DE202023105629U1 - Adapter board - Google Patents

Abstract

Adapter board (1), with which a surface-mountable component (3) can be attached to a circuit board (4), which has a different connection geometry or connection arrangement for the surface-mountable component (3) than the component (3) to be mounted, characterized in that the adapter board (1) is designed as a multilayer plate.

Description

The invention generally relates to an adapter board with which a component or IC package with a first solder connection arrangement can be mounted on a circuit board with a second solder connection arrangement, which is different from the first solder connection arrangement.

In particular, the invention relates to an adapter board with which a surface-mounted or surface-mountable component can be attached to a circuit board, which has a different connection geometry or connection arrangement for the surface-mountable component than the component to be mounted itself. For example, a small housing design can be mounted on a circuit board with the adapter board larger housing design (or vice versa) can be adapted.

In contrast to components for through-hole mounting (through hole technology, THT), i.e. the wired components (through hole device, THD), a surface-mounted component (surface-mounted device, SMD) does not have any wire connections, but is connected using solderable connection surfaces or connection legs (pins) soldered directly onto a circuit board (flat assembly). This process is also known as surface-mounting technology (SMT).

Problems arise in particular when IC housings with solder connections on four sides of the housing are to be attached to a circuit board which has a different connection geometry or connection arrangement than the component to be mounted, such as a Plastic Leaded Chip Carrier (PLCC) or Quad -Flat-J-Lead chip carrier (QFJ) or QFP (quad flat package).

According to the invention, an adapter board is designed as a multilayer board or multilayer board. A multilayer board is a circuit board that consists of more than two levels or layers carrying more than two conductor tracks and/or connection points. The individual levels or layers can be connected to one another using plated-through holes.

There are connection points for, for example, the supply voltage, the reference potential and/or electrical signals on one layer or the outer layers of the multilayer board or multilayer board, and only signal lines on one or more other layers, in particular within the multilayer board or multilayer board, i.e. the inner layers. In order to achieve better results with regard to electromagnetic compatibility, reference potentials and supply voltages can also be located in the inner layers. The number of layers is preferably even.

The conductor track layers lying between the contacting layers thus enable better utilization of space, in particular the use of through holes with a larger diameter for through-contacting between the layers, in particular between the contacting layers.

In this application, “top” is to be understood as meaning the side of an adapter board facing a component to be connected and “bottom” is to be understood as meaning the side of the adapter board facing a base circuit board or board, as shown schematically in 1 shown.

1. 1. eine obere Kontaktierungslage (Kontaktstellenmuster)
2. 2. eine obere Leiterbahnlage (Leitungsbahnmuster)
3. 3. eine untere Leiterbahnlage (Leitungsbahnmuster)
4. 4. eine untere Kontaktierungslage (Kontaktstellenmuster)

The adapter board has at least three and preferably four layers (4-fold multilayer), but can also have more than four layers, with each (horizontal) layer having a contact point pattern or a conductor track pattern, for example:

1. 1. an upper contact layer (contact pattern)
2. 2. an upper conductor track layer (conductor track pattern)
3. 3. a lower conductor track layer (conductor track pattern)
4. 4. a lower contact layer (contact pattern)

The upper contacting layer (1st layer) is used to connect several contacts of the component to be connected to the circuit board, which is placed on the adapter board, and is electrically connected to the upper conductor track layer underneath (2nd layer) by means of upper through contacts in through holes, in each case an upper through contact connected to a component contact meets a conductor track beginning of a conductor track of the upper conductor track layer. The conductor track end of each conductor track of the upper conductor track layer is electrically connected to a middle via contact, which is connected at its opposite lower end to a conductor track beginning of a conductor track of the lower conductor track layer (3rd layer). The conductor track end of a conductor track of the lower conductor track layer is electrically connected to the lower contact layer (4th layer) by means of lower through contacts in through holes, which can or is connected to the circuit board to which the component is to be electrically connected.

This means that one connection contact of the component to be attached to the adapter board can be electrically connected to a connection contact of the main circuit board, so that there is a one-to-one assignment of the respective connection contacts. A connection contact of the upper contacting layer is therefore assigned to exactly one connection contact of the lower contacting layer or is electrically connected to it. The cable routing from an upper connection contact of the upper contacting layer to a lower connection contact of the lower contacting layer can take place via one or more conductor tracks located between the connection contacts in one or more conductor track layers. The electrical connection between the connection contacts and conductor tracks or between the conductor tracks of different conductor track layers can be realized using through contacts. The line paths located between the upper and lower connection contacts make it possible for the through contacts not to have to be arranged corresponding to the connection points of the electronic component or the main circuit board, for example in a square, but instead to be distributed over the entire horizontal cross-sectional area of the adapter board can, which makes better use of space and thus enables larger through-contacts in cross section, which is advantageous, for example, with regard to electrical conductivity.

With an adapter designed in this way, for example, an electronic component with a larger housing design, such as the TQFP64 of the ATmega128A microcontroller, can be attached to a printed circuit board or circuit board which has connection points for a smaller housing design, such as QFN64.

The conductor track patterns of the conductor track layers can, for example, be designed in such a way that flat or solid conductor areas, for example copper areas, are provided between adjacent conductor tracks in order to shield the conductor tracks. Depending on the application, such a shield can be provided for every line path or only for individual line paths in which high-frequency signals can be present during operation.

The adapter board can be designed to have an upper section which has a larger cross section than a lower section, the upper section and the lower section being connected to one another or formed in one piece. For example, the adapter board can have a protrusion all around in the upper area, so that, as in 1 shown schematically, results in a T-shape in vertical cross section. This can be symmetrical or as in 1 shown acting asymmetrical shape. The space available on the base circuit board below the overhang can be used to attach additional electronic components, which would not be possible if a larger component were attached directly to the base circuit board.

The lower area of the adapter board thus forms a base that has connection points on its underside and can therefore be used, for example, as a pin adapter for attachment to the main circuit board. This means that no mechanical changes need to be made to the main circuit board if, for example, a component with a larger area is attached using the adapter board. Viewed from above, the components underneath the overhang are covered by it.

The mentioned four layers of the adapter board can consist of a conductive material or metal, in particular copper.

A soldering varnish can be applied to the upper contacting layer and/or to the lower contacting layer of the adapter board in order to facilitate the connection process of the adapter board.

According to a further aspect, the invention relates to a circuit board with an adapter board as described herein, for example soldered onto the circuit board or generally attached thereto, for example as an SMD

Another aspect of the invention relates to a method for producing the adapter board described here. In this case, a layer structure is produced in a manner known per se, which is constructed from top to bottom as follows: an upper soldering lacquer layer, an upper contacting layer, an upper prepress layer, an upper conductor track layer, a middle layer, a lower conductor track layer, a lower prepress layer. Layer, a lower contacting layer and a lower soldering varnish layer.

The contact layers and conductor track layers are therefore made as inner layers, for example from copper.

Optionally, only three or more than four inner layers can be provided.

The inner layers may be etched during the layering of the adapter board to form the pad patterns and trace patterns.

The layer structure can be milled to bring it into a desired shape, which, for example, as described herein, has a bottom side that has a different, for example smaller, horizontal cross-section or a smaller cross-sectional area than the top side. For example, the adapter board can be milled out of the layer structure so that it is rectangular or square when viewed from above and/or below. For example, the adapter board can be milled in such a way that a T-shape is created in the vertical cross section from top to bottom.

For mass production, for example, a larger layer structure can be formed as a frame, in which a plurality of, for example, 32 of the adapter boards described herein are or can be formed next to one another, for example in a grid structure. The individual adapter boards can, for example, be equipped with the desired electronic component, for example a microcontroller, already in the frame or after being separated and, for example, soldered to it, for example in an oven.

• 1 eine Querschnittsansicht einer Adapterplatine;
• 2A ein Kontaktstellenmuster einer oberen Kontaktierungslage;
• 2B ein Leitungsbahnmuster einer oberen Leiterbahnlage;
• 2C ein Leitungsbahnmuster einer unteren Leiterbahnlage; und
• 2D ein Kontaktstellenmuster einer unteren Kontaktierungslage.

The invention is described below using exemplary embodiments. Show it:

• 1 a cross-sectional view of an adapter board;
• 2A a contact pad pattern of an upper contacting layer;
• 2 B a wiring pattern of an upper wiring layer;
• 2C a trace pattern of a lower trace layer; and
• 2D a contact point pattern of a lower contacting layer.

1 shows a cross-sectional view of an adapter board or adapter circuit board 1, which is placed on contact points 4a of a base circuit board 4 and attached to it, for example as a surface-mounted component (SMD) by means of surface mounting (SMT).

For purposes of illustration, only a single line path or signal path S from the bottom to the top of the adapter board 1 is shown schematically. However, several such signal paths S can be present in a cross section.

The contact points 4a of the main circuit board 4 are arranged so that a small electronic component can be attached to the main circuit board 4. In order to attach a component 3, for example in terms of electronic functionality, but larger in the package, to the main circuit board 4, the adapter circuit board or adapter board 1 according to the invention is used.

The adapter circuit board or adapter board 1 has on its underside a plurality of contact points (pin adapters) 2d' of the lower contacting layer 2d, the arrangement of which corresponds to the contact points 4a of the base circuit board 4, for example in the top view in 2D shown.

Each individual contact point 2d' of the lower contact layer 2d of the adapter board 1 is connected by means of a lower through contact 5c to a conductor track 2c' of the lower conductor track layer 2c, which is connected to a middle through contact 5b, as in 2C shown.

Each middle through contact 5b connects a conductor track 2c` of the lower conductor track layer 2c with a conductor track 2b` of the upper conductor track layer 2b, which in 2 B is shown.

A conductor track 2b' of the upper conductor track layer 2b of the adapter board 1 is connected by means of an upper through-contact 5a to a contact point 2a' of the upper contact layer 2a, which corresponds in its arrangement to the contact points 3a of the component 3, for example in the plan view in 2A shown.

The through contacts 5a, 5b and 5c run vertically within the adapter board 1. The conductor tracks 2b` and 2c` run horizontally within the adapter board 1.

Through contacts 5a and 5b are each located on opposite sides of a conductor track 2b` of the upper conductor track layer 2b. Through contacts 5b and 5c are each located on opposite sides of a conductor track 2c` of the lower conductor track layer 2c. As a result, the large number of through contacts 5b can be distributed over the entire cross-sectional area of the adapter board 1, such as in the 2 B and 2C shown.

List of reference symbols:

1

Adapter board, adapter circuit board

2a

upper contact layer (contact pattern)

2a`

upper contact point

2 B

upper conductor track layer (conductor track pattern)

2b`

upper conductor track

2c

lower conductor track layer (cable trace pattern)

2c`

lower conductor track

2d

lower contacting layer

2d`

lower contact point

3

electronic component

4

Basic circuit board

4a

Contact points of the main circuit board

5a

upper through contacts

5b

medium through contacts

5c

lower through contacts

S

signaling pathway

Claims (15)

Adapter board (1), with which a surface-mountable component (3) can be attached to a circuit board (4), which has a different connection geometry or connection arrangement for the surface-mountable component (3) than the component (3) to be mounted, characterized in that the adapter board (1) is designed as a multilayer plate. Adapter board according to the preceding claim, wherein the multilayer plate has three, four or more layers (2a, 2b, 2c, 2d), each layer having a contact point pattern (2a, 2d) or a conductor track pattern (2b, 2c). Adapter board according to one of the preceding claims, wherein the multilayer plate has an upper contacting layer (2a) with upper contact points (2a`) and a lower contacting layer (2d) with lower contact points (2d`), each contact point (2a`) of the upper contacting layer ( 2a) is electrically connected to a contact point (2d`) of the lower contacting layer (2d). Adapter board according to the preceding claim, wherein the upper contact points (2a`) are arranged so that they correspond to the connection geometry or connection arrangement of the surface-mountable component (3) and the lower contact points (2d`) are arranged so that they correspond to the connection geometry or connection arrangement correspond to the circuit board (4). Adapter board according to one of the preceding claims, wherein the multilayer plate has an upper conductor track layer (2b) and a lower conductor track layer (2c). Adapter board according to one of the preceding claims, wherein the upper contacting layer (2a) is electrically connected to the upper conductor track layer (2b) underneath by means of upper through-contacts (5a) in through-holes, with an upper through-contact in each case on a conductor track beginning of a conductor track (2b`) of the upper The conductor track layer (2b) meets, the conductor track end of each conductor track (2b`) of the upper conductor track layer (2b) is electrically connected to a central through contact (5b), which at its opposite end is connected to a conductor track beginning of a conductor track (2c`) of the lower conductor track layer ( 2c) is connected and the conductor track end of the conductor track (2c`) of the lower conductor track layer (2c) is electrically connected to the lower contact layer (2d) by means of lower through contacts (5c) in through holes, which are connected to the circuit board (4) with which the component (3) should be, can be or is connected electrically. Adapter board according to one of the preceding claims, wherein the adapter board is a surface-mounted device (SMD). Adapter board according to one of the preceding claims, wherein the connection points (2a`) of the upper contacting layer (2a) are arranged so that they correspond to the solder connections of an IC housing with solder connections on four sides of the IC housing. Adapter board according to one of the preceding claims, wherein the connection points (2d`) of the lower contacting layer (2d) are arranged so that they correspond to the solder connections of a base circuit board (4). Adapter board according to one of the preceding claims, wherein the layers of the adapter board are made of metal, in particular copper. Adapter board according to one of the preceding claims, wherein a soldering varnish is applied to the upper contacting layer (2a) and/or to the lower contacting layer (2d) of the adapter board (1). Adapter board according to one of the preceding claims, wherein flat copper areas are provided between the conductor tracks of a conductor track layer (2b and/or 2c) in order to form a shield. Adapter board according to one of the preceding claims, wherein it has an upper section which has a larger cross section than a lower section of the adapter board. Adapter board according to one of the preceding claims with an electronic component (3) attached thereto. Circuit board with an adapter board (1) according to one of the preceding claims, which is attached to the circuit board (4) or soldered to it, for example as an SMD

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