DE102007046282A1 - Supporting pin for supporting substrate i.e. printed circuit board, has spring element and damper element cooperated with each other such that spring element and damper element form spring-damper system - Google Patents

Abstract

The pin (10) has a supporting element supporting a substrate (2) i.e. printed circuit board, where the supporting element is supported in a spring-loaded manner opposite to the base body by a spring element. A spring-loaded support of the supporting element exhibits a damper element i.e. pneumatic damper, additionally formed during assembly of the supported substrate, and deflection of the spring element is prevented. The spring and damper elements cooperate with each other such that the spring and damper elements form a spring-damper system.

Description

The The invention relates to a support pin for supporting a substrate to be equipped with components as well a placement machine.

at Placement machines for equipping substrates with components are the side of a transport route for the substrates component feeders arranged. A placement head that can be moved by a positioning system of the placement machine fetches the components from the feeders From, this moves to a Bestückbereich the Placement machines in which the substrate to be loaded and deposits the devices on the substrate. During the placement process, the substrate becomes fixed laterally at its edge areas.

The Substrates, especially printed circuit boards, are usually never ideal just, but usually slightly curved up or down. Since the components in a z-direction with a certain Aufsetzkraft pressed the substrate to get there on a sticky To adhere to medium (eg solder paste, glue or flux), the suction pipette pushes the substrate downwards. By the ever-increasing machine performance is additional the Aufsetzgeschwindigkeit the suction pipette very large, so that the substrate is excited by the Aufsetzimpuls to vibrations becomes. These are harmful on the one hand just to be assembled component, since by the springing back the substrate sensitive components are damaged On the other hand, the positioning accuracy of the Components negatively affected. Furthermore, it is possible that Components already positioned on the substrate slip through the vibrations during loading or detach completely from the substrate.

Out These reasons are especially for large substrates so-called substrate supports used. It acts it is a plurality of support pins oriented in the z-direction, which are arranged below the substrate and before the placement process moved to support from below to the substrate become.

From the JP 0918196 A is a support mechanism for substrates with height-adjustable support pins known, the individual support pins are mounted spring-loaded in holes in a base plate. The support pins are vertically adjustable by means of a clamping mechanism to the contour of the substrate to be supported. However, the solution shown requires a complex mechanical structure and fixed predetermined positions of the support pins. The latter is problematic, especially when substrates to be assembled on both sides, since components are already arranged on the underside of the substrate when the second substrate side is mounted, which components are not to be touched by the support pins so as not to jeopardize the placement quality and the process reliability.

It The object of the present invention is a support pin as well as to provide a placement machine by means of which high process reliability and high flexibility ensured in the arrangement of the support pins becomes.

These The task is performed by the support pin and the placement machines according to the independent claims solved. Advantageous embodiments are the subject of dependent claims.

According to claim 1, the support pin for supporting a with substrates to be equipped substrate a body and a support element for the to be supported Substrate on, which is opposite to the main body is suspended by means of a spring element. Further includes the support pin for the spring-loaded mounting of the Supporting element an additional damper element.

Become several support pins at the beginning of a placement process For example, by means of a lifting table slowly in a z-direction Move upwards against the underside of the substrate, so feathers those support elements which the substrate base first touch, opposite the main body of the respective support pin slightly, wherein the spring element is compressed accordingly. This will ensure that safe even with arched substrates each support element abuts the substrate, so that the substrate supports the whole area becomes.

By the use of the additional damper element is a compression of the spring element in response to the speed of the spring movement difficult. Especially with fast movements of the placement head and the associated high Aufsetzimpuls a high damping effect is achieved. For slow movements, for example when approaching the support pins to the substrate, is the spring movement hardly influenced. The support pin and Thus also the supported substrate thereby Placing the components on a higher rigidity. A ringing of the substrate, resulting from the high Aufsetzimpuls of the placement, is thus prevented. The placement accuracy and thus the process reliability can be clear increase. Slipping already more populated Components is prevented. Furthermore, in this embodiment the support pin no external mechanics for the Fixation of the support element, allowing for greater flexibility in terms the arrangement of the support pins is made possible.

When Spring element come all kinds of springs, for example mechanical screw or disc springs, but also elastomer springs or Air springs, into consideration.

In An embodiment of the support pin according to claim 2 the damper element designed such that when equipping a supported substrate a compression of the spring element is largely prevented.

Of the Expression "as far as possible" is to be interpreted as meaning that the substrate remains rigid when placing a device and does not resonate as a result of the placement force. The yielding of the Substrate and thus the compression of the spring element are in the sense to dampen this invention so far that the device can be safely and permanently positioned on the substrate. However, the Aufsetzkraft occurring must be sufficiently high be sure the component is safe on the solder paste or another Medium sticks. The placement accuracy must not be affected, damage sensitive Components (for example so-called bare dies) should be avoided. Therefore, the support pin is formed such that a compression damped the spring element when equipping so far is that a device can be placed securely on the substrate can.

Around the compression of the spring element when placing the components To prevent the substrate is the additional damper element designed so that the support element when placing the components due to the damping not on the placement force and thus the pressure of the pipette reacts. The spring element does not follow the Aufsetzimpuls the placement head. A yielding of the substrate is therefore no longer possible. Under the Aufsetzimpuls is In this case understood the impulse, when placing a device exerted by the placement on the substrate. The associated Aufsetzkraft is needed because in the SMT assembly, the device in an adhesive, For example, a solder paste or adhesive pressed It needs to be positioned safely and permanently on the substrate to be able to.

The Damping of the substrate by means of the invention Support pins takes place dynamically, d. H. The higher the momentum when placing the device on the substrate, the more harder the damping of this pulse by the damper element. This is the damper element formed such that the degree of damping or the damping effect increases with increasing speed of the spring movement. A compression the spring element and thus the support element is, for example during the slow approach of the support pin to the substrate, possible because the pulse occurring is small. At the Equipping with high traversing speeds of the placement head and a correspondingly high Aufsetzimpuls a compression of the Spring element due to the inertia of the damper element prevented.

One Another advantage of this dynamic damping is the independent Adaptation of the damping effect to the respective contact pulse of the Placement head. Because when loading substrates depending on the sensitivity of the device various placement parameters (for example the travel speed the pipette when discontinuing a component), Thus, the damping adapts automatically to the various Operating conditions with regard to the contact forces occurring and speeds.

In a further embodiment of the support pin according to claim 3, the spring element and the damper element act like this together that they form a spring-damper system.

at a spring-damper system is the dampening effect directed the damper element so that it the movement counteracts the spring element. When populating it will Spring element in a z-direction, which is perpendicular to the to be populated Surface of the substrate is oriented, compressed. These Movement of the spring element is through the damper element reduced or largely prevented. Likewise, the damper element acts a movement of the spring element in the opposite direction. Together with the support element form spring element and damper element a spring-mass damper system. Since it is used th Components is standard components, this solution is easy and inexpensive to realize.

In An embodiment of the support pin according to claim 4 the damper element as a hydraulic damper educated.

In a further embodiment of the support pin according to claim 5 is the damper element as a pneumatic damper educated.

In An embodiment of the support pin according to claim 6 the damper element designed as an elastomer damper.

at an elastomer damper is a solid-state damper, in which the damping effect is achieved by an elastomeric material becomes.

All embodiments according to claims 4, 5 and 6 have the advantage that it is the one set dampers are standard components. The support pins designed in this way are thus simple and inexpensive to produce.

In a further embodiment of the support pin according to claim 7, the support pin is magnetically supported on a base plate of a Placement machines can be fixed.

From this There is the advantage that the support pin at any Place on the base plate can be fixed. The position is thus flexible to the topology of the to be supported Substrate customizable. It does not matter if the magnet is in Foot area of the support pin or in the area of Support surface of the base plate is arranged.

Of the Placement machine for loading substrates with Components according to claim 8 has at least A support pin according to any one of claims 1 to 7 on.

Regarding the resulting benefits will be on the designs refer to the claims 1 to 7.

in the The invention will be described below with reference to the attached figures explained in more detail. In the figures are:

1 : a schematic representation of a placement machine

2 : A schematic representation of a transport route in the field of placement position in elevation

3 : a schematic representation of the support pin according to the invention in elevation

1 schematically shows a placement machine 1 for loading substrates 2 with components 3 , The placement machine 1 consists of a cross member 7 which extends in a Y-direction and is fixedly connected to a machine frame (not shown). At the cross member 7 is a portal arm 8th attached, which extends in the x direction and displaceable in the y direction on the cross member 7 is attached. crossbeam 7 and porch arm 8th together form the positioning device, wherein an orthogonal reference frame is formed by the x-axis and the y-axis. At the portal arm 8th is the placement head 6 slidably mounted in the x direction. Furthermore, a transport route 4 for transporting the substrates 2 intended for a placement position. Side of the transport route 4 are near the placement position feeders 5 arranged, which are the electrical components 3 provide.

For loading a substrate 2 this is about the transport route 4 transported to their placement position. In the area of the placement position are below the substrate 2 support pins 10 (please refer 2 ) in support of the substrate to be pieced 2 arranged. The from the feeder 5 provided electrical components 3 be from the placement head 6 picked up and on the substrate 2 positioned.

In 2 is the transport route 4 in the region of the placement position of the substrate 2 shown schematically in elevation. The substrate 2 lies in its border areas on two conveyor belts 19 on and is thus movable in an x-direction. In the area of the placement position are above the conveyor belts 19 so-called clamping elements 20 arranged. These are movable in a z-direction and clamp the substrate 2 when equipping with components 3 on both sides between the respective conveyor belt 19 and the associated clamping element 20 , Thus, the substrate 2 fixed during loading so that slipping of the substrate 2 safely prevented.

The loading of the substrate 2 with components 3 gets through a placement head 6 executed, which by means of the positioning system 7 . 8th (please refer 1 ) is movable in an xy plane. The placement head has at least one holding means 9 which is in a z-direction relative to the placement head 6 is movable and the component 3 holds. For safe placement of the device 3 on the substrate 2 needs that component 3 with a defined placement force F in the on the substrate 2 applied solder paste 21 be pressed. Since in this case the Aufsetzgeschwindigkeit of the holding means 9 is very high, the substrate would be 2 excited by the Aufsetzimpuls occurring to vibrate, which is to slip the already positioned components 3 lead and thus could adversely affect the placement accuracy. By supporting the substrate 2 by means of the support pins 10 This effect can be largely prevented.

Several support pins 10 are at defined locations on a base plate 18 , which is movable in the z-direction, below the substrate 2 arranged. At the upper end of the support pins 10 are support elements 12 arranged on which rests the substrate to be supported during loading. Is the substrate 2 Fixed in its Bestückposition, so moves the base plate 18 with the support pins 10 in the z-direction as far up that all support elements 12 the support pins 10 the substrate 2 touch at the bottom.

3 shows a schematic representation of one of the support pins according to the invention 10 in the elevation. The support pin 10 consists of a basic body 11 and a support element 12 on which the substrate rests when loading. On the main body has the support pin 10 a magnet 17 with which he helps on a magnetizable base plate 18 (please refer 2 ) can be fixed non-positively against slipping. The support element 12 is opposite the main body 11 by means of a spring element 14 (shown here as a spiral spring) spring-mounted. If a force F is applied in a z-direction, the spring element becomes 14 compressed or stretched, resulting in a change in length of the spring element 14 leads in z-direction.

Furthermore, the support pin has 10 via a damper element 15 , which with the support element 12 is connected and a compression of the spring element 14 or the support element 12 in the z direction, counteracts. The damper element 15 For example, it can be designed as a hydraulic, as a pneumatic damper or as an elastomer damper. spring element 14 and damper element 15 Together they form a spring-damper system. The damping takes place dynamically, ie the spring-damper system 14 . 15 The higher the speed or the momentum that acts on it, the slower it is. A compression of the support element 12 is quite possible, for example, if the support pin 10 slowly from below against the substrate 2 is driven. However, high pulses occur, for example when loading the substrate 2 with construction elements 3 the placement head 6 at high speed and moves the device 3 in the solder paste 21 presses (see 2 ), so dampens the damper element 15 the Aufsetzimpuls occurring during loading from such that a compression of the spring element 14 is largely prevented. The support element 12 does not respond to that of the holding element 9 on the substrate 2 transmitted pulse. This allows the substrate 2 no longer give in to the Aufsetzimpuls when loading. A ringing of the substrate 2 is thus prevented.

When loading is first the substrate 2 in the placement area of the placement machine 1 driven and there with the help of suitable clamping elements 20 fixed. Subsequently, several support pins, which are on the base plate 18 (please refer 2 ) are arranged at defined positions, moved upwards until all supporting elements 12 the support pins 10 the underside of the substrate to be supported 2 touch. Since the substrate is never completely flat, those support elements spring 12 touching the substrate first, in the z-direction, wherein the respective spring elements 14 be compressed accordingly. The support pins 10 thus match the contour of the bottom of the substrate 2 at. Since the startup of the support pins is comparatively slow, the impulse is on the damper element 15 relatively low, so the damper elements 15 barely react to that. When loading the components 3 however, at high speed on the substrate 2 set. The occurring impulse on the damper element 15 is correspondingly high, so that a compression of the spring element 14 due to the inertia of the spring-damper system 14 . 15 is prevented. This can also be the substrate 2 not yield, the device can be safely positioned on the substrate. Process reliability is significantly increased as a result.

1

automatic placement

2

substratum

3

module

4

transport distance

5

feeder

6

placement

7

crossbeam

8th

port alarm

9

holding means

10

support pin

11

body

12

support element

13

14

spring element

15

Damper element

17

magnet

18

baseplate

19

conveyor belts

20

clamping element

21

solder paste

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 0918196 A [0005]

Claims (8)

Support pin ( 10 ) for supporting a component ( 3 ) to be loaded substrate ( 2 ), with - a basic body ( 11 ), - a support element ( 12 ) for the substrate to be supported ( 2 ), which opposite the main body ( 11 ) by means of a spring element ( 14 ) is spring-mounted, wherein the spring-mounted mounting of the support element ( 12 ) additionally a damper element ( 15 ) having. Support pin ( 10 ) according to claim 1, wherein the damper element ( 15 ) is configured such that when loading a supported substrate ( 2 ) a compression of the spring element ( 14 ) is largely prevented. Support pin ( 10 ) according to one of claims 1 or 2, wherein the spring element ( 14 ) and the damper element ( 15 ) cooperate to form a spring-damper system. Support pin ( 10 ) according to one of claims 1 to 3, wherein the damper element ( 15 ) is designed as a hydraulic damper. Support pin ( 10 ) according to one of claims 1 to 3, wherein the damper element ( 15 ) is designed as a pneumatic damper. Support pin ( 10 ) according to one of claims 1 to 3, wherein the damper element ( 15 ) is designed as an elastomer damper. Support pin ( 10 ) according to one of claims 1 to 6, wherein the support pin ( 10 ) magnetically on a base plate ( 18 ) of a placement machine ( 1 ) is fixable. Placement machine ( 1 ) for loading substrates with components, which at least one support pin ( 10 ) according to one of claims 1 to 7.