AU2019100871A4 - A circuit board arrangement for protecting a circuit board against mechanical stress occurring during drilling and a drill tool - Google Patents

Abstract

The disclosure relates to a circuit board arrangement for protecting a circuit board (11) against mechanical stress occurring in drilling, comprising a circuit board (11) having an elastic modulus; a first protective layer (12) arranged to enclose the circuit board (11), the 5 first protective layer (12) having an elastic modulus; and a second protective layer (13) arranged to enclose the first protective layer (12) at least partly, the second protective layer (13) having an elastic modulus; wherein the elastic modulus of the first protective layer (12) is different from the elastic modulus of the second protective layer (13); the circuit board (11) is supported by the first protective layer (12); and the first protective layer (12) 0 is supported by the second protective layer (13). The disclosure relates also to a drill tool (2) comprising a cavity (21) for receiving a circuit board (11) within the drill tool (2) and a circuit board arrangement (1) as described above arranged in the cavity (21). (Figure 1) 11557365_1 (GHMatters) P111621.AU Fig. 1 Fig. 2

Description

A CIRCUIT BOARD ARRANGEMENT FOR PROTECTING A CIRCUIT BOARD AGAINST MECHANICAL STRESS OCCURRING DURING DRILLING AND A DRILL TOOL

FIELD OF THE DISCLOSURE

The present disclosure relates to a circuit board arrangement, and particularly to a circuit board arrangement for protecting a circuit board against mechanical stress occurring during drilling. The present disclosure further concerns a drill tool.

BACKGROUND OF THE DISCLOSURE

Document WO 2014/037619 A2 discloses a method for surveying drill holes and a drilling 0 arrangement and to a borehole survey assembly. The method comprises a first providing step for providing a drill tool comprising at least one drill rod and a drill bit assembly, and a second providing step for providing a borehole survey tool comprising sensor means for measuring a borehole. In the method, a drill tool comprising a central flushing channel for conducting flushing fluid to the drill bit assembly is used, and the borehole survey tool is 5 arranged in the arranging step in the central flushing channel so that flushing fluid can flow in the central flushing channel past the borehole survey tool.

A problem with placing the borehole survey tool, which comprises a circuit board, in the drill tool is that the circuit board may be damaged during drilling due to mechanical stress occurring during drilling.

Ό Document US 5 878 824 A discusses a boring tool having thermal protection for an electronic component assembly. Particularly, operational power to the electronic component assembly is disconnected when a sensed temperature reaches a maximum operation temperature. Document EP 3 056 657 A2 discusses a drilling tool having a borehole survey tool arranged in a first central flushing channel section of a drill bit 25 assembly. Document WO 2015/148826 A1 discusses an apparatus for protecting a module used in a borehole, the apparatus having a plurality of shock protection elements associated with the module. Document US 2006/003137 A1 discusses a system and method for encapsulating and protecting a component assembly is disclosed. A barrier system comprising a first layer having a first set of physical properties and a second layer 30 having a second set of physical properties is adapted to protectively surround the component assembly.

11557365_1 (GHMatters) P111621.AU

2019100871 08 Aug 2019

BRIEF DESCRIPTION OF THE DISCLOSURE

An object of the present disclosure is to provide a circuit board arrangement and a drill tool to solve the above problem.

The objects of the disclosure are achieved by a circuit board arrangement and a drill tool 5 which are characterized by what is stated in the independent claims. The preferred embodiments of the disclosure are disclosed in the dependent claims.

The disclosure is based on the idea of enclosing the circuit board in a first protective layer and then enclosing the first protective layer at least partly in a second protective layer, wherein the elastic modulus of the first protective layer is different from the elastic modulus 0 of the second protective layer. The enclosed circuit board can then be placed inside a drill tool, such as a drill bit or a drill rod.

An advantage of circuit board arrangement and the drill tool of the disclosure is that it provides more protection for the circuit board against mechanical stress occurring during drilling.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which

Figure 1 is a schematic view of a transversal cross section of a circuit board arrangement according to an embodiment of the disclosure; and

Figure 2 is a schematic view of a longitudinal cross section of a part of a drill tool according to an embodiment of the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The disclosure relates to a circuit board arrangement 1 for protecting a circuit board 11 against mechanical stress occurring during drilling. For example, the drilling is percussive 25 drilling or rotary drilling.

The circuit board arrangement 1 comprises a circuit board 11. The circuit board 11 has an elastic modulus.

The circuit board arrangement 1 comprises a first protective layer 12 arranged to enclose the circuit board 11. The circuit board 11 is supported by the first protective layer 12.

11557365_1 (GHMatters) P111621.AU

2019100871 08 Aug 2019

The circuit board arrangement 1 comprises a second protective layer 13 arranged to enclose the first protective layer 12 at least partly. The first protective layer 12 is supported by the second protective layer 13.

The first protective layer 12 has an elastic modulus. In other words, the material of the first 5 protective layer 12 has an elastic modulus. The second protective layer 13 has an elastic modulus. In other words, the material of the first protective layer 13 has an elastic modulus.

The elastic modulus of the first protective layer 12 is different from the elastic modulus of the second protective layer 13.

According to an embodiment, the elastic modulus of the first protective layer 12 is at least 0 10 % of the elastic modulus of the circuit board 11. In this way, the mechanical strength of the circuit board assembly, comprising the circuit board 11, components on the circuit board 11 and the first protective layer 12, is increased compared to a circuit board assembly without the first protective layer 12. In other words, the internal strain caused by mechanical stress acting upon the circuit board 11 is divided evenly between components 5 on the circuit board 11, the first protective layer 12 and the circuit board 11 itself. According to an embodiment, the elastic modulus of the first protective layer 12 is at least 0.1 GPa, such as 1-5 GPa.

When the rigidity of a structure is increased, the stress is also increased. In heavy mechanical stress the breaking point or the yield point is exceeded and the structure is Ό deformed. According to an embodiment, the elastic modulus of the first protective layer 12 is higher than the elastic modulus of the second protective layer 13. In other words, the first protective layer 12 is enclosed at least partly by the second protective layer 13, which is softer than the first protective layer 12.

It is not necessary for the second protective layer 13 to fully enclose the first protective 25 layer 12 and the circuit board 11, but it is sufficient that the second protective layer 13 is a part supporting the structure, i.e. the circuit board 11 and the first protective layer 12. In other words, the second protective layer 13 is adapted to be in contact with other objects that transmit mechanical force to the circuit board arrangement 1. The soft material of the second protective layer 12 will deform in elastic manner without breaking and thus reduces 30 the mechanical stress peaks that are transmitted to first protective layer 12 and to the circuit board 11. According to an embodiment, the elastic modulus of the second protective layer 13 is 0.005-0.06 GPa.

11557365_1 (GHMatters) P111621.AU

2019100871 08 Aug 2019

According to an embodiment, the first protective layer 12 is made of material that is permeable to radio waves, such as epoxy resin, polyurethane elastomer or ceramic material. According to an embodiment, the second protective layer 13 is made of material that is permeable to radio waves, such as polyurethane elastomer, silicone or natural or 5 synthetic rubber. In this way, wireless communication by the circuit board is allowed. The second protective layer 13 may also be made of material that is not permeable to radio waves, if the first protective layer 12 is not fully enclosed by the second protective layer 13. The radio waves are for example radio waves at frequencies within the ISM radio bands. According to an embodiment, the radio waves have a frequency of 2 to 6 GHz.

The disclosure relates also to a drill tool 2. For example, the drill tool 2 is a percussive drill tool or a rotary drill tool. For example, the drill tool 2 is a drill bit or a drill rod. Alternatively, the drill tool 2 is an adapter for use between a drill bit and a drill rod, or an adapter for use between two drill rods. The drill tool 2 comprises a cavity 21 for receiving a circuit board 11 within the drill tool 2. The drill tool 2 further comprises a circuit board arrangement 1 as 5 described above arranged in the cavity 21.

According to an embodiment, the circuit board arrangement 1 is supported by the second protective layer 13 contacting the drill tool 2, i.e. the walls of the cavity 21. The circuit board arrangement 1 may additionally be supported by one or more damping means 22 connected to the walls of the cavity 21 and to the circuit board arrangement 1.

Ό In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense,

i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments ofthe invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims (7)

1. A percussive drill tool, comprising a cavity (21) for receiving a circuit board (11) within the drill tool (2); and a circuit board arrangement (1) for protecting a circuit board (11) against mechanical

2. A percussive drill tool according to claim 1, characterized in that the first protective layer (12) is made of polymer or ceramic material, such as epoxy resin or polyurethane elastomer.

11557365_1 (GHMatters) P111621.AU

2019100871 08 Aug 2019

3. A percussive drill tool according to any one of the preceding claims, characterized in that the second protective layer (13) is made of elastomer, such as polyurethane, silicone or natural or synthetic rubber.

4. A percussive drill tool according to any one of the preceding claims, characterized in

5. A percussive drill tool according to any one of the preceding claims, characterized in that the drill tool (2) is a drill bit.

5 that the first protective layer (12) is made of material that is permeable to radio waves.

5 - a second protective layer (13) arranged to enclose the first protective layer (12) at least partly, the second protective layer (13) having an elastic modulus;

the elastic modulus of the first protective layer (12) is different from the elastic modulus of the second protective layer (13);

the circuit board (11) is supported by the first protective layer (12);

20 the first protective layer (12) is supported by the second protective layer (13);

the circuit board arrangement (1) is supported laterally by the second protective layer (13) contacting the walls of the cavity (21), and the elastic modulus of the first protective layer (12) is higher than the elastic modulus of the second protective layer (13), wherein the elastic modulus of the first protective 25 layer (12) at least 0.1 GPa and the elastic modulus of the second protective layer (13) is 0.005-0.06 GPa.

5 stress occurring during percussive drilling, the circuit board arrangement (1) being arranged in the cavity (21), wherein the circuit board arrangement (1) is supported longitudinally by one or more damping means (22) connected to the walls of the cavity (21) and to the circuit board arrangement (1);

0 characterized in that the circuit board arrangement (1) comprises

- a circuit board (11) having an elastic modulus;

- a first protective layer (12) arranged to enclose the circuit board (11), the first protective layer (12) having an elastic modulus; and

6. A percussive drill tool according to any one of claims 1 to 4, characterized in that the drill tool (2) is a drill rod.

0

7. A percussive drill tool according to any one of claims 1 to 4, characterized in that the drill tool (2) is an adapter between a drill bit and a drill rod, or an adapter between two drill rods.