand while moving the pickup head (505) along the X, Y axes. The scope viewing system performs the function of providing a zoomed-in high-altitude picture of the SMD part together with the CCD camera part (509), which shows all four ends of the small-pitch SMD part simultaneously and without parallax on the video monitor via the CCD camera . A computer (511) with user interface software communicates with the machine microcontroller (510) and vice versa via an RS-232 (512) interface. The microcontroller and associated electronics (510) perform various functions required for the operation of these machines, such as identification of rack components, identification of feeders, rotation of turntable components, operation of X, Y air brakes, Z control Automatic operation, receiving and sending data to the computer via RS-232, sending the X, Y coordinates of the pick-up nozzle to the computer, sending the completion status of the SMD component assembly. The computer and associated user interface software (511) process the completion data required for the PCB to be assembled. The computer sends completion data for each SMD component line by line to the microcontroller that performs the machine operations.

A flowchart of the user interface software is given in FIG. 6 . When the user runs the software, it initializes these variables and loads the following menu options for the user:

File, Edit, Startup, and Print, Statistics, Environment & Help.

File menu options are New, Open, Save As, Close, Exit. A flowchart for this menu is given in Fig. 6(M).

The Edit menu options are Form, Offline/Online, and the flowchart for this menu is given in Figure 6(N).

The Start menu options are Offset, Start Assembly. The flowcharts for this menu are given in Fig. 6(P), Fig. 6(P1), Fig. 6(P2), Fig. 6(P3), Fig. 6(P4).

The print menu options are All and Selected Range. A flowchart for this menu is given in Fig. 6(Q).

The Statistics menu options are Part Details, Part Composition and Total PCS per table. The software flowchart for this menu is given in Figure 6(R).

The context menu options are port settings, assembly settings (PCB type, number of PCBs, number of skipped lines), maximum number of parts, size, conversion. The software flowchart for this menu is given in Fig. 6(S), Fig. 6(S1), Fig. 6(S2).

The Help menu option is Online Help. A flowchart for this menu is given in Fig. 6(T).

Figure 7 shows various block diagrams of the electronics hardware required to implement the various functional requirements of the pick & place machine. In Figure 7, block 701 shows a Pentium II computer with user interface software, block 702 is the RS-232 physical interface cable, block 703 is an RS-232 driver, block 704 is a crystal oscillator, block 705 is the microcontroller block 706 is the EPROM where the microcontroller software resides, block 707 is the RAM for temporary data storage, block 708 is the input/output interface driver, block 709 is the rack sensor that decodes the number of racks, Block 710 is the feeder LED driver to indicate the correct feeder, block 711 is the turntable stepper motor driver and optocoupler circuit, block 712 is the tool, vacuum and turntable LED drivers, block 713 is the X,Y movement for the pickup head Block 714 is the brake relay driver for the Z movement of the pickup head, Block 716 is the vacuum ON/OFF relay driver circuit, Block 717 is the X, Y movement and direction vehicle circuit, Block 718 is the X , Y linear encoder scale, block 719 is the power required to drive this electronics module.

In Figure 7, the Pentium II computer communicates with the user interface software (701) via the RS-232 cable (702) and RS-232 driver MAX-232 (703) and the microcontroller Intel 8032 (705). After receiving the command from the computer, the microcontroller (705) decodes this command and jumps to the required subroutines stored in the EPROM (706) to perform various machine functions through the electronics block. Data received from the computer is stored in RAM (707). The microcontroller (705) drives the various electronics hardware of the machine through the input/output interface driver (708) 74LS245. The Address Decoder (720) 741s138 decodes the address to various blocks of the microcontroller like RAM (707), EPROM (706), and I/O Interface Drivers (708).

When power is applied to the machine, the microcontroller initializes the machine by initializing the stepper motors through the optocoupler circuit (711) and drives the feeder LEDs (710), tool LEDs (712), X, Y brakes (713 ), Z braking (714), and initializing the X, Y position coordinates to zero, all in a continuous manner. When the user clicks on the online menu, the computer and the microcontroller communicate.

Using the form menu in the user interface software, and the user entering the number of racks in the form, the computer communicates this number of racks to the microcontroller through the interface software (705). The microcontroller then goes through the stand sensor (709) and communicates with the computer as to whether the correct stand is placed on the machine, if not, the microcontroller sends an error message to the user via the computer display. Similarly, when the user loads the feeder number in the form menu, the computer (701) passes information about this to the microcontroller (705), which then drives the feeder LED driver circuit (710). When the user supplies the carousel number in the table menu, the computer interface software (701) passes information about this to the microcontroller (705), which in turn drives the stepper motor (711) to place the correct carousel case for the User picks up SMD components.

During the Tell option on the form menu, the microcontroller reads the X,Y coordinates of the pickup head via the X,Y movement block (717), which receives this input from the X,Y linear encoder scale (718). The microcontroller constantly increments/decrements the X and Y movement of the pick-up nozzle via its internal counter.

During the assembly option of the start menu, the computer interface software (701) transfers the table data saved in the edit menu to the microcontroller (705) line by line. This data is stored by the microcontroller in RAM (707). The microcontroller then performs the task of sensing the correct number of racks via the rack sensor (709), driving the feeder LEDs (710) or driving the carousel motors (711) and driving the tool LEDs (712) according to the data within the table range. The microcontroller keeps track of the X, Y movement of the pickup head via block (717). When the pick head reaches the X, Y pick coordinates, the Z brake relay (714) becomes deasserted to allow the user to lower the pick head to pick the part. When the pickup head contacts the part, the proximity sensor (715) senses the contact pressure and causes the vacuum ON/OFF circuit (716) to open. The part is lifted by vacuum and when the user lifts the pick head, the microcomputer senses it and activates the Z brake (714). The user cannot lower the pickup head now. The microcontroller keeps track of the pick-up head's X, Y coordinates (717). When it reaches the X, Y placement coordinates, the Z brake becomes inactive and the X, Y air brake (713) is activated through the microcontroller (701). The user is now able to place the part on the PCB, when the pick head is lowered, the proximity sensor senses the contact pressure of the pick head and the PCB, and switches the vacuum ON/OFF driver, i.e. it turns the vacuum relay OFF and the part is placed on the on the PCB. When the user releases the pick head to its normal inactive position after placing the part, the microcontroller senses it and communicates to the computer about the completion of the current row or SMD part assembly. After this command, the computer sends the next line to the microcomputer for assembly.

Figure 8 depicts the mounting frame for housing the PCB. The navigator subassembly is shown in Figure 8(a). The guide shoe subassembly moves forward and backward on the guide groove. The new idea of using a strip attached at the bottom of the guide block avoids scratches on the guide groove due to the screw tightening required to accommodate the guide block relative to the guide groove.

The following examples are given by illustrating the sequential operation of this machine, and it will not be construed as limiting the scope of the invention.

example

Machine operation:

1. Connect the RS-232 cable to the computer and the machine, connect the air compressor, vacuum pump and power cord to the machine. Turn on the machine.

User interface software that runs on a computer.

2. The user can use the following menus: File, Edit, Start, Print, Statistics, Environment and Help

3. (a) Use the File menu to create a new data file for the new PCB (or)

(b) Open the data file using the File menu if the file already exists (or)

(c) Convert the ORCAD PCB.brd file using the Convert option in the context menu, entering the name of the board definition file (assuming PCB.brd) and then entering the name of the data file (assuming Pcb.dat). Inform the machine of the X,Y coordinates of the PCB reference point. Then open this data file Pcb.dat using the Open option in the File menu,

5. (a) If the file is new or the data file was created using the convert option as in step 4(c), select the context menu to set the following options:

(i) Set the PCB type number

(ii) Set the number of PCBs (default is 1)

(iii) Set the measurement unit to mm or inch (default is mm)

(iv) Set the communication port number (the default is Coml)

(b) If Open Data option 4(b) was used, select the context menu

(i) Set the measurement unit to mm or inch (default is mm)

(ii) Set the communication port number (the default is Coml)

6. In order to enter data about the X, Y pick & place coordinates of the PCB, number of feeders, racks, turntables, etc., select the Edit menu

(a) Select the offline/online option

Power on the machine in order to edit data online (offline by default)

(b) Select form option

A table with rows and columns is displayed on a computer monitor. Enter different parameters of the PCB like X, Y pick & place coordinates, feeder, rack, number of turntables, etc.

(c) In order to increase or decrease the number of components according to the PCB, select the maximum number of components option in the environment menu (the default is 100 numbers)

(d) Various editing options like Insert, Paste, Mark, Tell, Sort, Exit can be used to construct the form. The Tell option can be used only with the Online option to tell the computer the X,Y coordinates of the pickup head.

(e) After the form is complete, use the Save As option in the File menu,

i) If New option 4(a) was used then enter the file name (or)

ii) Choose to overwrite the existing data file or exit in the message box.

7. To start the assembly of SMD components on the PCB, select the Start menu,

(a) Select the Offset menu:

i) If the PCB to be assembled is at the same X, Y point as the table was created, then the X, Y offset is zero (the default X, Y offset is zero) (or)

ii) If the PCB to be assembled is at a different X, Y coordinate point, then input the X, Y offset or inform the machine of the X, Y offset value.

(b) Set the communication port number (the default is coml)

(c) If a specific row in the table is to be skipped during assembly, set the Skip row number option in the context menu.

(d) Select the Assembly option in the Start menu.

(e) The options displayed for the assembly are as follows:

i) Start assembly from line number.

Select this option and enter the line number from which to start the assembly (default is 1)

ii) Start at the saved line number. Select this option if starting assembly from a previously saved line number.

(f) The parts get assembled line by line, except those specified in the Skip Line Numbers option.

(g) Exit the assembly option

i. Select the Save Line Numbers option

ii. Assembling the current row or part on the PCB.

iii. When the assembly of this part is complete, the program exits to the main menu.

8. Print menu:

a) To print the table range, click on the Select Range option.

b) To print the entire form, click on the All option.

9. Statistics menu:

a) According to PCB component statistics:

When clicked on this menu, this option shows the statistics of the parts needed to assemble the PCB by bar graph or table.

b) Statistics of components assembled on the PCB:

When this menu is clicked, it shows the statistics of the components that have been assembled by the user on this PCB, either by bar graph or table.

c) Total PCB assembly:

Displays the total number of PCBs assembled by this user.

10. Environment menu: The following five options are valid under this menu:

a) Communication port setting: When clicking this menu, the user can set the COM port of the computer connected to the machine (the default is coml).

b) Assembly Settings - When this menu is selected, three options are available

i) PCB Type Number: The user can enter the PCB name.

ii) PCB number: The user can input the PCB number.

iii) Skip line numbers: The user can define five line numbers that he wishes to skip during the assembly option of the start menu.

c) Maximum number of parts: The user can define the maximum number of parts per PCB that the user wishes to assemble. The maximum value is 2000 (the default is 100)

d) Measure: The user can click on the mm or inch option to make the machine compatible to work in inches as well (mm by default).

e) Convert: User can click this option to convert ORCAD PCB board definition file to data file.

11. Help menu:

For online help, the Help menu can be selected to display help for each menu related to the machine's user interface software and hardware.

Take the PRECIPLACER PP-2003 semi-automatic pick-and-place machine manufactured by M/s, Harotech Ag, Switzerland as an example for illustration. These models of pick and place machines are compared to our products as follows: serial number A submodel of a semi-automatic pick and place machine for SMD CSIO SAPP Swiss M/s.Harotech PP-2003 1. Brackets & Feeder Parts usable usable 2. Turntable parts usable usable 3(a). X, Y components: Minimum X, Y resolution for linear scales The linear encoder scale used in this machine has a resolution of 0.02mm. A linear scale with 1.0 mm resolution is used. 3(b). X, Y components: Minimum X, Y placement accuracy of SMD components The innovative idea of using a linear encoder scale provides an X, Y placement accuracy of ±0.1mm. This facilitates vibration-free placement of fine-pitch SMD components with 0.3mm pin pitch spacing. X, Y placement accuracy is ±1.0mm. Therefore it is difficult to place small pitch SMD components with this machine without vibration. 4. X, Y air brake components usable usable 5. Pickup head assembly, vacuum on/off control and vacuum pump usable usable 6. Z and Θ components of the pickup head usable usable 7. Mounting frame for accommodating the PCB The innovative clamping device provides adequate clamping of the bottom plate of the PCB holder and also protects the bearing surface between the plate and the base from scratches/damage by the clamping screws. Clamping screw scratches/damages base. 8. movable armrest usable usable 9. Scope part with CCD camera usable usable 10(a) Electronic hardware/software for microcontrollers and machines The electronic hardware of the machine is based on an Intel 8032 microcontroller. The electronic hardware of the machine is based on the Motorola68HC11F1 microcontroller. 10(b) The machine software stored in EPROM completes various machine operations, and senses and counts X, Y coordinates with a resolution of 0.02mm, and operates the X, Y air system with a minimum placement accuracy of ±0.1mm of the X, Y placement coordinates of SMD components move. This will help users to place SMD components with 0.3mm pin pitch pitch. The machine software stored in EPROM completes various machine operations, and senses and counts X, Y coordinates with a resolution of 1.0mm, and operates X, Y air with a minimum placement accuracy of ±1.0mm of X, Y placement coordinates of SMD components brake. 11(a) user interface software The user interface software resides on the hard disk of the Pentium-II computer. The user interface software was developed for Window 95 using VisualBasic 6.0 software. The user interface software resides on the computer's hard drive and was developed in the DOS environment. 11(b) The following menus are provided to make it a more user-friendly software: File, Edit, Start, Print, Statistics, Environment, Online Help The following menus are provided to the user: File, Edit, Start, Produce, Print, System 12 file menu The following options are available under this menu: New, Open, Save as, Close, Exit All of these options are also available 13 edit menu The following options are available under this menu: TABLE (table), OFFLINE/ONLINE (offline/online) All of these options are also available 14 Start Menu The following options are available under this menu: Offset (Enter Offset, Tell Offset) components All of these options are also available 15 print menu The following options are available: ALL, Select Range All of these options are also available 16 Statistics menu: The following options are available under this menu: Component Statistics per PCB Combination PCB Component Statistics Combination Total number of PCBs Only the Combined PCB Totals option is available under the Production menu. 17 Environment menu: The following options are available: Port Settings Assembly Settings (PCB Type, PCB Count, Skip Line Numbers) Maximum Number of Components Unit of Measure (mm or inches) Conversion (for ORCAD Board Definition Files) The following options are available in the Production and System menus: Port Settings Assembly Settings (PCB Type, Number of PCBs, Skip Line Numbers) Other options are not available. 18 help menu An online help menu is available The Help menu option is unavailable. Users must refer to the operating manual

Advantages of the invention

The main advantages of the invention in this machine are:

1. The machine provides a vibration-free structure to place SMD components with a placement accuracy of ±0.1mm for the manual action of the pick-up head on a length of 390mm in the X, Y axis. Vibration-free construction is achieved through the use of finely adjustable air resistance braking. Due to the miniaturization of current SMD components and the pitch of these SMD components of 0.3 mm, a placement accuracy of ±0.1 mm is required in the X, Y axes.

2. The innovative clamping device provides adequate clamping of the bottom plate of the PCB holder and protects the bearing surface between the plate and the base from scratches/damages by the clamping screws.

3. The user-friendly menu-driven software for operating the machine is Windows-based, using Visual Basic 6.0 as the software language.

4. The statistics menu option is displayed through histograms and tables to help users understand the statistics of SMD components needed to assemble a PCB, and the statistics of SMD components that have been assembled on PCBs by users who use this machine.

5. The conversion options menu allows users to directly link ORCAD PCB board definition (*.brd) files with tables. This saves time in the process of building the form before starting the assembly process of these components.

6. The maximum number of components per PCB menu option allows the user to assemble smaller as well as larger PCBs. PCBs with a maximum of 2000 components can be assembled with this option. This option also enables optimal use of computer memory during use of the machine.

7. The Measures menu option makes the machine compatible to work in measures as well as inches.

The X, Y assembly capability of this machine is approximately ten times better than that of semi-automatic machines available in the international market.

Claims (19)

1. an improved semi-automatic pick and place machine is used for assembling little spacing and standard surface erection unit element on printed circuit board (PCB) error freely, it is characterized in that comprising:

X, Y level cross-talk parts, carrying pick-up head and visual guidance equipment;

The guiding block subassembly is guided described X, Y level cross-talk parts;

Linear encoder is coupled to described X, Y level cross-talk parts, X and the Y position coordinates of the action of sensing pick-up head;

The microcontroller subassembly carries out communicating by letter of machine ruuning situation with the computer system with OO user interface software parts; Wherein, be embedded in the position coordinates of the pick-up head that the machine software monitoring in the Erasable Programmable Read Only Memory EPROM of microcontroller subassembly obtains by described linear encoder;

X, Y air damping parts are activated by the machine software in the Erasable Programmable Read Only Memory EPROM that is embedded in the microcontroller subassembly, with ± 0.1 millimeter positional precision X, the braking of Y level cross-talk parts are placed on the coordinate at X, the Y of expectation.

2. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: X, Y subassembly provide X and the Y position coordinates by the pick-up head action of the optical linear encoder sensing with 0.02 millimeter resolution ratio.

3. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: by X, Y subassembly, the manual action to pick-up head on 390 millimeters length of X, Y-axis realizes that at X, Y axle ± 0.1 millimeter X, Y place precision.

4. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: be embedded in X, the Y motion by being used for the locking pick-up head of software in the Erasable Programmable Read Only Memory EPROM, have ± X, the Y of the surperficial erection unit element of 0.1 millimeter m place the electronic hardware of coordinate precision, the braking of excitation air drag.

5. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: the X in this machine, Y parts comprise the subassembly that comprises base plate, X slide block, Y slide block, X, Y slide rail and linear encoder scale.

6. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: described subassembly base plate finish accommodating two X-axis slide track bars and accommodating they have the function of 10 microns precision.

7. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: the X, the Y slide block that only have one degree of freedom use friction free standard straight-line bearing to slide at slide track bar easily.

8. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: X, Y slide rail are installed a high-precision linear encoder scale with 0.1 millimeter resolution ratio as the reference graduation of the X-Y conversion that is used for measuring pick-up head.

9. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: but described machine provides shockproof structure to brake placing element by the air drag with fine tuning.

10. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: when vacuum pick up X, Y that mouth arrives surperficial erection unit element place coordinate ± 0.1 millimeter scope in the time, described X, Y air damping parts with air magnetic valve are automatically started by microcontroller.

11. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: described guiding block subassembly comprises one rectangular in the bottom side of this guiding block, and it provides protection in order to avoid be subject to infringement by the caused cut of pinching screw and infringement or any other generation to the bearing-surface of printed circuit board (PCB).

12. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: the hardware device of described machine is controlled by the software with OO feature.

13. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: the software of described novelty provides the statistics menu option, to show the statistics of determining required element in the printed circuit board (PCB) assembling and the statistics of having been assembled how many elements on printed circuit board (PCB) by this machine by histogram demonstration and form.

14. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: the described software of controlling this machine can be processed maximum 2000 different printed circuit board components at assembly process.

15. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: this software provides a conversion options in contextmenu, to help the user to avoid the artificially input or to inform that X, the Y of element on printed circuit board (PCB) places coordinate.

16. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: this software by provide to the user one use millimeter or inch as linear module in form, to input/to inform the option of X, Y coordinate, control machine.

17. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: described software places coordinate by direction, title, X, the Y that element is provided and the position is prepared form in advance, in order to these parameters can directly be carried in the form from ORCAD plate defined file.

18. improved semi-automatic pick and place machine as claimed in claim 1, it is characterized in that: the layout of the middle minute surface in the visualizer parts and the bias light under the printed circuit board support stand have illuminated the printed circuit board (PCB) zone, in order to alleviate operator's eye fatigue, and provide the more clearly pin of surperficial erection unit element to the operator.

19. improved semi-automatic pick and place machine as claimed in claim 1 is characterized in that: the described software of controlling this machine also provides the Online Help of relevant hardware and software operation to the user.

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